JP4764245B2 - Fault diagnosis device and method for tap switching device under load - Google Patents

Description

  The present invention relates to a failure diagnosis apparatus and method for determining an abnormal location in a load tap changer equipped with an electric operation mechanism.

  In general, an on-load tap switching device is used in a power transmission / distribution system in order to adjust and stabilize a voltage. This on-load tap switching device is a device installed in a transformer, and performs a tap switching operation by sequence control using an electric operation mechanism as a drive source. Here, the tap switching operation in the conventional on-load tap switching device will be specifically described with reference to the drawings.

  FIG. 3 is a control circuit of the electric operation mechanism. As shown in FIG. 3, the control circuit is roughly divided into a control unit 1A and a motor unit 1B, and three phases (R phase, S phase) supplied from operation power input contacts R, S, T on the motor unit 1B side. , T phase) as a power source. The motor unit 1B includes an electric motor 88M, a wiring circuit breaker 88, a normally open contact 88B-1 and a normally closed contact 88B-2 of a brake electromagnetic contactor 88B described later, and a normally open contact 88R-1 of a boost switching electromagnetic contactor 88R. , And a normally open contact 88L-1 of the step-down switching electromagnetic contactor 88L.

  The control unit 1A includes a step-up command input contact 2 and a step-down command input contact 3 to which a switching command is input, and four electromagnetic contactors 88R, 88L, 88X, and two mechanical contacts 34-1, 34. -2. Among the four electromagnetic contactors, the electromagnetic contactor 88R is for boost switching, and includes normally open contacts 88R-1 (motor unit 1B side), 88R-2, 88R-4, and normally closed contacts 88R-3. Yes. The electromagnetic contactor 88L is for step-down switching, and includes normally open contacts 88L-1 (motor part 1B side), 88L-3, 88L-4, and normally closed contacts 88L-2.

  Furthermore, the electromagnetic contactor 88B is for brakes, and includes normally open contacts 88B-1 (motor part 1B side), 88B-3, 88B-4, and normally closed contacts 88B-2 (motor part 1B side). . As described above, the normally open contacts 88R-1, 88L-1, 88B-1, and the normally closed contact 88B-2 are connected to the motor unit 1B.

  The electromagnetic contactor 88X is for stepping and includes normally open contacts 88X-3, 88X-4, 88X-5 and normally closed contacts 88X-1, 88X-2, 88X-6. Further, the mechanical contacts 34-1 and 34-2 are cam switches operated by a camshaft. 34-1 is for switching up and down pressure, and 34-2 is for stepping.

Subsequently, the switching operation will be described with reference to the operation sequence diagrams of FIGS. 3 and 4 taking the case of the boost switching command as an example. [A] to [k] below describe the states indicated by a to k in FIG. 4.
[A] First, a boost switching command is input from the boost command input contact 2.

[B] By the signal input a, the step-up switching electromagnetic contactor 88R is excited, the normally open contacts 88R-1, 88R-2, 88R-4 are closed, and the normally closed contact 88R-3 is opened. The step-up switching electromagnetic contactor 88R is self-held by the closed circuit of the normally open contact 88R-2 and the normally closed contact 88X-1 of the stepping electromagnetic contactor 88X. In addition, due to the opening of the normally closed contact 88R-3, the electromagnetic contactor 88L is interlocked at the time of a boost command.

[C] By closing the normally open contact 88R-4 of the step-up switching electromagnetic contactor 88R, the brake electromagnetic contactor 88B is excited and the normally open contacts 88B-1, 88B-3, 88B-4 are closed. The normally closed contact 88B-2 is opened.

[D] When the normally open contact 88R-1 of the step-up switching electromagnetic contactor 88R is closed at b and the normally open contact 88B-1 of the brake electromagnetic contactor 88B is closed at c, A current flows through the motor drive circuit, the motor 88M is started, and the tap switching operation is started in the boosting direction.

[E] The buck-boost switching cam switch 34-1 operates and closes.
[F] The stepping cam switch 34-2 operates and closes.

[G] When the step cam switch 34-2 is closed at f, the step electromagnetic contactor 88X is excited and the normally open contacts 88X-3, 88X-4, 88X-5 are closed. The normally closed contacts 88X-1, 88X-2, 88X-5, 88X-6 are opened. When the normally closed contact 88X-1 is opened, the self-holding circuit of the step-up switching electromagnetic contactor 88R moves to the step-up / step-down switching cam switch 34-1.

  Further, when the normally closed contact 88X-2 is opened, the connection between the step-up switching electromagnetic contactor 88R and the step-up command input contact 2 is disconnected. Therefore, the next command cannot be accepted unless the normally closed contact 88X-2 is closed again. In this way, a step circuit is formed in which tap switching is performed for one tap in response to one elevation command.

[H] The stepping cam switch 34-2 operates again to open the contact.
[I] The step-up / step-down switching cam switch 34-1 operates again to open the contact, thereby opening the self-holding circuit of the step-up switching electromagnetic contactor 88R. Subsequently, the excitation of the step-up switching electromagnetic contactor 88R is released, the normally open contacts 88R-1, 88R-2, 88R-4 are opened, and the normally closed contact 88R-3 is closed.

[J] When the normally open contact 88R-4 of the step-up switching electromagnetic contactor 88R is opened, the excitation of the brake electromagnetic contactor 88B is released, and the normally open contacts 88B-1, 88B-3, 88B-4 are released. Is opened, and the normally closed contact 88B-2 is closed. The motor drive circuit is opened by opening the normally closed contact 88B-1 and opening the normally open contact 88R-1 of the step-up switching electromagnetic contactor 88R in the previous stage i. Furthermore, the short circuit of the terminals U, V, and W of the electric motor 88M is formed by closing the normally closed contact 88B-2 of the electromagnetic contactor 88B for brake, and the electric motor 88M is stopped to complete the tap switching.

[K] Excitation of the stepping electromagnetic contactor 88X is released by opening the normally open contact 88B-3 of the brake electromagnetic contactor 88B at j. As a result, the normally closed contacts 88X-2 and 88X-6 of the stepping electromagnetic contactor 88X are closed, and the next command can be received.

  When a step-down switching command is input, first, the step-down switching command enters the step-down command input contact 3, and the step-down switching electromagnetic contactor 88L operates. The following operation sequence is the same as in the above-described step-up switching in place of the step-up switching electromagnetic contactor 88R in place of the step-down switching electromagnetic contactor 88L.

  By the way, the operation frequency of the on-load tap changer is very high, and tap energies (a state where tap change is not completed within a predetermined time) and tap runaway (the motor continues to be energized despite completion of tap change). Etc.) may occur. Monitoring of abnormalities in receiving / transforming equipment and transformers is usually performed in the central monitoring room where the operator monitors, controls, records, etc. You should check the status of the equipment and check for any abnormalities and where they are.

  However, most of the troubles during operation of the on-load tap changer are tap congestion and tap runaway, etc., which are transient things that appear in the contact contact of electromagnetic contactors and switches used in electric operation mechanisms. Met. For this reason, when the operator visits the site and investigates it later, the abnormality that has occurred is not reproduced, and it is difficult to find out the abnormal part.

  In order to cope with such a situation, a failure diagnosis technique that can accurately determine an abnormal portion of the on-load tap switching device has been proposed. For example, the technique disclosed in Patent Document 1 includes a “start-up time” from when a step-up command or a step-down command is issued until a motor current flows, and a “stop time” from when a motor stop command is issued until the motor current disappears. ”Is monitored to determine an abnormal part in the electric operation mechanism.

  However, with the technique of the above-mentioned Patent Document 1, it is possible to find an abnormality with respect to the electromagnetic contactor used in the electric operation mechanism and its contacts, but it is impossible to find a failure of the electric motor itself. Thus, there has been proposed an apparatus that determines an abnormal portion of the on-load tap switching device based on the switching time in the electromagnetic contactor for controlling the motor and the current flowing in the motor (see Patent Document 2).

  That is, when the switching time of the magnetic contactor is normal and the current flowing through the motor is abnormal, it can be determined that there is a problem in the mechanical system of the on-load tap switching device. Further, if a pulsation appears in the waveform of the motor current, the motor is open-phase activated, so that it can be determined that there is an abnormality in the motor circuit.

Further, when the current flowing through the motor is normal and the switching time of the magnetic contactor is abnormal, it is determined that there is a problem in the control system of the on-load tap switching device, that is, the contact of the electromagnetic contactor. In addition, when the switching time of the magnetic contactor ends instantaneously, an abnormal phenomenon is a circuit abnormality, and the abnormal part can be diagnosed as a malfunction of the contact of the electromagnetic contactor or a malfunction of the command circuit.
Japanese Utility Model Publication No. 3-30871 JP 2004-172408 A

  However, the following problems have been pointed out in the above-described prior art. That is, in both prior arts of Patent Documents 1 and 2, since the occurrence of abnormality is determined by monitoring the switching time and operation time at the magnetic contactor contact, even if an abnormal operation pattern occurs, While it was within the normal time, this could not be determined as abnormal, and the discovery of the abnormality could be delayed.

  As transformers increase in voltage and capacity as power demand increases, there is an ever-increasing demand for equipment safety. A high level of accuracy is also provided for fault diagnosis devices for on-load tap changers. And promptness is required. Therefore, there has been a need for a failure diagnosis technique that shortens the time required for determining an abnormal location as much as possible and quickly and accurately determines the abnormal location.

  The present invention has been proposed in order to solve the above-described problems, and the object thereof is to easily and quickly identify a defective portion without using the contact switching time or operation time of the magnetic contactor as a criterion. It is an object of the present invention to provide a failure diagnosis device and a method of a load tap changer that can be determined and can greatly contribute to improvement of reliability and safety.

In order to achieve the above object, according to the present invention, when a boost command is input, a sequence control is performed by a mechanical contact and an electromagnetic contactor, and the motor for driving the electric operation mechanism is energized to perform tap switching on the boost side. On the other hand, when the step-down command is input, the sequence control is performed by the mechanical contact and the electromagnetic contactor, and the failure of the on-load tap switching device that switches the tap to the step-down side by energizing the motor for driving the electric operation mechanism is diagnosed A command input sensor that detects that a step-up / step-down command is input, a current sensor that detects a current flowing through the electric motor, the mechanical contact, and the electromagnetic contactor, and a step-up / step-down pressure by the command input sensor The command input status is monitored, and the switching operation at the mechanical contact and the contact of the electromagnetic contactor is monitored based on the detection result of the current sensor. A state monitoring unit which, a pattern of the opening and closing operation in the command input sensor Buck command and the mechanical contact and the electromagnetic contactor of contacts by, and the standard pattern is detected and stored during advance normally, by comparison, It has an abnormality diagnosing unit for determining the presence / absence of abnormality of the electric motor and the electromagnetic contactor and an abnormal part.

  In the present invention, the presence / absence and abnormality of the on-load tap switching device are determined as follows. First, when the command input sensor is operated, it can be confirmed that the step-up / step-down switching command has entered normally. In addition, it can be confirmed that the contacts and the mechanical contacts of each electromagnetic contactor have operated normally by confirming that the current flows through the current sensor and finally the current is cut off.

  Further, the operation of the command input sensor and the current sensor is monitored by the state monitoring unit, and the monitoring result is compared with the standard pattern of the operation of each sensor detected and stored in the normal state. And when tap switching is performed to the last, it determines with it being normal.

  On the other hand, if the tap switching operation is stopped halfway and the current sensor for detecting the current of the magnetic contactor operates out of the standard pattern, whether or not the current is passed through the sensor. Therefore, it can be determined that there is a contact failure at the contact point or a failure of the electromagnetic contactor itself. Also, a current sensor for detecting the current of the motor, and if the operation deviates from the standard pattern, it is determined that the contact at the contact point for passing the current to the sensor is turned on or off, or the failure of the motor itself. it can.

  Further, when the tap switching is not started even though the command signal is sent to the electric operation mechanism, the abnormal part is determined from the operation of the command input sensor checked by the state monitoring unit. That is, if the command input sensor is operating, the failure factor is determined from the case where the command input is stopped halfway. If the command input sensor is not operating, it is determined that the failure is on the side that sends the command signal to the electric operation mechanism.

  According to the on-load tap switching device failure diagnosis device and method therefor according to the present invention, instead of judging abnormality based on the contact switching time or operating time of the magnetic contactor, the step-up / down command and mechanical By comparing the opening / closing operation at the contact point and the contact point of the magnetic contactor with the standard pattern at the normal time, it is possible to determine the presence / absence of the abnormality and the abnormal part, and to determine the defective part easily and in a short time. It was possible to make a significant contribution to the improvement of reliability and safety.

  Hereinafter, typical embodiments according to the present invention will be described in detail with reference to FIGS. FIG. 1 is a circuit diagram of an electric operation mechanism according to a representative embodiment of the present invention, and FIG. 2 is an operation sequence diagram of the first embodiment. In FIG. 1, the same parts as those of the prior art shown in FIG.

(1) Configuration As shown in FIG. 1, the present embodiment has a circuit configuration in which the current sensors CM, CR, CL, CX, CB, C1, C2, and boost command input are compared to the circuit of the prior art of FIG. A sensor P2, a step-down command input sensor P3, a state monitoring unit 101, and an abnormality diagnosis unit 102 are added.

  The current detection target devices in the current sensors CM, CR, CL, CX, CB, C1, and C2 are as follows. That is, the current sensor CM is an electric motor 88M, CR is a step-up switching electromagnetic contactor 88R, CL is a step-down switching electromagnetic contactor 88L, CX is a stepping electromagnetic contactor 88X, CB is a brake electromagnetic contactor 88B, C1 is The step-up / down switching cam switches 34-1 and C2 use the step-up cam switch 34-2 as current detection target devices.

  The step-up command input sensor P2 and the step-down command input sensor P3 are sensors that detect that a step-up command and a step-down command are input, respectively. The state monitoring unit 101 monitors the input state of the step-up / step-down command by the command input sensors P2 and P3, and is a mechanical contact based on the detection results of the current sensors CM, CR, CL, CX, CB, C1, and C2. The switching operation at the respective contacts of the step-up / step-down switching cam switch 34-1, the stepping cam switch 34-2 and the electromagnetic contactors 88R, 88L, 88X, 88B is monitored.

  In addition, the abnormality diagnosis unit 102 uses a standard pattern for the step-up / step-down command by the command input sensors P2 and P3 and the normal operation at each contact of the cam switches 34-1 and 34-2 and the electromagnetic contactors 88R, 88L, 88X, and 88B. The step-up / step-down command by the command input sensors P2 and P3 and the actual opening / closing operation at each contact of the cam switches 34-1 and 34-2 and the electromagnetic contactors 88R, 88L, 88X and 88B are stored in advance. This is a part for determining the presence / absence of abnormality in each part and the abnormal part by comparing with the standard pattern.

(2) Operation Next, the operation in the present embodiment will be described in detail taking the case of a boost switching command as an example. [A] to [k] below describe the states a to k in FIG.
[A] A boost switching command is input from the boost command input contact 2. At this time, the boost command input sensor P2 detects the input of the boost switching command.

[B] Upon input of the signal a, the current sensor CR detects the current, the step-up switching electromagnetic contactor 88R is excited, the normally open contacts 88R-1, 88R-2, 88R-4 are closed, The closed contact 88R-3 is opened.
[C] When the normally open contact 88R-4 of the step-up switching electromagnetic contactor 88R is closed, the current sensor CB detects the current and the brake electromagnetic contactor 88B is excited, so that the normally open contacts 88B-1 and 88B are excited. -3, 88B-4 are closed, and the normally closed contact 88B-2 is opened.

[D] When the normally open contact 88R-1 of the step-up switching electromagnetic contactor 88R is closed at b and the normally open contact 88B-1 of the brake electromagnetic contactor 88B is closed at c, A current flows through the motor drive circuit, and the current sensor CM detects the current. At the same time, the electric motor 88M is activated, and the tap switching operation is started in the boosting direction.

[E] The buck-boost switching cam switch 34-1 operates and closes. At this time, the current sensor C1 detects the current passing through the circuit of the step-up / down switching cam switch 34-1, the normally open contact 88R-2, the normally closed contact 88L-2, the boost switching electromagnetic contactor 88R, and the current sensor CR. To do.
[F] The stepping cam switch 34-2 operates and closes. At this time, the current sensor C2 detects a current passing through the circuit of the stepping cam switch 34-2 → the normally open contact 88B-3 → the stepping electromagnetic contactor 88X → the current sensor CX.

[G] When the step cam switch 34-2 is closed at f, the current sensor CX detects the current. The stepping electromagnetic contactor 88X is excited, the normally open contacts 88X-3, 88X-4, 88X-5 are closed, and the normally closed contacts 88X-1, 88X-2, 88X-5, 88X-6 are opened. To do. When the normally closed contact 88X-1 is opened, the self-holding circuit of the step-up switching electromagnetic contactor 88R moves to the step-up / step-down switching cam switch 34-1. In addition, a step circuit is formed by opening the normally closed contact 88X-2.

[H] The stepping cam switch 34-2 operates again and the current sensor C2 detects that the current has been cut off.
[I] The buck-boost switching cam switch 34-1 operates again and the current sensor C1 detects that the current has been cut off. By opening the contact of the cam switch 34-1, the current sensor CR detects that the current has been cut off, the excitation of the electromagnetic contactor 88R for boost switching is released, and the normally open contacts 88R-1, 88R-2 , 88R-4 is opened.

[J] When the normally open contact 88R-4 of the step-up switching electromagnetic contactor 88R is opened, it is detected that the current sensor CB is out of current, and the excitation of the brake electromagnetic contactor 88B is released. The open contacts 88B-1, 88B-3, 88B-4 are opened, and 88B-2 is closed. The motor drive circuit is opened by opening of 88B-1 and opening of the normally open contact 88R-1 of the step-up switching electromagnetic contactor 88R in the previous stage i. Furthermore, the short circuit of the terminals U, V, and W of the electric motor 88M is formed by closing the normally closed contact 88B-2 of the brake electromagnetic contactor 88B, the electric motor 88M is stopped, and the current flowing through the current sensor CM is cut off. This completes the tap switching.

[K] When the normally open contact 88B-3 of the brake electromagnetic contactor 88B in j is opened, the current to the current sensor CX is cut off, and the excitation of the stepping electromagnetic contactor 88X is released, thereby stepping up. The normally closed contacts 88X-2 and 88X-6 of the electromagnetic contactor 88X are closed, and the next command can be received.

(3) Operation The operation of the present embodiment as described above is as follows. In the above-described operations a to k, it can be confirmed that the boost switching command has entered normally by operating the boost command input sensor P2. Further, by confirming that the current flows through the current sensors CR, CB, CM, C1, C2, and CX and finally the current is cut off, the contacts of the electromagnetic contactors 88R, 88X, and 88B and the cam switch 34- 1 and 34-2 can be confirmed to operate normally.

  The state monitoring unit 101 monitors the operations of the boost command input sensor P2 and the current sensors CR, CB, CM, C1, C2, and CX, and the abnormality determination unit 102 stores the normal standard pattern stored in advance. The operation is compared with the actual operation monitored by the state monitoring unit 101, and when there is no significant difference and tap switching is performed to the end, it is determined as normal.

  When the tap switching operation is stopped halfway, if the current sensors CR, CX, CB that detect the currents of the magnetic contactors 88R, 88X, 88B are not performing a predetermined operation, whether the current is supplied to these current sensors. It is determined that the contact of the magnetic contacts 88R, 88X, 88B included in the magnetic contactors 88R, 88X, 88B to be cut is defective or that the magnetic contacts 88R, 88X, 88B themselves are defective.

  Further, when the current sensor CM that detects the current of the motor 88M does not perform a predetermined operation, it is determined that there is a contact failure at a contact point for causing the current sensor CM to flow or not, or a failure of the motor 88M itself. Furthermore, when the tap switching is not started even though the command signal is sent to the electric operation mechanism, the operation of the boost command input sensor P2 is checked, and if the boost command input sensor P2 is operating, the above-mentioned halfway stop is performed. The failure factor is determined from the above case, and if the boost command input sensor P2 is not operating, it is determined that the failure is on the side that sends a command signal to the electric operation mechanism.

  In the above description, the step-up command is input as an example. However, when the step-down command is input, the step-down command input sensor P3 operates instead of the step-up command input sensor sensor P2. Further, since the step-down switching electromagnetic contactor 88L operates in place of the step-up switching electromagnetic contactor 88R, the CB operates instead of the CR regarding the current sensor.

(4) Effects As described above, according to the present embodiment, an abnormal pattern is taken because the abnormal location is not determined based on the contact switching time or the operation time of the electromagnetic contactor as in the prior art. Even if the operation is within the time required for the normal standard pattern, the abnormal part can be found quickly and accurately. Therefore, it is possible to easily determine the defect location in a short time. As a result, it is possible to meet social demands such as improvement in reliability and safety in the present situation where transformers have higher voltages and larger capacities.

(5) Other Embodiments The present invention is not limited to the above-described embodiment, and the configuration, the number of arrangements, and the like of each sensor can be changed as appropriate.

1 is a circuit diagram of an electric operation mechanism in a representative embodiment according to the present invention. The operation | movement sequence diagram of this embodiment shown in FIG. The circuit diagram of the electric operation mechanism in the conventional tap switching device at the time of load. FIG. 4 is an operation sequence diagram of the electric operation mechanism shown in FIG. 3.

Explanation of symbols

1A ... Control unit 1B ... Motor unit R ... Operation power input contact (R phase)
S: Input contact for operation power supply (S phase)
T: Input contact for operation power supply (T phase)
2 ... Step-up command input contact 3 ... Step-down command input contact 88 ... Circuit breaker 88M ... Motor 88R ... Step-up switching electromagnetic contactor 88R-1-4 ... Step-up switching electromagnetic contactor contact 88L ... Step-down switching electromagnetic Contactor 88L-1-4: Step-down switching magnetic contactor contact 88X ... Stepping electromagnetic contactor 88X-1-6 ... Stepping electromagnetic contactor contact 88B ... Brake electromagnetic contactor 88B-1-4 ... Brake Magnetic contactor contact 34-1 ... Cam switch 34-2 for step-up / step-down switching ... Cam switch CM for stepping ... Motor current sensor CR ... Current sensor CL ... Current sensor CX ... Current sensor CB ... Current sensor C1 ... Current sensor C2 ... Current sensor P2 ... Step-up command input sensor P3 ... Step-down command input sensor 101 ... State monitoring unit 102 ... Abnormality diagnosis unit

Claims (2)

When the boost command is input, the sequence is controlled by the mechanical contact and the electromagnetic contactor, and the electric operation mechanism driving motor is energized to switch the tap to the boost side. A device for diagnosing a failure of the on-load tap switching device that is sequence-controlled by the contact and the electromagnetic contactor and energizes the electric motor for driving the electric operation mechanism to switch the tap to the step-down side,
A command input sensor for detecting that a step-up / down command has been input;
A current sensor for detecting a current flowing through the electric motor, the mechanical contact and the electromagnetic contactor;
A state monitoring unit that monitors an input state of a step-up / step-down command by the command input sensor, and monitors an opening / closing operation at the contact of the mechanical contact and the electromagnetic contactor based on a detection result of the current sensor;
By comparing the step-up / step-down command by the command input sensor and the pattern of opening / closing operation at the contact of the mechanical contact and the electromagnetic contactor with a standard pattern previously detected and stored at normal time, the motor and the electromagnetic contact A failure diagnosis device for an on-load tap switching device, comprising: an abnormality diagnosis unit that determines whether there is an abnormality in a vessel and an abnormality location. When a step-up command is input, the sequence is controlled by a mechanical contact and an electromagnetic contactor, and the electric operation mechanism driving motor is energized to switch taps to the step-up side. A method of diagnosing a failure of a load tap switching device that is sequence-controlled by an electromagnetic contactor and energizes an electric motor for driving an electric operation mechanism to perform tap switching on a step-down side,
A step-up / step-down command detection step for detecting that the step-up / step-down command is input by the command input sensor;
A current detection step of detecting a current flowing through the electric motor, the mechanical contact and the electromagnetic contactor by a current sensor;
A state monitoring step for monitoring an input state of the step-up / step-down command by the command input sensor, and monitoring an opening / closing operation at the contact of the mechanical contact and the electromagnetic contactor based on a detection result of the current sensor;
By comparing the step-up / step-down command by the command input sensor and the pattern of opening / closing operation at the contact of the mechanical contact and the electromagnetic contactor with a standard pattern previously detected and stored at normal time, the motor and the electromagnetic contact A failure diagnosis method for an on-load tap switching device, comprising: an abnormality diagnosis step for determining presence / absence of an abnormality of a vessel and an abnormality location.

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