Medium-voltage circuit breaker full-automatic commissioning method based on online insulation monitoring

Abstract

The invention belongs to the technical field of electrics, and particularly relates to a medium-voltage circuit breaker full-automatic commissioning method based on online insulation monitoring. The on-line insulation monitoring device receives a command from the master control system and feeds back a measurement result to the master control system, the circuit breaker trolley electric chassis device is arranged in a circuit breaker trolley chamber, and the circuit breaker trolley electric chassis device automatically pushes a trolley into and withdraws to a specified position after receiving a push-in and withdraw command of the master control system. The electric grounding knife switch automatically switches on or switches off the electric grounding knife switch after receiving a switching-on / switching-off command of the master control system, and feeds back switching-on / switching-off position information to the master control system, and the master control system is internally provided with a full-automatic input program, sends a command and receives feedback information. According to the invention, full-automatic commissioning of the circuit breaker is realized in a real sense, labor investment and human errors are reduced, investment time is shortened, and working efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrical complete distribution equipment, and particularly relates to a full-automatic commissioning method for medium-voltage circuit breakers based on on-line insulation monitoring. Background Art

[0002] The 3 - 35 kV medium-voltage switchgear is a switching device used in medium-voltage power distribution systems and is widely applied in power plants, substations, manufacturing industries, commercial, residential, and public facilities.

[0003] In the power system industry, when a medium-voltage circuit breaker supplies power to a load, generally there are many steps, mainly manual operations, which can be called manual commissioning. Taking the commissioning of a switchgear after maintenance in a power plant as an example, there are the following steps (flow chart see Figure 1 ): The main control operator issues an order for insulation measurement. The on-site operator goes to the switchgear site to open the grounding knife, measures the insulation of the load with a megohmmeter, closes the grounding knife after the measurement, and reports to the main control operator. After the main control operator determines that the insulation of the load is qualified, he orders the on-site operator to put the circuit breaker into the hot standby position. The on-site operator, in accordance with the operating regulations on site, opens the grounding knife, pushes the circuit breaker trolley into the working position, and supplies the control power. In this way, the circuit breaker is operated to the hot standby position and reports that the main control operation is completed. The main control operator presses the closing button on the control panel, the circuit breaker closes, and the load gets power and operates. Such operations involve multiple communications up and down and the execution of operations according to regulations. If the communication is not smooth or the regulations are not strictly implemented, human factor accidents are very likely to occur; the operation time is relatively long, and the operation of the load may be delayed in case of emergency; a relatively large amount of manpower is required, which is not conducive to the general trend of reducing labor costs.

[0004] In recent years, with the improvement of the intelligence of switchgear equipment, the opening and closing of the grounding knife in the switchgear and the pushing and pulling of the circuit breaker trolley have been automated. As long as the circuit breaker trolley is placed in the automatic position, the commissioning of the circuit breaker can be pre-set with a program and completed with a single key operation on the main control. This method can be called automatic commissioning. Still taking the above power supply as an example, the steps are (flow chart see Figure 2 ): The main control operator issues an order for insulation measurement. The on-site operator goes to the switchgear site to open the grounding knife, measures the insulation of the load with a megohmmeter, closes the grounding knife after the measurement, and reports to the main control operator. After the main control operator determines that the insulation of the load is qualified, he orders the on-site operator to put the circuit breaker trolley into the automatic position and supply the control power. The main control operator presses the one-key commissioning button, and according to the pre-set program, automatically opens the grounding knife, automatically pushes the trolley into the working position, and automatically closes the circuit breaker, enabling the load to get power and operate.

[0005] Compared to the first manual connection method, automatic connection eliminates some manual operation steps, reduces the workload of on-site operators, lowers the possibility of human error, and shortens the operation time. However, no matter how it is operated, the preceding manual insulation measurement step is always required, which greatly reduces the effectiveness of automatic connection and makes it impossible to achieve truly fully automatic connection. Summary of the Invention

[0006] The purpose of this invention is to provide a fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring. Utilizing existing electrical equipment, it achieves automatic measurement and judgment of load insulation, thereby automating the entire process from load insulation measurement to circuit breaker closing with a single click. This enables truly fully automatic commissioning of the circuit breaker, reducing manual labor, human error, and commissioning time, and improving work efficiency. Especially given the current trend of enterprises advocating for reduced manpower and fewer or no staff on duty, this method is particularly suitable for enterprises' cost reduction and efficiency improvement strategies.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring is disclosed. The online insulation monitoring device is installed in the cable compartment and has a communication interface to receive commands from the central control system and to provide feedback on measurement results. An electric chassis device for the circuit breaker trolley is installed in the circuit breaker trolley compartment. Upon receiving push-in and pull-out commands from the central control system, the electric chassis device automatically pushes the trolley in and out to the designated positions and provides feedback on the reached positions to the central control system. An electric grounding switch is installed in the cable compartment. Upon receiving closing / opening commands from the central control system, the electric grounding switch automatically closes or opens and provides feedback on the closing / opening position to the central control system. The central control system has a built-in fully automatic commissioning program that issues commands and receives feedback information.

[0009] One end of the online insulation monitoring device is connected to any load outlet in the cable room, and the other end is grounded.

[0010] The online insulation monitoring device consists of an isolation module, a current-limiting resistor, a DC power supply, and a sampling resistor. When the load is energized, the isolation module isolates the medium-voltage circuit from the measurement circuit and ensures effective isolation through a lockout circuit. When the load is de-energized, the isolation module receives a measurement command and turns on, forming a circuit with the load through its built-in DC measurement circuit. The insulation resistance of the load is calculated by measuring the voltage and current across the sampling resistor.

[0011] The circuit breaker trolley is installed in the circuit breaker trolley compartment. The circuit breaker automatically receives the opening / closing command from the main control system and feeds back the opening / closing signal. An electric chassis and sensors are installed at the bottom of the circuit breaker trolley. The chassis receives the trolley push-in / remove command from the main control system, automatically pushes the trolley in / remove to the designated position, and feeds back the trolley position information to the main control system.

[0012] One end of the electric grounding switch is connected to the indoor load line of the cable, and the other end is grounded.

[0013] The live / no-energized display device is installed in the relay instrument room. It obtains signals from the cable room and sends the energized / no-energized signal of the load to the main control system.

[0014] The overall control system enables fully automatic commissioning of the circuit breaker with a single button. It includes a main control unit, a circuit breaker control unit, a circuit breaker trolley electric chassis control unit, an online insulation monitoring device control unit, an electric grounding switch control unit, and a live display device control unit. The main control unit has a built-in fully automatic commissioning program, issues commands, and receives feedback information. The circuit breaker control unit receives the circuit breaker opening and closing commands from the main control unit and feeds back the circuit breaker opening and closing signals. The circuit breaker trolley electric chassis control unit receives the push-in and pull-out commands from the main control unit and feeds back the position information of the circuit breaker trolley. The online insulation monitoring device control unit receives the insulation measurement commands from the main control unit and feeds back the measurement data. The electric grounding switch control unit receives the closing and opening control commands from the main control unit and feeds back the switch position information. The live display device control unit sends signals to the main control unit indicating whether the load is energized or de-energized.

[0015] The control unit of the circuit breaker trolley electric chassis is equipped with interlocking logic: the trolley can only be pushed in after the online insulation monitoring device control unit reports that the insulation value is qualified and the electric grounding switch control unit reports that the position is open.

[0016] The control unit of the online insulation monitoring device is equipped with a lockout logic: insulation measurement is only allowed after the control unit of the live display device sends a load de-energization signal.

[0017] Initial state: The circuit breaker trolley is in the automatic position, and the grounding switch is in the closed position. The operator in the control room presses the one-button start button. The system automatically confirms that the circuit breaker trolley is in the automatic position; if the position is incorrect, an alarm is triggered. It then automatically confirms that the grounding switch is in the closed position; if the position is incorrect, an alarm is triggered. The system automatically issues a grounding switch opening command, and the grounding switch opens. The system automatically confirms that the grounding switch is in the open position; if the position is incorrect, an alarm is triggered. The system automatically confirms that the load is de-energized; if energized, an alarm is triggered. The system automatically issues a load insulation measurement command, and insulation measurement begins. The system automatically judges whether the insulation value is qualified; if it is not qualified, an alarm is triggered. The system automatically issues a command to push the trolley into the working position, and the trolley is pushed into the working position. The system automatically confirms that the trolley is in the working position; if the position is incorrect, an alarm is triggered. The system automatically issues a circuit breaker closing command, and the circuit breaker closes. The system automatically confirms that the circuit breaker is closed; otherwise, an alarm is triggered, and the process ends.

[0018] The beneficial effects achieved by this invention are as follows:

[0019] This invention, based on existing online insulation monitoring devices, circuit breaker electric chassis, electric grounding switches, and live display devices, establishes a fully automatic commissioning control system, enabling one-button start-up and fully automatic commissioning of medium-voltage circuit breakers. This reduces manual input, human error, and commissioning time, thereby improving work efficiency. Attached Figure Description

[0020] Figure 1 A flowchart for manually putting switchgear into operation after maintenance of a power plant;

[0021] Figure 2 A flowchart for the automatic commissioning of switchgear after maintenance of a power plant;

[0022] Figure 3 This is a schematic diagram of the structure of the present invention;

[0023] Figure 4 This is a basic schematic diagram of the online insulation monitoring device of the present invention;

[0024] Figure 5 This is a topology diagram of the fully automatic circuit breaker control system of the present invention;

[0025] Figure 6 This is a flowchart of the fully automated commissioning process of the present invention;

[0026] In the diagram: 101. Busbar compartment; 201. Circuit breaker trolley compartment; 301. Cable compartment; 401. Relay instrument compartment; 1. Circuit breaker trolley; 1-1 Circuit breaker trolley electric chassis; 2. Online insulation monitoring device; 3. Electric grounding switch; 4. Live display device. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0028] A fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring includes technical upgrades to existing medium-voltage switchgear, including the installation of an online insulation monitoring device, an electric chassis for the circuit breaker trolley, an electric grounding switch, and a central control system. The online insulation monitoring device (commonly available products) is installed in the cable compartment. This device has a communication interface to receive commands from the central control system and provide feedback on measurement results. The electric chassis for the circuit breaker trolley (commonly available products) is installed in the circuit breaker trolley compartment. Upon receiving push-in and pull-out commands from the central control system, this mechanism automatically pushes the trolley in and out to designated positions and provides feedback on the reached position to the central control system. The electric grounding switch (commonly available products) is installed in the cable compartment. Upon receiving closing / opening commands from the central control system, this mechanism automatically closes or opens the grounding switch and provides feedback on the closing / opening position to the central control system. The central control system has a built-in fully automatic commissioning program that can communicate with other modules, issuing commands and receiving feedback information.

[0029] This embodiment describes a fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring. It includes a busbar compartment 101, a circuit breaker trolley compartment 201, a cable compartment 301, a relay instrument compartment 401, a circuit breaker trolley 1, an electric chassis 1-1 for the circuit breaker trolley, an online insulation monitoring device 2, an electric grounding switch 3, and a live display device 4. The online insulation monitoring device 2 is installed in the cable compartment 301, with one end connected to any phase of the load output line and the other end grounded. The online insulation monitoring device 2 has a communication interface, receiving measurement commands from the main control system and outputting measurement results back to the main control system. The online insulation monitoring device 2 consists of an isolation module, a current-limiting resistor, a DC power supply, and a sampling resistor. Working principle: When the load is energized, the isolation module isolates the medium-voltage circuit from the measurement circuit, and a locking circuit ensures effective isolation when the load is energized. When the load is de-energized, the isolation module receives a measurement command and conducts, forming a circuit with the load through its built-in DC measurement circuit. The insulation resistance of the load is calculated using the voltage and current across the sampling resistor. The circuit breaker trolley 1 is installed in the circuit breaker trolley compartment 201. The circuit breaker can automatically receive opening / closing commands from the main control system and feed back opening / closing signals. Furthermore, an electric chassis 1-1 and some sensors are installed at the bottom of the circuit breaker trolley. Upon receiving the trolley's push-in / retract command from the main control system, it can automatically push the trolley in / out to a designated position and feed back the trolley's position information to the main control system. The electric grounding switch 3 is installed in the cable compartment 301, with one end connected to the indoor load outgoing line and the other end grounded. Furthermore, the device has a communication interface. Upon receiving the opening / closing command from the main control system, it can automatically close / open the grounding switch and feed back the closing and opening position information to the main control system. The live display device 4 is installed in the relay instrument compartment 401. It receives signals from the cable compartment and sends the load energized / de-energized signal to the main control system.

[0030] The main control system enables fully automatic one-button operation of circuit breakers. It comprises a main control unit, circuit breaker 1 control unit, circuit breaker trolley electric chassis 1-1 control unit, online insulation monitoring device 2 control unit, electric grounding switch 3 control unit, and live display device 4 control unit. The main control unit has a built-in fully automatic activation program, communicates with other control units, issues commands, and receives feedback information. Circuit breaker 1 control unit receives circuit breaker opening and closing commands from the main control unit and provides feedback on these signals. Circuit breaker trolley electric chassis 1-1 control unit receives push-in and pull-out commands from the main control unit and provides feedback on the trolley's position. Online insulation monitoring device 2 control unit receives insulation measurement commands from the main control unit and provides feedback on the measurement data. Electric grounding switch 3 control unit receives closing and opening control commands from the main control unit and provides feedback on the switch's position. Live display device 4 control unit sends signals indicating whether the load is energized or de-energized to the main control unit. The control unit of the circuit breaker trolley electric chassis 1-1 is equipped with a lockout logic: the trolley can only be pushed in after the online insulation monitoring device 2 control unit reports that the insulation value is qualified and the electric grounding switch 3 control unit reports that the position is open. The control unit of the online insulation monitoring device 2 is equipped with a lockout logic: insulation measurement can only be allowed after the live display device 4 control unit sends a load de-energization signal.

[0031] The operating procedure of this device is as follows: Initial state: The circuit breaker trolley is in the automatic position, the grounding switch is in the closed position, and the control power is on. The operator in the control room presses the one-button start button. The system automatically confirms that the circuit breaker trolley is in the automatic position; if the position is incorrect, an alarm is triggered. It then automatically confirms that the grounding switch is in the closed position; if the position is incorrect, an alarm is triggered. The system automatically issues a grounding switch opening command, and the grounding switch opens. It then automatically confirms that the grounding switch is in the open position; if the position is incorrect, an alarm is triggered. The system automatically confirms that the load is de-energized; if energized, an alarm is triggered. It then automatically issues a load insulation measurement command, begins insulation measurement, and automatically determines whether the insulation value is qualified; if it is unqualified, an alarm is triggered. The system automatically issues a command to push the trolley into the working position, and the trolley is pushed into the working position. The system automatically confirms that the trolley is in the working position; if the position is incorrect, an alarm is triggered. The system automatically issues a circuit breaker closing command, and the circuit breaker closes. The system automatically confirms that the circuit breaker is closed; otherwise, an alarm is triggered, and the process ends.

Claims

1. A fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring, characterized in that: The online insulation monitoring device is installed in the cable room. It has a communication interface to receive commands from the main control system and to send measurement results back to the main control system. The circuit breaker trolley electric chassis device is installed in the circuit breaker trolley compartment. After receiving push-in and pull-out commands from the main control system, the electric chassis device automatically pushes the trolley in and out to the designated position and sends the position information back to the main control system. The electric grounding switch is installed in the cable room. After receiving closing / opening commands from the main control system, the electric grounding switch automatically closes or opens and sends the closing / opening position information back to the main control system. The main control system has a built-in fully automatic activation program that issues commands and receives feedback information.

2. The fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring according to claim 1, characterized in that: One end of the online insulation monitoring device is connected to any load outlet in the cable room, and the other end is grounded.

3. The fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring according to claim 1, characterized in that: The online insulation monitoring device consists of an isolation module, a current-limiting resistor, a DC power supply, and a sampling resistor. When the load is energized, the isolation module isolates the medium-voltage circuit from the measurement circuit and ensures effective isolation through a lockout circuit. When the load is de-energized, the isolation module receives a measurement command and turns on, forming a circuit with the load through its built-in DC measurement circuit. The insulation resistance of the load is calculated by measuring the voltage and current across the sampling resistor.

4. The fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring according to claim 1, characterized in that: The circuit breaker trolley is installed in the circuit breaker trolley compartment. The circuit breaker automatically receives the opening / closing command from the main control system and feeds back the opening / closing signal. An electric chassis and sensors are installed at the bottom of the circuit breaker trolley. The chassis receives the trolley push-in / remove command from the main control system, automatically pushes the trolley in / remove to the designated position, and feeds back the trolley position information to the main control system.

5. The fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring according to claim 1, characterized in that: One end of the electric grounding switch is connected to the indoor load line of the cable, and the other end is grounded.

6. The fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring according to claim 1, characterized in that: The live / no-energized display device is installed in the relay instrument room. It receives signals from the cable room and sends the energized / no-energized signal of the load to the main control system.

7. The fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring according to claim 6, characterized in that: The overall control system enables fully automatic commissioning of the circuit breaker with a single button. It includes a main control unit, a circuit breaker control unit, a circuit breaker trolley electric chassis control unit, an online insulation monitoring device control unit, an electric grounding switch control unit, and a live display device control unit. The main control unit has a built-in fully automatic commissioning program, issues commands, and receives feedback information. The circuit breaker control unit receives the circuit breaker opening and closing commands from the main control unit and feeds back the circuit breaker opening and closing signals. The circuit breaker trolley electric chassis control unit receives the push-in and pull-out commands from the main control unit and feeds back the position information of the circuit breaker trolley. The online insulation monitoring device control unit receives the insulation measurement commands from the main control unit and feeds back the measurement data. The electric grounding switch control unit receives the closing and opening control commands from the main control unit and feeds back the switch position information. The live display device control unit sends signals to the main control unit indicating whether the load is energized or de-energized.

8. The fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring according to claim 7, characterized in that: The control unit of the circuit breaker trolley electric chassis is equipped with interlocking logic: the trolley can only be pushed in after the online insulation monitoring device control unit reports that the insulation value is qualified and the electric grounding switch control unit reports that the position is open.

9. The fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring according to claim 7, characterized in that: The control unit of the online insulation monitoring device is equipped with a lockout logic: insulation measurement is only allowed after the control unit of the live display device sends a load de-energization signal.

10. The fully automatic commissioning method for medium-voltage circuit breakers based on online insulation monitoring according to claim 1, characterized in that: Initial state: The circuit breaker trolley is in the automatic position, and the grounding switch is in the closed position. The operator in the control room presses the one-button start button. The system automatically confirms that the circuit breaker trolley is in the automatic position; if the position is incorrect, an alarm is triggered. It then automatically confirms that the grounding switch is in the closed position; if the position is incorrect, an alarm is triggered. The system automatically issues a grounding switch opening command, and the grounding switch opens. The system automatically confirms that the grounding switch is in the open position; if the position is incorrect, an alarm is triggered. The system automatically confirms that the load is de-energized; if energized, an alarm is triggered. The system automatically issues a load insulation measurement command, and insulation measurement begins. The system automatically judges whether the insulation value is qualified; if it is not qualified, an alarm is triggered. The system automatically issues a command to push the trolley into the working position, and the trolley is pushed into the working position. The system automatically confirms that the trolley is in the working position; if the position is incorrect, an alarm is triggered. The system automatically issues a circuit breaker closing command, and the circuit breaker closes. The system automatically confirms that the circuit breaker is closed; otherwise, an alarm is triggered, and the process ends.

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