JPH0666253U - Reactive power compensator - Google Patents

Abstract

(57) [Summary] [Purpose] Regardless of the presence or absence of busbar communication, only reactive power fluctuations in the relevant busbar section are compensated by a capacitor, and complex operation control etc. is not performed during busbar communication, and there is no biased operation or sensitivity deterioration. Achieve compensation of reactive power fluctuation. [Configuration] For each busbar section #A to #C, the section #A to #C
A plurality of current transformers 14 to 16 for detecting the current flowing in from the power source of C and the current flowing into and out of other sections, respectively.
And compensation control for controlling a plurality of capacitors 11 for compensation connected to the section according to the reactive power based on the total value of the secondary side outputs of the current transformers 14 to 16 and the bus voltage of the section. A device 17 is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a reactive power compensation device for each bus section that compensates for reactive power fluctuations with a capacitor.

[0002]

[Prior art]

 Conventionally, this kind of reactive power compensator is provided for each busbar section # 1, # 2 divided by the busbar breaker 1 as shown in FIG. Then, the current transformer 5 detects the current flowing from the upstream bus 2 through the transformer 3 and the circuit breaker 4 into the section # 1 or # 2.

Further, the secondary side output of the current transformer 5 and the bus voltage of the section # 1 or # 2 detected by the voltage transformer 6 are supplied to the reactive power relay section 8 of the compensation control device 7 to generate an electric power. Each switch 10 provided in the capacitor device 9 is selectively opened and closed according to the reactive power based on the current detected by the secondary output of the flow transformer 5 and the bus voltage, and the plurality of capacitors 11 for compensation are Controls bus connection and compensates for delay reactive power fluctuations caused by load equipment.

In the figure, reference numeral 12 is a circuit breaker provided at the busbar connection end of the capacitor device 9, and 13 is a circuit breaker provided in the power supply path of the load device.

[0005]

[Problems to be solved by the device]

 In the case of the conventional device shown in FIG. 3, when the circuit breaker 1 is opened and the busbar sections # 1 and # 2 are supplied from only the respective power sources, the current detected by the current transformer 5 and Based on the bus voltage detected by the voltage transformer 6, the reactive power fluctuations generated by the respective load devices of the bus sections # 1 and # 2 are detected separately and compensated by the compensators of the sections # 1 and # 2. Therefore, no inconvenience occurs.

On the other hand, when the circuit breaker 1 is turned on and the busbar sections # 1 and # 2 are connected to each other, the reactive power fluctuation generated in the busbar section # 1 or # 2 causes a change in the other busbar section # 2 or. The reactive current is shunted to the current transformer 5 of both the sections # 1 and # 2 after spreading to # 1, and based on the detection of this shunt, the compensating device of both the sections # 1 and # 2 is switched to another section # 2 or # 2. It also compensates for the reactive power fluctuation of 1.

At this time, the compensators of both sections # 1 and # 2 theoretically make the same amount of compensation by parallel operation, but in reality, the operating time, operating value, etc. of the relay unit 8 Due to the difference between the devices due to the variation of the relay characteristics of the two, it is easy to cause a time lag in the operation of both compensators. There are problems that arise.

Further, when this biased operation does not occur, the compensators of the bus section sections # 1 and # 2 are operated at the same time and the same amount of compensation is performed, so that the overall sensitivity to reactive power fluctuation is lowered. However, there is a problem in that compensation can be performed only in a unit of double that in independent operation.

In order to prevent this decrease in sensitivity, the settling (sensitivity) of the relay section 8 is halved and a difference in operating time between the compensating devices is provided when the bus bar is connected, and compensation is performed according to the amount of fluctuation in reactive power. It is conceivable to increase or decrease the number of operating machines, but in this case, it is inevitable that the above-mentioned uneven operation will occur.

Therefore, it is conceivable to reduce the settling of the relay section 8 by half and operate the compensator alternately or sequentially to prevent unbalanced operation and decrease in sensitivity when compensating for bus line connection. However, alternate operation or sequential operation of the compensator of each bus section requires a very complicated controller, which is not practical.

The present invention makes it possible to perform reactive power compensation without bias operation or sensitivity deterioration without performing complicated operation control even when each bus bar section is connected.

[0012]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, in the reactive power compensator of the present invention, the current flowing in from the power source of the section and the current flowing in and out of other sections are detected for each bus section. Control a plurality of capacitors for compensation connected to the relevant section according to the reactive power based on a plurality of current transformers and the total value of the secondary side output of each of the current transformers and the bus voltage of the section. And a compensation control device.

[0013]

[Action]

 In the case of the reactive power compensator of the present invention configured as described above, each current transformer detects the current flowing in from the power source of the bus section and the current flowing in and out of other bus sections, and Based on the total value of the secondary side output of the current transformer, the current supplied to the load device of the relevant bus bar section can be detected regardless of the presence or absence of bus line connection.

Then, based on the total value of the secondary side output of each current transformer and the bus voltage of the bus bar section, the reactive power fluctuation caused only by the load device of the bus bar section is detected, and the compensation control device is obtained. Controls each compensation capacitor so as to compensate for this reactive power fluctuation. Therefore, when the busbars are connected, the compensator for each busbar segment individually compensates for only the reactive power fluctuations within each segment, as in the case of independent operation, and does not perform complicated operation control, resulting in conventional biased operation. Reactive power compensation can be performed by a method that does not cause the problem of sensitivity deterioration.

[0015]

【Example】

 An example will be described with reference to FIGS. 1 and 2. (One Example) One example will be described with reference to FIG. In the figure, the same symbols as those in FIG. 3 indicate the same components. FIG. 1 shows only the compensator provided in the central busbar section #B of the busbar sections #A, #B, and #C divided by the circuit breaker 1, and the transformer 3 and the circuit breaker 4 are used. Then, the current flowing into the busbar section #B is detected by the current transformer 14, and the currents flowing into and out of the other busbar sections #A and #C are detected by the current transformers 15 and 16, respectively.

Further, the secondary side outputs of the current transformers 14 to 16 are supplied to the total current transformer 18 provided in the compensation control device 17 and added. The polarities of the secondary side outputs of the current transformers 14 to 16 differ depending on the direction of the current flowing through each of them (the power flow), and as a result, the addition of the total current transformer 18 is actually the addition or the addition depending on the power flow. It becomes a subtraction.

Then, by adding the so-called transformer coupling of the total current transformer 18, the amount of current actually supplied to the load device in the bus section #B is obtained as a total value of the secondary side outputs of the current transformers 14 to 16, The current detection signal of this total value is supplied to the relay unit 8, and this relay unit 8 responds to the reactive power based on the current detection signal of the total current transformer 18 and the detection signal of the bus voltage of the voltage transformer 6 according to the reactive power. Each switch 10 of the device 9 is selectively opened and closed to control the busbar connection of each capacitor 11.

Therefore, even when the circuit breaker 1 is closed and the busbar sections #A to #C are connected to each other and the busbars are connected, the relay section 8 operates by the fluctuation of the reactive power generated by the load equipment of its own section #B. The compensator of the section #B concerned compensates only the fluctuation of the reactive power generated in this section #B. Then, an invalid power compensator having the same configuration as the compensator of the bus bar section #B is provided in the other bus bar sections #A and #C, and at this time, the compensators of the bus bar sections #A to #C are connected to the bus bar. Since the compensation of only the reactive power fluctuations of each of the categories #A to #C is performed regardless of the presence or absence of the above, there is no inconvenience of the conventional bias operation and sensitivity decrease without performing the settling of the relay section 8 or complicated operation control. Does not happen.

Other Embodiments Next, other embodiments will be described with reference to FIG. 2, the same symbols as those in FIGS. 1 and 3 indicate the same components. Then, the reactive power compensator for the busbar sections # 1 and # 2 forms a current transformer for detecting the input and output of current with the other sections # 2 or # 1 by the common current transformer 19, and this current transformer is used. The secondary side output of 19 is supplied to the total current transformer 18 'of the compensation control device 17' of the sections # 1 and # 2 with the polarity changed.

This is because the current flowing into the section # 1 becomes the current flowing out from the section # 2. Then, the total current transformer 18 'adds the secondary side outputs of the current transformers 14 and 19 to obtain the current value (total value) supplied to the load equipment of the bus section # 1 or # 2.

Further, based on the current value obtained by the total current transformer 18 ′ and the bus voltage detected by the voltage transformer 6, the relay unit 8 and the capacitor device 9 operate as in the case of the first embodiment. , Only the reactive power fluctuation of its own bus section # 1 or # 2 is compensated. In this case, since the current transformer 19 is shared between the adjacent bus bar sections # 1 and # 2, there is an advantage that the total number of parts is reduced and the configuration is simplified.

In both of the above embodiments, the current transformers 14 to 16 or the secondary side outputs of the current transformers 14 to 16 or 14, 19 are added in an analog manner by the total current transformer 18 or 18 ′. Alternatively, if an A / D converter is provided on the secondary side of 14, 19 and the secondary side outputs of the current transformers 14 to 16 or 14, 19 are digitally added, the same effect can be obtained. In this case, The total current transformer 18 or 18 'can be omitted, and the compensation control device 17, 17' can be digitalized. Further, it is needless to say that the invention can be applied to the case where a semiconductor element such as a thyristor is used for controlling the bus bar connection of each capacitor 11 of the capacitor device 9.

[0023]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects. The current transformers 14 to 16 or 14, 19 detect the current flowing in from the power source of the bus bar section and the current flowing in and out of other bus bar sections, and 2 of these current transformers 14 to 16 or 14, 19 are detected. The total value of the secondary output is used to determine the current supplied to the load device of the relevant bus bar section, regardless of the presence or absence of bus line connection, and the reactive power based on this current and bus voltage is used to determine the load device of the relevant bus line section. Only the generated reactive power is detected.

Then, each busbar section is connected in order to control each compensating capacitor 11 connected to the section according to the fluctuation of the reactive power to compensate only the reactive power in the corresponding busbar section. It is possible to compensate reactive power fluctuations, etc., without performing complicated operation control or the like when connecting to the busbar, and without causing conventional biased operation or lowering of sensitivity.

[Brief description of drawings]

FIG. 1 is a connection diagram of an embodiment of a reactive power compensator of the present invention.

FIG. 2 is a connection diagram of another embodiment of the present invention.

FIG. 3 is a connection diagram of a conventional device.

[Explanation of symbols]

 11 capacitors 14, 15, 16 and 19 current transformers 17 and 17 'compensation control device

Claims (1)

[Scope of utility model registration request] 1. A plurality of current transformers for detecting, for each busbar segment, a current flowing in from a power source of the segment and a current flowing in and out of another segment, and secondary side outputs of the current transformers. Compensation control device for controlling a plurality of capacitors for compensation connected to the section according to the reactive power based on the total value of the above and the bus voltage of the section.