CN112136195B

CN112136195B - Electric operating device for tap changer and tap changing method

Info

Publication number: CN112136195B
Application number: CN201880093559.XA
Authority: CN
Inventors: 富冈和美; 石川拓; 江口直纪
Original assignee: Toshiba Corp; Toshiba Energy Systems and Solutions Corp
Current assignee: Toshiba Corp; Toshiba Energy Systems and Solutions Corp
Priority date: 2018-06-19
Filing date: 2018-06-19
Publication date: 2023-06-09
Anticipated expiration: 2038-06-19
Also published as: JPWO2019244235A1; EP3813086A1; JP6961821B2; CN112136195A; WO2019244235A1; EP3813086A4

Abstract

The electric operating device for a tap changer according to the embodiment includes a driving unit, a multi-turn rotary encoder, a monitoring unit, and a control unit. The driving unit drives the drive shaft by a motor to switch the tap of the tap changer. The multi-turn rotary encoder has a member that rotates n times with respect to the drive shaft, and detects the rotational position of the drive shaft by detecting the rotational position of the member. A monitoring unit monitors the state of the tap changer based on the rotational position detected by the multi-turn rotary encoder. The control unit controls the driving unit based on a monitoring result of the monitoring unit.

Description

Electric operating device for tap changer and tap changing method

Technical Field

The embodiment of the invention relates to an electric operation device for a tap changer and a tap changing method.

Background

Conventionally, an electrically operated device for switching the tap position of a tap changer when a load is placed on a transformer is known. The electric operating device rotates a drive shaft coupled to a gear by a motor driving unit as power, thereby switching the tap position. The operation control of the motor driving unit is performed by a step control mechanism constituted by a relay sequence circuit based on a motor shutter that performs opening and closing operations of a circuit, by an on/off signal of a cam switch connected to a drive shaft by a gear. The electric operating device further includes a dial switch coupled to the drive shaft by a gear. The dial switch outputs a tap position signal based on the rotational position of the drive shaft.

However, since the conventional electric operating device is configured mechanically by the structure such as the stepping control mechanism and the dial switch as described above, the number of components is large, and time is required for assembly and maintenance. In addition, during assembly or maintenance, a person familiar with the construction of the mechanism is required to perform the work, and repair and maintenance may not be easily performed due to a lack of workability during maintenance. Conventionally, the position information of the tap can be obtained by a dial switch, but this signal is used to grasp the limit (limit value) of the tap and is not effectively used for controlling the operation of the electric operation device.

Prior art literature:

patent literature:

patent document 1 Japanese patent laid-open No. 54-129367

Patent document 2 Japanese patent application laid-open No. 2010-502170

Disclosure of Invention

Problems to be solved by the invention

The invention provides an electric operating device for tap changer and a tap changing method, which can simplify adjustment during assembly of the electric operating device and can realize easy maintenance.

Means for solving the problems

Drawings

Fig. 1 is a diagram showing a configuration example of an electric operating device for a tap changer according to an embodiment.

Fig. 2 is a diagram showing an example of the component configuration of the motor 20 according to the embodiment.

Fig. 3 is a diagram showing the structure of the tap changer electric operating device shown in fig. 1 from the viewpoint of hardware.

Fig. 4 is a diagram for explaining tap switching control at the time of boosting.

Fig. 5 is a diagram for explaining tap switching control in the case where the boost control is further performed after the boost control.

Fig. 6 is a diagram for explaining tap switching control in the case where step-down control is performed after step-up control.

Fig. 7 is a diagram for explaining tap switching control in the case where step-down control is further performed after step-down control.

Fig. 8 is a diagram for explaining tap switching control at the time of voltage boosting and at the time of voltage dropping using a tap switching control table.

Fig. 9 is a flowchart showing an example of the processing of the tap changer electric operating device according to the embodiment.

Fig. 10 is a flowchart showing an example of the stop control process according to the embodiment.

Fig. 11 is a flowchart showing an example of exception handling at the time of blocking according to the embodiment.

Fig. 12 is a flowchart showing an example of exception handling at the time of runaway in the embodiment.

Detailed Description

Hereinafter, an electric operation device for a tap changer and a tap changing method according to embodiments will be described with reference to the drawings. In the following embodiments, as an example of the tap changer, a load tap changer is used.

Fig. 1 is a diagram showing a configuration example of an electric operating device for a tap changer according to an embodiment. The tap-changer electric operating device 1 includes, for example, a master disk operating unit 10, a motor 20, a multi-turn rotary encoder 30, and an operation control unit 100. The combination of the motor 20 and the motor drive control section 130 is an example of a "drive section".

The upper-panel operation unit 10 outputs a control signal to the operation control unit 100, the control signal being generated by an operation performed by an administrator or the like on an operation unit provided in the upper-panel device. The control signal related to the upper disk operation unit 10 includes, for example, a signal for upper control. The upper control is, for example, tap changing control associated with step-up control and step-down control for the load tap changer LTC.

The motor 20 rotates a rotatable shaft (for example, a drive shaft 21 described later) in a predetermined direction to switch the position of a tap of the tap changer LTC (a connection point along a winding of which a predetermined number of rotations can be selected) at the time of load switching. The motor 20 rotates the active shaft in the opposite direction by, for example, step-up control and step-down control. The electric operating device 1 for tap changer changes the winding ratio of the transformer in which the tap changer LTC is provided by changing the position of the tap changer LTC when the motor 20 changes the load, and adjusts the voltage of the transformer. The component configuration of the motor 20 according to the embodiment will be described in detail later.

The multi-turn rotary encoder 30 is mounted, for example, directly below a drive shaft rotated by driving of the motor 20. The multi-turn rotary encoder 30 has a member that rotates n (n > 0) times with respect to the drive shaft, and detects the rotational position of the drive shaft by detecting the rotational position of the member. The multi-turn rotary encoder 30 outputs the detected rotational position information to the operation control unit 100. The rotation position information is, for example, absolute position information (absolute value) including the rotation angle and the rotation number of the drive shaft at a plurality of rotations. The multi-turn rotary encoder 30 outputs rotational position information in the case where the rotational position of the drive shaft is changed (in the case where the rotational angle is deviated by several degrees).

The operation control unit 100 includes, for example, an operation unit 110, a switching control unit 120, and a motor drive control unit 130. The switching control unit 120 and the motor drive control unit 130 are each realized by executing a program (software) by a hardware processor such as a CPU (Central Processing Unit: central processing unit). Some or all of these components may be realized by hardware (circuit unit; including circuit) such as LSI (Large Scale Integration: large scale integrated circuit), ASIC (Application Specific Integrated Circuit: application specific integrated circuit), FPGA (Field-Programmable Gate Array: field programmable gate array), GPU (Graphics Processing Unit: graphics processing unit), or may be realized by cooperation of software and hardware. The program may be stored in advance in a storage unit (not shown) of the operation control unit 100, or may be stored in a removable storage medium such as a DVD or a CD-ROM, and the storage medium is mounted on the drive device and then mounted on the HDD (Hard Disk Drive) or flash memory of the operation control unit 100.

The operation unit 110 outputs the operation content of the manual operation by the user to the switching control unit 120. The manual operation is performed by, for example, a signal obtained by manually operating an operation button, which is provided as the operation unit 110 in advance, for instructing the voltage of the transformer to be increased or decreased, and controlling the voltage increasing operation and the voltage decreasing operation.

The switching control unit 120 includes, for example, an operation receiving unit 122, a monitoring unit 124, a command control unit 126, and an output unit 128. The command control unit is an example of a "control unit". The operation receiving unit 122 receives a control signal for instructing the tap change by the step-up or step-down of the load tap changer LTC from the operation unit 110 or the upper panel operation unit 10.

The monitoring unit 124 monitors the state of the tap changer LTC at the time of loading based on the rotational position information detected by the multi-turn rotary encoder 30. Specifically, the monitoring unit 124 monitors the state of the tap changer LTC at the time of loading based on the position and state of the motor 20 acquired based on the rotational position information. The position of the motor 20 includes, for example, the rotation angle and the rotation number of the drive shaft rotated by the motor 20. The monitoring unit 124 derives the position of the tap changer LTC at the time of loading based on the rotation angle and the rotation number. The monitoring unit 124 monitors the state (normal state or abnormal state) of the tap changer LTC at the time of loading based on the state of the motor 20 itself (for example, the state of whether the motor 20 is being driven in accordance with an instruction from the instruction control unit 126). Here, the abnormal state of the tap changer LTC at the time of load refers to, for example, a blocking state or a runaway state. The blocking state is, for example, a state in which the motor 20 is not rotated for a predetermined time after the rotation control command is output, or a state in which the time from the start of the operation of the motor 20 to the tap switching exceeds a predetermined time. The out-of-control state refers to, for example, a state in which the driving of the motor 20 is continued even though the stop control command is output to the motor 20 based on the end of the switching of the tap changer LTC at the time of the load. The monitor 124 stores and manages rotation position information obtained from the multi-turn rotary encoder 30 in a predetermined register by a counter value such as a binary counter.

The command control unit 126 outputs a command signal for controlling the rotation or stop of the motor 20 to the motor drive control unit 130 based on the control information received by the operation receiving unit 122.

The output unit 128 outputs a state of control of the operation control unit 100 (for example, a monitoring result of the monitoring unit 124), and the like. For example, the output unit 128 outputs a control signal such as an in-operation signal as a signal for upper notification to the upper disk operation unit 10 at a predetermined timing. The in-operation signal is, for example, a signal expressed as 1 when the motor 20 is in operation and expressed as 0 when the motor 20 is stopped. The output unit 128 includes, for example, a light emitting unit (for example, LED (Light Emitting Diode)) for notifying the processing state, and a display device for displaying an image. For example, when an error or an abnormality occurs in the tap switching control, the output unit 128 turns on the LED for detecting an abnormality or causes the display device to display that an abnormality has occurred.

Upon receiving the rotation control signal from the switching control unit 120, the motor drive control unit 130 rotates the motor 20 in a predetermined direction, and performs tap switching by the step control. Further, when receiving a signal for stopping control from the switching control unit 120, the motor drive control unit 130 executes drive control for stopping the rotation of the motor 20.

Next, the component configuration of the motor 20 in the embodiment will be described. Fig. 2 is a diagram showing an example of the component configuration of the motor 20 according to the embodiment. The motor 20 shown in fig. 2 includes, for example, a drive shaft 21, a motor-side pulley 22, a drive shaft-side pulley 23, a tension pulley 24, a timing belt (timing belt) 25, a bevel gear 26, a handle shaft 27, and a handle interlock 28. In addition, in the example of fig. 2, a multi-turn rotary encoder 30 is also shown.

The motor 20 is provided with a motor-side pulley 22 mounted on a rotation shaft, and is coupled to a drive shaft-side pulley 23 via a timing belt 25. The drive shaft 21 is attached to the drive shaft side pulley 23, and the multi-turn rotary encoder 30 is directly attached directly below the drive shaft 21 without via a reduction mechanism or the like. By attaching the multi-turn rotary encoder 30 to the drive shaft 21 as in the configuration of fig. 2, the rotational position information of the drive shaft 21 can be detected more accurately.

The tension pulley 24 also applies tension to the timing belt 25, thereby improving the interlocking performance of the motor 20 and the drive shaft 21. The drive shaft 21 is coupled to a handle shaft 27 by a bevel gear 26. A handle interlock 28 is attached to the handle shaft 27. For example, in the case where an operator manually switches the tap using a handle at the time of maintenance or the like, the handle interlock 28 is restricted so as not to perform an operation under electric power.

Fig. 3 is a diagram showing the structure of the tap changer electric operating device shown in fig. 1 from the viewpoint of hardware. In the example of fig. 3, the tap-changer electric operation device 1 includes a motor 20, a multi-turn rotary encoder 30, a power receiving unit 200, an NFB (No Fuse Breaker) 210, a motor switch 220, a power switching unit 230, an in-panel operation switch 240, a trip relay 250, a control board 260, a display device 270, and a host board 280. Here, the in-disc operation switch 240 corresponds to the operation unit 110, and the upper substrate 280 corresponds to the upper disc operation unit 10. The control board 260 corresponds to the operation control unit 100.

The power supply (for example, three-phase ac 210 v) supplied to the motor 20 is output to the motor shutter 220 via the NFB210, which is a circuit breaker for wiring, through the power receiving unit 200, and is supplied to the motor 20.

The in-disc operation switch 240 further includes a step-up switch for causing the control board 260 to execute processing based on step-up control, a step-down switch for executing step-down control, and an execution switch for executing stop control. The in-disc operation switch 240 may include a remote switch for remotely controlling the step-up, step-down, or stop.

Control signals (for example, step-up control or step-down control) from the in-disc operation switch 240 and the upper substrate 280 are input to the control substrate 260. The control board 260 is triggered by the input control signal to operate the motor shutter 220, thereby performing control of the rotation in the step-up direction, the rotation in the step-down direction, the brake for stopping the rotation, and the like of the motor 20.

The trip relay 250 is a circuit that receives an instruction from the control board 260 to trip (power off) the NFB210 when the control board 260 senses a runaway state. In addition, in the case where the stop switch is pressed by the in-disc operation switch 240, the trip relay 250 trips the NFB 210. By the power cut-off control by the trip relay 250, damage to the transformer due to the runaway can be avoided, for example.

The power conversion unit 230 converts the power supplied from the power receiving unit 200 via the NFB210 into a dc voltage 24 v used for the control board 260. The electric operating device 1 for a tap changer according to the embodiment does not have a mechanical structure such as a stepping control mechanism and a dial switch, but controls the motor 20 by electronic control based on information detected by the multi-turn rotary encoder 30, so that the control current to the motor shutter 220 can be made small. In addition, the motor shutter 220 can be reduced in size and capacity.

In addition, when the power supply is cut off due to a power failure or the like, the control in the control board 260 is no longer possible, and therefore, the power conversion unit 230 outputs a command to the trip relay 250 via the control board 260 before the power supply is completely lost. Thus, the trip relay 250 trips the NFB210 based on the instruction, shutting off the motor power.

The control board 260 includes, for example, an FPGA 262. The FPGA 262 performs the functions of the respective configurations of the switching control unit 120 described above, for example. In addition, the control board 260 performs counter control related to tap switching using a binary counter that stores rotation position information detected by the multi-turn rotary encoder 30 in a register. For example, the control board 260 parameterizes setting information including at least one of a switching position, a stop position, a limit value of a tap (for example, an upper limit position of a tap at the time of boosting, a lower limit position of a tap at the time of lowering) or an intermediate tap position of the tap changer LTC at the time of loading based on a binary counter, and stores the parameterized setting information in a register or the like. In addition, the control board 260 monitors the state of the tap changer LTC at the time of loading based on the stored parameters. The control board 260 performs display control on the display device 270 based on the monitoring result or the like.

The display device 270 is, for example, an LCD (Liquid Crystal Display: liquid crystal display), an organic EL (Electro Luminescence: electroluminescence) display device, or the like. The display device 270 displays information input and output through the control board 260, monitoring results, abnormal states, and the like in a predetermined display manner.

Next, tap switching control according to the embodiment will be described. Fig. 4 is a diagram for explaining tap switching control at the time of boosting. Fig. 4 shows a relationship between tap switching at the time of boosting and the number of rotations of the drive shaft 21 obtained from the multi-turn rotary encoder 30. In the following description, the tap of the tap changer LTC is changed over by rotating the driving shaft 21 33 times at the time of loading. Fig. 4 is a schematic diagram showing the standard start position at the tap switching point at the time of boosting at 0 degrees and the standard end position after the switching is completed at 180 degrees.

The operation control unit 100 performs control to rotate the drive shaft 21 from an initial value (standard start position 0[ deg ]) in the first direction at the tap switching at the time of boosting, and performs control to stop rotation at a standard stop position 180[ deg. ] after 33 rotations. However, in practice, during a period from when the control signal for stopping the motor 20 is outputted from the operation control unit 100 until the motor 20 is actually stopped, an overstroke of the double rotation amount is generated from the standard stop position, and the actual stop position is a position that is rotated twice more forward than the standard stop position.

Fig. 5 is a diagram for explaining tap switching control in the case where the boost control is further performed after the boost control. Fig. 5 shows, in an example, a relationship between the tap switching and the number of rotations of the drive shaft 21 obtained from the multi-turn rotary encoder 30 in the case where the boost control is further performed after the boost control of fig. 4. For example, when the step-up control is further performed after the step-up control, the operation control unit 100 rotates the drive shaft 21 in the same direction as the previous one (first direction), and thus switches the tap by rotating the drive shaft 21 33 times based on the position where the motor 20 was stopped last time.

Fig. 6 is a diagram for explaining tap switching control in the case where step-down control is performed after step-up control. In the example of fig. 6, the step-up control shown in fig. 5 is performed and then the step-down control is performed. When the step-up control is switched to the step-down control, the rotation direction of the drive shaft 21 is the opposite direction (second direction) to the first direction. Therefore, if the rotation control is performed regardless of the amount of the over-stroke, there is a possibility that the timing of the stop is deviated, and the tap switching control cannot be performed accurately. Therefore, when switching control from boost to buck, the operation control unit 100 rotates the drive shaft 21 until the number of rotations is the number of rotations obtained by adding the number of rotations caused by the overstroke to 33 rotations required for tap switching.

Specifically, as shown in fig. 6, the operation control unit 100 performs control of adding up to 37 rotations, which is a total of 2 rotations that cancel out the over-stroke amount of the previous step-up control and 2 rotations of the over-stroke caused by the step-down control, to 33 rotations required for switching the tap plus an additional 4 rotations. Although the above-described processing shows the case of switching from the step-up to the step-down, the control of 37 rotations is similarly performed in the case of switching from the step-down to the step-up.

Fig. 7 is a diagram for explaining tap switching control in the case where step-down control is further performed after step-down control. Fig. 7 shows, in an example, a relationship between the tap switching and the number of rotations of the drive shaft 21 obtained from the multi-turn rotary encoder 30 in the case where the step-down control is further performed after the step-down control of fig. 6. For example, when the step-down control is further performed after the step-down control, the operation control unit 100 rotates the drive shaft 21 in the same direction as the previous one (second direction), and thus switches the tap by rotating the drive shaft 21 33 times based on the position where the motor 20 was stopped last time. In this case too, an overstroke of two rotation amounts is generated.

In this way, the operation control unit 100 performs rotation control of 33 times of rotation amounts when rotation control in the same direction as the previous rotation control is performed from the step-up to the step-up or from the step-down to the step-down, and performs control of 37 times of rotation amounts when rotation control in the opposite direction to the previous rotation control is performed from the step-up to the step-down or from the step-down to the step-up. Thus, the operation control unit 100 can realize appropriate tap switching control.

The operation control unit 100 may store tap switching at the time of voltage increase and at the time of voltage decrease and information on the number of rotations in association with each other as a tap switching control table, and may perform rotation control at the time of voltage increase and at the time of voltage decrease based on the tap switching control table.

Fig. 8 is a diagram for explaining tap switching control at the time of voltage boosting and at the time of voltage dropping using a tap switching control table. In fig. 8, T1, T2, …, TN show identification information for identifying the tap after switching and the number of rotations related to tap switching at the time of boosting and at the time of stepping down. In the example of fig. 8, there is shown control of performing 33 rotations in the case of switching taps from step-up to step-up or from step-down to step-down, and rotation control of 37 rotations including 4 rotations of overstroke is performed at timing of changing the operation direction at the time of step-up to step-down or step-down to step-up. In this way, by performing the switching control of the tap position in consideration of the rotation number based on the rotation direction, the control for the overstroke can be realized by the electronic control by the operation control unit 100 without using a mechanical configuration.

In the embodiment, the number of rotations of the drive shaft 21 caused by the actual tap change is made to coincide with the number of rotations detected from the multi-turn rotary encoder 30 by using the multi-turn rotary encoder 30, and thus, it is possible to control the end of the process or the like by obtaining an abnormal state (jam) when the standard stop position is not reached and an abnormal state (runaway) when the standard stop position is exceeded. The blocking state can be grasped from the control time and the stop position, and the runaway state can be grasped from the number of rotations obtained from the multi-turn rotary encoder 30.

Next, a process of the electric operating device for a tap changer according to the embodiment will be described. Fig. 9 is a flowchart showing an example of the processing of the tap changer electric operating device according to the embodiment. In the process of fig. 9, the monitor 124 inputs the encoder signal from the multi-turn rotary encoder 30 (step S100). The output signal of the multi-turn rotary encoder 30 is output as an electrical signal such as a 16-bit (bit) gray code. Therefore, the monitoring unit 124 converts the inputted gray code into an electronic signal such as BCD (Binary Coded Decimal) code which can be recognized by the operation control unit 100 (step S102).

Next, the monitor 124 divides the converted electric signal into a signal for the rotation angle of one rotation and a signal for the multi-rotation count, and stores the signals in a register. Specifically, the monitor 124 acquires the rotation angle and stores the rotation angle in a 5-bit register (register a) (step S104), and acquires the rotation number and tap position and stores the rotation angle in an 11-bit register (register B) (step S106). The rotation number is, for example, a maximum amount that can be stored for 2048 rotations, but is not limited thereto.

Next, the operation receiving unit 122 receives a step-up instruction or a step-down instruction for the load tap changer LTC by the operation unit 110 or the upper panel operation unit 10 (step S108). Next, the command control unit 126 outputs a rotation control command for driving the motor 20 to the motor drive control unit 130 based on the command content, and drives the motor (step S110). Next, the monitoring unit 124 detects a change in rotational position information from the multi-turn rotary encoder 30 caused by driving of the motor 20 (step S112).

Next, the monitoring unit 124 monitors the time (first time) from outputting the rotation command to the operation of the multi-turn rotary encoder 30 (step S114). Next, the monitoring unit 124 monitors the time (second time) from the operation of the multi-turn rotary encoder 30 to the tap switching (step S116). Next, the monitoring unit 124 determines whether the first time or the second time has elapsed (step S118). The judgment as to whether or not to timeout is made, for example, when the first time exceeds the first threshold Th1 or when the second time exceeds the second threshold Th 2.

When the first time or the second time has not elapsed, the monitoring unit 124 monitors the change in the binary counter at the time of the voltage increase or the voltage decrease (step S120), and determines whether or not the control is normal based on the value of the binary counter that has changed (step S122). For example, in the processing of steps S120 and S122, the monitoring unit 124 monitors whether or not the rotation direction of the motor 20 at the time of the step-up control coincides with the rotation direction of the motor 20 at the time of the step-down control. When the control is abnormal, the output unit 128 outputs error information indicating that the control is abnormal (step S124). In addition, when the control is normal, the monitor 124 executes the stop control process (step S200).

In the process of step S118, if the first time or the second time has elapsed, it is determined that the processing is blocked and the abnormality processing is executed (step S300). This ends the processing of the present flowchart.

Next, the stop control process of step S200 will be described. Fig. 10 is a flowchart showing an example of the stop control process according to the embodiment. In the example of fig. 10, the monitoring unit 124 obtains information on the position where the motor 20 is to be braked by the stop control (step S202). The position to be braked is, for example, a position set at the X-th rotation-angle Y [ degree ] among the number of rotations (for example, 33 rotations) of the actual rotation. This is because, for example, when a stop control signal for stopping the motor 20 is output at a time when the rotation position is the angle 0[ degree ] of the 33 th rotation, the motor 20 rotates by inertia several more times, and thus, braking is performed before the actual stop position is not reached yet. As an example of the value of X, Y, for example, x=31 and y=120. The position to be braked is obtained by the above-described position registers of the register a and the register B.

Next, the monitoring unit 124 determines whether or not the motor 20 is to be braked at a timing (hereinafter referred to as a braking timing) based on the information on the position where the braking is to be performed (step S204). If the braking timing is not set, the monitoring unit 124 calculates the position of the next stop (step S206). In the process of step S206, the position register to be stopped next is calculated based on the values of the register a and the register B. Specifically, when the current step-up control is performed and the next step-up control is performed, +33 is added to the current position register corresponding to the rotation number, and when the current step-down control is performed and the next step-up control is performed, +37 is added to the current position register. In addition, when the current step-down is performed and the next step-down is performed, a value of-33 is added to the current position register, and when the current step-up is performed and the next step-down is performed, a value of-37 is added to the current position register.

Next, the monitoring unit 124 determines whether or not the motor 20 has stopped (step S208). When the motor is stopped, the output unit 128 notifies the outside of the stopped state (step S210), and ends the movement of one tap amount (step S212). In the process of step S204, when the braking timing is set, the command control unit 126 outputs a stop control command to the motor drive control unit 130 (step S216). Next, the monitoring unit 124 starts a stop timer (step S218).

After the process of step S218 is completed or when the motor 20 is not stopped in the process of step S208, the monitoring unit 124 checks the stop timer (step S220). Next, it is determined whether the stop timer has timed out (step S222). The judgment as to whether the stop timer has timed out is made, for example, when the count value (third time) of the stop timer exceeds the third threshold Th 3. If the time-out has elapsed, the monitoring unit 124 determines that the control is out of control and performs an exception process (step S400). In the process of step S222, if it is not time-out, the process returns to the process of step S208. This ends the present flowchart.

Next, the exception handling in the case where the determination is made as blocking will be described using a flowchart. Fig. 11 is a flowchart showing an example of exception handling at the time of blocking according to the embodiment. In the example of fig. 11, the command control unit 126 outputs a stop control command to the motor drive control unit 130 (step S302). Next, the output unit 128 performs an abnormal display indicating the blocking state (step S304). The abnormal display in the process of step S304 may be, for example, a display such as lighting an LED for detecting a blocked abnormal state, or a display indicating a blocked state on the display device 270. This ends the processing of the present flowchart.

Next, an abnormality process in the case where the determination is out of control will be described with reference to a flowchart. Fig. 12 is a flowchart showing an example of exception handling at the time of runaway in the embodiment. In the example of fig. 12, the monitoring unit 124 performs forced tripping in the NFB210 (step S402). Next, the output unit 128 performs an abnormality display indicating a runaway state (step S404). The abnormal display in the process of step S404 may be, for example, a display such as lighting an LED for detecting an abnormal state of the control, or a display indicating a state of the control of the display device 270. This ends the processing of the present flowchart.

According to at least one embodiment described above, the tap-changer electric operating device 1 includes: a motor drive control unit 130 that drives the drive shaft 21 by the motor 20 to switch the tap of the tap changer LTC; a multi-turn rotary encoder 30 having a member that rotates n times with respect to the drive shaft 21, the rotational position of the drive shaft 21 being detected by detecting the rotational position of the member; a monitoring unit 124 that monitors the state of the tap changer LTC based on the rotational position detected by the multi-turn rotary encoder 30; and a switching control unit 120 that controls the motor drive control unit 130 based on the monitoring result of the monitoring unit 124, thereby simplifying adjustment at the time of assembling the electric operation device and enabling easy maintenance.

Specifically, according to at least one embodiment, the mechanical structure such as the stepping control mechanism and dial switch of the conventional electric operation device is replaced with the electronic control of the multi-turn rotary encoder 30 and the operation control unit 100 capable of acquiring the absolute position information of the multi-turn rotation, so that the number of mechanical components can be reduced, and space saving can be achieved. Further, by directly connecting the multi-turn rotary encoder 30 directly under the drive shaft 21 without a speed reducing mechanism and acquiring the absolute position information outputted to the operation control unit 100, the exact rotation number (corresponding to the tap position and the drive shaft rotation number) and rotation angle of the drive shaft can be grasped more accurately. Thus, according to the present embodiment, it is possible to detect an abnormal state in which the tap is blocked without following, and the control position exceeds the standard and is out of control, or in which the control is stopped in the middle due to the accuracy of stopping, the blocking of the drive shaft, or the like, which is caused by the improvement of the resolution. Further, according to the present embodiment, the rotary position information can be detected with high accuracy by the multi-turn rotary encoder 30, and as a result, the motor stopping accuracy can be improved. Further, according to the present embodiment, the position detection is performed by the multi-turn rotary encoder 30 without passing through the dial switch, and the load of the motor 20 can be reduced, thereby improving the durability.

In the embodiment, for example, the tap switching operation by the operation control unit 100 may be statistically learned, and the automatic adjustment of the braking timing at the time of tap switching and the calculation of the tap switching speed may be performed. As a result, the operation control unit 100 can grasp the failure of the motor 20, the failure state of the tap changer LTC main body at the time of loading, and the like.

While several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other modes, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and their equivalents.

Claims

1. An electrically operated device for a tap changer, comprising:

a driving unit for switching the tap of the tap changer by driving the drive shaft with a motor;

a multi-turn rotary encoder having a member that rotates n times with respect to the drive shaft, the rotational position of the drive shaft being detected by detecting the rotational position of the member;

a monitoring unit configured to monitor a state of the tap changer based on a rotational position detected by the multi-turn rotary encoder;

a control unit that controls the driving unit based on a monitoring result of the monitoring unit; and

a display device for displaying the monitoring result,

the monitoring unit judges whether the tap changer is in an abnormal state based on the rotational position information and time information of the motor detected by the multi-turn rotary encoder, and judges that the tap changer is in a blocking state when a first time from when the control unit outputs a rotational control command of the motor to when the rotational position information detected by the multi-turn rotary encoder changes exceeds a first threshold value or when a second time from when the rotational position information detected by the multi-turn rotary encoder changes to when the tap changer changes exceeds a second threshold value,

the display device displays an abnormality indicating the blocking state.

2. An electrically operated device for a tap changer, comprising:

a display device for displaying the monitoring result,

the monitoring unit determines whether the tap changer is in an abnormal state based on rotational position information and time information of the motor detected by the multi-turn rotary encoder, and determines that the tap changer is in a run-away state when a third time from a start of stop control of the motor output by the control unit to a stop of the motor exceeds a third threshold value,

the display device displays an abnormality indicating the runaway state.

3. The electrically operated device for a tap changer according to claim 1 or 2, wherein,

the monitoring unit monitors, based on rotational position information detected by the multi-turn rotary encoder, setting information including at least one of a switching position, a stop position, a tap limit value, or an intermediate tap position of the tap changer by parameterizing the setting information.

4. A tap-switching method, wherein the tap-switching performs the following steps with an electrically operated device:

the motor driven by the driving part drives the driving shaft, so as to switch the tap of the tap changer,

detecting a rotational position of a member by using a multi-turn rotary encoder having the member rotated n times with respect to the driving shaft, thereby detecting the rotational position of the driving shaft,

based on the rotational position detected by the multi-turn rotary encoder, the state of the tap changer is monitored,

based on the monitoring result, the driving section is controlled by a control section,

the result of the monitoring is displayed in such a way that,

further, with respect to the monitoring of the state of the tap changer, it is determined whether the tap changer is in an abnormal state based on the rotational position information and time information of the motor detected by the multi-turn rotary encoder,

when a first time from when the control unit outputs a rotation control command for the motor to when the rotation position information detected by the multi-turn rotary encoder changes exceeds a first threshold value or when a second time from when the rotation position information detected by the multi-turn rotary encoder changes to when the tap is switched exceeds a second threshold value, the tap changer is determined to be in a blocking state,

and performing abnormal display representing the blocking state.

5. A tap-switching method, wherein the tap-switching performs the following steps with an electrically operated device:

the result of the monitoring is displayed in such a way that,

when a third time from the start of the stop control of the motor output by the control unit to the stop of the motor exceeds a third threshold value, it is determined that the tap changer is in a runaway state,

and performing abnormal display for representing the out-of-control state.