JP6133550B2 - Engine-driven inverter generator control method and engine-driven inverter generator - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an engine-driven inverter generator control method and an engine-driven inverter generator, and more particularly, an engine control method mounted on an engine-driven inverter generator and an engine that executes the control method. The present invention relates to a drive type inverter generator.

  Engine-driven generators that generate power by driving the generator body with an engine are widely used as emergency power supplies in the event of a power failure, and in particular, components such as the engine and generator body are housed in a package. Package-type engine-driven generators are widely used due to their portability, such as in construction sites and event venues, where it is necessary to secure power supplies outdoors.

  In such an engine-driven generator, when alternating current generated in the generator body is output as it is, the frequency of the alternating current output from the generator body is determined by the number of poles and the rotational speed of the generator body. In order to supply power stably, it is necessary to perform “constant speed control” that maintains the engine speed at a constant speed.

  However, the generator itself in an operation state with a constant rotation speed shows a “drooping characteristic” in which the output voltage decreases as the load current increases and the output voltage increases as the load current decreases. When an engine-driven generator that is controlled in this way is connected to a load that consumes less power than the rated output power of the generator, the output voltage increases as the load current decreases. As a result, the power consumed in the connected load becomes excessive by the increase in the output voltage, which means that the engine consumes useless fuel.

  Therefore, without supplying the AC output from the generator itself to the load as it is, it is first converted to DC through a converter composed of diodes, etc., and then converted to AC at the desired frequency and voltage by the inverter. As a result, the frequency of the power supplied to the load is not determined by the rotational speed of the generator body, and the voltage does not change even if the load current changes. An inverter type portable generator configured to automatically adjust the throttle valve opening of the engine so that the fuel consumption is minimized at the detected load current is also proposed (see Patent Document 1). .

Japanese Examined Patent Publication No. 63-46253

In the inverter type portable generator described in the above-mentioned Patent Document 1, as shown in FIG. 6, the change in the output current (load current) of the inverter and the rotation at which the fuel consumption of the engine is minimized with respect to the change in the output current. Engine that detects the correspondence with the speed (target rotation speed) in advance, sets the corresponding target rotation speed as the set target rotation speed based on the detected value of the load current according to this correspondence relation, and detects the rotation speed detector By adjusting the throttle valve opening and controlling the amount of fuel supplied to the engine so that the rotational speed of the engine approaches the set target rotational speed, the fuel consumption will be improved.

However, in this example, as shown in FIG. 6 as an example, the target rotational speed of the engine when the load current is A ₁ is NT ₁ , and the target rotational speed of the engine when the load current is A ₂ is NT ₂ . As shown in FIG. 7 (A), it is assumed that the load current is instantaneously reduced from A ₂ to A ₁ by stopping one of the loads connected to the generator and activated at time T ₁ . .

In this case, as shown in FIG. 7B, the control circuit provided in the inverter portable generator follows the correspondence shown in FIG. 6 by receiving the detection signal when the detector detects the output current A ₁ . the set target rotational speed of the engine at time T _1, the target rotation speed NT ₂ corresponding to the load current a _2, make the changes at once is reduced to the target rotation speed NT ₁ corresponding to the load current a _1, rotational speed detector The throttle valve opening is adjusted as shown in FIG. 7 (C) by controlling the throttle valve so that the engine rotational speed NA ₂ measured by the detector approaches the newly set target rotational speed NT ₁ . As a result, the amount of fuel supplied to the engine is drastically reduced.

In this way, the amount of fuel supplied to the engine is reduced by the control circuit, so that the engine operated at the rotational speed NA ₂ from time T ₀ to time T ₁ as shown in FIG. From the time T ₁ when the load suddenly decreases, it takes a predetermined time (T ₁ -T ₃ ) determined by the engine characteristics and the like, and finally settles down ( sets up ) to the rotational speed NA ₁ corresponding to the set target rotational speed NT ₁ . The fuel supply amount to the engine is also stabilized at a substantially constant amount F ₁ .

However, until the engine settles to the rotational speed NA ₁ from the state of the rotational speed NA ₂ in this way, the control circuit rapidly sets the rotational speed of the engine operated at the rotational speed NA ₂ to the target rotational speed NT _1. In order to decrease the throttle valve opening degree rapidly so that the difference between the detected rotational speed and the set target rotational speed NT ₁ becomes zero, as shown in FIG. The fuel supply amount is rapidly decreased to an amount lower than the fuel supply amount F ₁ for the engine that is stably operated at the new set target rotational speed NT ₁ in a very short time after detection of the load current A _1. It is done.

  For this reason, an engine in the middle of a sudden decrease in rotational speed is given an amount of energy (fuel supply) compared to an engine that is operating stably at a constant rotational speed even at the same rotational speed. The rate of change over time is negative.

From this, during the deceleration control in which the rotational speed of the engine is suddenly decreased with a sudden decrease in the load current, the stopped load is restarted and restarted, etc. If there is again increased to _2, this was changed again NT ₂ a set target rotational speed correspondingly, even if an attempt is rapidly increased again the rotation speed of the engine up to NA _2, the engine is a sharp rise in the rotational speed Even if it stalls without being able to follow the instructions, and even if the stall is avoided, it cannot supply the necessary power on the load side. There has been a problem of causing malfunction such as failure.

In particular, in such engine speed control, when control is performed to rapidly and drastically reduce the engine speed in response to a sudden load change, the engine speed is controlled as shown in FIG. The so-called “undershoot”, in which the decrease in the rotation speed does not stop at the rotation speed NA ₁ corresponding to the newly set target rotation speed NT ₁ but falls below this momentarily to the instantaneous minimum speed NAmin. Therefore, when undershoot occurs in this way (for example, during deceleration between T ₁ and T ₂ ), if the load current suddenly increases again as described above, the engine It becomes more difficult to change the rotation speed following such a change.

  Accordingly, the present invention has been made to solve the above-mentioned drawbacks of the prior art, and in the engine-driven inverter generator, as described above, the size of the total load connected to the engine-driven inverter generator. Even when the load value (for example, load current value or power consumption value) showing a drastic change from sudden decrease to rapid increase, the engine speed can be changed quickly following this, As a result, engine stall can be prevented, and output can be performed with the power supply corresponding to the change in load value, so that the operating load stops unintentionally, A method for controlling an engine-driven inverter generator capable of suitably preventing the occurrence of malfunction such as failure of starting the input load, and the control method are realized. And to provide a engine driven inverter generator.

  Hereinafter, means for solving the problem will be described together with reference numerals used in the embodiment for carrying out the invention. This code is used to clarify the correspondence between the description of the scope of claims and the description of the mode for carrying out the invention. Needless to say, it is used in a limited manner for the interpretation of the technical scope of the present invention. It is not a thing.

In order to achieve the above object, a method for controlling the engine-driven inverter generator 1 of the present invention includes:
An engine 21, a generator main body 22 driven by the engine 21, a converter 31 for converting alternating current generated in the generator main body 22 into direct current, and a direct current output from the converter 31 by converting the direct current into a predetermined alternating current with a supply inverter 32 to obtains a load value indicating the amount of power consumed by the load, the relationship between the target rotational speed is a rotational speed of the engine 21 corresponding to the amount of power the load value indicates beforehand and advance, based on the correspondence relation, the target rotational speed corresponding to the detected load value, the measured rotational speed of the engine is set as the set target rotation speed to be reached, the measured rotational speed of the engine 21 before serial set to be a target rotational speed, the engine-driven inverter generator that performs fuel supply quantity control for controlling the supply amount of the fuel to the engine 21 There,
When said detected load value decreases, the reference reduction rate is reduced a small amount [Delta] Nt _d per unit preset time _{ΔT b (ΔNT d / ΔT b} ), the target corresponding to the load value L ₂ before the change The set target rotational speed is gradually decreased from the rotational speed NT ₂ to the target rotational speed NT ₁ corresponding to the changed load value L ₁ .
Before Symbol reference reduction rate (ΔNT _d / ΔT _b) is
Time required until the actual rotational speed of the engine when said reduced synchronization with the set target rotational speed of the load values by low under performing the fuel supply amount control is settled at the set target rotational speed (T against the ₁ -T _3),
The time (T ₁ -T ₄ ) required to complete the gradual reduction of the target rotational speed in accordance with the reference reduction rate is set to be longer (Claim 1).

In the control method of the engine-driven inverter generator 1 having the above-described configuration , the above-described gradual decrease in the set target rotation speed is linearly reduced as the elapsed time increases from the decrease start time T ₁ of the set target rotation speed. (Claim 2: see FIGS. 2 and 3).

Alternatively, instead of such linear gradual decrease, the set target rotational speed may be divided into a plurality of times and gradually reduced (see claim 3: FIGS. 4 and 5).

As described above, when the set target rotational speed is gradually decreased, it is preferable that the set target rotational speed is gradually decreased at a time interval t of 1 sec or less per time. 4).

Similarly, when the set target rotational speed is gradually decreased step by step, an instantaneous decrease amount of the set target rotational speed at which the engine 21 does not cause an undershoot is obtained in advance.
It is preferable to set the reduction amount ΔNT _d (see FIG. 5) of the set target rotational speed per rotation to a value equal to or less than the instantaneous reduction amount (Claim 5), and more preferably, the set target rotation per rotation. The speed reduction amount ΔNT _d is set to 100 min ⁻¹ or less (claim 6).

Further, when the set target rotation speed is reduced stepwise in this way, each time the set target rotation speed is decreased once, the engine 21 is rotated at a rotation speed corresponding to the set target rotation speed after the decrease. It is preferable that the rotation speed be maintained for a predetermined time t _h (Claim 7).

The engine-driven inverter generator 1 of the present invention that realizes the above control method includes an engine 21, a generator main body 22 driven by the engine 21, and a converter that converts alternating current generated in the generator main body 22 into direct current. 31, and Bei example for supplying inverter 32 a DC output from the converter 31 to the load is converted into a predetermined AC,
Wherein a load value indicating the amount of power consumed by the load, storage means for storing correspondence between the (rotational speed correspondence table 81) between the target rotational speed is a rotational speed of the engine corresponding to the amount of power the load value indicates ( (Not shown)
Load value detecting means for detecting the load value (control unit 33 in the embodiment);
Based on the correspondence stored in the storage means, the measured rotational speed of the engine reaches the target rotational speed corresponding to the load value detected by the load value detecting means (control unit 33 in the embodiment) . set set as the target rotational speed to be such that the actual rotational speed of the engine 21 is in front Symbol set target rotational speed, the engine control unit (embodiment performs fuel supply quantity control for controlling the supply amount of the fuel to the engine 21 the controller 8, ECU 26, an electronic governor 24, speed sensor 25 across the "engine control unit" configuration) engine driven inverter generator equipped with,
When the detected load value decreases, the reference reduction rate is reduced a small amount [Delta] Nt _d per unit preset time _{ΔT b (ΔNT d / ΔT b} ), the target rotation corresponding to the load value L ₂ before the change A deceleration control means 82 for gradually decreasing the set target rotational speed to the target rotational speed NT ₁ corresponding to the load value L ₁ after the change from the speed NT ₂ ;
The reference reduction rate (ΔNT _d / ΔT _b ) used in the deceleration control means 82 is
When the fuel supply amount control is performed by reducing the set target rotational speed in synchronization with the decrease in the load value, the time required for the measured rotational speed of the engine 21 to settle to the set target rotational speed (T against the ₁ -T _3),
Characterized in that it is preset so it is longer the reference reduction rate time required for the gradual reduction of the set target rotational speed is completed in accordance with (T ₁ -T ₄₎ (claim 8).

Further, the deceleration control means 82, the gradual reduction of the set target rotational speed, be configured to perform control to decrease linearly with increase in the elapsed time from the decrease start time T ₁ of the said set target rotational speed (Claim 9) Alternatively, instead of this configuration, the set target rotational speed may be divided into a plurality of times and decreased stepwise (Claim 10).

In this case, the deceleration control means 82 can decrease the set target rotational speed at a time interval t of 1 sec or less per time (claim 11). the decrease [Delta] Nt _d of set target rotational speed per time, the engine can be performed as follows momentary decrease in the rotational speed which does not cause undershoot (claim 12), more preferably, set the per The target rotational speed reduction amount ΔNT _d can be set to 100 min ⁻¹ or less (claim 13).

When the deceleration control means 82 decreases the set target rotational speed step by step, the rotation corresponding to the set target rotational speed after the decrease every time the set target rotational speed decreases. it can be made to the rotational speed of the engine 21 given time t _h holding at a speed (claim 14).

  With the configuration of the present invention described above, according to the engine-driven inverter generator 1 of the present invention, the following remarkable effects can be obtained.

Detected load value, for example, by some or all of the stop of the load, rapid and if it demonstrated decrease, the reference reduction rate is reduced a small amount [Delta] Nt _d per unit time [Delta] T _b which is set in advance ([Delta] Nt _d / in [Delta] T _b), by which is gradually decreased to set the target rotational speed to the target rotational speed NT ₁ corresponding to the load value L ₁ after the change from the target rotation speed NT ₂ corresponding to the load value L ₂ before the change, the conventional As described in the art, the fuel supply amount to the engine is the same as when the set target rotational speed is instantaneously changed from the original target rotational speed NT ₂ to the new target rotational speed NT ₁ (see FIG. 7). It suddenly decreased or the fuel supply to the engine did not stop temporarily.

  As a result, the drive energy of the engine suddenly decreases and the occurrence of the “undershoot” described above can be prevented. Therefore, the load value rapidly increases again during the control to decrease the engine speed. Thus, even when the load value changes suddenly, the engine speed can be quickly followed by the sudden change in the load value. It was possible to suitably prevent the occurrence of malfunction such as stoppage of the load during start-up due to the inability to supply the required power (insufficient output power), and failure of start-up of the input load.

Such setting reference reduction rate when performing gradual decrease of the target speed (ΔNT _d / ΔT _b), the fuel supply by the low under the set target rotational speed [Delta] Nt _d in synchronism with a decrease in the load value In response to the time (T ₁ -T ₃ ) required for the measured rotational speed of the engine 21 to settle to the set target rotational speed ΔNT _d when the amount control is performed, an instruction to decrease the rotational speed , that is, the reference reduction rate Accordingly, the time required for completing the gradual reduction of the set target rotational speed (T ₁ −T ₄ ) is set in advance so that the engine 21 is not forced to decelerate, The occurrence of undershoot can be prevented more reliably, and as a result, the above-mentioned malfunction such as stalling of the engine, stop of the load during start-up, and failure of start-up of the input load can be more reliably generated. Could be prevented.

Note that such a gradual decrease in the set target rotational speed of the engine can be performed by decreasing it linearly over time. However, in a configuration in which it is divided into a plurality of steps, undershoot is more likely to occur. In addition to being able to prevent it reliably, even when the load value suddenly increased again during the control for reducing the engine speed, it was possible to respond quickly to the increase in the engine speed.

  In other words, when the engine speed is continuously reduced linearly, an inertial action is performed to maintain the state in which the engine speed is reduced, thus continuously reducing the engine speed. When the engine rotation speed is stabilized at a predetermined value or is to be increased again, it is necessary to turn off the inertial action described above and to operate in the opposite direction. The above-described undershoot is likely to occur without stopping, and even when the rotational speed of an engine that is operating at the same rotational speed is increased, the engine that is operating stably at the rotational speed is It is necessary to supply more energy (fuel) when increasing the engine speed while the engine speed is decreasing than when increasing the engine speed. To.

On the other hand, in the configuration in which the set target rotational speed is gradually reduced as described above, the rotational speed changes at each stage, so that “continuity” in the reduction of the engine rotational speed is cut off. As a result of the fact that the inertial action described above is less likely to occur, it is possible to prevent the occurrence of the above-described undershoot and to reduce the amount of energy supplied when the rotational speed is increased again.

In particular, each time the set target rotational speed is reduced, the holding time is maintained when the rotational speed of the engine 21 is held at a rotational speed corresponding to the set target rotational speed after the reduction for a predetermined time t _h. Since the rotational speed of the engine 21 is stable, the continuity of the lowering motion of the rotational speed can be reliably divided, and the above effect can be further promoted.

By reducing the set target rotational speed at intervals of 1 sec or less and at 100 min ^-1 or less per time, the engine sound generated during deceleration can be heard continuously, reducing the “noisiness” as an audibility. We were able to.

The block diagram which shows the structural example of the engine drive type inverter generator of this invention. (A): Load value, (B): Set target rotational speed, (C): Fuel supply amount, (D): Time chart showing the relationship between changes in engine rotational speed (when load value decreases instantaneously) In this example, the set target rotation speed is reduced linearly). (A): Load value, (B): Set target rotational speed, (C): Fuel supply amount, (D): Time chart showing the relationship of changes in engine rotational speed (Load value exceeds reference reduction rate) This is an example in which the set target rotational speed is linearly reduced). (A): Load value, (B): Set target rotational speed, (C): Fuel supply amount, (D): Time chart showing the relationship between changes in engine rotational speed (when load value decreases instantaneously) In this example, the set target rotation speed is decreased stepwise). It is the graph which showed the mode of change when setting target rotation speed is decreased in steps, (A) shows time- setting target rotation speed, (B) shows change of time-engine (measurement) rotation speed. . The graph which shows the correspondence of load value (load current)-target rotational speed. (A): Load value, (B): Set target rotational speed, (C): Fuel supply amount, (D): Change in engine rotational speed in a conventional engine-driven inverter generator .

  Hereinafter, an engine-driven inverter generator of the present invention and a control method performed in the engine-driven inverter generator will be described with reference to the accompanying drawings.

[Configuration of generator]
(1) Overall Configuration In FIG. 1, reference numeral 1 denotes an engine-driven generator according to the present invention. The engine-driven generator 1 has an engine 21 and a generator body 22 driven by the engine 21. The power conversion unit 3 includes a power generation unit 2, a converter 31 that converts alternating current generated in the power generation unit 2 into direct current, an inverter 32 that converts the direct current from the converter 31 into alternating current of a predetermined frequency, and outputs the alternating current. The waveform shaping unit 4 for improving the output waveform 3 is provided, and the AC output shaped by the waveform shaping unit 4 can be taken out from the output terminal block 6 connected via the breaker 5 or the like. .

  The engine-driven inverter generator 1 is provided with a controller 8 that controls the operation of the power generation unit 2 and the power conversion unit 3 based on a detection signal from a control unit 33 provided in the power conversion unit 3. ing.

(2) Power Generation Unit The power generation unit 2 includes an engine 21, a generator main body 22 driven by the engine, and an engine control unit (ECU) 26 that controls the rotational speed of the engine. The rotating shaft of the generator main body 22 is connected, and the engine 21 and the generator main body 22 rotate in synchronization.

  In this embodiment, the generator body 22 is a permanent magnet generator, and is driven by the engine 21 described above to generate and output a three-phase alternating current having a frequency corresponding to the rotational speed.

  The engine 21 is provided with an electronic governor 24 that adjusts the amount of fuel injected into the combustion chamber by an electrical signal, and a rotational speed sensor 25 that detects the rotational speed.

The engine control unit (ECU) 26 is an electronic control device for comprehensively performing electrical control of the engine 21, and by transmitting a control signal to the electronic governor 24 provided in the engine 21, The injection amount, the injection timing, and the like can be controlled, and the rotational speed of the engine 21 (measured rotational speed) detected by the rotational speed sensor 25 and the rotational speed ( set target rotational speed) output from the controller 8 described later. A fuel control signal for instructing the fuel injection amount (or fuel increase / decrease amount) is transmitted to the electronic governor 24 so that the deviation from the above becomes zero.

  Therefore, in the embodiment shown in FIG. 1, a controller 8, which will be described later, an ECU 26 controlled by the controller 8, an electronic governor 24 controlled by the ECU 26, and a rotation that feeds back the rotational speed of the engine 21 to the ECU 26. The “engine control device” according to the claims is configured to control the rotational speed of the engine by the speed sensor 25.

  In the present embodiment, the rotational speed sensor 25 transmits a rotational pulse signal at every predetermined rotational angle of the engine 21, and the ECU 26 calculates an actual rotational speed based on the rotational pulse signal.

(3) Power Conversion Unit The power conversion unit 3 includes a converter 31 that converts the three-phase alternating current output from the generator body 22 into direct current, and an inverter that converts the direct current output from the converter 31 into a predetermined three-phase alternating current. 32, a control unit 33 for controlling the converter 31 and the inverter 32, a current detection means 34 for detecting a current value of the three-phase AC input to the converter, and a current value of the three-phase AC output from the inverter Current detecting means 35 for performing the operation.

  The three-phase alternating current output from the generator main body 22 is input to the converter 31 provided in the power conversion unit 3, rectified to direct current, and then output.

  The direct current converted from the three-phase alternating current by the converter 31 is then input to the inverter 32 also provided in the power conversion unit 3, and is built in the inverter 32 so as to have a set predetermined frequency and output voltage value. After being converted into a three-phase alternating current by a plurality of transistors, it is output through a filter that modulates a sine wave.

  The converter 31 and the inverter 32 are controlled by a control unit 33 which is an electronic control device.

  The control unit 33 outputs the power consumption calculated from the current value of each phase of the three-phase AC output from the inverter 32 to the controller 8 connected to the engine-driven inverter generator 1.

  Therefore, in this embodiment, the control unit 33 realizes a load value detecting means for detecting the load value, but the load value detecting means is a load (total load) connected to the engine-driven inverter generator 1. ), That is, any change can be used as long as the change in power consumption can be extracted as an electric signal. From the current detection means 35 for detecting the output current of the inverter 32 and the waveform shaping section 4. Control according to the method of the present invention is performed based on a change in the load value obtained by the voltage monitoring means 83 provided in the controller 8 for monitoring the line voltage value between the phases of the output three-phase AC. May be.

  The rotation pulse signal transmitted from the rotation speed sensor 25 of the engine 21 may generate the rotation speed (measured rotation speed) of the engine by the control unit 33 and output it to the controller 8.

(4) Waveform shaping unit The three-phase alternating current having a predetermined frequency output from the power conversion unit 3 is then subjected to waveform shaping via the waveform shaping unit 4 and output to a load connected to the output terminal block 6. Is done.

(5) Controller The load-side power consumption (load value) output from the control unit 33, the rotational speed of the engine 21, and the line voltage values between the three-phase AC phases output from the waveform shaping unit 4 are as follows: Both are input to the controller 8 constituted by a microcontroller or the like.

  This controller 8 outputs the power consumption and rotational speed transmitted from the control unit 33 according to the program stored in the memory, and is output from the waveform shaping unit 4 between the three-phase AC phases detected by the voltage monitoring means 83. Based on the line voltage value, a signal for instructing control of the engine 21 and control of the converter 31 and the inverter 32 is transmitted to the ECU 26 and the control unit 33.

The storage means of the controller 8 is provided with a rotation speed correspondence table 81 showing the correspondence between the power consumption on the load side and the target rotation speed of the engine 21, and the consumption determined by the control unit 33 which is the load value detection means. Based on the electric power (load value), the aforementioned rotational speed correspondence table 81 is referred to obtain the logical rotational speed (target rotational speed) of the engine 21, and this logical rotational speed is set as the set target rotational speed by the rotational speed sensor 25. A command signal is output to the ECU 26 so as to control the fuel supply amount to the engine so that the actually measured engine rotation speed approaches the set target rotation speed.

Based on the fuel consumption curve of the engine 21, the rotational speed correspondence table 81 can correspond to the load fluctuation that can occur with respect to the detected power consumption on the load side and the output of the engine 21 necessary to generate the power consumption on the load side. In order to generate an output with a predetermined margin value added, a relationship with the target rotational speed of the engine 21 that is the smallest fuel consumption is set, and the consumption is between the set idle rotational speed and the maximum rotational speed. When the electric power is low or 0, the idle rotation speed is set as the set target rotation speed. Thereafter, in this embodiment, the set target rotation speed increases linearly as the power consumption increases, and the maximum rotation speed is reached. Set to clamp.

In the present embodiment, the correspondence relationship between the power consumption and the target rotation speed is stored in the controller 8 as the rotation speed correspondence table 81. Instead, the correspondence relationship between the power consumption and the target rotation speed is a calculation formula, This calculation formula may be stored in the controller 8.

In this embodiment, the power consumption is detected as the load value. However, when the load current value is detected as the load value instead, the correspondence between the current value and the target rotational speed is shown in FIG. The relationship may be stored in the controller 8 as a rotation speed correspondence table or a calculation formula.

  The predetermined margin value that can cope with the load fluctuation described above may be a constant value with respect to the power consumption on the load side, and the predetermined margin value is increased when the power consumption on the load side is small. When the power consumption on the load side is large, it may be reduced.

Controller 8 configured in this way, by the execution of further programmed, if a decrease of the detected load value by the load value detection means is confirmed, the reference is reduced a small amount [Delta] Nt _d per unit time [Delta] T _b which is set in advance The set target rotational speed is gradually decreased from the target rotational speed NT ₂ corresponding to the load value L ₂ before the change to the target rotational speed NT ₁ corresponding to the load value L ₁ after the change with the reduction rate (ΔNT _d / ΔT _b ). The deceleration control means 82 is configured to be realized.

The contents of the set target rotational speed commanded to the ECU 26 by the deceleration control means 82 will be described in detail in the operation description described later.

(6) Starter switch Note that reference numeral 76 in FIG. 1 is a starter switch for starting and stopping the engine-driven inverter generator 1. By operating the starter switch 76, the engine 21, the controller 8, A “stop” position where the power supply to the unit 33 and other electrical components is cut off, a “drive” position where the power supply to the engine 21 and electrical components is started and the engine 21 can be operated, and a diagram provided in the engine 21 A switch can be switched between “start” positions for energizing the cell motor (not shown) to start the engine 21. In this embodiment, the starter switch is inserted as a key. Therefore, a switch that enables switching between the positions is used.

  In the illustrated embodiment, a single switch can be used to switch between the three positions of stop, operation, and start. For example, a switch that switches between the “stop” and “run” positions (for example, a switch) A switch) and a switch (for example, a momentary switch) for starting the cell motor may be provided separately.

[Description of operation]
The operation of the engine-driven inverter generator 1 of the present invention configured as described above will be described.

(1) General operation When the starter switch 76 is moved from the “running” position to the “starting” position, the cell motor (not shown) provided in the engine 21 is energized, and the engine 21 is started by the rotation of the cell motor. After the engine 21 is started, the starter switch 76 is returned to the “operation” position to continue the operation.

In the present embodiment, when the rotational speed of the engine reaches a predetermined rotational speed (for example, 1200 min ⁻¹ ), the controller 8 outputs an output start signal (PON signal) to the control unit 33, and this PON signal When the control unit 33 receives the signal, the gate of the inverter 32 is turned ON, and the output from the inverter can be started.

When the load value (power consumption) detected by the load value detection means (control unit 33 in the present embodiment) increases due to the connection of the load, the controller 8 that has received this corresponds to the rotational speed stored in the storage means. In accordance with the correspondence defined in the table 81, based on the load value received from the control unit 33, the ECU 26 is caused to execute engine rotational speed control with the target rotational speed corresponding to this load value as the set target rotational speed.

(2) Control at the time of load reduction In the conventional engine-driven inverter generator configured as described above, the set target rotational speed is set based only on the correspondence defined in the rotational speed correspondence table 81 described above. In the case where the load value is instantaneously reduced from A ₂ to A ₁ at time T ₁ as described with reference to FIG. 7, the setting target rotational speed is also instantly changed from NT ₂ to NT ₁ at T _1. Control to decrease was performed.

In contrast, in the present invention, a reduced small amount [Delta] Nt _d per unit time [Delta] T _b, the reference rate of decrease advance predefined as (ΔNT _d / ΔT _b), when reduction of the set target rotational speed, by the reference reduction rate The set target rotation speed is gradually decreased from NT ₂ to NT ₁ over a predetermined time (time T _{b in} FIG. 2).

In the example shown in FIG. 2, the load value is instantly reduced from L ₂ to L _{1 at} time T ₁ , and the decrease L _d is shown as an example. As shown in FIG. 3 (A), not only when the load decreases instantaneously at T ₁ , but also when the load value decreases over a predetermined time, Become.

As an example, in the present embodiment, the above-mentioned unit time ΔT _b is instantaneously reduced by a reduction amount ΔNT _d to the set target rotational speed, and the fuel supply amount that brings the engine rotational speed close to the set target rotational speed. when performing control, the time required until the rotational speed of the engine 21 is stabilized at the set target rotation speed for example empirically, or, calculated on the basis of the data provided as specifications of the engine, the A unit time ΔT _b was set as a time longer than the time.

When the load value changes as described above, the load value L ₁ after the change from the target rotation speed NT ₂ corresponding to the load value L ₂ before the change of the set target rotation speed at the reference reduction rate described above. by gradually decreasing over time T _b to the target rotational speed NT ₁ corresponding to, also it becomes to be gradually reduced as shown in FIG. 2 (C) for the fuel supply quantity to the engine, has been described with reference to FIG. 7 Unlike conventional engine-driven inverter generators, the amount of fuel supplied to the engine decreases rapidly, or the supply of fuel to the engine does not temporarily stop, so the energy of the engine does not decrease rapidly. In addition, a gradual decrease corresponding to the slope set as the reference reduction rate is performed.

As a result, in the conventional control method described with reference to FIG. 7, for example, when the load value rises to A ₂ again at time T ₂ during the control of reducing the rotational speed of the engine 21, It is assumed that the engine 21 stalls due to a suddenly large load applied to the engine 21 in which the rotational speed has been reduced to Nmin due to undershoot and the fuel supply has been cut off. However, the rotation speed of the generator main body 22 cannot be increased following the rapidly increased load value (load-side power consumption), the supply power is insufficient, and the load being started is stopped. There was a malfunction such as failure to start the input load.

However, in the method of the present invention, even when the control for reducing the engine speed is being performed, even if the load value suddenly increases to L ₂ again at time T ₂ in FIG. Is in NA _m and fuel is supplied at a supply amount F _m corresponding to the rotational speed, so that even if such a sudden increase in load value occurs, the stall of the engine 21 In addition, it was possible to suitably prevent malfunctions such as stoppage of the load during start-up and failure of start-up of the input load.

In addition, when the control of reducing the engine speed rapidly is performed, the inertial action to maintain the decrease in the engine speed works to stop the engine speed decrease at the target engine speed. However, as a result of the continued decrease in the rotational speed, the “undershoot” in which the rotational speed of the engine decreases to the minimum rotational speed NAmin greatly below the rotational speed NA ₁ corresponding to the target rotational speed NT ₁ has already been explained. (See FIG. 7).

In contrast, it in the present method as described above, it has gradually decreased target rotational speed over a predetermined time, in particular, which gradually decreases the target rotation speed over time or more time required to settle the above-mentioned As a result, the engine speed is reduced while suppressing the engine's effect of continuing to reduce the engine speed, so that the occurrence of the undershoot described above can be suitably prevented. Even when the load value suddenly increases again during the deceleration control of the engine and it becomes necessary to increase the engine speed, the engine speed can be rapidly increased again. It has become.

As described above, in the configuration of the present invention described with reference to FIGS. 2 and 3, it is assumed that control is performed to linearly decrease the decrease in the set target rotational speed when the load value decreases. However, the reduction of the set target rotation speed may be performed step by step as shown in FIGS.

Even in this case, as described with reference to FIGS. 2 and 3, the target rotational speed N ₂ corresponding to the load value L ₁ after the decrease is changed from the target rotational speed N ₂ corresponding to the load value L ₂ before the decrease. until _1, the time T _b of the total required for the reduction of the set target rotational speed, as well, the decrease [Delta] Nt _d set the target rotation speed is decreased in synchronization with the decrease of the load rotational speed of the engine is the set target rotation When the fuel supply amount control is performed so as to achieve the speed, it is desirable to set the time as a time longer than the time required for the rotational speed of the engine 21 to settle to the set target rotational speed .

Then, during this time T _b, by a constant value nt _d every predetermined time interval t reduce the setting target rotational speed, continuous by setting the target rotational speed decrease amount NT _d over time T _b of this work Reduce.

The individual time intervals t divided in this way can be set to 1 sec or less, preferably 300 msec or less, as an example. The decrease value nt _d of the set target rotation speed per rotation is the minimum at which the above-described undershoot occurs. Is preferably determined in advance as a trial, and the deceleration amount nt _d per one time is preferably set to a value smaller than this, and more preferably, the reduction value nt _d of the set target rotational speed per time. the, 100 min ^-1 or less, further preferably 30min ^-1 or less.

Thus, 1 sec intervals t time per one or less, preferably 300msec or less, the deceleration amount nt _d of set target rotational speed per one 100 min ^-1 or less, preferably by a 30min ^-1 or less, The ability to hear the engine sound when reducing the rotational speed is continuously heard, thereby reducing the “noisiness” as an audible feeling.

Furthermore, in this embodiment, for each deceleration of the set target rotational speed, the rotational speed of the engine 21 is held at a rotational speed corresponding to the set target rotational speed for a certain holding time t _h. , The set target rotation speed was reduced step by step.

Therefore, in the change in the set target rotation speed shown in FIG. 5A, each time interval t is the time required to reduce the engine rotation speed with respect to the set target rotation speed reduction amount nt _d per one time. the sum of t _s (although the time t _s can be the rotational speed of the engine 21 to the drop in instantaneous reduction nt _d is set to a time required until the settling, but is not limited thereto.) and the retention time t _h Thus, when the target rotational speed is changed as shown in FIG. 5 (A), the rotational speed of the engine changes as shown in FIG. 5 (B).

That is, when decreasing by deceleration amount nt _d the set target rotational speed each time, over time t _s required for reduction of the nt _d, after the rotational speed of the engine 21 is lowered nt _d, the retention time t _h During this time, the reduced rotational speed is maintained, and this operation is repeated to reduce the rotational speed to the rotational speed NA ₁ .

  Note that, when the rotational speed of the engine 21 is to be drastically reduced, as described above, the engine 21 has an inertial action for maintaining the action of reducing the rotational speed. As described in the embodiment, the continuity of the reduction effect of the rotational speed is interrupted at each stage by decreasing the rotational speed of the engine in stages and maintaining the reduced rotational speed for a certain period of time. I'm trying to droop.

  As a result, the engine speed at which the engine rotation is stably maintained at each stage is compared with the case where the engine speed continuously decreasing is increased again. In the case of re-raising, less energy is given to the engine due to the re-raising of the rotational speed, and the load value is increased as if there is a sudden increase in the load value following a sudden decrease in the load value. Even when the engine speed changes abruptly, the engine speed quickly follows this change, causing the engine to stall or the output power to temporarily decrease, causing the load to start. It was possible to suitably prevent the occurrence of malfunction such as failure or stopping of the load being started.

DESCRIPTION OF SYMBOLS 1 Engine drive type inverter generator 2 Electric power generation part 21 Engine 22 Generator main body 24 Electronic governor 25 Rotational speed sensor 26 Engine control unit (ECU)
DESCRIPTION OF SYMBOLS 3 Power conversion part 31 Converter 32 Inverter 33 Control unit 34 Current detection means 35 Current detection means 4 Waveform shaping part 5 Breaker 6 Output terminal block 76 Starter switch 8 Controller 81 Rotational speed correspondence table 82 Deceleration control means 83 Voltage monitoring means

Claims (14)

An engine, a generator main body driven by the engine, a converter for converting alternating current generated in the generator main body into direct current, and an inverter for converting direct current output from the converter into predetermined alternating current and supplying it to a load In addition, a correspondence relationship between a load value indicating the amount of power consumed by the load and a target rotation speed that is the engine rotation speed corresponding to the amount of power indicated by the load value is obtained in advance, and based on the correspondence relationship. Te, the target rotational speed corresponding to the detected load value, the measured rotational speed of the engine is set as the set target rotation speed to be reached, so that the measured rotational speed of the engine is before Symbol set target rotational speed, An engine- driven inverter generator that controls the amount of fuel supplied to an engine,
When said detected load value decreases, the reference reduction rate is small reduction per unit preset time, corresponding target rotation to the load value after the change from the target rotational speed corresponding to the load value before the change made by the is gradually decreased to set the target rotational speed to the speed,
Before Symbol reference decrease rate,
To the time it takes for the actual rotational speed of the engine when said synchronism with decrease in the load value reduces the set target rotational speed was the fuel supply amount control is settled at the set target rotation speed ,
A control method for an engine-driven inverter generator, characterized in that the time required for completing the gradual reduction of the set target rotational speed in accordance with the reference reduction rate is set longer . The method of the setting the gradual decrease of the target rotational speed, the set target from the decrease start rotation speed in response to an increase in elapsed time according to claim 1, wherein the reducing linearly engine driven inverter generator. 2. The method for controlling an engine-driven inverter generator according to claim 1, wherein the set target rotation speed is gradually decreased by gradually decreasing the set target rotation speed in a plurality of times. The method for controlling an engine-driven inverter generator according to claim 3, wherein the stepwise decrease in the set target rotational speed is performed at a time interval of 1 second or less per time. An instantaneous reduction amount of the set target rotational speed at which the engine does not cause undershoot is obtained in advance,
The method for controlling an engine-driven inverter generator according to claim 3 or 4, wherein a reduction amount of the set target rotational speed per rotation is set to a value equal to or less than the instantaneous reduction amount. The method for controlling an engine-driven inverter generator according to any one of claims 3 to 5, wherein a reduction amount of the set target rotational speed per rotation is set to 100 min ^-1 or less. Each time decreases once the set target rotational speed, according to claim 4-6 any one, characterized in that to hold the rotational speed of the engine a predetermined time at a rotation speed corresponding to the set target rotational speed after under low The control method of the engine drive type inverter generator as described. An engine, a generator main body driven by the engine, a converter for converting alternating current generated in the generator main body into direct current, and an inverter for converting direct current output from the converter into predetermined alternating current and supplying it to a load Huh,
A load value indicating the amount of power consumed by the load, a storage means for storing a correspondence relationship between the target rotational speed is a rotational speed of the engine corresponding to the amount of power the load value is shown,
Load value detecting means for detecting the load value;
Based on the correspondence stored in the storage means, the target rotational speed corresponding to the load value detected by the load value detecting means is set as a set target rotational speed that the measured rotational speed of the engine should reach. the so that actual rotational speed of the engine is before Symbol set target rotational speed, an engine-driven inverter generator having an engine control unit for the fuel supply amount control for controlling the amount of fuel supplied to the engine,
The engine control device, when the detected load value decreases, the reference reduction rate is small reduction per unit preset time, after the change from the target rotational speed corresponding to the load value before the change load value A deceleration control means for gradually decreasing the set target rotational speed to a target rotational speed corresponding to
The reference reduction rate used in the deceleration control means is:
To the time it takes for the actual rotational speed of the engine when said synchronism with the decrease of the load value reduces the set target rotational speed was the fuel supply amount control is settled at the set target rotation speed ,
Engine-driven inverter generator, wherein the direction of the time required for the gradual reduction of the set target rotational speed is completed is set in advance to be longer according to the reference rate of decrease. Said deceleration control means, a gradual reduction of the set target rotational speed, the engine driven inverter according to claim 8, wherein the reducing linearly with increase in the elapsed time from the decrease start of the set target rotation speed Generator. 9. The engine-driven inverter generator according to claim 8, wherein the deceleration control means performs the gradual decrease of the set target rotation speed by gradually reducing the set target rotation speed in a plurality of times. . 11. The engine-driven inverter generator according to claim 10, wherein the deceleration control means reduces the set target rotational speed at a time interval of 1 second or less per time. The engine according to claim 10 or 11, wherein the deceleration control means performs a reduction amount of the set target rotational speed per rotation as not more than an instantaneous reduction amount of the rotational speed at which the engine does not cause an undershoot. Drive type inverter generator. The engine-driven inverter generator according to any one of claims 10 to 12, wherein the deceleration control means performs a reduction amount of the set target rotational speed per rotation at 100 min ^-1 or less. The deceleration control means holds the rotational speed of the engine for a predetermined time at a rotational speed corresponding to the set target rotational speed after the decrease every time the set target rotational speed is decreased. The engine drive type inverter generator of any one of 10-13.

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