JP2007174723A - Ac/dc converting power supply and light emitting diode driving system using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an AC/DC converting power supply for improving a waveform of an input current, having a power factor of 1 or a slightly advanced power factor, and simplifying a control pulse. <P>SOLUTION: A power supply frequency is resonated by connecting a magnetic energy regenerative switch comprising four reversely conducting semiconductor switches and an energy storage capacitor to a reactor and an AC power supply in series and turning on/off the switch in synchronization with an AC voltage. If a resonance voltage is extracted by a diode rectifying circuit, a DC voltage higher than the AC input voltage is obtained, and an input current has less harmonic component and the improved power factor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an AC / DC conversion power supply device that converts AC power into DC, and in particular, the input current waveform is clean and power factor is optimal as a DC power supply for driving a number of light emitting diodes (LEDs) connected in series. The present invention relates to an AC / DC conversion power supply apparatus that is good and that does not perform PWM control and that can perform output control to the same extent as in PWM control.

For power generation and transmission, alternating current is advantageous, and alternating current is the mainstream in the electric power field, but at the end, the field of converting electric power from alternating current to direct current is increasingly widespread. Among them, plant factories and vegetable factories, which grow light plants using light-emitting diodes (LEDs) instead of sunlight, which are expected to use electricity in the future, are becoming popular. I have done it. It is expected that enormous power will be used for agriculture in the future. When converting AC power to DC, an efficient power supply device is desired that has a good power factor of input current, low harmonics, low manufacturing costs, and high efficiency.
Next, an example in which a large number of light emitting diodes are driven to produce a plant for growing plants will be described.

  In general, terrestrial plants are irradiated with light energy in a wide range of wavelengths from the sun to ultraviolet to infrared. However, plants do not use energy at all wavelengths. Therefore, it is possible to select and irradiate a specific wavelength effective for plant growth by using the LED. In addition, taking advantage of the power saving feature of LEDs, it is possible to cultivate plants at low power and low cost compared to plant cultivation using other lighting lamps. By irradiating with red light for 24 hours, the growth of lettuce, which normally takes about two and a half months, is reduced to about one month, and a certain amount can be shipped every day regardless of the season or weather. Sunfield, a farming association in Toyota Town, Shizuoka Prefecture, is operating the LED vegetable factory for the first time in the world. The production volume is 125 square meters, comparable to 3 hectares of field.

In terms of nutrition, vitamins A, C, and E are high in content compared to general lettuce, and vitamin A is said to be 14 times more effective than outdoor products.
It is also known that sugar content tends to increase when LEDs are irradiated to house-grown strawberries and tomatoes.

  It can be grown under complete control without natural light, and can be irradiated for 24 hours, so it is efficient and lettuce, which is a representative of leafy vegetables, has already been well received on the market. 28% of the vegetable plant production costs are for electricity. In the future, it is expected that the time will come when all vegetables are made in factories. At that time, the cost and power efficiency of the LED drive circuit are major issues directly related to vegetable production costs.

  Conventionally, in the case of a single LED, driving is performed by a constant voltage power source with a current limiting resistor connected in series. The power loss of the current limiting resistor is large. At the vegetable factory, a large number of LEDs are connected in series, rectified by a diode bridge, directly connected to the power supply, and the transformer reactance drop is used. ing.

  FIG. 2 shows the most basic LED driving circuit in the past, and the current waveform flows at a point exceeding the junction voltage of the LEDs connected in series, so that it is a pulsed current. This is the same as the capacitor input type AC / DC converter circuit shown in Fig. 2 (A). The current waveform is pulsed and the phase of the fundamental wave may be the same as that of the voltage. It has a waveform. In order to obtain a sine waveform instead of a pulsed current, a reactor input type may be used as shown in FIG. This makes the waveform clean, but the power factor is poor and the DC voltage is low. At low voltage, the number of LEDs connected in series cannot be increased.

  A method of converting a current waveform into a sine wave by using a PWM (Pulse Width Modulation) converter or a PWM / PFC (Power Factor Correction) circuit also called PAM (Pulse Amplitude Modulation) control is well known. Fig. 3 shows the PWM converter circuit (A) and the PWM / PFC circuit (A).

The PWM converter circuit secures the DC voltage, generates a sine wave Vpwm, and inserts a reactance X between the power supply voltage Vin and the power flow is
P = Vin * Vpwm * sinδ / X
The voltage phase difference δ determines the direction of power. The phase of the PWM sine wave is delayed by δ from the power supply phase. A DC output can be obtained with the input current waveform as the fundamental wave, but the power factor changes under the influence of δ and the DC voltage, but the power factor can be made 1 by selecting the operating point. This is based on the fact that the voltage on the DC side is constant, which is greatly different from the present invention, and is a cause of increased switching loss due to hard switching on / off. It is also a disadvantage that a filter is indispensable so that harmonic current does not flow to the power supply side.

  The PWM / PFC circuit can be said to be a kind of reactor input type AC / DC converter that performs feedback control of the current waveform on the DC side. In addition, since this PWM type can make the DC voltage higher than the AC input voltage by interrupting the coil current, it is convenient to use this circuit to connect a number of LEDs in series. Further, the output current / voltage can be easily adjusted continuously. However, high-speed gate on / off control of PWM control is necessary, and there are problems of harmonic generation and switching loss due to hard switch on / off. When the power factor of the input current is other than 1, the current waveform is greatly disturbed, so current control other than the power factor of 1 cannot be performed.

In an AC / DC conversion power supply device, it is needless to say that it is important that there is less power loss, less harmonics in the input current, and a better power factor. Also, it is important to reduce the probability of failure by simplifying the number of parts of the device. The problems of the conventional method are listed.

The method of FIG. 2 has a large AC side power transmission loss because the power factor of the current waveform is poor. When the power factor is 0.7 and the power factor is 1, the Joule heating of the distribution line is twice different. The Joule loss of the distribution line is calculated to be 5V with 100m of cable per ampere, resulting in a loss of 5W. Power factor must be good.

The generation of harmonic currents associated with the PWM control in FIG. 3 can cause many harmonic problems and must be dealt with, so a filter circuit or the like is required. In addition, the loss associated with on / off switching of a high-speed (several tens of kHz) semiconductor switch is as large as the conduction loss.

Since the LED has the property of a diode, it is difficult to divert current due to the parallel connection due to the influence of temperature, etc., so that the series connection drive is preferable. In plant factories, a high DC voltage greater than 100V AC is required to drive hundreds of LEDs in series. When a transformer is used, the iron loss and winding loss of the transformer increase, so driving without using this is preferable in terms of efficiency.

The object of the present invention is to provide a DC power supply for driving a large number of series LEDs, with a clean input current waveform and good power factor, and without performing PWM control that generates switching loss and harmonics. An object of the present invention is to provide an AC / DC conversion power supply device that is possible to the same extent as the case.

The present invention relates to an AC / DC conversion power supply device, and the object of the present invention is connected between a bridge circuit composed of four reverse conducting semiconductor switches and a DC terminal of the bridge circuit, and at the time of current interruption. A magnetic energy regenerative bidirectional current switch consisting of a capacitor for storing magnetic energy, a reactor, and an AC power supply are connected in series, and the input side of the rectifier diode bridge is connected between the AC terminals of the bridge circuit. In the AC / DC conversion power supply device in which a smoothing capacitor is connected to the rectified output side of the diode bridge,
Control means for applying a control signal to the gate of each reverse conducting semiconductor switch to control on / off of each semiconductor switch, the control means comprising four reverse conducting types constituting the bridge circuit Of the semiconductor switches, control is performed so that the on / off operations of the pair of reverse conducting semiconductor switches located on the diagonal line are simultaneously performed, and when one of the two pairs is on, The resonance circuit is controlled so that the pair is turned off, the on / off operation is switched in synchronization with the voltage of the AC power supply, and the Q of the resonance circuit including the reactor and the capacitor for storing magnetic energy is 1 By setting it to be large, a resonance voltage higher than the AC power supply voltage is generated, and the resonance voltage is taken out via the diode bridge. Thus it is achieved.

  The above-mentioned object of the present invention is to replace the magnetic energy regenerative bidirectional current switch with a half bridge circuit composed of two reverse conducting semiconductor switches and one or two capacitors, Is effectively achieved by controlling so that when one of the two reverse conducting semiconductor switches is on, the other is turned off.

  Furthermore, the object of the present invention is that the AC / DC conversion power supply device further includes a transformer, and the AC terminal of the magnetic energy regenerative bidirectional current switch is connected to the primary side of the transformer. This is effectively achieved by connecting the secondary side to the input side of the diode bridge.

  Still further, the above object of the present invention can be achieved more effectively by replacing the diode bridge with a double wave rectifier circuit composed of two diodes and two smoothing capacitors.

The present invention relates to an AC / DC conversion power supply device, and the object of the present invention is connected between a bridge circuit composed of four reverse conducting semiconductor switches and a DC terminal of the bridge circuit, and at the time of current interruption. A magnetic energy regenerative bidirectional current switch comprising a capacitor for storing magnetic energy, a reactor, and an AC power supply are connected in series, and further, a diode anode is connected to the positive side of the DC terminal of the bridge circuit, In an AC / DC conversion power supply device in which a smoothing capacitor is connected between the cathode of the diode and the negative side of the DC terminal of the bridge circuit,
Control means for applying a control signal to the gate of each reverse conducting semiconductor switch to control on / off of each semiconductor switch, the control means comprising four reverse conducting types constituting the bridge circuit Of the semiconductor switches, control is performed so that the on / off operations of the pair of reverse conducting semiconductor switches located on the diagonal line are simultaneously performed, and when one of the two pairs is on, The resonance circuit is controlled so that the pair is turned off, the on / off operation is switched in synchronization with the voltage of the AC power supply, and the Q of the resonance circuit including the reactor and the capacitor for storing magnetic energy is 1 By setting it to be large, a resonance voltage higher than the AC power supply voltage is generated, and a DC load is connected to both terminals of the smoothing capacitor. It is also achieved me.

  The present invention relates to a light emitting diode driving system for supplying artificial light for growing vegetables and plants, and the object of the present invention is to provide a plurality of light emitting diodes in series with a DC output of the AC / DC conversion power supply device. This is achieved by connecting a plurality of connected series diode units in parallel.

  Also, the above object of the present invention is effectively achieved by making the light emitting diode a red light emitting diode.

  Further, an optical sensor is provided, a change in illuminance of the light emitting diode is detected by the optical sensor, and the detected signal is fed back to the control means so that the luminous intensity of the light emitting diode is maintained at a predetermined value. This is achieved more effectively by controlling the resonance voltage.

According to the present invention, when converting from alternating current to direct current, the harmonics of the alternating current input current are small, the power factor is good, and the direct current output can be controlled by the advance control of the on / off phase of the gate. Thus, it is possible to provide a converter capable of controlling the output while proceeding.
The number of on / off times is minimized, the gate control circuit is simplified, and it is also a zero voltage zero current switch, so the loss due to the switch is reduced. INDUSTRIAL APPLICABILITY The present invention can be applied to many fields in which resonance is caused by synchronous switching to an alternating current frequency to convert the resonance voltage across the magnetic energy regenerative switch into direct current when obtaining direct current from an alternating current power supply.

When a magnetic energy regenerative switch is connected in parallel to a generator whose frequency changes, such as wind power generation, and gate control is performed in synchronization with the frequency of the generator and resonates as a variable capacitor, a ferrant phenomenon occurs and the voltage is increased. To rise. If this voltage is used after DC conversion, a larger DC output can be taken out.

  A magnetic energy regenerative switch composed of four reverse conducting semiconductor switches and an energy storage capacitor functions as a resonance capacitor by combining with a reactor and turning on and off the switch synchronized with an AC voltage. We propose a method that incorporates the advantages of the conventional reactor input type shown in Fig. 2 (a) and the PWM converter shown in Fig. 3 (a) and eliminates the bad points of Fig. 3 (a).

In order to achieve the above object, this apparatus connects a magnetic energy regenerative switch 1 including four reverse conducting semiconductor switches and an energy storage capacitor shown in FIG. 1 in series to a reactor 2 and an AC power source 3. . A parallel resonance occurs when the switch having the switch gate control means 4 is synchronized with the AC voltage, and a high voltage with a square wave higher than the power supply voltage is generated. If it is taken out via the rectifier circuit 5, it has such a configuration that a direct current having a voltage higher than the alternating current input voltage is generated.

In the AC / DC conversion power supply device according to the present invention, since the semiconductor switch is switched only once during one cycle, no harmonics are generated.

In addition, in this device, since the resonance of the frequency is basically caused, the waveform of the input current is a sine wave, and the phase of the output current voltage and the means for controlling the switching phase so that the current power factor becomes 1. And means for controlling the output to be constant regardless of changes in the input voltage.

According to the present invention, since the series reactor and the capacitor are connected in parallel, when the switch is turned on / off, the zero voltage is turned off and the zero current is turned on. It is possible to construct a conversion system that reduces the number of on / off switches and further reduces switching loss.

Further, according to the present invention, a diode rectification facility such as voltage doubler rectification is provided, which can obtain a high DC voltage when converting high-voltage AC obtained by parallel resonance into DC. Further, it is also characterized in that a device for taking out a direct current from a capacitor of a magnetic energy regenerative switch through a diode bridge is provided.

According to the present invention, in the facility for converting from alternating current to direct current, the input waveform from the alternating current power source is close to the fundamental wave, the power factor is close to 1, and the input current can be made into a leading phase by the control to reduce the power. Power factor improvement can also be performed. High-speed on / off switching by PWM control is not performed, so semiconductor loss is small. A DC current having a voltage higher than the AC voltage can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 shows an embodiment of a parallel resonant AC / DC conversion power supply device using a magnetic energy regenerative switch that forms the center of the present invention. In the present apparatus, a magnetic energy regenerative switch 1, a reactor 2, and an AC power source 3 including four reverse conducting semiconductor switches and an energy storage capacitor shown in FIG. 1 are connected in series.

With the control means 4 for controlling on / off of the gate of the reverse conducting semiconductor switch, parallel resonance occurs when the series resistance is smaller than the reactance due to the on / off of the switch synchronized with the AC voltage. A square-wave high voltage is generated from the power supply voltage. If this resonance voltage is extracted from the AC terminal of the magnetic energy regenerative switch 1 via the diode rectifier circuit 5, a high voltage direct current is generated.

In the embodiment, the reactor 2 used is about 700 mH and the electric resistance is 17Ω. The capacitor of the magnetic energy regenerative switch 1 is 5 μF, and the four P-MOSFETs are 2SK2186 (500V-10A on-resistance 1Ω). There is a control means 4 for continuously generating an on / off signal in accordance with the positive / negative of the power supply voltage for half a cycle in accordance with “tasking” of the four P-MOSFETs. This on / off signal can be output with an arbitrary phase advance from the voltage waveform.

Phase advance is a simple configuration that uses only one CR delay circuit and one operational amplifier. FIG. 4 shows a circuit of an embodiment of the gate control means 4. For example, in order to advance the gate on / off signal by 90 degrees, the signal polarity can be reversed after performing the control to delay 90 degrees, so the delay from 0 degrees to 140 degrees in two stages of the CR delay circuit The signal is reversed to generate a lead signal from 40 degrees to 180 degrees. Here, it is possible to measure the input current, the output current, and the voltage and perform feedback control to control the phase.

The gate signal of the P-MOSFET uses a photocoupler (TLP590B) called a photovol that can be directly turned on by photovoltaic power. The operating delay should be fast enough for 50 Hz, so a delay of about 0.2 mS of Photobol is not a problem. This is another advantage of not using the PWM control method. Of course, it is effective to use a high-speed pulse control generation circuit in this control circuit and add a partial minimum PWM control within a range that does not increase the switching loss.

The operation of the present invention configured as described above will be described.
The magnetic energy regenerative switch 1 that is turned on and off in synchronization with the voltage phase of the power supply advances 90 degrees with respect to the phase of the power supply voltage, and generates a voltage that is advanced 90 degrees. Will be. If it is connected in series with the inductance, the voltage of the inductance is opposite to that of the inductance and a series resonance state is obtained.

In the steady state of series resonance, both reactance voltages cancel each other, and the current becomes a value determined by the series resistance with respect to the power supply voltage. This is also a state in which the power factor is 1, and this power factor improvement effect is a prior patent. Here, considering the case where the resistance is only the internal resistance of the reactance, the current is Q times that of the circuit, and the voltage across the coil and switch is Q times that of the power supply voltage. Here, Q (Quality factor) means a value obtained by dividing reactance by resistance.
Q = ωL / R Current at resonance = I = Input voltage / Series resistance = Vin / R
Reactance voltage Vc = VI = ωL * I = ωL * Vin / R = Q * Vin = Q times input voltage

Since the magnetic energy regenerative switch 1 is a voltage source that is turned on / off in accordance with the power supply cycle, it does not depend on the capacity of the storage capacitor C of the magnetic energy regenerative switch 1. Although it is necessary to hold the voltage for a short time, this voltage is automatically charged from the circuit so that it has a power factor of 1, so a charging circuit is not required. Magazine D April 2005 issue).

In addition, when the capacitor voltage of the storage capacitor C becomes zero every cycle, that is, when the resonance frequency of the inductances L and C is higher than the power supply frequency, in that case, the switch has zero current and zero voltage switching. This can be realized and the switching loss is further reduced.

The reactance voltage and the switch voltage are in antiphase and up to Q times the power supply, so the voltage in the circuit of FIG. 1 is obtained by rectifying the voltage with a diode bridge. Since it is higher than the power supply voltage, it can be driven by connecting many LEDs with a junction voltage of about 2V in series. Here, 100 red LEDs are connected in series.

The total junction voltage does not exceed the peak of the power supply voltage. When the magnetic energy regenerative switch is stopped, the voltage across the switch does not exceed the junction voltage, so the current stops. Because. As a result, the operation of the magnetic energy regenerative switch becomes an LED switch as it is.

When the voltage across the magnetic energy regenerative switch exceeds the capacitor voltage, the diode bridge conducts and charges the smoothing capacitor. Therefore, if the capacitor capacity is sufficiently large, a direct current flows through the LED. The same applies to a general capacitor input type DC load instead of the LED.

The DC output can be adjusted by shifting the switching phase from the optimum phase state. In particular, the current phase of the AC input is advanced by advancing the switching phase. This is shown in FIG.

The input current waveform is shown in FIG. 9, and it can be said that the waveform is almost a sine wave and has less harmonics than the current waveform of the fluorescent lamp.

(Embodiment 2)
FIG. 5 (1) shows an AC / DC converter circuit that uses a double-wave rectifier circuit instead of the AC / DC converter diode bridge of the present invention to further increase the voltage. (A), (B), and (C) of FIG. 5 (2) are circuit diagrams of a magnetic energy regenerative switch that is half-bridged.
Half-bridge shapes have already been filed as prior patents. This has other variations, each with its advantages. In (A), a DC electrolytic capacitor can be used, but the loss is large. (B) is good when using capacitors with low AC loss, but the capacitor shape is larger than that of electrolytic capacitors. The semiconductor switch can be a reverse conducting GTO thyristor. (C) has an advantage that the conduction loss can be halved by the connection as shown in the circuit diagram when a reverse current blocking type switch is used. The control means for controlling the magnetic energy regenerative switch is not shown.

FIG. 6 shows a development of the present invention. The characteristics of this circuit are as follows.
1) By using a double-wave rectifier circuit instead of an AC / DC conversion diode bridge, the voltage can be further increased. If the DC voltage is the same, the switch element breakdown voltage, capacitor breakdown voltage, etc. can be halved. There are many advantages.
2) The magnetic energy regenerative switch has a half-bridge shape. In FIG. 6, the type shown in FIG. 5 (2) (a) is adopted. The control means for controlling the magnetic energy regenerative switch is not shown.

(Embodiment 3)
FIG. 7 shows a further development of the present invention. In the resonating magnetic energy regenerative switch of the present invention, an AC voltage is generated at both ends of the AC terminal, so that the DC output can be made a low voltage and a large current by stepping down with a transformer. At this time, the power factor can be improved including the leakage inductance of the transformer. The control means for controlling the magnetic energy regenerative switch is not shown.

With conventional PFC converters, it was not possible to obtain step-down DC only by boosting, but a transformer can be used by connecting to the AC side of the magnetic energy regenerative switch. The range is greatly expanded.

(Embodiment 4)
If the capacitor capacity of the magnetic energy regenerative switch is made sufficiently large, it becomes possible to maintain a substantially constant DC voltage. However, when taking out DC power from it, the well-known three circuits shown in FIG. It is the same as a single-phase PFC converter in the same way as a phase PFC / AC / DC conversion circuit, but the DC voltage does not become zero in three phases. This is because the DC power goes to other phases between phases.

As shown in Fig. 8 where a single-phase PWM converter is realized, if the energy storage capacitor C is made smaller, the magnetic energy is stored and as a result, the voltage rises and the diode becomes conductive when the capacitor voltage becomes larger than the DC circuit voltage. Therefore, the zero voltage zero current switching can be realized because the capacitor voltage becomes non-conductive when the capacitor voltage is lower than the DC circuit voltage. If three of these are connected to a three-phase AC, a zero-voltage zero-current switching converter can be realized with a three-phase PWM / PFC circuit.

The circuit of FIG. 8 has an advantage that the number of parts is reduced. On the contrary, all the current flowing through the load flows to the magnetic energy regenerative switch, which is not preferable. The invention up to FIG. 7 proposes that the current flowing in the magnetic energy regenerative switch and the current flowing in the DC side are separated, so that it is economical as much as the current flows in the diode having a cost advantage.

In the circuit of FIG. 8, the method of the PAM converter of FIG. 3 (a) that measures the current with a current sensor and performs PWM control according to the current reference is switched to the AC side using a magnetic energy regenerative switch. You can also. Effective when PFC is important. All the present inventions so far are characterized by soft switching. The control means for controlling the magnetic energy regenerative switch is not shown.

Here, an example has been described in which the number of on / off of the switch is minimized to one in one cycle, but the effect of the present invention can be sufficiently exerted even if PWM control is performed as in the prior art. . In other words, all the four embodiments realize switching at zero voltage and zero current, and therefore, the loss is smaller than the hard switching of the PWM / PFC control of FIG. 3 which is the conventional method.

Since the waveform is also important as well as the power factor, it is naturally possible to increase the number of on / off times and convert it to PWM. This can introduce a technique already known as partial PWM and fixed pulse control.

(Embodiment 5)
As already mentioned that the cost of electricity at vegetable factories accounts for about 30% of the cost, LED lighting and drive circuit production costs are also significant. Therefore, a simple and trouble-free LED drive circuit is desired.

FIG. 10 shows a design example that can reduce the initial production cost by using the present invention for vegetable factories. The magnetic energy regenerative switch adopts the half-bridge method and halves the number of switches, and the charging capacitor uses the electrolytic capacitor shown in Fig. 5 (2) (a). In the vegetable factory, 500 LEDs are one unit, and 4000 units are lit in total.

Since the electrolytic capacitor is lower in cost and smaller than the switch, a DC voltage can be obtained even without the switch if the capacitance of the capacitor is increased to approach the resonance condition.
In most units, all reverse conducting semiconductor switches are turned off, and resonance conditions are obtained only with capacitors. Some units operate this semiconductor switch when the power supply voltage rises at night, when fluctuations such as flicker are to be removed, or when the brightness of the LED is controlled and driven. In this way, we propose a method of dividing the design and usage for each unit.

This method is characterized by obtaining DC high voltage with a minimum of AC reactor, smoothing capacitor, and diode bridge, and is highly efficient because there is no steady iron loss such as with a transformer.

100 LEDs are connected in series, 5 are connected in parallel, and 500 are used as one unit. By mixing one or more LEDs of different colors in each series, the state of parallel shunting can be seen by human eyes. It can also be confirmed. If it is composed of one color, it is harsh to the human eye, so other colors are mixed. However, the difference in color may be detected by the optical sensor 14 and used for illuminance feedback control. The optical sensor 14 is provided with a color filter.

It is a figure which shows the typical structural example of the alternating current / direct current | flow conversion power supply device of this invention. It is a figure which shows the example of the conventional AC / DC converting circuit. Capacitor input type and reactor input type are shown. This is a conventional AC / DC converter circuit with PWM of sine wave input. (A) is a three-phase PWM converter, and (A) is a boost PWM (PAM) converter. It is a figure which shows an example of a gate signal generation circuit. Instead of the AC / DC conversion bridge according to the present invention, a double-wave voltage doubler rectifier circuit is used to further increase the voltage. (2) (A), (B), and (C) are circuit diagrams of a magnetic energy regenerative switch that is half-bridged. It is a circuit diagram at the time of making a magnetic energy regenerative switch into a half bridge and making direct current double voltage rectification. This is an AC / DC conversion circuit that steps down or boosts the voltage via a transformer instead of the AC / DC conversion bridge of the present invention. The direct current is taken out by being coupled by a diode from the energy storage capacitor of the magnetic energy regenerative switch directly without using the diode bridge of the present invention. FIG. 5 is a diagram showing feedback control by providing a current sensor and performing PWM control of current. It is a figure which shows the waveform of simulation. FIG. 5 is a circuit diagram for explaining a simplest and most efficient method of driving a large number of LEDs for a vegetable factory. It is the figure which showed that the electric current phase of alternating current input is advanced by advancing a switching phase.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic energy regeneration bidirectional | two-way current switch 2 Reactor 3 AC power supply 4 Control means 5 Diode rectifier circuit 6 Smoothing capacitor 7 Series diode unit 8 DC load 9 Variable resistor 10 for delay adjustment Op amp 11 Inverter 12 Transformer 13 Diode 14 Optical sensor

Claims (9)

A magnetic energy regenerative bidirectional current switch comprising a bridge circuit composed of four reverse conducting semiconductor switches and a capacitor for storing magnetic energy when the current is interrupted, connected between the DC terminals of the bridge circuit; And an AC power supply connected in series, and further, an AC / DC converter in which an input side of a rectifier diode bridge is connected between AC terminals of the bridge circuit, and a smoothing capacitor is connected to the rectified output side of the diode bridge In power supply,
Control means for applying a control signal to the gate of each reverse conducting semiconductor switch to control on / off of each semiconductor switch, the control means comprising four reverse conducting types constituting the bridge circuit Of the semiconductor switches, control is performed so that the on / off operations of the pair of reverse conducting semiconductor switches located on the diagonal line are simultaneously performed, and when one of the two pairs is on, Control the pair to be turned off, and switch the on / off operation in synchronization with the voltage of the AC power supply;
Further, by setting the Q of a resonance circuit including the reactor and a capacitor for storing magnetic energy to be greater than 1, a resonance voltage higher than the AC power supply voltage is generated, and the resonance voltage is supplied to the diode bridge. AC / DC conversion power supply device characterized by being taken out via Replacing the magnetic energy regenerative bidirectional current switch with a half bridge circuit composed of two reverse conducting semiconductor switches and one or two capacitors;
2. The AC / DC conversion power supply device according to claim 1, wherein the control unit performs control so that when one of the two reverse conducting semiconductor switches is on, the other is turned off. 3.   Further comprising a transformer, wherein the AC terminal of the magnetic energy regenerative bidirectional current switch is connected to the primary side of the transformer, and the secondary side of the transformer is connected to the input side of the diode bridge, The AC / DC conversion power supply device according to claim 1 or 2. 4. The AC / DC conversion power source according to claim 1, wherein the diode bridge is replaced with a double-wave voltage doubler rectifier circuit composed of two diodes and two smoothing capacitors. apparatus. A magnetic energy regenerative bidirectional current switch comprising a bridge circuit composed of four reverse conducting semiconductor switches and a capacitor for storing magnetic energy when the current is interrupted, connected between the DC terminals of the bridge circuit; And an AC power supply in series, and further, an anode of a diode is connected to the positive side of the DC terminal of the bridge circuit, and smoothing is performed between the cathode of the diode and the negative side of the DC terminal of the bridge circuit. In an AC / DC conversion power supply device with a capacitor connected,
Control means for applying a control signal to the gate of each reverse conducting semiconductor switch to control on / off of each semiconductor switch, the control means comprising four reverse conducting types constituting the bridge circuit Of the semiconductor switches, control is performed so that the on / off operations of the pair of reverse conducting semiconductor switches located on the diagonal line are simultaneously performed, and when one of the two pairs is on, Control the pair to be turned off, and switch the on / off operation in synchronization with the voltage of the AC power supply;
Further, by setting the Q of a resonance circuit including the reactor and a capacitor for storing magnetic energy to be greater than 1, a resonance voltage higher than the AC power supply voltage is generated,
An AC / DC conversion power supply apparatus, wherein a DC load is connected to both terminals of the smoothing capacitor.   6. The AC / DC conversion power supply device according to claim 1, wherein the control means controls the gate by advancing the phase of the gate control signal relative to the phase of the AC power supply. 7. A light emitting diode driving system comprising: a plurality of units connected in parallel to a series diode unit in which a plurality of light emitting diodes are connected in series to the direct current output of the AC / DC conversion power supply device according to claim 1; . 8. The light emitting diode driving system according to claim 7, wherein the light emitting diode is a red light emitting diode and is used as a light source for growing vegetables or plants. Further, an optical sensor is provided, a change in illuminance of the light emitting diode is detected by the optical sensor, and the detected signal is fed back to the control means so that the luminous intensity of the light emitting diode is maintained at a predetermined value. The light emitting diode driving system according to claim 8, wherein the resonance voltage is controlled.

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