Electric operating device, electric operating mechanism, and fault determination method

Abstract

To provide an electric operation mechanism and a failure determination method that do not require a dedicated device and require no human determination.SOLUTION: In the electric operation mechanism 1, an electric operation device 100 that controls the electric operation mechanism provided with a motor 20 that drives an on-load tap changer 10 capable of switching taps provided in a stationary induction electric machine includes a computing unit that obtains the rotational position of the motor in the rotational direction and calculates the number of rotations and the rotational speed of the motor, and a determination unit that determines an abnormal mode indicating an abnormality in the on-load tap changer and the electric operation mechanism on the basis of the calculated amount of change in the number of rotations and the rotational speed of the motor.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to an electric operating device, an electric operating mechanism, and a fault determination method for operating an on-load tap changer used in a stationary induction electric appliance such as a transformer. [Background technology]

[0002] In a static induction device such as a transformer, the output voltage can be changed by changing the turns ratio of the coil. By providing taps with multiple turns ratios on the coil, it becomes possible to output multiple voltages. An on-load tap changer (LTC) is known as a means for switching the turns ratio of the coil in a static induction device without interrupting the voltage load. An on-load tap changer is provided inside the housing of the static induction device, and can change the output voltage of the static induction device while supplying voltage to the load.

[0003] The on-load tap changer includes an electric operating mechanism that switches between multiple taps provided on the coil of the stationary induction electric machine. The electric operating mechanism generates a driving force for operating the tap changing mechanism of the on-load tap changer. Here, the driving force for operating the tap changing mechanism is exemplified by the driving torque of a motor. The electric operating mechanism supplies the driving force to the on-load tap changer based on an external tap changing command, and the on-load tap changer performs the switching operation of the taps in the stationary induction electric machine.

[0004] On-load tap changers change taps in static induction equipment without interrupting the voltage load, so if a malfunction occurs that prevents normal operation during tap changing, it is necessary to quickly restore the equipment. To restore an on-load tap changer malfunction, it is necessary to identify whether the cause is in the drive system, electrical components, or control components.

[0005] Conventionally, to identify the cause of a malfunction in an on-load tap changer, a current clamp was attached to the cable of the motor that generates the driving force in the electric operation mechanism, and the motor overcurrent or motor phase loss due to a single-phase current loss was determined based on the current value detected by the current clamp. However, such a determination based on the motor's driving current could not isolate the faulty part in the on-load tap changer or the electric operation mechanism, and the faulty part had to be identified by manual judgment. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6310905 [Patent Document 2] Patent Publication No. 2006-128237 Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, conventional electric operating devices, electric operating mechanisms, and failure determination methods have the problem that they require dedicated equipment and manual judgment is required to identify the faulty part and to detect a fault at the stage of minor faults that lead to a serious fault. The problem that the present invention aims to solve is to provide an electric operating device, an electric operating mechanism, and a failure determination method that can eliminate the need for manual judgment without providing a dedicated device. [Means for solving the problem]

[0008] According to an embodiment, an electric operating device controls an electric operating mechanism including a motor that drives an on-load tap changer that can switch a tap provided in a stationary induction electric appliance. The electric operating device includes a calculation unit that acquires a rotational position in a rotational direction of the motor to calculate a number of rotations and a rotational speed of the motor, and a determination unit that determines an abnormality mode that indicates an abnormality in the on-load tap changer and the electric operating mechanism based on the calculated amount of change in the number of rotations and the rotational speed of the motor.

[0009] According to an embodiment, the motor operation mechanism controls an on-load tap changer capable of switching a tap provided in a stationary induction electric appliance, and includes a motor for driving the on-load tap changer, an angle sensor coupled to the motor for detecting a rotational position in a rotational direction of the motor, a calculation unit for calculating a number of rotations and a rotational speed of the motor by acquiring the rotational position in the rotational direction of the motor detected by the angle sensor, and a determination unit for determining an abnormality mode indicating an abnormality in the on-load tap changer and the motor operation mechanism based on the calculated amounts of change in the number of rotations and the rotational speed of the motor.

[0010] Furthermore, according to an embodiment, a fault determination method determines a fault in an on-load tap changer and an electric operation mechanism including a motor that drives an on-load tap changer capable of switching a tap provided in a stationary induction electric appliance and an angle sensor that detects a rotational position in a rotational direction of the motor. This fault determination method is characterized in that it obtains the rotational position in the rotational direction of the motor from the angle sensor, calculates the number of rotations and the rotational speed of the motor based on the obtained rotational position, and determines the type of abnormality in the on-load tap changer and the electric operation mechanism based on the calculated amounts of change in the number of rotations and the rotational speed of the motor. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a block diagram showing a configuration of an electric operation mechanism according to the embodiment. [Diagram 2] 4 is a block diagram showing an outline of a judgment table in the electric operation mechanism of the embodiment. FIG. [Diagram 3] 10 is a diagram showing an example of speed profile pattern information in the electric operation mechanism of the embodiment. FIG. [Figure 4] 11A and 11B are diagrams illustrating an example of actual measurement data of speed profile pattern information in the electric operation mechanism of the embodiment. [Diagram 5] 5 is a flowchart showing a failure determination operation in the electric operation mechanism of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In the embodiment, speed profile pattern information is generated from rotational position information and time information obtained from the output of an angle sensor attached to the motor of the electric operation mechanism. As samples, speed profile pattern information in an expected abnormal state and speed profile pattern information in a normal state are acquired in advance, and the cause of the failure is determined by comparing them with the actually measured pattern information. In addition, by recognizing the pattern information, an abnormality mode discrimination system that can identify the type and location of the failure can be constructed, making it possible to predict the tendency of the failure in advance. With this configuration, a dedicated device such as a conventional failure point discrimination device is not required.

[0013] Hereinafter, an electric operation mechanism and an abnormality determination method thereof according to an embodiment will be described in detail with reference to the drawings. Here, the same or similar parts are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0014] (Configuration of the Electric Operation Mechanism of the Embodiment) As shown in FIG. 1, the electric operation mechanism 1 of the embodiment includes a motor 20, an angle sensor 30, and an electric operation device 100. The motor 20 has a rotatable electric shaft 22. The motor 20 is connected (coupled) to an on-load tap changer 10 via the electric shaft 22. The motor 20 generates a driving force by rotating the electric shaft 22. The generated driving torque is transmitted to the on-load tap changer 10 via the electric shaft 22. The on-load tap changer 10 performs tap switching of a stationary induction machine (not shown) by the driving torque of the motor 20 transmitted by the electric shaft 22. In the following description, the rotation of the electric shaft 22 of the motor 20 may be simply referred to as the rotation of the motor 20.

[0015] The angle sensor 30 is a sensor that outputs the mechanical displacement of the rotation of the motor 20 as an electric signal. The angle sensor 30 can be realized by, for example, an encoder, but is not limited to this as long as it can detect the rotation angle. The angle sensor 30 outputs, for example, the rotation displacement or the rotation angle as a pulse signal. The mechanical displacement of the rotation can be expressed as a relative position (rotational position) regarding the rotation. That is, the angle sensor 30 can detect the relative position in the circumferential direction of the vertical cross section in the axial direction of the electric shaft 22 as the rotational position of the electric shaft 22. The angle sensor 30 is connected to the electric shaft 22, for example, coaxially with the electric shaft 22 or via a gear, but is not limited to this. The angle sensor 30 does not need to be directly connected to the electric shaft 22 as long as the rotation is synchronized with the electric shaft 22. Based on the rotational position of the electric shaft 22 detected by the angle sensor 30, it is possible to calculate the number of rotations and the rotational speed of the electric shaft 22. In the following description, the "rotational position" includes the "rotational angle." Here, the rotation speed is determined as the number of rotations per unit time, or the change over time in the number of rotations (differential value with respect to time).

[0016] The electric operating device 100 has a function of controlling the motor 20 and judging faults occurring inside and outside the electric operating mechanism 1. The electric operating device 100 provides a start signal and a stop signal to the motor 20 and receives the detection result of the angle sensor 30. The electric operating device 100 has a control panel 110, an instruction processing unit 120, a memory unit 130, a counter 140, a motor control unit 150, an angle sensor processing unit 160, and a profile determination unit 170.

[0017] The control panel 110 is an interface that receives a tap change command for the electric operating device 100. The tap change command may be input by a switch or the like provided on the control panel 110, or may be input as a signal from a higher-level device.

[0018] The instruction processing unit 120 is a calculation block that processes the tap changing command received by the control panel 110. The instruction processing unit 120 calculates the number of rotations of the motor 20 required by the on-load tap changer in response to the tap changing command, and issues a motor control command to the motor control unit 150. The number of rotations of the motor 20 corresponding to the tap changing command may be specified in advance in the form of a correspondence table, and a value may be selected from the table.

[0019] The memory unit 130 stores, as motor control information, the number of rotations of the motor 20 required in response to a tap changing command referenced by the instruction processing unit 120. In addition, the memory unit 130 stores judgment information for fault detection and fault judgment in the on-load tap changer 10 and the motor operation mechanism 1 performed by the motor operating device 100. Examples of judgment information for fault judgment include monitoring information, a judgment table that associates corresponding abnormality modes, malfunction events, and fault contents / faulty parts, and speed profile pattern information that records the relationship between the number of rotations and the rotation speed of the motor 20 obtained in advance by operating the on-load tap changer 10 and the motor operation mechanism 1.

[0020] The counter 140 is an arithmetic block that counts time based on an externally applied trigger, and generates counts and timing signals required for calculating the number of rotations and rotation speed of the angle sensor 30.

[0021] The motor control unit 150 is a circuit block that generates a start signal and a stop signal that control the supply of drive power to the motor 20. The motor control unit 150 generates a start signal and a stop signal for the motor 20 based on a motor control command sent from the instruction processing unit 120, and outputs the start signal and the stop signal to a control unit of a power supply switching device such as an electromagnetic contactor (not shown). The start signal is a signal that commands the motor 20 to supply power from a drive power source, and the stop signal is a signal that commands the motor 20 to stop supplying the drive power to the motor 20. The motor control unit 150 is configured to receive the number of rotations of the motor 20 from the angle sensor processing unit 160, and after generating the start signal, generates and outputs a stop signal when the number of rotations of the motor 20 reaches the number of rotations specified in the motor control command. Note that the calculated (or specified) number of rotations may be set as a target value, and the output signal of the angle sensor 30 after the motor is started may be used as a feedback signal to control the rotation angle.

[0022] The angle sensor processing unit 160 is a calculation block that calculates the number of rotations and the rotation speed of the motor 20 based on an electrical signal indicating the rotation position of the motor 20 sent from the angle sensor 30. In detail, the angle sensor processing unit 160 performs a calculation to convert the rotation position signal from the angle sensor 30 into one rotation for every rotation angle of 2π (360 degrees), and calculates an integrated value. The angle sensor processing unit 160 also calculates the rotation speed by performing a differential calculation of the rotation position signal from the angle sensor 30. The number of rotations of the motor 20 calculated by the angle sensor processing unit 160 is used as a reference for the motor control unit 150 to stop the motor 20. The number of rotations and the rotation speed of the motor 20 calculated by the angle sensor processing unit 160 are used as basic data for the profile determination unit 170 to determine the fault location and fault type of the on-load tap changer 10 and the electric operating device 1.

[0023] The profile determination unit 170 is a calculation block that determines the location and type of a fault in the on-load tap changer 10 or the motor operation mechanism 1, based on the number of rotations and the rotation speed of the motor 20 calculated by the angle sensor processing unit 160 and the speed profile pattern information stored in the storage unit 130. In addition, the profile determination unit 170 also realizes calculations such as updating the speed profile pattern information and predicting the future.

[0024] (Judgment table and speed profile pattern information) The electric operation mechanism 1 of the embodiment shown in Fig. 1 uses the number of rotations and the rotation speed of the motor shaft 22 of the motor 20 that drives the on-load tap changer 10 to determine the location and nature of a fault in the on-load tap changer 10 and the electric operation mechanism 1. The determination of the location and nature of the fault is performed based on a determination table exemplified in Fig. 2. The determination table is stored in advance in the storage unit 130.

[0025] The judgment table associates each element of "monitoring information", "abnormal mode", "malfunction event" and "fault content / location". As shown in FIG. 2, when the profile judgment unit 170 acquires the number of rotations and the rotation speed of the electric shaft 22 of the motor 20 from the angle sensor processing unit 160 as monitoring information, the abnormality mode (abnormal mode) and the malfunction event are selected based on the value and the change over time. When the malfunction event is specified, the candidates of the fault location and the fault content are narrowed down. Examples of the abnormal mode include "speed reduction", "unresponsive", "halt 1", "halt 2", and "runaway". The threshold value and the reference time that are the basis for the profile judgment unit 170 to judge the abnormal mode are set in consideration of the characteristics of the pattern of each abnormal mode. In other words, the threshold value and the time can be set as the reference with a certain degree of width.

[0026] "Speed ​​drop" is an event in which the rotation speed of the motor 20 does not reach a predetermined rotation speed after the motor 20 has been started up, and since a certain load torque is applied to the motor 20, causing a speed drop due to an increase in load, it is determined to be a failure of a mechanical part in the drive system of the motor 20 (a in Fig. 2). In this case, examples of failures include sticking of the mechanism of the on-load tap changer 10, sticking of the handle mechanism, sticking of the limit mechanism, and sticking of the bevel gear for the electric shaft.

[0027] "No response" is an event in which the on-load tap changer 10 does not respond to a switching command, and is presumed to be caused by an electrical failure that causes the motor 20 to not rotate at all (b) or a mechanical failure that causes the motor 20 to rotate only a little and then stop (c). If the motor 20 does not rotate at all, this is considered to be a malfunction in the circuit, and it is determined that there is a malfunction in the electric components for the motor circuit and control. For example, electrical malfunctions include a disconnection of the motor connection line, a malfunction of the relay for operating the electromagnetic switch, a malfunction of the electromagnetic switch, an abnormality in the MCCB, and a malfunction due to a ground fault or insulation breakdown in the power line of the motor 20. If the motor 20 rotates only a little, this is considered to be a malfunction in the mechanical components, and it is determined that there is a malfunction in the mechanical components of the on-load tap changer 10 or the motor 20. For example, mechanical malfunctions include a malfunction due to a stuck mechanism of the on-load tap changer 10, a stuck handle mechanism, a stuck limit mechanism, or a stuck bevel gear for the electric shaft.

[0028] "Halt 1" is an event in which the operation of the on-load tap changer 10 does not complete and stops midway, in which excessive load torque is applied to the motor 20, causing the starting current to continue to flow, and since the rotation of the motor 20 drops suddenly and stops due to, for example, the operation of a relay, it is determined to be a failure of a mechanical part in the drive system of the motor 20 (d)). For example, examples of mechanical failures include failures due to sticking of the mechanism of the on-load tap changer 10, sticking of the handle mechanism, sticking of the limit mechanism, and sticking of the bevel gear for the electric shaft.

[0029] "Halt 2" is an event where the on-load tap changer 10 does not complete its operation and stops midway, and since no driving torque is applied to the motor 20 and the rotation gradually drops and stops, it is determined to be a failure in the motor circuit and control electrical components (e in the same article). In this case, examples of failures include a broken motor connection line, a failure of the relay for operating the electromagnetic switch, a failure of the electromagnetic switch, and a failure due to an abnormality in the MCCB.

[0030] "Runaway" is an event in which the rotation of the motor shaft 22 of the motor 20 does not stop at a predetermined timing, and occurs when power continues to be supplied to the motor 20 and the motor 20 does not stop, so it is determined to be a failure in an electrical part that supplies power to the motor circuit (ibid. f). In this case, examples include a failure of a relay for operating an electromagnetic switch or a failure of the electromagnetic switch itself.

[0031] As basic information for determining an abnormal mode in the determination table, the electric operation mechanism 1 uses speed profile pattern information that records the relationship between the number of rotations and the rotation speed of the motor 20 that drives the on-load tap changer 10. Fig. 3 is an example of the speed profile pattern information.

[0032] As shown in Fig. 3, the speed profile pattern information describes changes in the number of rotations and the rotation speed of the motor 20 from when the on-load tap changer 10 and the motor operation mechanism 1 start to when they stop operating. The horizontal axis of Fig. 3 represents the integrated value of the number of rotations since the start of the motor 20, and the vertical axis represents the rotation speed of the motor 20. In Fig. 3, the speed profile pattern information includes a profile during normal operation ("normal" in Fig. 3) and profiles during abnormal operation ("a" to "f" in Fig. 3).

[0033] In the profile shown by "a" in FIG. 3, the number of rotations of the motor 20 is the same as in normal operation, but the rotation speed during steady rotation remains lower than the normal rotation speed. This is a profile corresponding to the abnormal mode "speed reduction". Similarly, in the profile shown by "b", the number of rotations and the rotation speed of the motor 20 do not increase at all, and the motor 20 does not rotate. This is a profile corresponding to the abnormal mode "no response", and the malfunction event in the judgment table shown in FIG. 2 is the state "b) the motor does not rotate at all". Similarly, in the profile shown by "c", the number of rotations and the rotation speed of the motor 20 increase only to a significantly low value, and the rotation stops. This is a profile corresponding to the abnormal mode "no response", and the malfunction event in the judgment table shown in FIG. 2 is the state "c) the motor rotates only slightly".

[0034] In the profile shown by "d" in FIG. 3, the rotation speed of motor 20 drops suddenly and stops before the rotation count reaches a normal value (33 times in the example shown in FIG. 3). This is a profile corresponding to abnormal mode "intermediate stop 1". Similarly, in the profile shown by "e", the rotation speed of motor 20 drops gradually and stops before the rotation count reaches a normal value. This is a profile corresponding to abnormal mode "intermediate stop 2". Similarly, in the profile shown by "f", the rotation speed of motor 20 reaches a normal value, but the rotation count exceeds the normal value. This is a profile corresponding to abnormal mode "runaway".

[0035] In this way, the profile determination unit 170 can determine the abnormal mode of the on-load tap changer 10 and the electric operation mechanism 1 based on the number of rotations and the rotation speed of the motor 20 acquired from the angle sensor processing unit 160 and the determination table and the speed profile pattern information stored in the storage unit 3. In addition, by using the determination table and the speed profile pattern information, it becomes possible to present the location of the failure and the candidate for the failure content. In the electric operation mechanism 1 of the embodiment, the determination table and the speed profile pattern information are stored in the storage unit 130, and the amount of change in the rotation and the rotation speed of the motor shaft 22 that occurs during the operation of the on-load tap changer 10 is compared with the determination table and the speed profile pattern information to realize the determination of the location of the failure and the candidate for the failure content.

[0036] Fig. 4 shows an example of a speed profile obtained by actually measuring the rotation and rotation speed of the motor shaft 22 during operation of the on-load tap changer 10. As shown in Fig. 4, in normal operation of the motor operating mechanism 1, the motor shaft 22 reaches a predetermined rotation speed within two rotations, and the rotation speed becomes zero when the motor shaft 22 has rotated a predetermined number of times (34 times in the example of Fig. 4).

[0037] On the other hand, when the abnormal mode of the electric operation mechanism 1 is runaway, the rotation speed of the electric shaft 22 becomes zero after the rotation of the electric shaft 22 exceeds a predetermined number of rotations. When the abnormal mode of the electric operation mechanism 1 is speed reduction, the rotation speed of the electric shaft 22 does not reach the rotation speed during normal operation. When the abnormal mode of the electric operation mechanism 1 is unresponsive, the rotation of the electric shaft 22 is zero or stops after a few rotations. When the abnormal mode of the electric operation mechanism 1 is stop 1 or stop 2, the rotation speed of the electric shaft 22 drops sharply (stop 1) or drops gradually (stop 2) before the rotation of the electric shaft 22 reaches a predetermined number of rotations.

[0038] The speed profile pattern information is stored in advance in the storage unit 130, but may be updated based on the number of rotations and the rotation speed actually measured while the electric operation mechanism 1 is in operation.

[0039] (Operation of the Electric Operation Mechanism of the Embodiment) The operation of the electric operation mechanism 1 of the embodiment will be described below with reference to Fig. 1 and Fig. 5. A judgment table and speed profile pattern information are stored in advance in the storage unit 130. The control panel 110 receives a switching command from a user (S200). The switching command may be sent by a signal from a higher-level device.

[0040] Upon receiving the switching command, the instruction processing unit 120 calculates the number of rotations of the motor 20 required by the on-load tap changer 10 according to the content of the switching command. Corresponding information may be stored in advance in the storage unit 130, and the instruction processing unit 120 may select the number of rotations by referring to the corresponding information. The instruction processing unit 120 sends a motor control command including the calculated number of rotations to the motor control unit 150. The motor control unit 150 generates a start signal and a stop signal for the motor 20 based on the motor control command to control the motor 20 (S210). When the motor 20 receives a supply of driving power based on the start signal, the motor 20 rotates the motor shaft 22 to supply a driving torque to the on-load tap changer 10.

[0041] When the motor control unit 150 generates a start signal for the motor 20, the counter 140 starts counting the drive control time (S220). This count is used for timeout in the event of a malfunction.

[0042] The angle sensor 30 outputs an electric signal (pulse signal) corresponding to the rotational position of the electric shaft 22 in response to the rotation of the electric shaft 22. The angle sensor processing unit 160 receives the electric signal output by the angle sensor 30, and calculates the number of rotations and the rotation speed of the electric shaft 22 after the motor control unit 150 generates the start signal (S230).

[0043] The profile determination unit 170 records the number of rotations and the rotation speed of the motorized shaft 22 calculated by the angle sensor processing unit 160 in the storage unit 130, and generates actually measured speed profile pattern information (S240).

[0044] The profile determination unit 170 compares the actually measured speed profile pattern information with the prepared speed profile pattern information stored in the storage unit 130 (S250). The parameters to be compared are determined based on a determination table stored in the storage unit 130. For example, the comparison targets may be the number of rotations of the electric shaft 22 corresponding to the abnormal mode "unresponsive", the rotation speed of the electric shaft 22 corresponding to "speed reduction", the rotation speed reduction of the electric shaft 22 corresponding to "mid-stop 1" and "mid-stop 2", and the number of rotations of the electric shaft 22 corresponding to "runaway". The comparison of the speed profile pattern information may be performed by comparing parameters with each other, or by comparing profile patterns as image data with each other.

[0045] If there is no information on the rotation position (No in S250), that is, if the profile determining unit 170 cannot obtain the number of rotations or the rotation speed from the angle sensor processing unit 160, the profile determining unit 170 refers to the count value of the counter 140 and determines whether or not a timeout has occurred (S260). If the timeout has not occurred (No in S260), the profile determining unit 170 continues to receive the number of rotations and the rotation speed and to generate the speed profile pattern information (S240). If the timeout has occurred (Yes in S260), the profile determining unit 170 determines the abnormal mode as "unresponsive" (S270).

[0046] If there is information on the rotational position (Yes in S250), the profile determination unit 170 monitors whether the rotational speed becomes zero after increasing (S280). If the rotational speed becomes zero and the rotation of the motorized shaft 22 stops (Yes in S280), the stop occurs within a reference time (Yes in S290), and the number of rotations required for deceleration is within a predetermined threshold (Yes in S300), the profile determination unit 170 determines that the abnormal mode is "Halt 1" in which the rotational speed drops sharply (S310). On the other hand, if the number of rotations required for deceleration exceeds a predetermined threshold (No in S300), the profile determination unit 170 determines that the abnormal mode is "Halt 2" in which the rotational speed drops gently (S320). Here, the reference time on which the profile determination unit 170 makes a determination may be specified with a certain degree of width.

[0047] If the rotation speed does not become zero and the rotation of the electric shaft 22 does not stop, the motor control unit 150 generates a stop signal and stops the supply of drive power to the motor 20 when the actual number of rotations of the motor 20 received from the angle sensor 30 reaches the number of rotations of the motor 20 specified in the motor control command (S330).

[0048] When the motor 20 stops based on the motor control command (S330) or when the rotation speed becomes zero and the rotation of the electric shaft 22 stops (Yes in S280) and the stoppage exceeds a reference time (No in S290), the profile determination unit 170 determines whether the rotation position of the electric shaft 22 has exceeded a predetermined position, i.e., whether the rotation of the electric shaft 22 has exceeded a predetermined number of rotations (S340). When the rotation of the electric shaft 22 has exceeded the predetermined number of rotations (Yes in S340), the profile determination unit 170 determines the abnormal mode as "runaway" (S350).

[0049] If the rotation of the motorized shaft 22 does not exceed the predetermined number of rotations (No in S340), the profile determination unit 170 stops the counting operation of the counter 140 and determines whether the steady-state value of the rotation speed of the motorized shaft 22 is within a predetermined threshold value (S370). If the steady-state value of the rotation speed is equal to or less than the threshold value (Yes in S370), the profile determination unit 170 determines the abnormal mode as a "speed drop" in which the specified speed is not reached (S390).

[0050] If the steady-state value of the rotation speed exceeds the predetermined threshold value (No in S370), the profile determination unit 170 determines that the on-load tap changer 10 has been switched normally (S380). The result of the determination is provided to the user through the control panel 110 and is recorded in the memory unit 130.

[0051] When the profile determination unit 170 determines an abnormal mode (S270, S310, S320, S350, S360), the profile determination unit 170 provides the predicted fault location and fault content to the user through the control panel 110 based on the type of abnormal mode and the contents of the determination table stored in the memory unit 130, and records the same in the memory unit 130 (S400).

[0052] (Correction of speed profile pattern information) The speed profile pattern information stored in the memory unit 130 specifies basic information of the abnormal mode, but the operating load conditions may differ depending on individual differences in the equipment and the type of on-load tap changer 10. In such cases, it becomes difficult to accurately determine the abnormal mode.

[0053] Therefore, the on-load tap changer 10 and the motorized operating mechanism 1 are set in an operable state, and then the on-load tap changer 10 and the motorized operating mechanism 1 are operated multiple times. As a result, the profile determining unit 170 records the acquired number of rotations and rotation speed in the storage unit 130, and calculates the average value of the maximum rotation speed from the record and adds it to the speed profile pattern information as basic information. In the subsequent determination operation by the profile determining unit 170, the ratio to the maximum rotation speed in a normal operating state is multiplied as a parameter, thereby making it possible to correct threshold values ​​of the rotation speed of the speed reduction and the number of reduced rotations included in the speed profile pattern information. Such corrections may be performed when the on-load tap changer 10 and the motorized operating mechanism 1 are not operating, or may be performed by the profile determining unit 170 at any time during operation.

[0054] (Reuse of speed profile pattern information) The profile determination unit 170 periodically records the speed profile, and by combining the measured speed profile with the time series information at the time of measurement, it is possible to extrapolate and estimate the transition in the rotation speed, thereby calculating the number of years until a speed drop occurs due to an increase in load caused by aging. The calculated result can be output via the control panel 110.

[0055] In this way, the electric operation mechanism of the embodiment is capable of detecting multiple abnormalities compared to the conventional fault point determination device, and the labor required for fault determination can be reduced. Also, the basic configuration of the electric operation mechanism makes it possible to detect the fault mode of the on-load tap changer without adding devices such as an ammeter, torque meter, or voltmeter, which allows for cost and labor savings and sophistication in maintenance. Furthermore, it is possible to automatically determine the fault mode from a speed profile consisting of the number of rotations and the rotation speed of the motor's electric shaft, so the cause of the fault can be determined at an earlier stage than with the conventional configuration.

[0056] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0057] 1...electric operation mechanism, 10...on-load tap changer, 20...motor, 22...electric shaft, 30...angle sensor, 100...electric operation device, 110...control panel, 120...instruction processing unit, 130...memory unit, 140...counter, 150...motor control unit, 160...angle sensor processing unit, 170...profile determination unit 170.

Claims

1. An electric operating device for controlling an electric operating mechanism having a motor that drives an on-load tap changer that can change a tap provided in a stationary induction electric appliance, a calculation unit that acquires a rotational position of the motor in a rotational direction and calculates a number of rotations and a rotational speed of the motor; a determination unit that determines an abnormality mode indicating an abnormality in the on-load tap changer and the electric operation mechanism based on the calculated changes in the number of rotations and the rotation speed of the motor; An electrically operated operating device comprising:

2. A storage unit stores profile pattern information indicating a relationship between the number of rotations and the rotation speed of the motor during operation of the on-load tap changer, and a judgment table correlating amounts of change in the number of rotations and the rotation speed of the motor during the operation in the profile pattern information with the abnormal mode in each of the on-load tap changer and the electric operation mechanism, the determination unit determines abnormalities in the on-load tap changer and the motor operation mechanism based on the number of rotations and the rotation speed of the motor calculated by the calculation unit, and the profile pattern information and the determination table stored in the storage unit; 2. The electric operating device according to claim 1,

3. 3. The electric operating device according to claim 2, wherein the judgment table includes information correlating the amount of rotational displacement of the motor, the value of the rotational speed of the motor and the amount of change therein with a fault location and a fault mode characterized by these.

4. 3. The electric operating device according to claim 2, wherein the determination unit generates a speed profile pattern in which an amount of change in rotational speed for each rotation of the motor is recorded from the start of rotation of the motor to the end of rotation, and determines the abnormality mode, which indicates an abnormality in the on-load tap changer and the electric operating mechanism, by comparing the generated speed profile pattern with the profile pattern information stored in the memory unit.

5. 5. The electric operating device according to claim 4, wherein the determination unit identifies a fault location and a fault mode in the on-load tap changer and the electric operating mechanism from the abnormal mode based on the determination table.

6. 6. The electric operating device according to claim 4, wherein the determination unit updates the speed profile pattern using the number of rotations and the rotation speed of the motor calculated by the calculation unit.

7. The electric operating device according to claim 4, characterized in that the determination unit stores a plurality of the calculated speed profile patterns in the memory unit, compares the calculated plurality of speed profile patterns in a chronological order, and estimates a recommended maintenance timing.

8. An electric operation mechanism for controlling an on-load tap changer capable of switching a tap provided in a stationary induction electric appliance, a motor for driving the on-load tap changer; an angle sensor coupled to the motor to detect a rotational position of the motor in a rotational direction; a calculation unit that acquires a rotational position in a rotational direction of the motor detected by the angle sensor and calculates a number of rotations and a rotational speed of the motor; a determination unit that determines an abnormality mode indicating an abnormality in the on-load tap changer and the electric operation mechanism based on the calculated changes in the number of rotations and the rotation speed of the motor; An electrically operated mechanism equipped with

9. An electric operation mechanism including a motor that drives an on-load tap changer that is capable of switching a tap provided in a stationary induction electric appliance and an angle sensor that detects a rotational position in a rotational direction of the motor, and a method for determining a fault in the on-load tap changer, comprising: acquiring a rotational position of the motor in a rotational direction from the angle sensor; Calculating the number of rotations and the rotation speed of the motor based on the acquired rotation position; Determining the content of an abnormality in the on-load tap changer and the electric operation mechanism based on the calculated changes in the number of rotations and the rotation speed of the motor. A failure determination method comprising the steps of:

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