JP5486847B2 - Power converter - Google Patents

Description

The present invention relates to a power conversion device, a power conversion system, and a method for controlling the power conversion device, and particularly suppresses shaft torsional vibration generated between a turbine and a generator when connected to a system having a generator on the power supply side. about the optimal power conversion equipment to.

  A large number of studies on shaft torsional vibration between turbine generators have been made in a DC power transmission system. For example, Japanese Patent Application Laid-Open No. 2000-224896 discloses a case where a turbine generator is linked to the vicinity of a DC converter station of a DC power transmission system. It has been shown that depending on the conditions of power control performed at the DC converter station, the shaft of the turbine generator vibrates due to interference between the DC power transmission system and the turbine generator. Also, shaft torsional vibration is related to the state of torque acting on the generator rotor, and the vibration phenomenon is detected from the frequency fluctuation of the bus voltage of the DC converter station of the DC power transmission system, and the control angle is changed to change the shaft torsional vibration. Technology to suppress this is shown.

  In addition to the DC power transmission system, for example, in Japanese Patent Application Laid-Open No. 11-27993, in a power conversion device and a power supply system using a power generation device constituted by a combination of an engine and a generator as a power source, the resonance frequency component of the power generation device is A control technology for a power converter that detects and suppresses vibration persistence and increase by interfering with the resonance frequency of the mechanical system of the power generator by detecting and canceling the vibration component of the power generator by the resonance frequency elimination circuit is shown. Yes.

JP 2000-224896 A JP-A-11-27993

  Here, from the viewpoint of energy saving, a technique for converting the generated power of a turbine generator into a variable frequency by a power converter and applying it has come to be used. For example, a system that has been directly driven by a machine until now has been electrified with a motor and a power converter to be variable speed, and depending on the system, a turbine generator was installed as a power supply facility, which was obtained here There are cases where electric energy is converted into mechanical energy that can be adjusted again by a power converter and an electric motor and driven at a variable speed.

At this time, the torsional vibration of the turbine generator may occur. An object of the present invention is to provide a possible power conversion equipment suppressing torsional vibration of the turbine and the generator.

  In order to achieve the above object, in the present invention, a command value, which is an electrical physical quantity, is calculated, a response value is calculated so as to obtain electric power according to fluctuations in the rotational speed of the generator, and the calculated response value is calculated. Based on this, the power converter connected to the system having the generator was controlled.

  According to the present invention, a turbine generator is installed as a power supply facility, and the electric energy obtained here is converted by a power converter, for example, converted into mechanical energy that can be adjusted again by an electric motor. It becomes possible to drive the electric motor and the like while suppressing the torsional vibration between the machines.

The block diagram of the power converter device which shows the 1st Embodiment of this invention. The block diagram of the power converter device which shows the 2nd Embodiment of this invention. The block diagram of the power converter device which shows the 3rd Embodiment of this invention. The block diagram of the power converter device which shows the 4th Embodiment of this invention. The 2 mass model block diagram which shows the vibration system of a turbine generator. The characteristic view which shows the influence degree of (DELTA) P / (DELTA) omega to a total damping coefficient.

  The best mode for carrying out the invention will be described below with reference to the drawings.

  FIG. 1 is an overall configuration diagram of the present invention. 1 is a gas turbine, 2 is a generator for converting mechanical energy of the gas turbine 1 into electric energy, and the gas turbine 1 and the generator 2 are coupled by a mechanical shaft 3. 4 is a transformer for converting the output voltage of the generator 2 into a system voltage, 5 is a transformer for converting the system voltage into an input voltage of the power converter, and the transformer 4 and the transformer 5 are connected via the system 6. The 7 is a power converter that converts the power output from the transformer 5 into desired power, 8 is a motor driven by the power output from the power converter, and 9 is a driven device driven by the motor. The electric motor 8 and the driven device 9 are coupled by a mechanical shaft 10. Here, the configuration of the power converter control device 11 is described as a device such as a speed command generator 111 and a vector controller 112, but each of these configurations is not limited to an electronic circuit. The whole or a part of the converter control device 11 can be constituted by an electronic computer, and each function of the constituent elements described as “device” such as the speed command generator 111 and the vector controller 112 can be used as a program.

  Reference numeral 11 denotes a power converter control device that operates the power converter 7 so that the output torque and speed of the motor 8 satisfy desired characteristics. A power converter output current detector 12 (hereinafter referred to as a current detector) detects and outputs the output current of the power converter 7. Reference numeral 13 denotes a power converter output voltage detector (hereinafter referred to as a voltage detector) that detects the output voltage of the power converter 7. Output signals of the current detector 12 and the voltage detector 13 are input to a power converter control device 11, which performs various arithmetic processes and outputs a signal for operating the power converter 7. To do.

  Next, main operations of the power converter control device will be described. First, in the power converter control device 11, the speed command value output from the speed command generator 111 and the current detection value output from the current detector 12 are input to the electric motor vector controller 112, and the electric motor vector controller 112 The voltage command value of the power converter 7 is calculated and output so that the output torque and speed of the electric motor 8 have desired characteristics. Specifically, the deviation between the speed command value output from the speed command generator 111 and the speed estimated value output from the speed estimation calculator 151 is input to the speed controller 152, and the speed controller 152 The current command value is calculated and output so that is equal to the speed command value. Here, a speed command value, a current detection value, and a voltage command value are input to the speed estimation calculator 151. In the speed estimation calculator 151, an induced voltage component of the motor calculated from the speed command value and a current controller are calculated. The estimated value of the rotational speed of the electric motor 8 is calculated using the voltage command value and the current detection value. In some cases, the rotational speed of the electric motor 8 is directly detected by a speed detector without using the estimated speed value. Next, a deviation between the current command value calculated by the speed controller 152 and the current detection value output from the current detector 12 is input to the current controller 153, and the current controller 153 detects the current detection value as the current command value. The voltage command value is calculated and output so as to match. The voltage command value is input to the pulse generator 113. The pulse generator 113 turns on / off the switching element of the power converter 7 so that the output voltage of the power converter 7 matches the output voltage command value. Calculate and output the pulse signal.

  Here, the relational expression regarding the power source side vibration will be described. FIG. 5 shows the torsional vibration between the turbine generators in a two-mass system, where K is the spring constant, Dm is the mechanical damping coefficient, J1 is the turbine inertia, J2 is the generator inertia, Is the total inertia represented by the sum of J1 and J2, and n is the inertia ratio of J1 and J2. De is a damping coefficient of the electric system and represents that a torque that reduces the speed fluctuation of the generator is electrically generated by a load (including a control device) connected to the generator. From the state equation of the secondary vibration system obtained from FIG. 5, the characteristic equation of the system is expressed by equation (1).

  The vibration characteristics at this time are approximated from the expression (1) to become the expressions (2) and (3).

  Here, ζ is a damping coefficient, ωn is a natural frequency, and n is an inertia ratio. The total damping coefficient Ds and the spring constant Ks are changed to the expressions (4) and (5) from the expressions (2) and (3), and the vibration characteristics (ζ, ωn) of the system change depending on the electric damping coefficient.

  Next, the electrical damping coefficient will be described. The output P of the generator is expressed by P = ω · τ from the rotational speed ω of the generator and the torque τ of the generator, and considering the change in the output equation P0 = ω0 · τ0 in the vicinity of the operating point, Equation (6) Is obtained. When the electrical damping coefficient De (= Δτ / Δω) is obtained from the equation (6), the equation (7) is obtained.

  From equation (7), the electric system damping coefficient De is negative damping with De = −1 / ω · P0 / ω0 when constant power control is performed (ΔP = 0), and depending on the damping value of the mechanical system, the total damping The coefficient becomes negative and unstable phenomenon occurs. When the ratio of the power fluctuation to the generator rotational speed fluctuation is the same as the ratio at the operating point (ΔP / Δω = P0 / ω0), De = 0 and the total damping coefficient is only the damping value of the mechanical system, and the vibration phenomenon is the mechanical system. Attenuates with the damping coefficient. When the ratio of the power fluctuation to the generator rotational speed fluctuation is larger than the ratio at the operating point, De> 0 and the total damping coefficient is the sum of the mechanical damping value and the electrical damping coefficient, and the greater damping force. Is obtained.

  Focusing on the above relationship, the control operation in the present invention will be described next. In order to make the electric damping De positive from the equation (7), the electric power may be changed according to the fluctuation of the generator rotational speed. Here, when the fluctuation of the generator rotational speed is the fluctuation of the amplitude of the input voltage of the power converter, the output current of the power converter also fluctuates due to the voltage fluctuation, and is almost 2 when viewed from the generator side. It can be regarded as a load whose power fluctuates due to the power. On the other hand, the current controller 153 operates so that the output current of the power converter 7 detected by the current detector 12 matches the current command in order for the power converter 7 to output the power required by the load. When the response of the current controller 153 is high, the current controller corrects the influence of the voltage fluctuation and outputs a voltage command that matches the output current with the command. For example, when the electric power is controlled to a constant level, the electrical damping becomes negative. Therefore, since the fluctuation of the generator rotational speed appears as frequency fluctuation or amplitude fluctuation of the input voltage of the power converter, the voltage is detected by the voltage detector 14 and the detected value is input to the fluctuation calculator 114. The fluctuation amount calculator 114 calculates and outputs the fluctuation amount. In addition, the output current of the power converter detected by the current detector 12 and the output voltage of the power converter 7 detected by the voltage detector 13 are input to the power calculator 115, and the power calculator 115 The output power is calculated and output. Then, the fluctuation amount from the fluctuation amount calculator 114 and the power calculation value from the power calculator 115 are input to the power regulator 116, and the power regulator 116 changes the power calculation value according to the fluctuation amount. For example, the response (control gain) of the current controller 153 of the power converter is reduced until the response gain with respect to the fluctuation frequency of the input voltage decreases.

  Here, in the power regulator 116, the power fluctuation ΔP is proportional to the generator rotational speed fluctuation Δω, that is, power fluctuation ΔP / generator rotational speed fluctuation Δω = power P0 at the operating point / generator rotational speed at the operating point. If the disturbance response is reduced so as to satisfy the relationship of ω0 (ΔP / Δω = P0 / ω0: same as the ratio at the operating point), the electrical damping becomes 0 and the vibration characteristics of the turbine generator are the characteristics of only mechanical damping. Can be. Furthermore, the square of the power fluctuation ΔP and the generator rotational speed fluctuation Δω is preferably squared so as to be larger than the proportionality defined above (ΔP / Δω> P0 / ω0: larger than the ratio at the operating point). If the disturbance response is reduced, the damping of the electric system becomes positive, and the vibration characteristics of the turbine generator are the sum of the mechanical damping and the electrical damping. The obtained vibration can be suppressed.

  The operation of reducing the disturbance response will be described more specifically. Here, the disturbance response, that is, the response (control gain) of the current controller 153 indicates a gain at which the current control system responds to the fluctuation frequency. Normally, the current is constant when the gain is set to 0 dB up to the response frequency in which the response of the current control system is set in the so-called Bode diagram of the current control system so that the current control can respond to the frequency of the power supply fluctuation. As described above, the current control system calculates a voltage command that cancels the power supply fluctuation, and controls the output voltage of the power converter to be constant and the current to be constant.

  On the other hand, in order to suppress the vibration of the mechanical shaft 3 that couples the gas turbine 1 and the generator 2, the rotational speed fluctuation of the generator is detected as the fluctuation frequency of the input voltage with respect to the response (control gain) of the current controller 153. Then, the response of the current control system is reduced (the control gain is reduced) so that the gain with respect to the fluctuation frequency is lowered. That is, the current control system suppresses the reaction and does not issue a voltage command for canceling the power supply fluctuation, the output voltage fluctuates according to the power fluctuation, and the current also fluctuates according to the voltage fluctuation. Although the phase is shifted, it is influenced by the power factor. However, since power is actually equal to voltage × current, the power varies depending on the power source. As the disturbance response is reduced in this way, the power fluctuates according to the power supply fluctuation. Therefore, power fluctuation ΔP / generator rotational speed fluctuation Δω = operating point power P0 / operating point generator rotational speed ω0. The response is reduced so as to satisfy the relationship (ΔP / Δω = P0 / ω0: the same as the ratio at the operating point). Since the amount of power fluctuation due to the response can be changed by reducing the response, the response is reduced until a proportional relationship (ΔP / Δω = P0 / ω0: same as the ratio at the operating point) is obtained.

  Although the case where ΔP / Δω = P0 / ω0 is set as an example in response reduction has been described, the present invention is not limited to this case, and mechanical damping and electrical damping of the turbine generator are increased so that the electrical damping is positive or increased. Of course, it can be replaced with the description of another embodiment in order to obtain a larger damping force against the vibration phenomenon that increases the total system damping.

  Although FIG. 1 shows an embodiment in which the current controller 153 is used to reduce the disturbance response to the power supply fluctuation, the disturbance to the power supply fluctuation using the voltage fluctuation correction function that directly reflects the influence of the power supply fluctuation in the voltage command is shown. May increase response. In this case, a filter delay element is added to the voltage fluctuation correction function, and by increasing the filter time constant, the disturbance response to the power fluctuation can be reduced, and the same effect can be obtained.

Further, in FIG. 1, the response of the current controller 153 is varied by the power regulator 116. However, when there is no need to increase the disturbance response to the power supply fluctuation, the power calculation value is a low response that varies depending on the fluctuation amount. The gain may be fixed.
As described above, the example in which the vibration is suppressed by reducing the control gain has been described. However, for example, it can be realized by positively changing the command current value. Although the control target is the control gain in the current control, the same effect can be obtained even if the control target is a voltage if the circuit is devised in addition to the current control.

  FIG. 2 shows another embodiment of the apparatus according to the present invention, and pays attention to the fact that the effect of the electrical damping coefficient De on the total damping coefficient Ds varies depending on the mechanical conditions of the turbine generator. 1 is different from FIG. 1 in that the relationship (ΔP / Δω) between the power calculation value used when calculating the response reduction amount output by 116 and the fluctuation amount (rotation speed fluctuation amount of the generator) is varied. Only parts different from the first embodiment will be described, and description of similar parts will be omitted. The same applies to other embodiments. First, from the equation (2), the damping coefficient of the mechanical system is represented by equation (8) from the relational expression when De = 0. Here, ζ0 and ωn0 are a damping coefficient and a natural frequency determined by mechanical conditions of the turbine generator. When Ds / Dm is derived from the equations (4) and (7) and (8), the equation (9) is obtained.

  From equation (9), ΔP / Δω is used as a parameter, for example, the damping coefficient ζ0 and the natural frequency ωn0 are fixed to certain numerical values, and Ds / when the inertia ratio n is input to the horizontal axis as ΔP / Δω · P0 / ω0. FIG. 6 shows the calculated change in Dm. FIG. 6 shows that the vibration characteristics greatly change due to ΔP / Δω when the inertia ratio is small. Similarly, as shown in the equation (9), the vibration characteristics greatly change depending on ΔP / Δω as the damping coefficient ζ0, the natural frequency ωn0, and the total inertia are smaller. On the other hand, since the power converter is intended to output the desired power required from the load side, the power adjustment means for suppressing the torsional vibration on the generator side is a disturbance, and the response reduction amount for that is It is desirable to be as small as possible. Therefore, the power generator 116 can change the relationship of ΔP / Δω for calculating the response reduction amount at least within a range where the total damping coefficient is not negative by the turbine generator condition setting unit 117 that sets the mechanical conditions of the turbine generator. I was able to do it.

  That is, the power regulator 116 calculates ΔP / Δω that is at least a range in which the total damping coefficient is not negative, calculates the power fluctuation ΔP with respect to the fluctuation frequency Δω, and calculates a response that realizes the power fluctuation ΔP. is there.

  By doing so, the influence on the control performance on the load side can be minimized due to the machine condition on the power source side, and the vibration on the power source side can be suppressed with the smallest possible response reduction amount.

  FIG. 3 shows another embodiment of the device of the present invention, which is different from FIG. 1 in that the response reduction amount output from the power regulator 116 is increased or decreased depending on the condition of sudden power change due to vibration suppression on the load side or instantaneous power failure. Different. In a power converter in which a driven device driven by an electric motor is connected to the load side, shaft torsional vibration may occur at the axial resonance frequency of the electric motor and the driven device, and the shaft torsion between the motor and the driven device may occur. A shaft vibration suppression function for suppressing vibration may be added. For example, the load-side shaft torsional vibration is detected as the speed fluctuation of the electric motor 8 from the fluctuation amount of the speed estimation value output from the speed estimation computing unit 151, and a current command value that suppresses the vibration is output. A vibration suppressor 154 is installed, and the output of the load side vibration suppressor 154 is added to the output of the speed controller 152. At this time, a current control response is required because the detected current value matches the current command value of the resonant vibration frequency on the load side. Further, in order to prevent the current from fluctuating greatly due to a sudden change in the power supply due to a momentary power interruption or the like, it is necessary to increase the disturbance response to the power supply fluctuation.

  Therefore, the load obtained from the vibration component included in the output current command of the load side vibration suppressor 154 and the response reduction amount adjuster 118 by a function such as a variable gain that increases or decreases the response decrease amount output from the power adjuster 116. Response reduction that calculates a limit amount to the response reduction amount adjuster 118 according to the vibration phenomenon (magnitude, frequency) on the power source side and the fluctuation phenomenon (magnitude, frequency) on the power source side detected by the voltage detector 14 A limit computing unit 119 is installed so that the response reduction amount by the power regulator 116 can be increased or decreased by the response reduction amount regulator 118 according to the situation on the load side and the power source side. Since the resonance frequency on the generator side and the resonance frequency on the load side can often be grasped from the machine constant, it is necessary to discriminate non-periodic fluctuations such as the vibration phenomenon on the generator side and the vibration phenomenon on the load side or instantaneous interruption. When non-periodic fluctuations such as load-side vibration suppression operation or instantaneous power failure occur, the response reduction amount is limited at least within a range where the total damping coefficient is not negative.

  For example, the response reduction amount adjuster 118 stores in advance a response reduction amount map corresponding to the vibration phenomenon (size, frequency) on the load side and the fluctuation phenomenon (size, frequency) on the power supply side, and is detected. The response reduction amount is read from the map according to the vibration phenomenon and the power supply side fluctuation phenomenon, and the response is calculated by correcting the control gain determined by the power regulator 116. In this case, the response reduction amount is limited so that at least the total damping coefficient is in a range that is not negative.

  By doing in this way, the disturbance response can be enhanced at the time of sudden power change such as suppression of vibration on the load side or momentary power interruption, and simultaneous use within a range capable of suppressing vibration on the power source side.

  Further, in FIG. 3, the shaft torsional vibration is detected as the speed fluctuation of the electric motor 8, but the load side shaft torsional vibration is detected as the fluctuation amount of the current detection value output from the current detector 12, and the vibration is suppressed. Such a voltage command value may be output to suppress load side vibration. Even in this case, an equivalent effect can be obtained by increasing or decreasing the response reduction amount in accordance with the vibration phenomenon (magnitude, frequency) on the load side obtained from the vibration component included in the voltage command by load side vibration suppression.

  FIG. 4 shows another embodiment of the device of the present invention, which is different from FIG. 3 in that the vibration of the turbine generator is suppressed by a plurality of power conversion devices. In FIG. 4, although 5 to 13 are distinguished by suffixes a and b, they have the same function. When a plurality of power conversion devices are connected to the same system, vibration on the power source side can be suppressed by the total of the plurality of power adjustment means. Therefore, a power-supply-side vibration suppression condition distribution unit 20 is installed, and the response reduction restriction is determined from the voltage detection value from the voltage detector 14 that detects the input voltage of the power converter and each of the power converters 11a, 11b,. The limit value from the calculator 119 and the calculated power value from the power calculator 115 are input to the power supply side vibration suppression condition distribution unit 20, and the power supply side vibration suppression condition distribution unit 20 supplies the power supply side vibration in each power converter. The suppression condition (response reduction distribution value) is output. Next, the control operation of the power supply side vibration suppression condition distributor 20 will be described. In order to make the electric damping De positive from the equation (7), the electric power may be changed according to the fluctuation of the generator rotational speed. Since the fluctuation of the generator rotational speed appears as frequency fluctuation or amplitude fluctuation of the input voltage of the power converter, the voltage is detected by the voltage detector 14 and the detected value is input to the fluctuation calculator 201. The fluctuation amount calculator 201 calculates and outputs the fluctuation amount. Moreover, the power calculation value from each power converter control apparatus 11a, 11b, ... is input into the total power calculator 202, and the total power calculator 202 calculates and outputs the total output power of a plurality of power converters. To do. Then, the fluctuation amount from the fluctuation amount calculator 201 and the power calculation value from the total power calculator 115 are input to the total power adjuster 203. In the total power adjuster 203, the total power calculation value changes according to the fluctuation amount. Thus, the response reduction amount for reducing the disturbance response to the power supply fluctuation of the power converter is output to the response reduction amount distributor 204.

Here, the output current of the power conversion device fluctuates due to the voltage fluctuation due to the response reduction, and it can be regarded as a load in which the power fluctuates in a nearly square relationship when viewed from the generator side. Greater damping force can be obtained for the phenomenon and vibration can be suppressed. The response reduction amount distributor 204 includes a response reduction amount from the total power adjuster 203, a limit value from the response reduction limit calculator 119 from each power converter controller 11a, 11b,. The power ratio with respect to the total power of each power converter output calculated in 202 is input, and the response reduction amount distributor 204 calculates the response reduction amount distributed to each power converter from the input power ratio and the limit value. To do. For example, the shortage of the response reduction amount due to the power converter having a large limit value is supplemented by increasing the ratio of the reduction amount of the other power converters so that the total power can be adjusted.
The response reduction amount of each power converter calculated by the response reduction amount distributor 204 is sent to each power converter control device 11a, 11b,..., And each power converter control device sends the response reduction sent. The response reduction amount adjuster 118 adjusts according to the amount.

  That is, assuming that there are two power converter control devices (power converter control devices 11a and 11b), the power at the operating point is Pa and Pb, and the power fluctuations ΔP0a and ΔP0b. The sum (P0a + P0b) of the powers P0a and P0b becomes the power P of the entire system, and the sum of the power fluctuations ΔPa and ΔPb (ΔPa + ΔPb) becomes the power fluctuation amount ΔP of the whole system. Therefore, in order to reduce the electrical damping coefficient of the entire system so that more damping force can be obtained with respect to the vibration phenomenon, power fluctuation (ΔPa + ΔPb) / generator rotational speed fluctuation Δω = power at operating point (P0a + P0b) / operation The response of each of the power converter control devices 11a and 11b is reduced so that the relationship of the generator rotational speed ω0 at the point is satisfied (ΔP / Δω = P0 / ω0: the same as the ratio at the operating point).

  Here, if the response reduction amount of one power converter control device 11a is suppressed and the power fluctuation according to the reduction amount is ΔPa, the response reduction amount of the other power converter control device 11b is It is calculated as a value that can realize a value (ΔP−ΔPa) obtained by dividing the power fluctuation ΔPa from the power reduction amount.

  Of course, when there are three power converter control devices (power converter control devices 11a, 11b, and 11c), or more than that, the response reduction amount is obtained according to the above. Also, the response (control gain) is calculated using a relationship that increases the electrical damping coefficient other than (ΔP / Δω = P0 / ω0: same as the ratio at the operating point) or increases the total damping coefficient. Of course.

  In this way, the disturbance response can be increased during sudden changes in the power source, such as vibration suppression on the load side or momentary power interruption, the response reduction amount of multiple power converters can be distributed, and the power can be adjusted by adjusting the total power. Side vibration can be suppressed.

  Further, in a power conversion device in which a driven device driven by an electric motor is connected to the load side, shaft torsional vibration that occurs at the axial resonance frequency of the electric motor and the driven device may occur at a specific speed. Therefore, not only the response reduction amount distribution value but also the speed command value of each power conversion device is added to the power supply side vibration suppression condition output from the power supply side vibration suppression condition distributor 20, and the speed command of the power conversion device having a large limit amount is added. By manipulating the value, the limit amount can be relaxed and vibration on the power supply side can be suppressed.

  In the embodiment shown in FIG. 4, the input power calculation value to the total power calculation means is from the power converter, but the total load power other than the power converter connected to the same system is also added. Adjustment with electric power is also possible, and in this case, there is an effect of suppressing the response reduction amount distribution ratio to each power converter.

  The essence of each of the above embodiments is summarized as follows. That is, paying attention to the fact that the damping characteristic to the shaft torsional vibration between turbine generators depends on the power change on the load side, in the power converter connected to the system having the generator on the power source side, the rotation of the generator Fluctuation amount calculation means for detecting speed fluctuation as frequency fluctuation or amplitude fluctuation of the input voltage of the power converter, power calculation means for calculating power of the power converter, and the power calculation value according to the fluctuation amount The power adjustment means for reducing the disturbance response to the power supply fluctuation of the power converter is installed so that the power changes. For example, in this adjustment, the ratio of the power fluctuation to the generator rotational speed fluctuation is the same as the ratio at the operating point (ΔP / Δω = P0 / ω0), or the ratio of the power fluctuation to the generator rotational speed fluctuation is the operating point. The disturbance response to the power supply fluctuation of the power converter is reduced so as to be larger than the ratio at. Focusing on the fact that the damping characteristics depend on the inertia ratio, damping coefficient, natural frequency, etc. of the turbine generator, the relational expression between the power for power adjustment and the amount of fluctuation can be changed according to the mechanical conditions of the turbine generator. I was able to do it.

  Further, in a power converter connected to a system having a generator on the power supply side and connected to a driven device driven by an electric motor on the load side, the rotational speed fluctuation of the generator is calculated based on the input voltage of the power converter. Fluctuation amount calculation means for detecting frequency fluctuations or amplitude fluctuations, power calculation means for calculating the power of the power converter, and a power source of the power converter so that the power calculation value changes according to the fluctuation amount Power adjustment means for reducing disturbance response to fluctuation, response reduction amount adjustment means for increasing / decreasing the response reduction amount output by the power adjustment means, and calculating the limit amount of the response reduction amount adjustment means according to the vibration phenomenon on the load side The response reduction limit calculation means is installed, and the response reduction amount by the power adjustment means is increased or decreased by the response reduction amount adjustment means according to the vibration phenomenon on the load side.

  Further, in a system in which a plurality of power converters connected to a system having a generator on the power source side and connected to a driven device driven by an electric motor on the load side are connected to a common system, the rotation of the generator Fluctuation amount calculation means for detecting speed fluctuation as frequency fluctuation or amplitude fluctuation of the input voltage of the power converter, power calculation means for calculating power of the power converter, and the power calculation value according to the fluctuation amount According to the vibration phenomenon on the load side and the power adjustment means for reducing the disturbance response to the power fluctuation of the power conversion device, the response reduction amount adjustment means for increasing or decreasing the response reduction amount output by the power adjustment means, and Response reduction limit calculation means for calculating the limit amount of the response reduction amount adjustment means is installed in each of the plurality of power conversion devices, and the power values of the power calculation means of each power conversion device are summed up. Combined power calculation means, fluctuation amount calculation means for detecting fluctuations in the rotational speed of the generator as frequency fluctuations or amplitude fluctuations of the input voltage of the power converter, and the total power calculation value changes according to the fluctuation amount. The total power adjusting means for reducing the disturbance response to the power supply fluctuation of the power converter, the limit value of the response reduction limit calculating means of each power converter and the total power of each power converter output from the total power calculating means Response reduction amount distribution means for calculating the response reduction amount distributed to each power conversion device from the power ratio is installed, and the response reduction amount adjustment means of each power conversion device by response reduction amount distribution from the response reduction amount distribution means The amount of response reduction was increased and decreased to adjust the total power.

  In the above embodiment, the example in which the driven device 9 (for example, a compressor for producing liquefied natural gas) is driven by the electric motor 8 has been described. However, the present invention is not limited to this and may be applied to a ship. Is configured so that a generator & motor drive system can be loaded on the ship, and the motor drive system drives the screw of the ship. Moreover, you may apply to an eco-train. In this case, the generator is a diesel generator for trains, and the wheels are driven using a diesel generator & motor drive system. Moreover, you may apply as emergency generator + UPS. In this case, UPS (uninterruptible power supply) will be comprised as a converter. Further, the present invention may be applied to an electric dump system. In this case, the generator & motor drive system is configured to be loaded on the vehicle, and the drive wheel of the vehicle is rotated by the motor drive system. However, these examples are merely examples of application, and needless to say, the present invention can be applied to any system of a generator + motor driving system.

DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Generator 3 Mechanical shaft between gas turbine and generator 4 Transformer from generator voltage to system voltage 5 Transformer from system voltage to power converter input voltage 6 System 7 Power converter 8 Electric motor 9 Covered Drive device 10 Mechanical shaft 11 between motor and driven device 11 Power converter controller 12 Power converter output current detector 13 Power converter output voltage detector 14 Power converter input voltage detector 111 Speed command generator 112 Motor vector Controller 113 Pulse generator 114 Fluctuation amount calculator 115 Power calculator 116 Power adjuster 117 Turbine generator condition setter 118 Response reduction amount adjuster 119 Response reduction limit calculator

Claims (6)

Command value calculation that calculates a command value that is an electrical physical quantity in a power conversion device that is connected to a system having a generator and converts the power output from the generator into alternating current of a predetermined frequency to drive the motor. and means, and control means for controlling the converting operation so as to approach the command value with a predetermined response, a response setting means for setting the response such that the power corresponding to the rotational speed fluctuation of the generator possess, It has power amount detection means for detecting the amount of AC power that is converted into power and supplied to the motor, and detects the rotational speed fluctuation of the generator as a frequency fluctuation or amplitude fluctuation of the input voltage, The response setting means, based on the value obtained by dividing the fluctuation amount of power by the rotation speed fluctuation amount, the value obtained by dividing the detected power at the operating point by the rotation speed, and the mechanical constant on the power source side, Machine da Power conversion device and sets the response so that the total damping coefficient composed of a ping coefficient and electrical damping factor is power corresponding to zero or more.
2. The power conversion device according to claim 1, wherein the command value is a current command value, the response is a disturbance response with respect to a current, and the response is reduced according to a fluctuation in a rotational speed of the generator. Power converter.
The power converter according to claim 1, and detecting means for detecting vibration phenomena of the load, the power conversion apparatus characterized by comprising a correction means for correcting the response in response to the detection.
A command that is connected to a system having a generator and that converts a common power output from the generator into a plurality of alternating currents and drives a corresponding motor to calculate a command value that is an electrical physical quantity A value calculating means; a control means for controlling each conversion operation so as to approach the command value with a predetermined response; and detecting an amount of each AC power that is converted into power and supplied to the motor. It has a power amount detection means, and has a response setting means for setting a response so as to obtain electric power according to the rotational speed fluctuation of the generator, and the rotational speed fluctuation of the generator is changed in frequency fluctuation or amplitude fluctuation of the input voltage The response setting means divides the detected total power at the operating point by the rotation speed from a value obtained by dividing the fluctuation amount of the total power supplied in each conversion operation by the rotation speed fluctuation amount. value A reduced value, based on the power supply side of the machine constants, power, characterized in that mechanical damping coefficient and the total damping factor constituted by the electric damping coefficient is set to respond so that the power corresponding to zero or more Conversion device.
5. The power conversion device according to claim 4 , further comprising response limiting means for limiting a response of a part of the power conversion devices of the power conversion devices according to a vibration phenomenon on a load side of each power conversion device. A power conversion device characterized in that at least a part of the response of another power converter is determined according to .
5. The power conversion device according to claim 4, wherein total power of the power conversion device is controlled by each response .

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