JP5579795B2 - Transformer maintenance support device and maintenance support method - Google Patents

Description

  The present invention relates to a transformer maintenance support apparatus and a maintenance support method that support determination of a maintenance time of a transformer.

  In an electric power company, when supplying electricity to a customer, a high voltage of, for example, 110 kV is converted into a voltage of 6.6 kV by a transformer installed in a substation and sent to a transformer on a pole. In such a state, for example, when the customer's power demand increases, such as during the daytime, the voltage drops below the specified value. Conversely, when the customer's power demand decreases, such as at night, the voltage falls below the specified value. Go up. In such a case, the substation switches the transformer taps and adjusts the voltage so that the voltage is within the specified range. For this purpose, for example, as shown in FIG. 6, the transformer 100 includes a winding portion 110 and a load tap switching device 120. The winding unit 110 transforms a high voltage and includes a tap for voltage adjustment on the primary side of the winding unit 110, for example. The on-load tap switching device 120 performs voltage adjustment by switching the voltage adjustment tap of the winding unit 110.

An example of the on-load tap switching device 120 is shown in FIG. In FIG. 7, a portion corresponding to one phase among the three phases of the transformer 100 is shown. The on-load tap switching device 120 includes a tap selector 121 provided in the primary winding 111 of the winding unit 110. Tap selector 121, a fixed contact 121A ₁ which is connected to the odd-numbered taps TP7 of the primary winding 111, the fixed contact which is connected to the even-numbered tap TP6, TP8 of the primary winding 111 121A ₂ and 121A ₃ . Moreover, the tap selector 121 is provided with a movable contact 121B ₁ in contact with the fixed contact 121A ₁ and movable, and a movable contact 121B ₂ in contact with the fixed contact 121A _2, 121A ₃ and movable.

Further, the on-load tap switching device 120 includes a switching switch 122. The switching switch 122 includes a conductive curved drive unit 122A. On the outside of the drive unit 122A, and the contact 122B ₁ of the main contact 122B and contact 122C ₁ resistor contact 122C is provided. Similarly, on the outside of the drive unit 122A, a contact 122D ₁ resistor contact 122D and contacts 122E ₁ of the main contacts 122E are provided.

Contact 122B ₂ of the main contact 122B is connected to the movable contact 121B _1, contact 122C ₂ of the resistor contact 122C is connected to the movable contact 121C ₁ through limiting resistor 123A. Similarly, contactor 122D ₂ resistor contact 122D is connected to the movable contactor 121D ₁ via a current limiting resistor 123B, contact 122E ₂ main contacts 122E is connected to the movable contact 121E ₁ Yes.

The main contacts 122B and 122E and the resistance contacts 122C and 122D are closed or opened by the drive unit 122A. For example, the contact 122B is closed, in contact with the movable contactor 121B ₁ of the main contact 122B and the contact 122B ₂ is the main contact 122B is turned on. Conversely, when the main contact 122B is opened, the main contact 122B is separated and becomes non-conductive. The same applies to the other main contacts 122E and the resistive contacts 122C and 122D.

  In the on-load tap switching device 120, as shown in FIG. 8, when the main contact 122B is closed and the main contact 122E and the resistance contacts 122C and 122D are opened by the drive unit 122A. In addition, the current from the tap TP7 of the primary winding 111 flows along the path i1. In this state, when switching from the tap TP7 to the tap TP6, the drive unit 122A performs the switching operation as follows. In FIG. 8, the drive unit 122A is simplified for the sake of clarity.

  When the on-load tap switching device 120 starts the switching operation, the drive unit 122A closes the resistive contact 122C together with the main contact 122B, as shown in FIG. Thereby, the current from the tap TP7 of the primary winding 111 flows along the path i1 and flows along the path i2.

  Next, as shown in FIG. 10, the drive unit 122A opens the main contact 122B and closes the resistance contact 122D. Thereby, the current from the tap TP7 of the primary winding 111 flows along the path i2, and the current from the tap TP6 of the primary winding 111 flows along the path i3. As a result, the current from the tap TP7 decreases and flows due to the current limiting resistor 123A, and the current from the tap TP6 decreases and flows due to the current limiting resistor 123B.

  Thereafter, as shown in FIG. 11, the drive unit 122A opens the resistance contact 122C and closes the main contact 122E. Thereby, the current from the tap TP6 of the primary winding 111 flows along the path i3 and also flows along the path i4.

  Thereafter, the drive unit 122A opens the resistance contact 122D as shown in FIG. Thereby, the current only from the tap 6 flows along the path i4.

  Thus, in the on-load tap switching device 120, when switching from the tap 7 to the tap 6 by the drive unit 122A, the current at the time of the current limiting resistors 123A and 123B is once flowed to reduce the shock at the time of tap switching.

  The switching switch 122 including the main contacts 122B and 122E and the resistance contacts 122C and 122D is immersed in insulating oil. However, even in this state, when the main contacts 122B and 122E and the resistance contacts 122C and 122D are separated, that is, when the main contacts 122B and 122E are opened from the closed state, a spark is generated, and the main contacts 122B and 122E and the resistance contacts 122C and 122D exhaust.

  By the way, the switching switch 122 is manufactured so as to satisfy 200,000 times, which is an electrical life defined by the JEC standard. For this purpose, there is an apparatus for determining the life of a transformer (for example, see Patent Document 1). This device counts the number of tap switching of the transformer as described above to determine the life of the transformer. Further, this device excludes the number of times of no-load switching when counting the number of tap switching. Further, since the consumption is small when the current value of the contact is small, this apparatus estimates the contact life, that is, the life of the transformer with reference to the wear coefficient according to the current value.

Japanese Patent Laid-Open No. 2004-23013

  However, the above-described apparatus for determining the life of a transformer has the following problems. According to the latest knowledge about transformer load and contact wear, it has been found that the contact wear is simply not proportional to the load current. For this reason, this apparatus has the subject that the state of a transformer is estimated and the maintenance time etc. of a transformer cannot be determined appropriately.

  An object of the present invention is to provide a maintenance support device and a maintenance support method for a transformer that can solve the above-described problems and can appropriately determine the state of the transformer.

In order to solve the above-mentioned problems, the invention of claim 1 is provided with a load tap switching device for switching a tap at the time of load by an electric operation box for controlling tap switching, and a current flowing according to the load is changed. A transformer maintenance support apparatus for determining a state of a transformer provided with a current transformer, wherein the current detection means detects a current flowing in the transformer by a current of the current transformer, and the on-load tap switching When a signal indicating tap switching is received from the device, the load of the transformer at the time of tap switching is checked based on the current detected by the current detection means, and the tap switching at load is based on the load of the transformer. together determine the consumption of the main contacts of the device examines the amount of wear resistance contacts of the load tap switching device, Bei give a, a determination unit configured to determine a state of the transformer by the two consumption, the Size When the amount of consumption of the resistance contact is examined, the means is configured such that when the load of the transformer is lower than the load at the reference point where the consumption of the main contact and the resistance contact is the same, the reference The transformer maintenance support device is characterized in that the consumption amount of the resistive contact is checked by increasing the consumption amount of the resistive contact compared to the consumption amount of the point .

  In the invention of claim 1, the current detection means detects the current flowing through the transformer by the current of the current transformer. When the determination unit receives a signal indicating tap switching from the on-load tap switching device, the determination unit checks the load on the transformer at the time of tap switching based on the current detected by the current detection unit. Thereafter, the determination means checks the consumption amount of the main contact of the on-load tap switching device and the consumption amount of the resistance contact of the on-load tap switching device based on the load of the transformer. And a determination means determines the state of a transformer with two consumption amounts.

The invention according to claim 2 determines the state of the transformer provided with the on-load tap switching device for switching the tap at the time of load by the control by the electric operation box and provided with the current transformer for flowing the current according to the load. A transformer maintenance support method comprising: detecting a current flowing through the transformer by a current of the current transformer by a current detection means; and receiving a signal indicating tap switching from the on-load tap switching device; Based on the current detected by the detection means, the load of the transformer at the time of tap switching is checked by the determination means, and based on the load of the transformer, the determination means determines the main contact of the on-load tap switching device. along with examining the consumption, the load of the transformer is lower than the load of the reference point consumption is the same between the main contacts and the load resistance contacts of the tap switching device, wherein the group By increasing the consumption of the resistor contacts as compared to consumption of the points, the examined consumption of the resistor contact, the checked by two determination means the state of the transformer by consumption, that This is a maintenance support method for a transformer.

According to the first and second aspects of the present invention, since the amount of consumption of the main contact of the on-load tap switching device is determined and the amount of consumption of the resistive contact is also checked, it is possible to appropriately determine the state of the transformer. to enable.

Further , when the load on the transformer is low, a correction of increased consumption of the resistive contact can be reflected in the consumption, and it is possible to determine the state of the transformer more appropriately.

It is a block diagram which shows an example of the maintenance assistance apparatus of the transformer by embodiment of this invention. It is a figure which shows a transformer load and consumption. It is a flowchart which shows an example of a consumption calculation process. It is a flowchart which shows an example of a determination process. It is a figure explaining the mode of determination. It is a block diagram which shows an example of a transformer. It is a block diagram which shows an example of the tap switching apparatus at the time of load. It is explanatory drawing explaining operation | movement of the tap switching apparatus at the time of load. It is explanatory drawing explaining operation | movement of the tap switching apparatus at the time of load. It is explanatory drawing explaining operation | movement of the tap switching apparatus at the time of load. It is explanatory drawing explaining operation | movement of the tap switching apparatus at the time of load. It is explanatory drawing explaining operation | movement of the tap switching apparatus at the time of load.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. A transformer maintenance support device (hereinafter simply referred to as “maintenance support device”) according to this embodiment is shown in FIG. In this embodiment, components that are the same as or the same as those in FIGS. 6 and 7 described above are denoted by the same reference numerals, and description thereof is omitted.

  The transformer maintenance support device of FIG. 1 is provided for the electric operation box 200 for operating the on-load tap switching device 120 of the transformer 100. The electric operation box 200 is for operating the on-load tap switching device 120. For this purpose, the electric operation box 200 includes a tap switching circuit 210, and the tap switching circuit 210 controls the tap switching with respect to the on-load tap switching device 120. Thus, in the on-load tap switching device 120, the drive unit 122A operates, and the main contacts 122B and 122E and the resistive contacts 122C and 122D open and close.

  The maintenance support device provided for the electric operation box 200 includes a current detection circuit 1, a tap switching detection circuit 2, an input circuit 3, an arithmetic circuit 4, a storage circuit 5, a determination circuit 6, an alarm circuit 7, and a display unit. 8 is provided.

  The current detection circuit 1 detects a load current flowing through the transformer 100 from a current flowing through a current transformer 1 </ b> A provided together with the transformer 100. When detecting the load current, the current detection circuit 1 sends a current detection signal to the input circuit 3. Note that the current transformer 1A is provided in the electric wire 300 of the substation where the transformer 100 is installed.

  The tap switching detection circuit 2 detects tap switching performed by the tap switching circuit 210 of the electric operation box 200. The tap switching detection circuit 2 sends a tap switching signal to the input circuit 3 when detecting a tap switching by the tap switching signal from the tap switching circuit 210. This tap switching signal constantly monitors the voltage applied to the tap switching circuit, and is detected from “the portion where the voltage is applied only during tap switching” in the circuit.

  The input circuit 3 sends the current detection signal received from the current detection circuit 1 and the tap switching signal received from the tap switching detection circuit 2 to the arithmetic circuit 4.

  The arithmetic circuit 4 checks the amount of consumption of the main contacts 122B and 122E and the resistive contacts 122C and 122D of the transformer 100 based on the current detection signal and the tap switching signal from the input circuit 3. At this time, the arithmetic circuit 4 calculates the ratio of the detected load current to the prescribed current of the transformer 100 (hereinafter referred to as “transformer load”). In this embodiment, depending on the magnitude of the calculated transformer load, the main contacts 122B and 122E (hereinafter simply referred to as “main contact”) of the switching switch 122 and the resistance contacts 122C and 122D (hereinafter referred to as “the main contact”). It is taken into account that the state of wear is simply different from that of a “resistive contact”.

That is, in the arithmetic circuit 4,
a1. When the transformer load is 70 to 80%, the main contact and the resistance contact are evenly worn a2. When the transformer load is higher than the above, the consumption of the main contact is increased and the consumption of the resistance contact is reduced. A3. Based on the knowledge that when the transformer load is less than the above, the consumption of the main contact is reduced and the consumption of the resistance contact is increased. Specifically, when the reference inspection interval (number of times) is 100,000, the arithmetic circuit 4
b1. When the transformer average load is 40% or less, the inspection interval is adjusted from 100,000 to 60,000 times, and the wear amount of the resistance contact is corrected b2. In the case of an average transformer load of 40 to 50%, the relationship between the amount of wear of the resistance contact and the transformer load is used so that the wear amount of the resistance contact is corrected from 100,000 times to 80,000 times.

  These correction values apply to on-load tap changers designed to wear the contacts evenly at transformer loads of 70-80%. Other than this can be dealt with by changing the setting, and can be changed according to the latest knowledge.

  FIG. 2 shows a relationship (hereinafter referred to as “predetermined relationship”) between the consumption amount of the main contactor and the resistance contactor and the transformer load. In FIG. 2, the point at which the main contact and the resistance contact are evenly worn is used as a reference point, and the amount of consumption at this reference point is 100%. In FIG. 2, the consumption of the main contact is proportional to the transformer load. In contrast, the consumption amount of the resistive contact is as follows. When the transformer load is 40% or less, which is lower than the reference point, the consumption amount of the resistive contact is 167% based on the ratio between the inspection interval of 100,000 times and 60,000 times according to b1. When the transformer load is 40 to 50%, which is lower than the reference point, the consumption amount of the resistive contact is 125% from the ratio of 100,000 times and 80,000 times of the inspection interval due to b2. Furthermore, when the load is 50% or more, since the inspection interval is 100,000 times, the consumption amount of the resistive contact is 100%.

  When the arithmetic circuit 4 based on such a background receives the tap switching signal, the arithmetic circuit 4 performs, for example, a consumption amount calculation process shown in FIG. When the calculation circuit 4 starts the consumption calculation process, the current flowing through the transformer 100 is checked from the current detection signal from the current detection circuit 1 at the time when the tap switching signal is received (step S1). The transformer load of the transformer 100 is calculated (step S2). In step S2, the arithmetic circuit 4 calculates the transformer load described above based on the ratio of the current checked in step S1 and the prescribed current of the transformer 100.

When step S2 ends, the arithmetic circuit 4 calculates the amount of wear between the main contact and the resistance contact according to a predetermined relationship (FIG. 2) (step S3). In step S3, for example, when the transformer load is 30%, the arithmetic circuit 4 corresponds to 30% of the transformer load and, based on the consumption amount of the main contact at the inspection interval of 100,000 times, Calculate the current consumption. Since the inspection interval is 100,000 times as a standard, and the consumption amount of the main contact in this inspection interval is 40%, for example, the arithmetic circuit 4 sets 40 × 10 ⁻⁵ % to the main contact by the current tap switching. Consumption amount. In addition, when the transformer load is 30%, the arithmetic circuit 4 corresponds to 30% of the transformer load and is based on the consumption amount of the resistance contact 167% when the inspection interval is 100,000 times. Calculate consumption. Since the inspection interval is 100,000 times and the consumption amount of the resistance contact is 167%, the arithmetic circuit 4 sets 167 × 10 ⁻⁵ % as the consumption amount of the resistance contact due to the current tap switching. .

  Thereafter, the arithmetic circuit 4 stores the calculation result in step S3 in the storage circuit 5 (step S4). When step S4 ends, the arithmetic circuit 4 refers to the tap switching signal and determines whether or not there is a next tap switching (step S5). When there is a next tap switching signal in step S5, the arithmetic circuit 4 returns the processing to step S1. If there is no next tap switching in step S5, the arithmetic circuit 4 ends the consumption amount calculation process.

  The storage circuit 5 stores consumption amounts of the main contact and the resistance contact by tap switching, which are calculated by the arithmetic circuit 4 in step S3 of the consumption amount calculation process. As a result, the storage circuit 5 sequentially records the consumption amounts of the main contact and the resistance contact due to the tap switching.

  The determination circuit 6 checks the consumption amount of the main contactor and the resistance contactor at the present time from the consumption amounts of the main contactor and the resistance contactor by each tap switching, which is data recorded in the storage circuit 5. The time when the transformer 100 is scheduled to be checked and the time when it is scheduled to be updated are determined. For this purpose, the determination circuit 6 periodically performs, for example, the determination process shown in FIG. When the determination process is started, the determination circuit 6 selects, for example, a main contact as a determination target contact (step S21). Thereafter, the determination circuit 6 extracts the amount of consumption due to each tap switching from the storage circuit 5 to the present time for the main contact that is the contact corresponding to the selection in step S21 (step S22). When step S22 ends, the determination circuit 6 integrates the extracted consumption amounts (step S23), and calculates the current integrated value of the main contact. Then, the determination circuit 6 determines whether or not it is a scheduled inspection time, as shown in FIG. 5, from the calculated integrated value (step S24). In FIG. 5, the amount of wear equivalent to 100,000 times is 100% consumption, and the amount of wear equivalent to 200,000 times is 200% consumption. The amount of wear may be represented by the thickness of the main contact and the resistance contact or the number of tap switching.

  If it is time to schedule the inspection in step S24, the determination circuit 6 outputs an alarm signal indicating that the time scheduled for inspection has come to the alarm circuit 7 (step S25). If it is determined in step S24 that the current time is not scheduled for inspection, the determination circuit 6 determines whether it is time for updating (FIG. 5) (step S26). If it is time to update in step S26, the determination circuit 6 outputs an alarm signal indicating that the time to update is coming to the alarm circuit 7 (step S27). If the current time is not an update scheduled time in step S26, the determination circuit 6 outputs a consumption state signal indicating a consumption state such as the current consumption amount of the contact to the display unit 8 (step S28). In step S28, the determination circuit 6 determines the scheduled inspection time and the update schedule from the consumption amount of the main contactor and the resistance contactor at the present time, as well as the consumption amount of the main contactor and the resistance contactor up to the current time point. The time is estimated and the estimation result is displayed on the display unit 8.

  When step S25, step S27, or step S28 ends, the determination circuit 6 determines whether there is an unselected contact (step S29). If there is an unselected contact in step S29, the determination circuit 6 selects the next contact (step S30) and returns the process to step S22. If there is no unselected contact in step S29, the determination circuit 6 ends the determination process.

  Next, a maintenance support method for a transformer by the maintenance support device of this embodiment will be described. The electric operation box 200 instructs the tap switching circuit 210 to control the on-load tap switching device 120 so that the voltage sent from the transformer 100 to the customer becomes constant. Thereby, the on-load tap switching device 120 switches the tap of the transformer 100.

  When the tap switching detection circuit 2 of the maintenance support device detects the tap switching by the tap switching signal from the tap switching circuit 210, the tap switching detection circuit 2 sends the tap switching signal to the input circuit 3. When receiving the tap switching signal, the input circuit 3 sends the tap switching signal to the arithmetic circuit 4 and sends the current detection signal from the current detection circuit 1 to the arithmetic circuit 4.

  The arithmetic circuit 4 is based on the current detection signal from the input circuit 3 and the tap switching signal, and the main contact and the resistive contact of the switching switch 122 of the transformer 100 according to the magnitude of the transformer load of the transformer 100. The amount of consumption of the main contact and the resistance contact is calculated in consideration of the fact that the amount of consumption is different. The arithmetic circuit 4 records the calculation result in the storage circuit 5.

  Thereafter, the determination circuit 6 periodically determines the inspection or update schedule of the transformer 100 from the consumption amount recorded in the storage circuit 5. The determination circuit 6 outputs an alarm signal to the alarm circuit 7 when at least one of the main contactor and the resistance contactor is scheduled to be inspected. As a result, the alarm circuit 7 informs that the scheduled time for inspection of the transformer 100 has come. Further, when at least one of the main contactor and the resistance contactor is scheduled to be updated, the determination circuit 6 outputs an alarm signal to the alarm circuit 7. As a result, the alarm circuit 7 notifies that the scheduled time for renewal of the transformer 100 has come. On the other hand, if the inspection schedule or update schedule has not arrived, the determination circuit 6 outputs a consumption state signal to the display unit 8. The display unit 8 displays the consumption amount of the main contact and the resistance contact at the present time.

  Thus, according to this embodiment, the consumption amount of the main contact is determined and the consumption amount of the resistance contact is also determined, so that it is possible to appropriately determine the inspection and update timing of the transformer 100. . Thereby, the transformer 100 can be inspected at an appropriate time, and failure / accident can be prevented. In addition, wasteful costs can be reduced by optimizing the inspection and renewal timing.

1 Current detection circuit (current detection means)
2 Tap change detection circuit (determination means)
3 Input circuit (determination means)
4 arithmetic circuit (determination means)
5 Memory circuit (determination means)
6. Judgment circuit (determination means)
7 Alarm circuit 8 Display section

Claims (2)

Transformer for determining a state of a transformer provided with a load tap switching device for switching a tap at the time of load by an electric operation box for controlling tap switching and provided with a current transformer for passing a current according to the load Maintenance support device,
Current detecting means for detecting a current flowing through the transformer by a current of the current transformer;
Upon receiving a signal indicating tap switching from the load tap switching device, based on the current detected by the current detection means, examine the load of the transformer at the time of tap switching, based on the load of the transformer, Checking the consumption amount of the main contact of the on-load tap switching device and examining the consumption amount of the resistive contact of the on-load tap switching device, and determining means for determining the state of the transformer by the two consumption amounts, Bei to give a,
When determining the consumption amount of the resistance contact, the determination means, when the load of the transformer is lower than the load of the reference point where the consumption amount of the main contact and the resistance contact is the same, By examining the consumption of the resistive contact by increasing the consumption of the resistive contact compared to the consumption of the reference point,
A maintenance support device for a transformer. Transformer maintenance support method for determining the state of a transformer provided with a load tap switching device for switching a tap at the time of load by control by an electric operation box and provided with a current transformer for passing a current according to the load Because
Detecting the current flowing through the transformer by the current of the current transformer by current detection means,
When receiving a signal indicating tap switching from the on-load tap switching device, based on the current detected by the current detection means, examine the load of the transformer at the time of tap switching by the determination means,
Based on the load of the transformer, by the determination means, the amount of consumption of the main contact of the on-load tap switching device is examined, and the consumption of the main contact and the resistance contact of the on- load tap switching device When the load of the transformer is lower than the load of the reference point where the amount is the same, the consumption of the resistive contact is increased by increasing the consumption of the resistive contact compared to the consumption of the reference point. Check
The determination unit determines the state of the transformer based on the two consumption amounts.
A maintenance support method for a transformer.

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