JP7034883B2 - Controls, control methods, and programs - Google Patents

Description

Embodiments of the present invention relate to control devices, control methods, and programs.

In recent years, the introduction of power generation devices using renewable energy such as renewable energy has been progressing, but the power generation devices using renewable energy have large fluctuations in power generation output depending on the weather. For this reason, there is a concern that the power quality will deteriorate when a large number of power generation devices using renewable energy are connected to the existing power system.

Against this background, as a method of maintaining power quality in a situation where a large amount of renewable energy is connected to the power system, for example, a system storage battery system that suppresses voltage fluctuations by charging and discharging the secondary battery is used. SVC (Static Var) that controls the reactive power with a reactor by phase control of STATCOM (Static Synchronous Compensator) using a self-extinguishing semiconductor element such as IGMP (Insulated Gate Bipolar Transistor) and a silista connected in antiparallel. There is a way to use a static power regulator such as Compensator).

The grid storage battery system is a system in which an energy storage device such as a secondary battery is installed near a power generation device that uses renewable energy to suppress voltage fluctuations by charging and discharging the battery, and its development and demonstration have been promoted in recent years. Has been done. However, since the storage battery system has a limited amount of energy storage, it often responds mainly to short-period output fluctuations, and in that case, it is not possible to suppress the reverse power flow from the consumer side to the substation. Therefore, there is a possibility that the voltage fluctuation caused by reverse power flow cannot be sufficiently suppressed.

A static power regulator such as SVC (Static Var Compensator) uses a semiconductor element such as a thyristor to control the phase of the firing angle of a reactor connected in parallel with a fixed capacitor to continuously control the phase from advance to delay. Moreover, the reactive power can be controlled at high speed. The reactive power regulator is suitable for suppressing voltage fluctuations caused by output fluctuations of the power source derived from the natural energy because there are no restrictions such as energy storage amount which is a problem in the system storage battery system.

However, the reactive power regulator such as SVC mainly takes in the voltage of the interconnection point and adjusts the output of the reactive power so that the voltage is as per the command value. Although the voltage fluctuation could be suppressed, there was a possibility that the voltage fluctuation at other points could not be suppressed.

Japanese Unexamined Patent Publication No. 2009-11053

An object to be solved by the present invention is to provide a control device, a control method, and a program capable of suppressing voltage fluctuations in a wider range in an AC system.

The control device of the embodiment has a differential voltage index value generation unit and a signal generation unit. The differential voltage index value generation unit includes the difference between the first voltage detection value and the first voltage command value detected at the first location where the reactive power regulator is connected to the AC system, and one or more of the AC systems. A differential voltage index value that reflects both the sum of the differences between the second voltage detected value detected at the second location and the second voltage command value corresponding to each of the one or more second locations is generated. The signal generation unit generates a control signal for the reactive power adjustment device so that the differential voltage index value generated by the differential voltage index value generation unit becomes small.

The figure which shows an example of the structure of the power grid to which the control device which concerns on 1st Embodiment is applied. The figure which shows an example of the structure of the reactive power adjustment device 60 which concerns on 1st Embodiment. The figure which shows another example of the structure of the reactive power adjustment device 60 which concerns on 1st Embodiment. The figure which shows an example of the structure of the control device 100 of 1st Embodiment. The figure which shows an example of the structure of the control device 100A of the modification of the 1st Embodiment. The figure which shows an example of the structure of the control device 100B of the 2nd Embodiment. The figure which shows an example of the structure of the control device 100C of 3rd Embodiment. The figure which shows an example of the structure of the control device 100D of 4th Embodiment. The figure which shows an example of the structure of the power grid of 5th Embodiment. The figure which shows an example of the structure of the control device 100E of 5th Embodiment. FIG. 6 is a diagram showing an example of a configuration of a power transmission network to which the automatic voltage regulator 600 of the fifth embodiment is applied. The figure which shows an example of the time-dependent change of the voltage detection value _Vtdt of the voltage adjustment relay device in 5th Embodiment.

Hereinafter, the control device, the control method, and the program of the embodiment will be described with reference to the drawings.

(First Embodiment)
The first embodiment will be described with reference to FIGS. 1 to 4.

FIG. 1 is a diagram showing an example of a configuration of a power transmission network to which the control device according to the first embodiment is applied. As shown in FIG. 1, the reactive power adjustment device 60, which is the control target of the control device 100, is connected to the target AC bus 21, which is the target bus for suppressing voltage fluctuations. The point where the reactive power regulator 60 is connected to the target AC bus 21 is called an interconnection point. The interconnection point is an example of the first location. The target AC bus 21, reference AC bus 22, 23, 24, 25, and 26 are connected to each other via some or all of the transmission lines 31, 32, 33, 34, 35, and 36. The step-down transformers 41, 42, and 43 are connected to the reference AC bus 23, 24, 26, and 25, respectively. The connection points of the step-down transformers 41, 42, and 43 and the reference AC bus lines 23, 24, and 26, respectively, are an example of the second place. The reference AC bus is also an example of the second location. The AC bus, transmission line, and step-down transformer shown in FIG. 1 are configuration examples for illustration purposes, and are not limited to this configuration.

The target AC bus voltage detector 3 is connected to the target AC bus 21. The target AC bus voltage detector 3 is, for example, an instrument transformer (VT: Voltage Transformer). The target AC bus voltage detector 3 measures the instantaneous value of the voltage of the target AC bus 21, converts the measured instantaneous value into an effective value, and converts the measured instantaneous value into an effective value, and the target AC bus voltage detection value V _tdt (an example of the first voltage detection value). Is output to the control device 100. The control device 100 controls the reactive power regulator 60 by generating a switching signal _Sw and outputting the generated switching signal _Sw to the reactive power regulator 60. Each of the reference AC bus voltage detectors 11, 12, 13, and 14 is connected to any part of the AC system of the same voltage class (for example, 66 kV) as the target AC bus 21. Each of the reference AC bus voltage detectors 11, 12, 13, and 14 measures the instantaneous values of the respective voltages of the reference AC bus 23, 24, 25, and 26, and converts the measured instantaneous values into effective values. , Reference AC bus voltage detection values V _1dt , V _2dt , V _3dt , and V _4dt (an example of the second voltage detection value) are output to the control device 100. In FIG. 1, the number of voltage detection points in the power grid is four, but the number of voltage detection points is not limited to four. Further, the conversion from the instantaneous value to the effective value of the voltage may be performed by the control device 100 instead of the target AC bus voltage detector 3, the reference AC bus voltage detectors 11, 12, 13, and 14. In this case, each voltage detector transmits the instantaneous value of the voltage to the control device 100, and the control device 100 converts the instantaneous value into an effective value.

FIG. 2 is a diagram showing an example of the configuration of the reactive power adjusting device 60. The static power regulator 60 is, for example, an SVC (Static Var Compensator) of a thyristor controlled reactor (TCR). The reactive power regulator 60 includes, for example, a switching circuit 63, a reactor 64, a filter 65, and a transformer 66. The switching circuit 63 has thyristors 63A and 63B connected in antiparallel. The switching circuit 63 and the reactor 64 are connected in series with each other and are connected to the target AC bus 21 via the transformer 66. The filter 65 may be connected in parallel with the switching circuit 63 and the reactor 64. Originally, the filter 65 is inserted to remove noise generated in the switching circuit 63, but since the filter 65 has a fixed capacitor 65B, it has an ability to supply reactive power on the leading side. Therefore, the filter 65, together with the reactor 64, functions as a control means for the reactive power.

The reactive power adjusting device 60 controls the reactive power generated in the reactor 64 by controlling the phases of the firing angles of the thyristors 63A and 63B of the switching circuit 63 according to the control of the control device 100. As a result, the reactive power adjusting device 60 can adjust the reactive power steplessly from the leading reactive power supplied by the filter 65 having the fixed capacitor 65B to the delayed reactive power provided by the reactor 64. .. For example, in order to generate the reactive power on the leading side, the thyristors 63A and 63B are turned off (the firing phase is brought closer to 180 degrees), the reactive power on the lagging side is set to zero, and the reactive power on the leading side is disabled by the fixed capacitor 65B. Generates electricity. On the contrary, in order to generate the disabled power on the lagging side, the thyristors 63A and 63B are turned on (the firing phase is brought close to 90 degrees), and the lagging side is disabled by the total susceptance of the reactor 64 and the fixed capacitor 65B. Generates electricity. The thyristor-controlled reactor type SVC may be added to the thyristor-controlled reactor type SVC, and a thyristor-switched capacitors control means may be added to the thyristor-controlled reactor type. A thyristor controlled transformer (TCT) may be used in which the role of the reactor 64 as shown in the above is replaced by the transformer 66.

FIG. 4 is a diagram showing an example of the configuration of the control device 100 of the first embodiment. The control device 100 includes, for example, an adder / subtractor 101, a voltage controller 102, a switching signal generator 103, subtractors 201, 202, 203, and 204, an average calculation unit 301, and a corrector 302. The combination of the adder / subtractor 101, the subtractors 201, 202, 203, and 204, the average calculation unit 301, and the corrector 302 is an example of the “difference voltage index value generation unit”. The combination of the voltage controller 102 and the switching signal generator 103 is an example of the "signal generator". These components are realized by, for example, a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components are hardware (circuit parts) such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), GPU (Graphics Processing Unit). It may be realized by (including circuits), or it may be realized by the cooperation of software and hardware. The program may be stored in advance in a storage device (a storage device including a non-transient storage medium) such as an HDD (Hard Disk Drive) or a flash memory, or a removable storage device such as a DVD or a CD-ROM. It is stored in a medium (non-transient storage medium) and may be installed by mounting the storage medium in a drive device.

The addition / subtractor 101 is a target AC bus voltage command value V _tref (first) set in advance from the target AC bus voltage detection value V _tdt (an example of the first voltage detection value) input from the target AC bus voltage detector 3. An example of the voltage command value) is subtracted, the differential voltage index value ΔV _tdiff is calculated by further adding the correction signal _{Direction, and the calculated differential voltage index value ΔV tdiff is} output to the voltage controller 102.

On the other hand, the subtractor 201 calculates the difference ΔV _1diff between the input reference AC bus voltage detection value V _1dt and the reference AC bus voltage command value V _1ref of the reference AC bus 23. The subtractor 202 calculates the difference between the input reference AC bus voltage detection value V _2dt and the reference AC bus voltage command value V _2ref of the reference AC bus 24. The subtractor 203 calculates the difference between the input reference AC bus voltage detection value V _3dt and the reference AC bus voltage command value V _3ref of the reference AC bus 26. The subtractor 204 calculates the difference between the input reference AC bus voltage detection value V _4dt and the reference AC bus voltage command value V _4ref of the reference AC bus 25. The reference AC bus voltage command value V _1ref of the reference AC bus 23, the reference AC bus voltage command value V _2ref of the reference AC bus 24, the reference AC bus voltage command value V _3ref of the reference AC bus 26, and the reference AC bus 25. The reference AC bus voltage command value V _4ref may be a preset value or, as will be described later, a value obtained through a low-pass filter 104.

Reference AC bus voltage detection values V _1dt , V _2dt , V _3dt , and V _4dt and reference AC bus voltage command values V _1ref , calculated by the subtractor 201, subtractor 202, subtractor 203, and subtractor 204, respectively. The differences ΔV _1diff , ΔV _2diff , ΔV _3diff , and ΔV _4diff from V _2ref , V _3ref , and V _4ref are output to the average calculation unit 301. As shown in the following equation (1), the averaging unit 301 has the differences ΔV _1diff , ΔV _2diff , ΔV _3diff , and the differences output from the subtractor 201, the subtractor 202, the subtractor 203, and the subtractor 204, respectively. The average value of the voltage difference V, which is the average value of _{ΔV 4 subtract} , is _obtained .

V _diffavg = {(V _1dt -V _1ref ) + (V _2dt -V _2ref ) + (V _3dt -V _3ref ) + (V _4dt -V _4ref )} / 4 ... (1)

In this embodiment, the number of voltage detection points is four, but the voltage detection points may be any natural number n. In that case, the average calculation unit 301 sets the reference AC bus voltage detection values V _1dt , V _2dt , ..., V _ndt and the reference AC bus voltage command value V _1ref according to the formula (2) which is a generalization of the formula (1). , V _2ref , ..., V _nref difference ΔV _1diff , ΔV _2diff , ..., ΔV _ndiff The voltage difference average value V _diffavg which is the average value is obtained.

V _diffavg = {(V _1dt -V _1ref ) + (V _2dt -V _2ref ) ... (V _ndt -V _nref )} / n ... (2)

The voltage difference average value V _diffavg calculated by the average calculation unit 301 is input to the corrector 302. The corrector ₃₀₂ generates a correction signal S _direct based on the input voltage difference average value V differential, and outputs the generated correction signal S _direct to the adder / subtractor 101. The corrector 302 is, for example, an integrator or a proportional integrator. The integrator and the integrator process performed by the integrator and the proportional integrator are examples of feedback operations. The corrector 302 is a difference between the reference AC bus voltage detection values V _1dt , V _2dt , V _3dt , and V _4dt and the reference AC bus voltage command values V _1ref , V _2ref , V _3ref , and V _4ref ΔV _1diff , ΔV _2diff. , ΔV _3diff , and ΔV _4diff so that the voltage controller 102 generates a control signal _Stctrl that controls the reactive power output by the reactive power regulator 60 so that the differential voltage index value ΔV _tdiff becomes smaller. A correction signal _voltage for correcting the voltage is generated.

The voltage controller 102 generates a control signal _Stctrl based on the input differential voltage index value ΔV _tdfl , and outputs the generated control signal _Stctrl to the switching signal generator 103. The voltage controller 102 is, for example, a proportional integrator. The proportional integration process performed by the proportional integrator is an example of a feedback operation. The voltage controller 102 is invalid so that the absolute value of the differential voltage index value ΔV _tdiff , which is the difference between the target AC bus voltage detection value V _tdt and the target AC bus voltage command value V _treff , plus the correction signal _Direct , becomes smaller. A control signal _Stctrl that controls the reactive power output by the power regulator 60 is generated. The target AC bus voltage command value V _tref of the target AC bus 21 may be a preset value, or as described later, the target AC bus voltage detection value V _tdt of the target AC bus 21 is used in the low-pass filter 104. It may be a value obtained through.

The switching signal generator 103 is a gate pulse that controls the phases of the firing angles of the thyristors 63A and 63B in the switching circuit 63 of the reactive power regulator 60 based on the control signal _Stctrl input from the voltage controller 102. The switching signal _Sw is generated. In the reactive power regulator 60, the thyristors 63A and 63B of the switching circuit 63 switch according to the switching signal _Sw input from the switching signal generator 103. As a result, the reactive power adjusting device 60 adjusts the output of the reactive power and brings the target AC bus voltage detection value V _tdt of the target AC bus 21 closer to the target AC bus voltage command value V _tref . By combining the functions of the voltage controller 102 and the switching signal generator 103, "a control signal for the reactive power regulator is generated so that the differential voltage index value generated by the differential voltage index value generator becomes smaller. "be able to.

Hereinafter, examples of suppressing voltage fluctuations according to the embodiment will be specifically described as <Case 1> to <Case 4>. To simplify the study, it is assumed that there are two remote voltage capture points (reference AC bus voltage detector 11 for reference AC bus 23 and reference AC bus voltage detector 12 for reference AC bus 24). Give an explanation. The reference AC bus voltage detection value V _1dt detected by the reference AC bus voltage detector 11 and the reference AC bus voltage command value V _1ref are the same, and the reference AC bus voltage detection detected by the reference AC bus voltage detector 12 It is assumed that the value V _2dt and the reference AC bus voltage command value V _2ref are the same. In the following, this state is referred to as an "initial state".

<Case 1>
From the initial state, when the reference AC bus voltage detection value V _1dt becomes + ΔV with respect to the reference AC bus voltage command value V _1ref , and the reference AC bus voltage detection value V _2dt becomes −ΔV with respect to the reference AC bus voltage command value V _2ref . do. In this case, the difference between the reference AC bus voltage detection value V _1dt and the reference AC bus voltage command value V _1ref ΔV _1diff (+ ΔV) and the difference between the reference AC bus voltage detection value V _2dt and the reference AC bus voltage command value V _2def ΔV _2diff ( The voltage difference average value V _diffavg , which is the average of −ΔV), is {+ ΔV + (−ΔV)} / 2 = 0, and the target AC bus voltage command value V _tref is not corrected by the corrector 302. The maximum value of the voltage fluctuation width of the entire AC system at this time is ΔV in the reference AC bus 23 and the reference AC bus 24, and does not change. (Because the target AC bus voltage command value V _tref is not corrected by the corrector 302, the voltage fluctuation widths of the reference AC bus 23 and the reference AC bus 24 remain as they are.)

<Case 2>
Next, from the above initial state, the reference AC bus voltage detection value V _1dt is + ΔV with respect to the reference AC bus voltage command value V 1 _ref , and the reference AC bus voltage detection value V _{2 dt} is with respect to the reference AC bus voltage command value V _{2 ref} . It is assumed that it becomes + ΔV. In this case, the average of the difference (+ ΔV) between the reference AC bus voltage detection value V _1dt and the reference AC bus voltage command value V _1ref and the difference (+ ΔV) between the reference AC bus voltage detection value V _2dt and the reference AC bus voltage command value V _2ref . The voltage difference average value V differentialavg is { _ΔV + ΔV} / 2 = + ΔV. Therefore, since the corrector 302 outputs + ΔV, the target AC bus voltage command value V _tref of the target AC bus 21 is reduced by ΔV. As a result, the voltage fluctuation width of the reference AC bus 23 and the reference AC bus 24 can be set to 0. The maximum value of the voltage fluctuation width of the entire AC system at this time is ΔV in the target AC bus 21. (Because the target AC bus voltage command value V _tref is lowered by ΔV). The maximum value of the voltage fluctuation width of the entire AC system was originally ΔV in the reference AC bus 23 and the reference AC bus 24, but as a result of correction, the maximum value of the voltage fluctuation width of the entire AC system is Although it became ΔV on the target AC bus 21, the value does not change because both are ΔV.

<Case 3>
Next, from the initial state, the reference AC bus voltage detection value V _1dt is + ΔV with respect to the reference AC bus voltage command value V 1 _ref , and the reference AC bus voltage detection value V _{2 dt} is with respect to the reference AC bus voltage command value V _{2 ref} . It is assumed that it becomes + ΔV / 2. In this case, the difference between the reference AC bus voltage detection value V _1dt and the reference AC bus voltage command value V _1ref (+ ΔV) and the difference between the reference AC bus voltage detection value V _2dt and the reference AC bus voltage command value V _2ref (+ ΔV / 2). The voltage difference average value V _diffavg , which is the average of the above, is {ΔV + ΔV / 2} / 2 = + 3ΔV / 4. Therefore, since the corrector 302 outputs + 3ΔV / 4, the target AC bus voltage command value V _tref of the target AC bus 21 is reduced by 3ΔV / 4. As a result, the maximum value of the voltage fluctuation width of the reference AC bus 23 and the reference AC bus 24 is suppressed from ΔV to ΔV / 4. Instead, the voltage fluctuation width of the target AC bus 21 is 3ΔV / 4. Therefore, the maximum value of the voltage fluctuation width of the entire AC system at this time is suppressed from ΔV to 3ΔV / 4. (Originally, the maximum value of the voltage fluctuation width of the entire AC system was ΔV in the reference AC bus 23, but as a result of lowering the target AC bus voltage command value V _treff by 3ΔV / 4, the voltage fluctuation of the entire AC system The maximum value of the width was 3ΔV / 4 on the target AC bus 21.)

<Case 4>
Next, from the initial state, the reference AC bus voltage detection value V _1dt is + ΔV with respect to the reference AC bus voltage command value V 1 _ref , and the reference AC bus voltage detection value V _{2 dt} is with respect to the reference AC bus voltage command value V _{2 ref} . It is assumed that it becomes −ΔV / 2. In this case, the difference (+ ΔV) between the reference AC bus voltage detection value V _1dt and the reference AC bus voltage command value V _1ref , and the difference between the reference AC bus voltage detection value V _2dt and the reference AC bus voltage command value V _2ref (-ΔV / 2). ), The voltage difference average value V _diffavg is {ΔV + (−ΔV / 2)} / 2 = + ΔV / 4. That is, the output of the corrector 302 becomes + ΔV / 4, and the target AC bus voltage command value V _tref of the target AC bus 21 is reduced by ΔV / 4. As a result, the maximum value of the voltage fluctuation width of the reference AC bus 23 and the reference AC bus 24 is suppressed from ΔV to 3ΔV / 4. Therefore, the maximum value of the voltage fluctuation width of the entire AC system at this time is suppressed from ΔV to 3ΔV / 4. (Originally, the maximum value of the voltage fluctuation width of the entire AC system was ΔV in the reference AC bus 23, but as a result of lowering the target AC bus voltage command value V _treff by ΔV / 4, the voltage fluctuation of the entire AC system The maximum width was 3ΔV / 4 on the reference AC bus 23 and the reference AC bus 24.)

As shown in <Case 1> to <Case 4> described above, the target AC bus voltage command value V _treff of the target AC bus 21 is the reference AC bus voltage detection value V _1dt and the reference AC bus voltage command value V 1 _ref . Difference and reference AC bus voltage detection value V _2dt and reference AC bus voltage command value V By correcting with voltage difference average value V _diffavg , which is the average of the difference between _2ref , the voltage fluctuation width in the entire AC system is corrected before correction. It is possible to suppress the equivalent or less than before the correction. In <Case 1> to <Case 4>, it is assumed that there are two remote voltage capture points, but even if the number of remote voltage capture points is arbitrary, the AC system is similarly used. It is possible to suppress the voltage fluctuation range as a whole to be equal to or less than that before correction.

According to the first embodiment described above, at the first location where the disabled power regulator is connected to the AC system (the interconnection point where the disabled power regulator 60 is connected to the target AC bus 21). The difference between the detected first voltage detection value (target AC bus voltage detection value V _tdt ) and the first voltage command value (target AC bus voltage command value V _tref ) and one or more second points (target AC bus voltage command value V tref) in the AC system. The second voltage detection value (reference AC bus voltage detection value V _1dt ) detected at each of the step-down transformers 41, 42, and 43 and the connection points of the reference AC bus 23, 24, 26, and 25, respectively. The difference between V _2dt , V _3dt , and V _4dt ) and the second voltage command value (reference AC bus voltage command value V _1ref , V _2ref , V _3ref , V _4ref ) corresponding to the one or more second points, respectively. Difference voltage index value generation unit (addition / subtractor 101, subtractors 201, 202, 203, and 204, average calculation unit 301, and correction) that generate a differential voltage index value (ΔV _tdiff ) that reflects both the sum and the sum. A control signal ( _Stctrl ) for the ineffective power regulator (60) so that the differential voltage index value (ΔV _tdiff ) generated by the differential voltage index value generator (combined with the device 302) becomes smaller. By having a signal generation unit (a combination of the voltage controller 102 and the switching signal generator 103) that generates the voltage, voltage fluctuation can be suppressed in a wider range. That is, the voltage fluctuation of the power system (reference AC bus 23, 24, 26, and 25) of the same voltage class as the target AC bus 21 which is the target bus for suppressing the voltage fluctuation to which the reactive power adjustment device 60 is connected can be detected. It can be suppressed. Further, since the correction signal _Direction is generated by the processing of the average calculation unit 301 and the corrector 302, the voltage of the target AC bus 21 excessively fluctuates due to the voltage fluctuations of the reference AC bus 23, 24, 25, and 26. It can be suppressed.

FIG. 5 is a diagram showing an example of the configuration of the control device 100A, which is a modification of the first embodiment. The configuration of the control device 100A shown in FIG. 5 is controlled in that the value obtained by passing the target AC bus voltage detection value V _tdt of the target AC bus 21 through the low pass filter 104 is the target AC bus voltage command value V _tref . Different from device 100. According to the configuration of the control device 100A, the control device 100A responds to a voltage fluctuation having a short fluctuation cycle in the target AC bus 21. According to the control device 100A of the reactive power regulator 60, the reactive power regulator 60 adjusts the output of the reactive power only for the voltage fluctuation having a short fluctuation cycle in the target AC bus 21. Therefore, the reactive power regulator 60 does not adjust the output of the reactive power for the voltage fluctuation having a long fluctuation cycle, so that the reactive power regulator 60 causes the instantaneous voltage fluctuation of the renewable energy derived from the natural energy. On the other hand, since the adjusting power can be secured, it is possible to effectively suppress the voltage fluctuation of the target AC bus 21.

(Second embodiment)
Hereinafter, the second embodiment will be described. FIG. 6 is a diagram showing an example of the configuration of the control device 100B of the reactive power adjustment device 60 of the second embodiment. Since the configuration of the power transmission network and the configuration of the reactive power regulator 60 in the second embodiment are the same as those in the first embodiment, FIGS. 1 and 2 and the description thereof of the first embodiment are incorporated. .. The control device 100B of the second embodiment replaces the corrector 302 of the control device 100 of the first embodiment shown in FIG. 1 with a corrector 303 having an upper / lower limit limiter as shown in FIG. The point is that it is different from the control device 100 of the first embodiment. Since the configuration of the entire transmission network and the configuration of the reactive power adjustment device 60 are the same as the configurations of FIGS. 1 and 2 described in the first embodiment, the description thereof will be omitted.

Similar to the first embodiment, the corrector 303 with the upper and lower limit _limiters determines the correction signal Direction based on the voltage difference average value V differential, and the determined correction signal S _{direction sets} the lower limit (VL). When it is lower than the lower limit, the correction signal _voltage is replaced, and when the upper limit ( _VH ) is exceeded, the correction signal direct is replaced by the upper limit. The lower limit (VL) and upper limit (VH) of the corrector 303 with the upper and lower limit limiters are set to values in the same range as or slightly narrower than the voltage fluctuation range allowed in the target AC bus 21. Specifically, for example, when the allowable voltage fluctuation width (regulated value) of the target AC bus 21 is ± 2%, the upper limit of the corrector 303 with the upper and lower limit limiters is + 2%, and the lower limit is -2%. Is set to. As a result, the voltage correction range of the target AC bus voltage command value V _tref of the target AC bus 21 falls within the range of ± 2%, so that the reference AC bus voltage detection values V _1dt , V _{2 dt} , V _{3 dt} , and V _{4 dt} are used. The voltage fluctuation width of the target AC bus 21 due to the correction of the differential voltage index value ΔV _tdiff with respect to the voltage fluctuation can be suppressed to within ± 2%.

According to the second embodiment, the reference AC bus voltage detection values V _1dt , V _{2 dt} , and V are further provided by further providing an upper / lower limit limiter that applies an upper limit and a lower limit to the correction signal _Scroll input to the adder / subtractor 101. The voltage fluctuation width of the target AC bus 21 due to the correction of the differential voltage index value _{ΔV tiff} for the voltage fluctuations at 3 dt and V _{4 dt exceeds} the allowable voltage fluctuation width (regulated value) of the target AC bus 21. It is possible to prevent this from happening.

(Third embodiment)
Hereinafter, the third embodiment will be described. FIG. 7 is a diagram showing an example of the configuration of the control device 100C of the reactive power adjustment device 60 according to the third embodiment. Since the configuration of the power transmission network and the configuration of the reactive power regulator 60 in the third embodiment are the same as those in the first embodiment, FIGS. 1 and 2 and the description thereof of the first embodiment are incorporated. .. The control device 100C of the third embodiment is a multiplier as shown in FIG. 7 between the subtractors 201, 202, ... Of the control device 100 of the first embodiment shown in FIG. 1 and the average calculation unit 301. The addition of 251, 252, ... Is a difference from the control device 100 of the first embodiment. Since the configuration of the entire transmission network and the configuration of the reactive power adjustment device 60 are the same as the configurations of FIGS. 1 and 2 described in the first embodiment, the description thereof will be omitted.

The multiplier 251 multiplies the difference ΔV _1diff between the input reference AC bus voltage detection value V _1dt and the reference AC bus voltage command value V _1ref by a predetermined weighting coefficient W ₁ to obtain the detection value at each location. Weight the difference between the command values. Similarly, in the multipliers 252, 253, ..., The difference between the input reference AC bus voltage detection values V _2dt , V _3dt , ... And the reference AC bus voltage command values V _2ref , V _3ref , ..., ΔV _2diff , ΔV _3diff , ... By multiplying ... with predetermined weighting coefficients W ₂ , W ₃ , ..., The difference between the detected value and the command value at each location is weighted. For example, the weighting coefficients W ₁ , W ₂ , ... Are reduced for reference AC bus wires in which other voltage regulators are located nearby. In this case, for the reference AC bus whose voltage fluctuation can be suppressed to a small value by a nearby voltage regulator, the influence of the voltage fluctuation on the target AC bus voltage command value V _tref can be reduced. Further, for example, the weighting coefficients W ₁ , W ₂ , ... Are increased for the reference AC bus whose voltage fluctuation is extremely large. In this case, it becomes possible to focus on eliminating the voltage fluctuation of the reference AC bus whose voltage fluctuation is extremely large.

According to the third embodiment, it is possible to appropriately suppress the voltage fluctuation of the AC system of the same voltage class to which the reactive power adjusting device 60 is connected according to the importance (weighting) of each.

(Fourth Embodiment)
Hereinafter, the fourth embodiment will be described. FIG. 8 is a diagram showing an example of the configuration of the control device 100D of the reactive power adjustment device 60 according to the fourth embodiment. Since the configuration of the power transmission network and the configuration of the reactive power regulator 60 in the fourth embodiment are the same as those in the first embodiment, FIGS. 1 and 2 and the description thereof of the first embodiment are incorporated. .. In the control device 100D of the fourth embodiment, the reference AC bus voltage command values V _1ref , V _2ref , ... Of the control device 100 of the first embodiment shown in FIG. 1 are referred to as shown in FIG. The difference from the control device 100 of the first embodiment is that the AC bus voltage detection values V _1dt , V _2dt , ... Are taken as values obtained by passing through the low pass filters 271, 272, .... ..

The values obtained by passing the reference AC bus voltage detection values V _1dt , V _2dt , ... Through a low-pass filter are set as the reference AC bus voltage command values V _1ref , V _2ref , ... The corrector 302 responds only to a voltage fluctuation having a short fluctuation cycle in the reference AC system bus. In FIG. 8, the time constants of the low-pass filters 271 and 272 are set to different values of T1 and T2, respectively, but the time constants of the low-pass filters may be the same.

According to the fourth embodiment, the control device 100D responds to a voltage fluctuation having a short fluctuation cycle in the reference AC bus 23, 24, 25, and 26. According to the control device 100D of the reactive power regulator 60, the reactive power regulator 60 adjusts the output of the reactive power only for voltage fluctuations having a short fluctuation cycle in the reference AC bus 23, 24, 25, and 26. Therefore, the reactive power regulator 60 does not adjust the output of the reactive power for the voltage fluctuation having a long fluctuation cycle, so that the reactive power regulator 60 causes the instantaneous voltage fluctuation of the renewable energy derived from the natural energy. On the other hand, since it is possible to have a control reserve, it is possible to effectively suppress the voltage fluctuation of the AC system of the same voltage class connected to the reactive power adjustment device 60. Further, the fourth embodiment may be appropriately combined with the first embodiment, the second embodiment, and the third embodiment.

(Fifth Embodiment)
Hereinafter, a fifth embodiment will be described. FIG. 9 is a diagram showing an example of the configuration of the power transmission network according to the fifth embodiment. FIG. 10 is a diagram showing an example of the configuration of the control device 100E of the reactive power adjusting device 60 according to the fifth embodiment. Since the configuration of the power transmission network and the configuration of the reactive power regulator 60 in the fifth embodiment are the same as those in the first embodiment, FIGS. 1 and 2 and the description thereof of the fifth embodiment are incorporated. .. In the fifth embodiment, as compared with the configuration of the power transmission network of the first embodiment shown in FIG. 2, a current detector 4 for detecting the output current of the reactive power regulator 60 is added, and the target AC bus is added. 21 is configured to receive power from the automatic voltage regulator 600 instead of the power transmission line 31, and the control device 100D of the reactive power regulator 60 of the fifth embodiment is the first embodiment shown in FIG. In addition to the configuration of the control device 100 of the above, the low pass filter 104 and the low pass filter 304 are provided.

Next, the automatic voltage adjusting device 600 of the fifth embodiment will be described with reference to FIG. FIG. 11 is a diagram showing an example of a configuration of a power transmission network to which the automatic voltage regulator 600 of the fifth embodiment is applied. As shown in FIG. 11, the automatic voltage regulator 600 includes a tapped step-up transformer 610, a voltage regulator relay device 620, and a voltage regulator voltage detector 630. The step-up transformer 610 with a tap changes the voltage on the secondary side of the automatic voltage regulator 600 by sequentially switching the taps T1 to T9 according to the control of the voltage regulating relay device 620. The voltage adjustment relay device voltage detector 630 detects the voltage of the target AC bus 21, measures the instantaneous value of the voltage, converts the measured instantaneous value into an effective value, and performs the voltage adjustment relay device voltage detection value V. It is output to the voltage adjustment relay device 620 as _tdt . The conversion from the instantaneous value of the voltage to the effective value may be performed by the voltage adjusting relay device 620. In this case, the voltage adjustment relay device voltage detector 630 transmits the instantaneous value of the voltage to the voltage adjustment relay device 620, and the voltage adjustment relay device 620 converts the instantaneous value of the voltage into an effective value. In the present embodiment, the step-up transformer 610 with taps having taps T1 to T9 will be described, but the number of taps of the step-up transformer 610 with taps is not limited to this, and the number of taps may be less than 9. The number may be 10 or more, and the step-up transformer 610 with taps may be provided with a plurality of taps. Further, as the operation of the tapped step-up transformer 610, it has been explained that the tapped step-up transformer 610 sequentially switches the taps T1 to T9, but the tapped step-up transformer 610 is one of these plurality of taps. It is also to select one tap.

The voltage adjustment relay device 620 sets the voltage on the secondary side of the automatic voltage adjustment device 600 to a constant voltage range based on the effective value of the voltage of the target AC bus 21 received from the voltage adjustment relay device voltage detector 630. A tap switching command is issued to the step-up transformer 610 with a tap to adjust the voltage. Specifically, the voltage adjustment relay device 620 taps when the voltage detection value V _tdt of the voltage adjustment relay device exceeds a predetermined dead zone upper limit threshold VT _upper and the time integration value of the excess amount exceeds the tap operation threshold. When a command (tap down command) is given to the step-up transformer 610 with a tap, the voltage adjustment relay device voltage detection value V _tdt exceeds the predetermined dead zone lower limit threshold VT _lower , and the excess time integrated value exceeds the tap operation threshold. , A tap operation command (tap up command) is given to the step-up transformer 610 with a tap. The tap-up command is to switch taps so that the tap number (Tn) of the tapped step-up transformer 610 increases. The tap down command is to switch taps so that the tap number (Tn) of the step-up transformer 610 with a tap decreases.

In the control device 100E of the fifth embodiment shown in FIG. 10, the subtractor 305 is a signal obtained by passing the correction signal Direction generated by the correction device ₃₀₂ and the correction signal _Direction through the low-pass filter 304. And the difference is calculated, and the calculated difference is output to the adder / subtractor 101 as a low-frequency suppression correction signal _Scorrecth . As a result, for voltage fluctuations with long fluctuation cycles on the reference AC bus 23, 24, 25, and 26, the differential voltage index value ΔV so as to reduce the absolute value of the reactive current output by the reactive power regulator 60. The _tdiff is corrected by the low frequency suppression correction signal S _correcth .

Further, the value obtained by passing the target AC bus voltage detection value V _tdt through the low-pass filter 104 is set as the target AC bus voltage command value V _tref of the target AC bus 21. As a result, the differential voltage index value ΔV _tiff input to the voltage controller 102 reduces the absolute value of the reactive power output by the reactive power regulator 60 for voltage fluctuations having a long fluctuation cycle in the target AC bus 21. Change direction.

The current detector 4 is, for example, a current transformer (CT). The current detector 4 measures the instantaneous value of the output current output by the reactive power regulator 60, converts the measured instantaneous value into an effective value, and uses it as the detected value _Itdt of the output current output by the reactive power regulator 60. Output to the control device 100E. The conversion of the output current from the instantaneous value to the effective value may be performed by the control device 100E. In this case, the current detector 4 transmits the instantaneous value of the output current to the control device 100E, and the control device 100E converts the instantaneous value of the output current into an effective value.

The invalid current calculator 105 sets the target AC bus voltage detection value Vtdt detected by the target AC bus voltage detector 3 and the output current detection value _Itdt of the invalid power regulator 60 detected by the current detector 4 to the target AC bus voltage detection value _Vtdt . Based on this, the disabled current I _reactive included in the reactive power output by the reactive power regulator 60 is calculated. The multiplier 106 calculates the voltage drop V _slope due to the slope reactance by multiplying the reactive current I _reactive by a predetermined value (gain of slope reactance). The adder / subtractor 107 is a voltage drop amount calculated by the invalid current calculator 105 from the difference voltage index value ΔV _tdf between the target AC bus voltage detection value V _tdt and the target AC bus voltage command value V _tref output from the adder / subtractor 101. V _slope is subtracted, and the differential voltage index value ΔV _tdiffs having the characteristic of slope reactance is output to the voltage controller 102. Since the subsequent operations are the same as those in the first embodiment, the description thereof will be omitted.

Next, the operation of the automatic voltage adjusting device 600 and the control of the reactive power adjusting device 60 by the control device 100E in the fifth embodiment will be described with reference to FIG. FIG. 12 is a diagram showing an example of a change with time of the voltage detection value _Vtdt of the voltage adjustment relay device according to the fifth embodiment. The vertical axis of the graph of FIG. 12 shows the voltage detection value _Vtdt of the voltage adjustment relay device detected by the voltage regulator voltage detector 630, and the horizontal axis shows the passage of time. For example, it is assumed that a voltage fluctuation occurs in _one of the AC bus lines at time t1. In the fifth embodiment, the output of the high-pass filter configured by subtracting the output of the low-pass filter 104 and the output of the high-pass filter configured by subtracting the output of the low-pass filter 304 are input to the voltage controller 102. For a voltage fluctuation with a short fluctuation cycle, the voltage is adjusted by adjusting the disabled power output by the disabled power adjusting device 60. Therefore, from immediately after the time t ₁ to the time t ₂ , the reactive power adjusting device 60 adjusts the voltage fluctuation having a short fluctuation cycle in the target AC bus 21. However, for voltage fluctuations with a long fluctuation cycle, the high-pass filter prevents the reactive power regulator 60 from adjusting the reactive power. Therefore, since the reactive power adjusting device 60 does not adjust the reactive power for the voltage fluctuation having a long fluctuation cycle after the _time t2, the voltage rises from the _time t2. Then, the voltage-adjusted relay device voltage detection value _Vtdt of the target AC bus 21 gradually increases, and the voltage-adjusted relay device voltage detection value _{Vtdt exceeds} the predetermined dead zone upper limit threshold VT _upper at time t3. Since the time integration value of the quantity exceeds the tap operation threshold, the voltage adjustment relay device 620 gives a tap operation command (tap down command) to the tapped step-up transformer 610. According to the tap operation command (tap down command), the step-up transformer 610 with a tap lowers the voltage of the target AC bus 21 by switching the taps so that the output voltage drops. As described above, in the fifth embodiment, for voltage fluctuations having a long fluctuation cycle, voltage adjustment is performed by tap switching of the voltage adjustment relay device 620 instead of the reactive power adjustment device 60. Therefore, after that, when the voltage rise occurs again at time _t4 , the reactive power regulator 60 has a control reserve, so that the reactive power regulator 60 immediately receives the reactive power for the voltage fluctuation having a short fluctuation cycle. The voltage can be adjusted by adjusting the output.

According to the fifth embodiment, the high-pass filter configured by subtracting the output of the low-pass filter 104 and the high-pass filter configured by subtracting the output of the low-pass filter 304 are invalid for voltage fluctuations having a short fluctuation cycle. The power regulator 60 adjusts the output of the reactive power, but the reactive power regulator 60 reduces the absolute value of the reactive power to be output for a voltage fluctuation having a long fluctuation cycle. Therefore, the voltage fluctuation of the target AC bus 21 becomes large due to the voltage fluctuation having a long fluctuation cycle, and the voltage adjustment relay device 620 enters the operating region (the voltage detection relay device voltage detection value V _tdt is a predetermined dead zone upper limit threshold VT. When the _upper is exceeded and the time integration value of the excess amount exceeds the tap operation threshold), the voltage adjustment relay device 620 gives a tap operation command to the tapped step-up transformer 610, so that the tapped step-up transformer 610 is tapped. It switches and the output voltage of the tapped step-up transformer 610 changes in steps. As a result, the voltage adjustment amount can be shared between the step-up transformer 610 with a tap and the reactive power adjustment device 60. That is, the reactive power adjusting device 60 adjusts the voltage for the voltage fluctuation having a short fluctuation cycle, and the step-up transformer 610 with a tap adjusts the voltage for the voltage fluctuation having a long fluctuation cycle. Therefore, in the configuration of the fifth embodiment, since the invalid power adjustment device 60 does not carry all the voltage adjustment amounts on its back, the ineffective power adjustment device 60 is compared with the configuration without the automatic voltage adjustment device 600. The capacity of the reactor can be reduced.

The configurations of the above-described embodiments are not mutually exclusive and may be combined as appropriate.

According to at least one embodiment described above, at the first location (the interconnection point where the disabled power regulator 60 is connected to the target AC bus 21) where the disabled power regulator is interconnected to the AC system. The difference between the detected first voltage detection value (target AC bus voltage detection value V _tdt ) and the first voltage command value (target AC bus voltage command value V _tref ) and one or more second points (target AC bus voltage command value V tref) in the AC system. The second voltage detection value (reference AC bus voltage detection value V _1dt ) detected at each of the step-down transformers 41, 42, and 43 and the connection points of the reference AC bus 23, 24, 26, and 25, respectively. The difference between V _2dt , V _3dt , and V _4dt ) and the second voltage command value (reference AC bus voltage command value V _1ref , V _2ref , V _3ref , V _4ref ) corresponding to the one or more second points, respectively. Difference voltage index value generation unit (addition / subtractor 101, subtractors 201, 202, 203, and 204, average calculation unit 301, and correction) that generate a differential voltage index value (ΔV _tdiff ) that reflects both the sum and the sum. A control signal ( _Stctrl ) for the ineffective power regulator (60) so that the differential voltage index value (ΔV _tdiff ) generated by the differential voltage index value generator (combined with the device 302) becomes smaller. By having a signal generation unit (a combination of the voltage controller 102 and the switching signal generator 103) that generates the voltage, voltage fluctuation can be suppressed in a wider range. That is, the voltage fluctuation of the power system (reference AC bus 23, 24, 26, and 25) of the same voltage class as the target AC bus 21 which is the target bus for suppressing the voltage fluctuation to which the reactive power adjustment device 60 is connected can be detected. It can be suppressed. Further, since the correction signal _Direction is generated by the processing of the average calculation unit 301 and the corrector 302, the voltage of the target AC bus 21 excessively fluctuates due to the voltage fluctuations of the reference AC bus 23, 24, 25, and 26. It can be suppressed.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof, as are included in the scope and gist of the invention.

3 ... Target AC bus voltage detector, 4 ... Current detector, 11, 12, 13, and 14 ... Reference AC bus voltage detector, 21 ... Target AC bus, 22, 23, 24, 25, and 26 ... Reference AC Bus, 31, 32, 33, 34, 35, 36 ... Transmission line, 41, 42, 43 ... Step-down transformer, 60 ... Invalid power regulator, 63 ... Switching circuit, 63A, 63B ... Cylister, 64 ... Reactor, 65 ... Filter, 66 ... Transformer, 100, 100A, 100B, 100C, 100D, 100E ... Control device, 101 ... Addition / subtractor, 102 ... Voltage controller, 103 ... Switching signal generator, 104 ... Low pass filter, 105 ... Invalid current Calculator, 106 ... Multiplier, 107 ... Addition / subtractor, 201, 202 ... Subtractor, 251, 252 ... Multiplier, 271, 272 ... Low pass filter, 301 ... Average calculator, 302 ... Corrector, 303 ... Upper and lower limit Corrector with instrument, 304 ... Low pass filter, 305 ... Subtractor, 600 ... Automatic voltage regulator, 610 ... Boost transformer with tap, 620 ... Voltage adjustment relay device, 630 ... Voltage adjustment relay device Voltage detector, T1 ~ T9 ... Tap

Claims (8)

The difference between the first voltage detection value and the first voltage command value detected at the first location where the reactive power regulator is connected to the AC system, and the second detected at one or more second locations in the AC system. A differential voltage index value generator that generates a differential voltage index value that reflects both the sum of the differences between the two voltage detection values and the second voltage command value corresponding to each of the one or more second locations.
A signal generation unit that generates a control signal for the reactive power adjustment device so that the difference voltage index value generated by the differential voltage index value generation unit becomes smaller.
A control device equipped with. The differential voltage index value generation unit totals the differential voltage index value, the difference between the first voltage detection value and the first voltage command value, and the result of performing feedback calculation on the sum of the differences. Ask
The control device according to claim 1. Further provided with an upper / lower limit limiter that applies an upper limit and a lower limit to the sum of the differences input to the difference voltage index value generation unit.
The control device according to claim 1 or 2. The differential voltage index value generation unit determines the difference between the second voltage detection value detected at one or more second locations in the AC system and the second voltage command value corresponding to each of the one or more second locations. , The weighting coefficient is multiplied, and the sum of the differences multiplied by the weighting coefficient corresponds to the second voltage detection value detected at one or more second points in the AC system and the one or more second points, respectively. Obtained as the sum of the differences from the second voltage command value,
The control device according to any one of claims 1 to 3. The differential voltage index value generation unit subtracts a value obtained by applying a low-pass filter to the second voltage detection value from the second voltage detection value detected at one or more second points in the AC system. The differential voltage index value is obtained so as to reflect the sum of the obtained values.
The control device according to any one of claims 1 to 4. The signal obtained by applying a low-pass filter to the first voltage detection value is defined as the first voltage command value.
The difference voltage index value generation unit obtains the difference voltage index value so as to reflect the signal obtained by subtracting the sum of the differences from the signal obtained by applying a low-pass filter to the sum of the differences. ,
The control device according to any one of claims 1 to 5. The computer
The difference between the first voltage detection value and the first voltage command value detected at the first location where the reactive power regulator is connected to the AC system, and the second detected at one or more second locations in the AC system. To generate a differential voltage index value that reflects both the sum of the differences between the two voltage detection values and the second voltage command value corresponding to each of the above-mentioned one or more second points.
Generating a control signal for the reactive power regulator so that the generated differential voltage index value becomes smaller.
Control method including. On the computer
The difference between the first voltage detection value and the first voltage command value detected at the first location where the reactive power regulator is connected to the AC system, and the second detected at one or more second locations in the AC system. A differential voltage index value that reflects both the sum of the differences between the two voltage detection values and the second voltage command value corresponding to each of the above-mentioned one or more second points is generated.
A control signal for the reactive power regulator is generated so that the generated differential voltage index value becomes smaller.
program.

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