JPH0715875A - Controller for reactive power compensator - Google Patents

Abstract

PURPOSE:To sufficiently compensate when a voltage drop occurs in an AC system and to prevent a commutation failure by increasing an operating range of compensating the voltage drop of an operating range of a reactive power compensator in the same substation or near the substation while a separately excited AC/DC converter is operating as an inverter. CONSTITUTION:A converter controller 19 applies a command of whether a separately excited AC/DC converter 17 is operating as a power rectifier or a power inverter to a level setter 22 as an operating state signal 21. The setter 22 which receives the signal switches a level value of an output in response to the signal 21. This switched value is used as an upper limit value or a lower limit value by a level detector 11. The switched value is set to a little larger value, i.e., a value of increasing inductive reactive power consumption of a reactive power compensator 3 as compared with an operation of a power rectifier when the signal 21 indicates an operation of a power inverter. Thus, an operating range for compensating the voltage drop is increased, and even if the AC voltage is lowered, it can be sufficiently compensated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control apparatus for a separately-excited and self-excited reactive power compensator using semiconductor elements applied to a power system.

[0002]

2. Description of the Related Art A reactive power compensator generally applied to a power system has a structure as shown in FIG. There are two types of reactive power compensators using a semiconductor element, a separately excited type using a thyristor and a self-excited type using a GTO thyristor, etc. However, since the basic control device configuration is the same, here A commonly used separately excited apparatus will be described. A reactive power compensator 3 is connected to an AC bus 1 in a substation via a phase-transforming transformer 2. Further, several phase-tuning capacitors 5 which are opened and closed by the circuit breaker group 4 are installed. The reactive power compensator 3 is of a type generally called TCR (Tyristor controlled reactor), in which a thyristor switch 6 is connected in antiparallel for each phase, and the amount of current flowing through the reactor 7 is controlled by the energization time of the thyristor switch. is doing.
The longer the energization time, the larger the effective value of the inductive current flowing in the reactor 7 and the larger the amount of inductive reactive power consumed.

In order to control the reactive power compensator 3,
The AC voltage detector 15 detects the AC voltage detection value V _det , _{compares the} AC voltage detection value V _det with the AC voltage setting value V _ref , and inputs the difference to the voltage controller 8. The voltage controller 8 is, for example, a proportional-integral type controller, and outputs such that the voltage detection value V _det and the set value V _ref are equal. The output value is specifically the firing angle of the thyristor, and the larger the firing angle, the shorter the energization time of the thyristor and the smaller the amount of inductive reactive power consumed by the TCR type reactive power compensator 3.

On the other hand, in order to constantly operate the reactive power compensator 3 with the reactive power consumption within a constant bandwidth, the firing angle value which is the output signal of the voltage controller 8 has a corresponding inductive reactive value. It is converted into electric power consumption Q _L level detector
Entered in 11. In the level detector 11, the upper limit value B _max and the lower limit value B _{min of the} reactive power consumption desired to be constantly operated are set as level values. Normally, the upper limit value and the lower limit value are, as shown in FIG.
With respect to 0%, a value around the midpoint, that is, 50%, such as an upper limit value B _max = 60% and a lower limit value B _min = 40%, is set. In Fig. 2, the rating is 100% to B _max
The range up to is the operating area to compensate for voltage rise,
The range from B _min to 0% is an operation region for compensating for the voltage drop, and these two regions have the same width.

When the driving reactive power value Q _L exceeds the respective limits, a constant signal is output. For example, Q _L > B _max
Outputs "+1" in the case became, in the case of a Q _L> B _min outputs "-1". This output is counter 12
Then, the level detector output is integrated, and when it exceeds the positive and negative constant values, a signal is given to the circuit breaker controller 13. Specifically, a signal for opening the circuit breaker is given when the constant value on the positive side is exceeded, and a signal for closing the circuit breaker is given when the constant value on the negative side is exceeded. The circuit breaker control device 13 gives an operation command 14 to the circuit breaker group 4 in response to the signal. That is, when a closing signal is received, a circuit breaker in the circuit breaker group 4 which is in an open state is selected, and a closing command is given to the circuit breaker. A circuit breaker in the closed state is selected from the circuit breakers of group 4 and an opening command is given to the circuit breaker. By turning on and off the circuit breaker, the number of capacitors 5 put in the system is controlled.

By using the control device having this configuration, when the AC voltage becomes a high value for a long time for some reason, the detected value V _{det of the} AC voltage becomes large, so that the output of the voltage control device 8 is obtained. The firing angle becomes a small value, and the operating point of the reactive power compensator 3 shifts to a point where the inductive reactive power consumption is larger than usual. Therefore, the value of Q _L becomes large and exceeds the upper limit value B _max of the level detector 11, the signal of “+1” continues to be output from the level detector 11, and if the state continues, the output of the counter 12 becomes a constant value. A signal for opening the circuit breaker is given to the circuit breaker control device 13 beyond. The circuit breaker control device 13 selects the circuit breaker in the closed state from the circuit breaker group 4 and gives an opening command 14 to the circuit breaker, whereby the circuit breaker is opened and the circuit breaker is closed. The number of phasing capacitors 5 present is reduced by one. Since the capacitor is a capacitive reactive power supply source, the number of input capacitors is reduced, so that the amount of reactive power that the TCR-type reactive power compensator must consume in order to keep the AC voltage constant is reduced.

Therefore, the upper limit value B _max of the level detector 11
Operating point of the reactive power compensator 3 that has been shifted to a point greater dielectric reactive power consumption than Q _L is roasted enter a value between B _max and B _{mi n} return to, disabled steadily The power compensator operates between B _max and B _min . By performing this control, the reactive power compensator 3 performs a compensating operation between the rating of 100% and B _max with respect to the transient voltage rise, and from the B _min to 0% with respect to the transient voltage drop. Compensation operation is performed between. For constant voltage adjustment, use the capacitor 5
Is controlled by controlling the number of supplied electric power so that the amount of reactive power supplied by the device is balanced with the amount of reactive power consumption of the reactive power compensator 3.

[0008]

In the conventional reactive power compensator described above, the upper limit value and the lower limit value of the level detector 11 are
A predetermined constant value is used. Consider a case where the separately excited AC / DC converter is installed in the same substation as the reactive power compensator operated by such a control device or in a substation near the same. There are three types of separately excited AC / DC converters: one that operates a forward converter that converts AC power to DC power, one that operates a reverse converter that converts DC power to AC power, and one that stops. There is a driving mode. When the inverse converter is operating, if the voltage of the connected AC system drops or the voltage is distorted in waveform, a phenomenon called commutation failure that prevents normal operation may occur. This phenomenon of commutation failure occurs because the margin angle γ of the converter becomes smaller than the minimum margin angle γ _min required for commutation, but it does not occur between the control advance angle β and the margin angle γ and the overlap angle u. Has the relationship of equation (1).

[Equation 1] β = γ + u …………………… (1)

In this case, as a protection for preventing continuous commutation failures, protection generally called β advancement is performed. This is a method of securing a margin angle γ by increasing the control advance angle β, which is normally operated at about 40 °, to about 60 °. On the other hand, DC voltage E
There is a relation of equation (2) between d and the control advance angle β, and a relation of equation (3) between the DC voltage Ed and the capacitive reactive power consumption Qc of the converter.

[Equation 2] However, Edo is DC voltage without load, Id is DC current operation value,
X is a commutation impedance value. Therefore, when the β advance control is performed, β increases in the expression (2), the DC voltage Ed decreases, and Ed decreases in the expression (3), which increases the reactive power consumption Qc. The AC voltage drops because the consumption of capacitive reactive power increases.

As described above, when the converter is operating as the inverse converter, the β advance control, which causes a drop in the AC voltage, is frequently applied. On the other hand, in the state where β advance is not applied, if the AC voltage drops due to another cause, such as turning on the reactor, it will cause commutation failure, so when the converter is operating the reverse converter, It is important from the viewpoint of stable operation of the converter to compensate for the drop in AC voltage. If a reactive power compensator having the characteristics shown in FIG. 2 is installed near such a converter, the reactive power compensator can compensate for the AC voltage drop. However, in the conventional control device, since the steady operating point is operated at about half the rated capacity,
The operating range that can be compensated for the voltage drop is limited to half the capacity. Therefore, if the rate of voltage drop is large, the reactive power compensation required for stable operation of the inverse converter cannot be performed, and a large voltage drop due to β advance control or a commutation failure due to voltage drop may occur. There is.

On the other hand, when the converter is operating or when the forward converter is operating, the need for compensation for the voltage drop and the need for compensation for the voltage rise are about the same. Since the phenomenon that causes a decrease and the phenomenon that causes a voltage increase are almost the same frequency, in the vicinity of the midpoint of the rating so that the compensating ability is the same for both decrease and increase in the voltage of the reactive power compensator. It is desirable to drive.
The present invention has been made in view of the above circumstances, and an operation of compensating for a voltage drop in an operation region of a reactive power compensator in or near the same substation while the AC / DC converter is operating the inverse converter. By widening the area, when a voltage drop occurs in the AC system, sufficient compensation is provided to prevent commutation failure due to the voltage drop, and when the β advance control is performed by the converter. It is an object of the present invention to provide a control device for a reactive power compensator capable of reducing the rate of AC voltage drop.

[0012]

According to a first aspect of the present invention, there is provided a control device for a reactive power compensator according to the first aspect of the present invention, wherein the control device for a reactive power compensator using a semiconductor element is different from the same substation or a nearby substation. When an excited AC-DC converter is installed, when the converter is operating as an inverse converter, the steady state of the reactive power compensator is more stable than when the converter is operating and when the converter is stopped. Incorporate the converter operating status signal into the controller of the reactive power compensator so that the operating point is the one that consumes more inductive reactive power, and if it is in reverse converter operation Change the upper and lower limits of the steady operation bandwidth of the power compensator to a value that consumes more inductive reactive power than when the forward converter is operating and when it is stopped,
When the actual operating point exceeds the bandwidth for a certain period of time or more, the attached capacitor is disconnected when it exceeds the upper limit value, and the attached capacitor is disconnected when it exceeds the lower limit value. A circuit that operates to turn on is provided.

According to a second aspect of the present invention, there is provided a control device for a reactive power compensating device, wherein a separately excited AC / DC converter is installed in the same substation or in a substation near the same substation. If the converter is operating in the reverse converter and the converted power is above a certain value, the converted power is operating in the forward converter, when the converter is stopped, and when the reverse converter is operating. Compared with the case where it is less than a certain value, the converter operating status signal and DC current set value are reactive power compensated so that the steady operating point of the reactive power compensator becomes the operating point that consumes more inductive reactive power. If the DC current setting value is taken into the control device of the equipment and the inverse converter is operating, and the DC current setting value is a certain value or more, the upper limit value and the lower limit value of the steady operation bandwidth of the reactive power compensator are set in order. When the converter is operating and when it is stopped In the reverse converter operation, when the DC current setting value is changed to a value that consumes more inductive reactive power than when it is below a certain value, and the actual operating point is operated for more than a certain time beyond its bandwidth, A circuit is provided that operates so as to disconnect the attached capacitor when it exceeds the upper limit and to turn on the attached capacitor when it exceeds the lower limit.

[0014]

The control device for a reactive power compensator according to claim 1 of the present invention gives a command as to whether the converter is a forward converter operation or an inverse converter operation to the level setter as an operation state signal. The level setter which receives this switches the output level value according to the operating state signal. The switched values are used as the upper limit value B _max and the lower limit value B _min by the level detector. The value to be switched is a larger value when the operation status signal is "inverter converter operation" than when it is "forward converter operation", that is, the inductive reactive power consumption of the reactive power compensator becomes large. Set to the value. By using this control device, when the AC / DC converter is operating the inverse converter, the upper limit value B _max and the lower limit value B _min of the level detector are when the forward converter is operating or the converter is operating. It will be a larger value than when it is stopped. Since the steady operating point of the reactive power compensator is between B _min and B _max , B _min, which is the operation region for compensating for the voltage drop in FIG.
To 0% increases. Therefore, when operating in that state, even if the AC voltage drops, the reactive power compensator can sufficiently compensate for the voltage drop.

According to a second aspect of the present invention, the control device for a reactive power compensator adds a condition that the converted power is equal to or more than a certain value at the time of reverse conversion of the converter, and in this case, the forward converter operation is performed. Compared to the case where the converter is stopped and the converted power is less than a certain value during the reverse converter operation, the steady operating point of the reactive power compensator becomes the operating point that consumes more inductive reactive power. It is a thing. And doing the reverse transformation,
Further, the upper limit value and the lower limit value of the bandwidth during steady operation are changed under the condition that the set value of the direct current is equal to or more than a certain value.

[0016]

Embodiments will be described below with reference to the drawings. Figure 1
FIG. 1 is a configuration diagram of an embodiment of a controller for a reactive power compensator according to the present invention. In FIG. 1, the same parts as those in FIG. 6 are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 16 is a transformer for a converter, which is connected to the AC bus 1. The transformer is connected to another AC / DC converter and the AC system behind it via the separately excited AC / DC converter 17 and the DC reactor 18. It
The separately excited AC / DC converter 17 is operated in any one of a mode in which the converter is operated to convert AC power into DC power, the inverter is operated to convert DC power into AC power, or stopped.
Which of these modes is selected depends on the system, but is generally determined by an instruction from a distant central power supply command station, and the converter control unit 19 controls the instruction signal to convert the ignition pulse 20. The operation is performed by feeding it to the container 17.

In order to control the reactive power compensator 3,
AC voltage detection value V by AC voltage detector 15_detDetect
And this and AC voltage set value V_refMatch the difference
Is input to the voltage control device 8 and the detected voltage value V_detAnd set value
V_refAre controlled so that On the other hand, reactive power
Force compensator 3 is constantly used to eliminate reactive power within a constant bandwidth.
The output signal of the voltage control device 8 is used to operate at a cost.
The corresponding firing angle value corresponds to the inductive reactive power consumption Q
_LAnd is input to the level detector 11. Level inspection
The upper limit value B of the reactive current value that you want to operate steadily in the output device 11
_max, Lower limit value B_{mi n}Is set as the level value,
In this embodiment, this upper limit value B_max, Lower limit value B_minAs
The output of bell setter 22 is used.

In order to determine the upper limit value B _max and the lower limit value B _min , in the present embodiment, the operation status signal 21 in the control device 19 of the AC / DC converter 17, that is, whether the converter 17 is in the forward converter operation, The signal 21 indicating whether the inverse converter is operating or stopped is given to the level setter 22.
Switch output according to 21. FIG. 3 is a block diagram showing the configuration inside the level setter 22. In Figure 3, in the level setter 22, there is a switch circuit 23 for performing ON / OFF of the margins signal .DELTA.B, also fixed upper limit B _{ma x} ', fixed lower limit value B _min' is set.

The switch circuit 23 is a converter operating state signal 21.
ON / OFF is controlled by. For example, the operating state signal 21 is set to be "1" when the inverse converter is operating and "0" otherwise. The switch circuit 23 is controlled to be ON when the signal 21 is “1” and OFF when the signal 21 is “0”. As the margin ΔB, for example, a value of about 20% of the rated capacity of the reactive power compensator 3 is set. The fixed upper limit value B _max ′ and the fixed lower limit value B _min ′ are set to values such as 60% and 40%, respectively.

The level detector 11 having the above configuration gives the upper limit value B _max and the lower limit value B _min.
, The firing angle value point which is the output signal of the voltage control unit 8 is input is converted in the inductive reactive power consumption Q _L corresponding thereto. The level detector 11 outputs a constant signal when Q _L exceeds the respective limits. For example, Q _L > B
in the case of a _max output "+1", in the case of a Q _L> B _min outputs "-1". This output is input to the counter 12, and the counter 12 integrates it, and gives a signal to the circuit breaker control device 13 when the integrated value exceeds a fixed plus or minus value. Specifically, a signal for opening the circuit breaker is given when the constant value on the positive side is exceeded, and a signal for closing the circuit breaker is given when the constant value on the negative side is exceeded. The circuit breaker control device 13 gives an operation command 14 to the circuit breaker group 4 in response to the signal. By turning on and off the circuit breaker, the number of capacitors 5 put in the system is controlled.

Next, the operation will be described. AC / DC converter 17
While the forward converter is in operation and stopped, the switch circuit 23 in the level setter 22 is turned off, and the upper limit value B _max and the lower limit value B _min given to the level detector 11 are fixed upper limit value B _max. ′ Becomes a value equal to the fixed lower limit value B _min ′. Therefore, the TCR reactive power compensator 3 is normally
is operable 'to B _{max' min} consume reactive power Q _L between. And for transient voltage rise, B
Compensation control for voltage fluctuations is performed within the operating range from _max 'to 100%, and operation is performed so that the AC voltage value is constant. Further, with respect to the voltage drop, compensation control for the voltage fluctuation is performed in the operation region from 0% to B _min ′, and the operation is performed so that the AC voltage value becomes constant.

When the AC / DC converter 17 is operated as an inverse converter, the switch circuit 23 in the level setter 22 is turned on, and the upper limit value B _max and the lower limit value B _min given to the level detector 11 are set. Is a value obtained by adding a margin ΔB to the fixed upper limit value B _max ′ and the fixed lower limit value B _min ′. For that reason it continues to operation 'from B _min' Until the B _max at the operating point between the operating reactive power Q _{L is, Q L <(B min '} +
Since ΔB) = B _{min, the} level detector 11 continues to output “−1”, whereby the integrated output of the counter 12 gradually changes to a large negative value. Then, when the preset negative constant level is exceeded, a closing signal is given to the circuit breaker control device 13. The circuit breaker controller 13 gives a closing command to the circuit breakers in the circuit breaker group 4 which are in an open state, and the circuit breakers are closed.

By turning on the circuit breaker, the number of capacitors 5 inserted in the system increases, and the amount of capacitive reactive power supplied increases. Since the reactive power supply amount increases, the voltage of the AC bus 1 rises, and the value of V _det detected by the AC voltage detector 15 increases, so that the output of the voltage control device 8 changes to decrease. This output is a firing angle signal to the thyristor 6 of the reactive power compensator 3, and if the firing angle becomes smaller, the current flowing through the reactor 7 increases and the consumption of reactive power increases. That is, changes in the direction of the operation reactive power Q _L is increased, eventually _{(B min '+ ΔB) <} Q
_{When L} <(B _max ′ + ΔB), the steady state is reached. In this state, (B
Compensation control for voltage fluctuations is performed within the operating range from _max '+ ΔB) to 100%, and voltage fluctuations within the operating range from 0% to (B _min ' + ΔB) against transient voltage drop. Is performed so that the AC voltage value becomes constant.

According to the above-described embodiment, the operating range of the reactive power compensator 3 for the AC voltage drop is from 0% to B _min ′ while the AC / DC converter 17 is in the forward converter operation and stopped. On the other hand, from 0% to (B _min ′ + Δ
B), and the operating region becomes wider by ΔB during the operation of the inverse converter. As a result, sufficient compensation for a transient voltage drop can be performed, and commutation failure due to voltage drop can be prevented from occurring in the AC / DC converter 17 operating in the inverse converter. Further, due to voltage waveform distortion or the like, the β-advance control is performed by the AC / DC converter 17 operating in the inverse converter, and even if the reactive power consumption of the converter increases and the voltage of the AC bus 1 decreases,
By sufficiently compensating for it, the voltage fluctuation width can be reduced.

In the first embodiment shown in FIG. 1, an AC / DC converter is used as the signal 21 for switching the switch circuit 23.
Although the operating state signal in the control device 19 of 17 is used, instead of this, as the second embodiment, the active power P flowing from the AC bus 1 to the transformer 16 for the converter is detected, and P is changed from the DC side to the AC side. The same effect as that of the embodiment of FIG. 1 can be obtained even if the switch 23 is turned on in the direction of flowing to the other direction and turned off in other cases.

As a third embodiment, a method of combining not only the driving condition signal but also the driving condition signal and the magnitude of the converted power can be adopted. That is, as shown in FIG.
Similar to the first embodiment, the operating state signal 21 is fetched from the converter control device 19 and the operating power set value 24 is also fetched.
As the operating power set value 24, specifically, the direct current set value Id _ref is used. This operating power set value 24 is input to the level detector 25, and the value at the level detector 25 is a certain value or more,
For example, if the converter rated output is 50% or more, "1" is output. On the other hand, the operation state signal 21 outputs "1" when the inverse converter is operating, and "0" otherwise in the same manner as in the first embodiment. These two signals are given to the AND circuit 26, and the AND circuit 26
The output of 26 is used as a control signal for the switch 23 of the level setter 22. When using this embodiment, the inverse transformer operation converter 17, and if the conversion power is above a certain value, the normal operation region of the reactive power compensator 3 _{(B min '+ ΔB) <} Q L <
(B _max ′ + ΔB).

The margin angle γ of the inverse converter is expressed by equation (4).

[Equation 3] That is, when the DC current Id becomes small, the margin angle γ becomes large, and it becomes difficult for commutation to fail. Further, even if β advance is applied from the equation (3), if the direct current Id is small, the fluctuation of the reactive power is small, so that the drop of the AC voltage is small. Therefore, the converter
Even when 17 is the reverse converter operation, when the direct current Id is small, it is not necessary to widen the operation region for the transient voltage drop of the reactive power compensator 3 as compared to when the forward converter is operating or when it is stopped. Therefore, in the embodiment shown in FIG. 4, control is performed so as to widen the operation region for the transient voltage drop of the reactive power compensator 3 on condition that the inverter operation is performed and the direct current has a large value. . Also in the third embodiment shown in FIG. 4, the same effect as that of the first embodiment can be obtained.

Further, as a fourth embodiment, as in the second embodiment, the active power P flowing from the AC bus 1 to the transformer 16 for the converter is detected, and P is the direction from the DC side to the AC side. And if the value is a constant value, for example, 50% or more of the converter rating, the switch 23 is turned on, otherwise it is turned off.
With this method, the same operation as that of the third embodiment is performed, and the same effect as that of the embodiment of FIG. 1 is obtained. Further, in the first embodiment, is in the level setter 22 and has a configuration as shown in Figure 3, an output upper limit value B _max, the lower limit value B _{mi n} is
The fixed values B _max ′ and B _min ′ were determined by adding the margin ΔB via the switch circuit 23. Instead, the values are set in the level setter 22 as shown in FIG.
Fixed upper limit value B _max 1, B _max 2, fixed lower limit value B of the type
_min 1, B _{mi n} 2 a is prepared, it switch circuit
Switch with 27, 28.

B _max 2 and B _min 2 are respectively B _max 1 and B
Set it to a value greater than _min 1. Switch circuit 2
As the control signal 21 for 7 and 28, the same control signals as in the first to fourth embodiments are used. Here, when the signal 21 is "1", that is, when the AC / DC converter 17 is in the inverse converter operation, or when the conversion power is a certain value or more in the inverse converter operation, the switch circuits 27 and 28 are respectively connected to the terminal A. Select the 'and B'sides. Under other operating conditions, that is, when the signal 21 is "0", the terminals A and B are selected. This allows
Upper limit value B _max and lower limit value B used in the level detector 11
_{As min} , when the converter is in the reverse converter operation, or when the conversion power is higher than a certain value in the reverse converter operation, the steady operating point of the reactive power compensator 3 is less than that in other cases. It becomes an operating point that consumes a lot of static reactive power, and the compensation area for transient voltage drop becomes wider. Therefore, FIG.
Even if the circuit shown in (1) is used, the same effects as those of the first to fourth embodiments can be obtained.

[0030]

As described above, according to the present invention, in the control device of the reactive power compensator in which the separately excited AC / DC converter is connected in or near the same substation, the AC / DC converter operates as the inverse converter. If the converter is operating, or if the converted power is above a certain value, the upper and lower limits of steady operation of the reactive power compensator are changed to induce a steady operating point. Since the operating point that consumes more active reactive power is configured, the compensation area of the reactive power compensator for the transient AC voltage drop is expanded and sufficient voltage drop can be compensated. It is possible to prevent the commutation failure due to the decrease, and it is possible to suppress the AC voltage decrease when the β advance control is applied by the inverse converter.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a control device of a reactive power compensation device to which the present invention is applied.

FIG. 2 is a diagram illustrating an operating region of a reactive power compensator.

3 is a diagram showing an example of an internal configuration of a level setting device in FIG.

FIG. 4 is a diagram showing another embodiment.

FIG. 5 is a diagram showing another embodiment.

FIG. 6 is a configuration diagram of a control device of a conventional reactive power compensation device.

[Explanation of symbols] 1 AC bus 2 Phase transformer 3 Reactive power compensator 4 Circuit breaker group 5 Phase condenser 6 Thyristor 7 Reactor 8 Voltage controller 9 Pulse generator 10, 20 Firing pulse 11, 22 Level Setting device 12 Counter 13 Circuit breaker control device 14 Circuit breaker operation command 15 AC voltage detector 16 Transformer for transformer 17 AC / DC converter 18 DC reactor 19 Converter control device 21 Converter operation signal 23, 27, 28 Switch circuit 24 Operation lower limit B _max 'reactive power consumption of the power set point 25 the level detector 26 the AND circuit Q _L inductive reactive power consumption ΔB upper limit of reactive power consumption of the margin B _max var consumption B _min reactive power consumption Fixed upper limit value of B _min ′ Fixed lower limit value of reactive power consumption B _max 1, B _max 2 Fixed upper limit value of reactive power consumption B _min 1, B _min 2 Fixed lower limit value of reactive power consumption

Claims (2)

[Claims] 1. A control device for a reactive power compensator using a semiconductor device, wherein when a separately excited AC / DC converter is installed in the same substation or a nearby substation, the converter operates as an inverse converter. When the converter is operating, the converter operates so that the steady operating point of the reactive power compensator becomes the operating point that consumes more inductive reactive power than when the converter is operating or when the converter is stopped. When the operating condition signal of the above is taken into the control device of the reactive power compensator and it is operating in the inverse converter, the upper and lower limits of the steady operation bandwidth of the reactive power compensator are set during the forward converter operation. If the actual operating point exceeds the upper limit value and the actual operating point exceeds the bandwidth for a certain period of time, the capacitor installed will be changed to a value that consumes more inductive reactive power than when stopped. Is exceeded and the lower limit is exceeded. A control device for a reactive power compensating device, which is provided with a circuit that operates so as to turn on a capacitor provided together. 2. In a control device for a reactive power compensator using a semiconductor element, when a separately excited AC / DC converter is installed in the same substation or in a substation nearby, the converter operates as an inverse converter. However, when the converted power is above a certain value, the steady state of the reactive power compensator is higher than when the forward converter is operating and when the converted power is below a certain value while the converter is stopped and the inverter is running. The operating state signal of the converter and the DC current setting value are taken into the controller of the reactive power compensator so that the operating point becomes the operating point that consumes more inductive reactive power. If the DC current setting value is a certain value or more, the upper and lower limits of the steady operation bandwidth of the reactive power compensator are set to the DC current during forward converter operation and during stop and inverse converter operation. When the set value is below a certain value If the actual operating point is changed to a value that consumes a large amount of inductive reactive power and the actual operating point exceeds the bandwidth for a certain period of time, if it exceeds the upper limit value, the attached capacitor is disconnected. However, the control device for the reactive power compensating device is provided with a circuit that operates so as to turn on the attached capacitor when the lower limit value is exceeded.