JP4108614B2 - Phase control switchgear - Google Patents

Description

  The present invention controls the switching time of a power switchgear such as a circuit breaker in consideration of the residual magnetic flux of the transformer core, thereby making a transient accompanying the switching of the switchgear severe for a transformer connected to the power system. The present invention relates to a phase control switching device that suppresses generation of a typical excitation inrush current to a minimum.

  Conventionally, when there is residual magnetic flux in the transformer or shunt reactor, the residual magnetic flux of each phase of the transformer or shunt reactor is predicted, and the breaker is operated at the optimal application timing according to the residual magnetic flux of each phase Thus, there is a phase control switching device that suppresses a transient switching surge phenomenon (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2001-218354, paragraph numbers 0004 and 0007, FIGS. 1 and 24, and the like

  In the conventional phase control switchgear, the trigger for calculating the residual magnetic flux of each phase of the transformer is used as the opening command, so that the opening command is not sent to the circuit breaker without going through the phase control calculation processing unit, such as when an accident occurs. When given directly to each operating device, the residual magnetic flux could not be calculated because it was impossible to determine when the opening command was generated. Therefore, in the event of an abnormality such as when an accident occurs, even if there is residual magnetic flux in each phase of the transformer, the residual magnetic flux in each phase of the transformer is set to zero to control the closing operation of the circuit breaker. When there is a residual magnetic flux in each phase, there is a drawback that a transient excitation inrush current associated with opening / closing of the switchgear, which is severe for the transformer, cannot be suppressed.

  The present invention has been made to solve the above-described problems, and in the event of an abnormality such as the occurrence of an accident, an opening instruction is directly given to each operation device of the circuit breaker without going through the phase control switching device. Even in this case, an object of the present invention is to provide a phase control switching device capable of calculating the residual magnetic flux of each phase of the transformer and controlling the closing operation of the circuit breaker in consideration of the residual magnetic flux of each phase.

The present invention is connected to a transformer provided in the power system and to the primary side and the secondary side of the transformer, respectively, to cut off the fault current and load current of the transformer and to excite the transformer. In addition, the voltage at the transformer side of each circuit breaker for each of the three phases for generating the switching pole contact signal or the switching pole auxiliary contact signal indicating the switching state according to the switching operation, and each of the circuit breakers for each of the above three phases. A voltage measuring unit for measuring, and a phase control opening / closing operation processing unit for performing opening / closing control of the circuit breaker on the primary side in consideration of the residual magnetic flux of the transformer, the phase control opening / closing operation processing unit Breaker open / close state identification means for identifying the open / close state of each circuit breaker of each phase on the primary side and secondary side of the transformer from the open / close pole contact signal or the open / close pole auxiliary contact signal, and the open / close state of each breaker all from the closed state of the time that has changed to the open state A phase control switching device comprising: a residual magnetic flux detecting means for calculating a residual magnetic flux of each phase of the transformer from a voltage value measured by the voltage measuring unit provided in each subsequent phase. .

  The present invention has a function of identifying the switching state of each circuit breaker from each switching pole contact signal or switching pole auxiliary contact signal of each circuit breaker of each phase, and all the circuit breaker switching states are from a closed state to an open state. A function to calculate the residual magnetic flux of each phase of the transformer from the voltage value measured by the voltage measurement unit provided in each phase before and after the time when the trigger is turned on. As a result, it is possible to calculate the residual magnetic flux of each phase of the transformer even when an opening command is directly given to each operating device of the circuit breaker without going through the phase control switching calculation processing unit, such as when an accident occurs. Can do. For this reason, even when an accident occurs, the closing operation of the circuit breaker can be controlled in consideration of the residual magnetic flux of each phase, and the transient excitation inrush current accompanying switching of the switchgear, which is severe for the transformer, is minimized. It can be suppressed.

Embodiment 1 FIG.
1 is a block diagram showing a configuration of a phase control switching apparatus according to Embodiment 1 of the present invention. In FIG. 1, a circuit breaker 50 is connected to the primary side of the transformer 10, and each contact in the arc extinguishing chambers 52a, 52b, 52c of this circuit breaker 50 can be operated as a switching pole independently. , Each has an independent operation device 54a, 54b, 54c. On the operation devices 54a, 54b, 54c, the switching pole contact signals or switching pole auxiliary contact signals (which may be switching pole auxiliary contacts) of the respective phases of the circuit breaker 50 are shown as 56a, 56b, 56c. The circuit breaker 51 is connected to the secondary side of the transformer 10, and each contact in the arc extinguishing chambers 53a, 53b, 53c of the circuit breaker 51 can be independently operated as a switching pole. Operation devices 55a, 55b, and 55c are provided. In the operation devices 55a, 55b, and 55c, switching circuit contact signals or switching circuit auxiliary contact signals (or switching circuit auxiliary contacts) of the respective phases of the circuit breaker 51 are indicated as 57a, 57b, and 57c.

  Voltage measuring units 72a and 72b that measure voltages between the primary side of each R, S, and T phase transformer 10 and the circuit breaker 50 and between the secondary side of the transformer 10 and the circuit breaker 51, respectively. 72c, 74a, 74b, 74c. Further, voltage is measured on the power transmission line side (right side in the figure) of each R, S, T-phase circuit breaker 50, and voltage is also measured on the power transmission line side (left side in the figure) of the voltage measuring units 73a, 73b, 73c. Voltage measuring units 75a, 75b, and 75c for measuring are provided. The phase control open / close calculation processing unit 80 is configured by a computer or the like, and stores, as functions, a reference phase detection unit 82, a calculation / operation control unit 81, a residual magnetic flux detection unit 83, voltage values measured by each voltage measurement unit described later, and the like. A memory 89 to be stored. Particularly in the present invention, the residual magnetic flux detection unit 83 includes a circuit breaker open / close state identification means 83a, an accident occurrence position determination means 83b, and a residual magnetic flux detection means 83c.

  Further, the opening signal 34 and the closing signal 35 in the normal mode, and the measurement data 36 of the ambient temperature, the operating pressure, and the control voltage of the operating device are input to the calculation / operation control unit 81, and the opening signal in the abnormal mode. 32 is input to the operation devices 54a, 54b, 54c of the circuit breaker 50. The operating devices 55a, 55b, and 55c of the circuit breaker 51 are supplied with the opening / closing pole signal 31 in the normal mode and the opening signal 32 in the abnormal mode. These signals 31 to 35 are switching pole commands to the circuit breaker.

  FIG. 2 is a diagram showing the primary side, secondary side voltage, current, and magnetic flux behavior of each phase transformer for explaining the operation of the phase control switchgear according to the present invention. In order from the top in FIG. 2, the primary voltage of the transformer, the magnetic flux predicted from the primary voltage of the transformer, the internal voltage of the transformer, the magnetic flux predicted from the internal voltage of the transformer, and the secondary voltage of the transformer , Magnetic flux predicted from transformer secondary side voltage, Current flowing through breaker (○ 1) (breaker first opened), Current at fault point, Breaker (○ 2) (Later opened) Circuit breaker), switching circuit contact signal of circuit breaker (○ 1), switching contact signal of circuit breaker (○ 2), trigger signal for detecting residual magnetic flux, primary or secondary side of transformer The period during which the residual magnetic flux is predicted from the voltage is shown.

  FIG. 3 is a diagram showing an example of an opening sequence between the accident point and the circuit breaker. 3 (a) shows an accident point between the primary side of the transformer 10 and the circuit breaker 50. When the circuit breakers 50 and 51 are opened in this order, (b) shows the primary side of the transformer 10. If there is an accident point between the circuit breaker 50 and the circuit breakers 51 and 50 are opened in this order, (c) shows that there is an accident point between the secondary side of the transformer 10 and the circuit breaker 51. When the contacts are opened in the order of 51 and 50, (d) shows a case where there is an accident point between the secondary side of the transformer 10 and the circuit breaker 51, and the circuit breakers 50 and 51 are opened in this order.

  The operation will be described below with reference to the drawings. The voltage on the primary side and the secondary side of each R, S, T phase transformer 10 is measured by each voltage measuring unit 72a, 72b, 72c and 74a, 74b, 74c, and the phase control opening / closing arithmetic processing unit 80. Is sent to the residual magnetic flux detector 83. When the trigger signal TRI is turned on, the residual magnetic flux detector 83 starts calculating the residual magnetic flux based on the voltages measured by the voltage measuring units 72a, 72b, 72c and 74a, 74b, 74c.

  The switching pole state of each contact in each arc extinguishing chamber 52a, 52b, 52c of the circuit breaker 50 is interlocked with the switching pole contact signal or switching pole auxiliary contact signal 56a, 56b, 56c of the circuit breaker of each phase, For example, as shown in FIG. 2, when each contact in the arc extinguishing chambers 52a, 52b, 52c of the circuit breaker 50 is in a closed state, the switching pole contact signal or the switching pole auxiliary contact signals 56a, 56b, 56c of the circuit breaker 50 are ON. In the open state, it is OFF. The switching pole contact signals or switching pole auxiliary contact signals 56a, 56b, and 56c are sent to the residual magnetic flux detection unit 83 of the phase control switching calculation processing unit 80, and the residual magnetic flux detection unit 83 outputs the switching pole contact signal or the switching pole auxiliary signal. From the ON / OFF signals of the contact signals 56a, 56b, 56c, the open / close pole state of each contact in each arc extinguishing chamber 52a, 52b, 52c of the circuit breaker 50 is detected.

  Similarly, in the circuit breaker 51, the switching pole state of each contact in each arc-extinguishing chamber 53a, 53b, 53c is linked to the switching pole contact signal or switching pole auxiliary contact signal 57a, 57b, 57c of each phase circuit breaker 51. For example, as shown in FIG. 2, when each contact in each arc-extinguishing chamber 53a, 53b, 53c of the circuit breaker 51 is in a closed state, the switching pole contact signal or switching pole auxiliary contact signal 57a, 57b, 57c is ON, and OFF in the open state. This switching pole contact signal or switching pole auxiliary contact signal 57a, 57b, 57c is sent to the residual magnetic flux detection unit 83 of the phase control switching calculation processing unit 80, and the residual magnetic flux detection unit 83 receives this switching pole contact signal or switching pole. From the ON / OFF signals of the auxiliary contact signals 57a, 57b, 57c, the open / close pole state of each contact in each arc extinguishing chamber 53a, 53b, 53c of the circuit breaker 51 is detected.

  Now, if an accident occurs on the transformer 10 side of each of the circuit breakers 50 and 51, in order to eliminate this accident, for example, as shown in FIG. It is assumed that a pole command is issued, and a contact opening command is issued to the circuit breaker 51 in a closed state after several cycles. When the circuit breaker 50 in the closed state receives the opening command and opens each contact in each arc extinguishing chamber 52a, 52b, 52c, the switching contact signal or switching electrode of the circuit breaker 50 of each phase The auxiliary contact signals 56a, 56b, and 56c change from ON to OFF as shown in FIG. 2, for example.

  Next, when the circuit breaker 51 in the closed state receives the opening command and opens each contact in each arc extinguishing chamber 53a, 53b, 53c, the switching contact signal or the switching pole auxiliary signal of the circuit breaker 51 The contact signals 57a, 57b, and 57c change from ON to OFF as shown in FIG. 2, for example. FIG. 2 shows that the behavior of the magnetic flux converges to a constant value when both the primary circuit breaker 50 and the secondary circuit breaker 51 of the transformer 10 are opened.

  From this, the residual magnetic flux detection unit 83 is provided with the switching pole contact signal or switching pole auxiliary contact signal 56a, 56b, 56c of the circuit breaker 50 and the switching pole contact signal or switching pole auxiliary contact signal 57a, 57b, 57c of the circuit breaker 51. Is detected (breaker open / close state identification means 83a), and the trigger is turned on. When the trigger is turned on, the residual magnetic flux detector 83 is provided with voltage measuring units 72a provided on the primary side and the secondary side of the transformer 10 of the circuit breaker of each phase before and after the time when the trigger is turned on. From the voltage values measured by 72b, 72c and 74a, 74b, 74c, the residual magnetic flux of each phase of the transformer 10 can be calculated (residual magnetic flux detecting means 83c). Note that the voltage value measured by each voltage measuring unit may be always stored in the memory 89 and used. Accordingly, even when an opening command is given to each operation device of the circuit breaker without passing through the phase control opening / closing operation processing unit 80, such as when an accident occurs, the residual magnetic flux of each phase of the transformer can be calculated. .

  FIG. 4 corresponds to FIG. 3 and measures the voltage on the primary side and the secondary side of each R, S, T phase transformer 10 in the case of each accident type, accident occurrence position and each opening sequence. From the voltages measured by the units 72a, 72b, 72c and 74a, 74b, 74c, the residual magnetic flux of each phase of the transformer 10 is obtained by analysis. The error in the figure is based on the residual magnetic flux obtained from the internal voltage of the transformer (in the analysis, since the voltage of the excitation circuit can be directly read, the magnetic flux calculated from the voltage is regarded as a true value).

  From FIG. 4, regardless of the type of the accident, the opening sequence of the circuit breaker 50 and the circuit breaker 51, and the position where the accident occurred, the switching pole contact signal or switching pole auxiliary contact signals 56a, 56b, 56c and the circuit breaker. By detecting that all of the 51 open / close pole contact signals or the open / close pole auxiliary contact signals 57a, 57b, and 57c have changed from ON to OFF and turning on the trigger, the R, S, and T phase transformers 10 If the voltage of each phase of either the primary side or the secondary side can be measured by each voltage measuring unit 72a, 72b, 72c or 74a, 74b, 74c, the residual magnetic flux of each phase of the transformer is within several percent. It can be seen that the error can be calculated.

  The residual magnetic flux detection unit 83 may include an accident occurrence position determination unit 83b that determines an accident occurrence position. The accident occurrence position determination means 83b includes, for example, the voltage measuring units 73a, 73b, 73c on the power transmission line side (right side in FIG. 1) of the circuit breaker 50 connected to the primary side of the transformer 10, and the primary of the transformer 10. Voltage measuring units 72a, 72b, 72c between the circuit side and the circuit breaker 50, voltage measuring units 74a, 74b, 74c between the secondary side of the transformer 10 and the circuit breaker 51, and the secondary side of the transformer 10 The voltage waveform from each voltage measuring unit 75a, 75b, 75c on the power transmission line side (the left side in FIG. 1) of the circuit breaker 51 connected to is monitored, and for example, the model voltage at the time of an accident or abnormality is stored in the memory 89 in advance. The waveform is stored, and the accident position is determined by comparing with the waveform.

  According to this determination result, the residual magnetic flux detection means 83c is connected to the primary side of the transformer 10 in the case of an accident between the primary side of the transformer 10 and the circuit breaker 50 or in the case of an accident on the power transmission line side of the circuit breaker 50. The residual magnetic flux of each phase of the transformer is calculated from the voltage value measured by the voltage measuring units 72a, 72b, 72c provided in each phase. In the case of an accident between the secondary side of the transformer 10 and the circuit breaker 51 or in the case of an accident on the power transmission line side of the circuit breaker 51, voltage measuring units provided in the respective phases on the secondary side of the transformer 10 The residual magnetic flux of each phase of the transformer is calculated from the voltage values measured from 74a, 74b, and 74c. In addition, without determining the occurrence position of the accident, the voltage value measured by the voltage measuring unit provided on either the primary side or the secondary side of the transformer 10 is used to determine the phase of each transformer. The residual magnetic flux may be calculated.

  The operation of the reference phase detection unit 82 and the calculation / operation control unit 81 of the phase control opening / closing calculation processing unit 80 will be described with respect to the circuit breaker 50 according to the timing chart of the voltage of each unit in FIG. The period of the voltage zero point of each R, S, T phase is detected from the voltage value measured by the voltage measuring units 73a, 73b, 73c provided on the power transmission line side of the phase breaker 50, and the voltage zero point as a reference Is set as a reference point Tstandard.

  Next, for example, when the circuit breaker 50 receives a closing (injection) command, the calculation / operation control unit 81 is predicted from the measurement data of the ambient temperature, operation pressure, and control voltage of the operation devices 54a, 54b, and 54c. In addition to calculating the closing operation time tclose and the leading arc time tprearc and taking into account the residual magnetic flux of each phase of the transformer 10, the optimum closing (closing) time at which the magnetizing inrush current at the time of turning on each phase is minimized ( Electrical angle) Subtract the predicted closing operation time tclose from the time from the point Ttarget (the point where the residual magnetic flux of each phase of the transformer matches the steady magnetic flux) to the reference point Tstandard, and the preceding arc time tprearc An operation synchronization time tcont obtained by addition is calculated. The calculation / operation control unit 81 gives an input signal to each of the operation devices 54a, 54b, 54c after the operation synchronization time tcont calculated from the reference point Tstandard has elapsed, and each contact in each arc-extinguishing chamber 52a, 52b, 52c. Control is performed so that the child performs a closing operation independently at a predetermined electrical angle.

It is a block diagram which shows the structure of the phase control switching apparatus in one embodiment of this invention. It is a timing chart for demonstrating operation | movement of the phase control switchgear in this invention. It is a figure which shows the example of the opening sequence of an accident point and a circuit breaker. It is a figure which shows the result of having calculated | required the residual magnetic flux in the case of each opening sequence of FIG. 3 by analysis. It is a timing chart for demonstrating operation | movement of the reference | standard phase detection part of a phase control opening / closing arithmetic processing part, and a calculation / operation control part.

Explanation of symbols

  10 transformer, 50, 51 circuit breaker, 52a, 52b, 52c, 53a, 53b, 53c arc extinguishing chamber, 54a, 54b, 54c, 55a, 55b, 55c operating device, 56a, 56b, 56c, 57a, 57b, 57c Open / close pole contact signal (open / close pole auxiliary contact signal), 72a, 72b, 72c, 73a, 73b, 73c, 74a, 74b, 74c, 75a, 75b, 75c Voltage measurement unit, 80 phase control open / close calculation processing unit, 81 Operation control unit, 82 reference phase detection unit, 83 residual magnetic flux detection unit, 83a circuit breaker open / close state identification unit, 83b accident occurrence position determination unit, 83c residual magnetic flux detection unit, 89 memory.

Claims (3)

A transformer provided in the power system;
Switching pole contact signal connected to the primary side and the secondary side of this transformer, which is turned on to cut off the fault current and load current of the transformer and to excite the transformer, and indicates the switching state according to the switching operation Alternatively, each circuit breaker for three phases that generates a switching pole auxiliary contact signal,
A voltage measuring unit for measuring the voltage on the transformer side of each circuit breaker for each of the three phases; and
A phase control switching arithmetic processing unit for controlling switching of the circuit breaker on the primary side in consideration of the residual magnetic flux of the transformer;
With
Breaker open / close state identification for identifying the open / close state of each breaker of each phase on the primary side and secondary side of the transformer from the open / close pole contact signal or open / close auxiliary contact signal From the voltage value measured by the voltage measuring unit provided in each phase before and after the time when all the switching states of the circuit breakers and the circuit breakers changed from the closed state to the open state, Including residual magnetic flux detection means for calculating the residual magnetic flux,
A phase control switchgear characterized by the above.   The residual magnetic flux detecting means calculates a residual magnetic flux of each phase of the transformer from a voltage value measured by a voltage measuring unit provided in each phase of the primary side or the secondary side of the transformer. The phase control switchgear according to claim 1. A voltage measuring section for measuring a voltage on the power transmission line side opposite to the transformer side of each circuit breaker of each phase on the primary side and secondary side of the transformer,
The phase control opening / closing operation processing unit further includes an accident occurrence position determination means for determining an accident occurrence position on the power system from the voltage measured by the voltage measurement unit,
In the case where the residual magnetic flux detection means is an accident between the primary side of the transformer and the circuit breaker or on the power transmission line side of the circuit breaker, the voltage measurement provided in each phase on the primary side of the transformer The residual magnetic flux of each phase of the transformer is calculated from the voltage value measured by the section, and in the case of an accident between the secondary side of the transformer and the circuit breaker or on the power transmission line side of the circuit breaker, The phase control switching device according to claim 1, wherein the residual magnetic flux of each phase of the transformer is calculated from the voltage value measured by the voltage measuring unit provided in each phase on the secondary side.

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