A method for improving the electrical life of switchgear assemblies

Abstract

This invention proposes a method for improving the electrical life of complete switchgear systems, belonging to the field of power supply and distribution. The method includes controlling the action of an electric clamping mechanism through logical judgment to clamp and lift a hand-operated circuit breaker, preventing loosening of the circuit breaker's sprite-shaped contact connections. Using the method proposed in this invention, by performing the clamping operation, the circuit breaker is clamped to a predetermined pressure value, resulting in a more secure fit between the circuit breaker and the complete switchgear system. After clamping, the complete switchgear system will not loosen at the sprite-shaped contact connections when performing short-circuit current switching, effectively improving its electrical life.

Description

Technical Field

[0001] This invention belongs to the field of power supply and distribution, and particularly relates to the field of complete switchgear, specifically a method for improving the electrical life of complete switchgear. Background Technology

[0002] Switchgear assemblies refer to switchgear used in power systems to control and protect power equipment. They include high-voltage switches, low-voltage switches, instruments, and protection devices, which are usually assembled in a cabinet to form a high- and low-voltage switchgear assembly.

[0003] Generally, high and low voltage switchgear consists of a cabinet and cabinet doors, while withdrawable switchgear is equipped with a trolley that can be pushed and pulled horizontally. The trolley allows the circuit breakers, relays, instruments and other devices installed inside the switchgear to be pulled out and pushed in, making it convenient for operators to troubleshoot and perform routine maintenance.

[0004] The external lines of the switchgear first enter the main control switch inside the cabinet, and then enter the branch control switches. Each branch is set according to its needs, such as instruments, automatic control, motor magnetic switches, various AC contactors, etc. Some also have high-voltage and low-voltage switchgear rooms and high-voltage busbars, such as power plants.

[0005] A circuit breaker is a device that can connect, carry, and disconnect current under normal circuit conditions. It is used to distribute electrical energy and protect lines and power supply equipment from overload, undervoltage, short circuit, etc. It is widely used in complete sets of switchgear and is generally used in power distribution circuits such as incoming lines, interconnections, and feeders.

[0006] Existing switchgear uses handcart-type circuit breakers for opening and closing. When switching on and off to handle short-circuit current, the electrodynamic force and vibration of the circuit breaker itself can cause the sprite contact connections to loosen, thus affecting the electrical life of the switchgear.

[0007] There are currently no measures in place to address this issue. Summary of the Invention

[0008] This invention is proposed to solve the above-mentioned technical problems. By stabilizing the circuit breaker body, the loosening of its connections is reduced, thereby improving the electrical life of the equipment.

[0009] To achieve the purpose of the invention, the present invention proposes the following technical solution: a method for improving the electrical life of complete switchgear, the method comprising controlling the action of an electric clamping mechanism through a logic interlock to clamp the handcart circuit breaker and prevent the connection of the circuit breaker's stud contacts from loosening.

[0010] The electric clamping mechanism is controlled by an automatic control device, which is connected to a power supply, the electric clamping mechanism, and an auxiliary switch.

[0011] The automatic control device determines the on / off state of the auxiliary switch, and performs a logical interlocking judgment based on the on / off state of the auxiliary switch to control the action of the electric pressing mechanism.

[0012] Furthermore, the electric clamping mechanism includes a motor fixed inside the complete switchgear and in the space above the circuit breaker, a motor-driven push rod, and a pressure cover set at the bottom of the push rod. The motor drives the push rod to press the pressure cover onto the top of the circuit breaker.

[0013] Furthermore, the auxiliary switches include an auxiliary switch for the aircraft insertion locking mechanism, an auxiliary switch for the insertion position of the propulsion mechanism handle, a micro switch for the removal component, and a maintenance switch.

[0014] Furthermore, the formula for determining the logical chain is as follows: Result=(SS4 OR SS3) AND SS2 AND SS1 Among them, SS1, SS2, SS3, and SS4 are the switch states of the auxiliary switch for the aircraft insertion locking mechanism, the auxiliary switch for the insertion position of the propulsion mechanism handle, the micro switch for the removal component, and the maintenance conversion switch, respectively. When a switch is closed, the corresponding switch state is 1, and when a switch is open, the corresponding switch state is 0. Result is the judgment result. When Result is 1, the motor is controlled to press; when Result is 0, the motor is controlled to lift.

[0015] Furthermore, the electric clamping mechanism also includes a pressure sensor installed at the position corresponding to the pressure cover above the circuit breaker. The automatic control device performs clamping operations with different force values ​​according to the set clamping value and in conjunction with the feedback value of the pressure sensor.

[0016] This invention uses the state of an auxiliary switch to determine the logical interlock. When the conditions are met, the motor is started to press the handcart-type circuit breaker.

[0017] Beneficial effects: Using the method proposed in this invention, the circuit breaker is pressed to a predetermined pressure value by performing a pressing operation, making the circuit breaker and the complete switchgear more securely matched; after pressing, the complete switchgear will not loosen at the sprite contact connection when performing short-circuit current switching, which can effectively improve the electrical life.

[0018] The present invention will be further illustrated by specific embodiments below. Attached Figure Description

[0019] Figure 1 This is a structural schematic diagram of a complete set of switchgear. Figure 2 This is a schematic diagram of the electric clamping mechanism. Figure 3This is a schematic diagram of the logic control of an automatic control device. Figure 4A , 4B This is a schematic diagram of the operation of the aircraft insertion locking mechanism. Figure 5 This is a schematic diagram of the handle pulling out and inserting mechanism. Figure 6 A schematic diagram of two sets of electric clamping mechanisms installed in a complete switchgear assembly.

[0020] Among them, 1: complete set of switchgear, 2: circuit breaker, 2-1: circuit breaker linkage plate, 3: automatic control device, 4: electric clamping mechanism, 4-1: motor, 4-2: push rod, 4-3: pressure cover, 4-4: pressure sensor, 4-5: fixing plate, 5: aviation plug locking mechanism, 5-1: locking rod, 5-2: locking wheel, 5-3: rotating shaft, 5-4: top block, 5-5: locking mechanism return spring, 6: propulsion mechanism, 6-1: handle position linkage rod, 6-2: linkage roller, 6-3: insertion pin, 6-4: linkage rod return spring, 6-5: propulsion mechanism return spring, 6-6: lead screw, 6-7: handle slot, 6-8: handle locking button, 7: handle, 8: reference line, 9: front stop, S1: aviation plug locking mechanism auxiliary switch, S2: propulsion mechanism handle insertion position auxiliary switch, S3: removal component micro switch, S4: maintenance conversion switch. Detailed Implementation

[0021] This invention proposes a method for improving the electrical life of complete switchgear. Through logical judgment, when preset conditions are met, a motor is used to press the handcart-type circuit breaker tightly, so that the circuit breaker and the complete switchgear are more firmly connected, and the connection of the circuit breaker's stud contacts is prevented from loosening.

[0022] Complete switchgear that implements this method, such as Figure 1 As shown. The handcart-type circuit breaker 2 is installed in the circuit breaker compartment inside the complete switchgear 1; the electric clamping mechanism 4 is fixed by the fixing plate 4-5 and is integrated with the complete switchgear 1; the automatic control device 3 is installed on the complete switchgear 1.

[0023] See Figure 2 The electric clamping mechanism 4 includes a motor 4-1 fixed inside the complete switchgear 1 and the space above the circuit breaker 2, a push rod 4-2 driven by the motor 4-1, and a pressure cover 4-3 set at the bottom of the push rod 4-2. The motor 4-1 drives the push rod 4-2 to move up and down, pressing the pressure cover 4-3 onto the top of the circuit breaker 2.

[0024] Motor 4-1 is controlled by automatic control device 3, which has a built-in MCU and is connected to DC or AC power supply, motor 4-1 and auxiliary switch through internal circuitry.

[0025] The control device 3 determines the on / off state of the auxiliary switch, and performs a logical interlocking judgment based on the on / off state of the auxiliary switch to control the pressing and lifting actions of the motor 4-1.

[0026] In this embodiment, the auxiliary switches include four: an auxiliary switch S1 for the aircraft insertion locking mechanism, an auxiliary switch S2 for the insertion position of the propulsion mechanism handle, a micro switch S3 for the removal component, and a maintenance switch S4.

[0027] The auxiliary switch S1 of the aircraft plug locking mechanism is located above the aircraft plug locking mechanism 5 and is controlled by the aircraft plug locking mechanism 5. The aircraft plug locking mechanism 5 is arranged side by side with the electric pressing mechanism 4. When the aircraft plug locking mechanism 5 is locked, the auxiliary switch S1 of the aircraft plug locking mechanism is closed.

[0028] The auxiliary switch S1 of the plug locking mechanism is mounted on the lower end of the locking rod of the locking mechanism. It is a normally open contact. Plug locking indicates that the circuit breaker has entered the working position and the contacts are closed.

[0029] See Figure 4A The locking mechanism 5 includes a locking rod 5-1, a locking wheel 5-2, a rotating shaft 5-3, a top block 5-4, and a locking mechanism return spring 5-5. The locking rod 5-1, the locking wheel 5-2, and the top block 5-4 are designed as a whole and are mounted on the complete switchgear 1 via the rotating shaft 5-3.

[0030] When circuit breaker 2 leaves the working position, circuit breaker linkage plate 2-1 disengages from locking wheel 5-2. Under the action of locking mechanism reset spring 5-5, locking rod 5-1, locking wheel 5-2 and top block 5-4 rotate to reset. Top block 5-4 disengages from auxiliary switch S1 of the aircraft plug locking mechanism, and auxiliary switch S1 of the aircraft plug locking mechanism is in the open state.

[0031] See Figure 4B When the circuit breaker 2 enters the switchgear 1 and reaches the operating position, the circuit breaker linkage plate 2-1 enters the switchgear 1, raising the locking wheel 5-2. The locking rod 5-1, the locking wheel 5-2, and the top block 5-4 rotate around the rotating shaft 5-3. The top block 5-4 presses the auxiliary switch S1 of the aircraft plug locking mechanism, and the auxiliary switch S1 of the aircraft plug locking mechanism closes and remains in the closed state.

[0032] Locking rod 5-1 is in place to prevent accidental operation of the aviation plug after circuit breaker 2 is in place.

[0033] A locking mechanism for controlling the locking rod 5-1, such as a locking spring with a hook, can be installed on the complete switchgear 1 to keep the closed state of the auxiliary switch S1 of the locking mechanism stable.

[0034] The auxiliary switch S2 for the insertion position of the propulsion mechanism handle is located inside the complete switchgear 1 and is controlled by the insertion of the handle 7 into the propulsion mechanism 6. When the handle 7 is inserted, the auxiliary switch S2 for the insertion position of the propulsion mechanism handle is disconnected.

[0035] See Figure 5 The propulsion mechanism 6 includes a handle position linkage rod 6-1, a linkage roller 6-2, an insertion pin 6-3, a linkage rod return spring 6-4, a propulsion mechanism return spring 6-5, a lead screw 6-6, a handle slot 6-7, and a handle locking button 6-8.

[0036] The function of the propulsion mechanism 6 is to, after the handle 7 is inserted into the handle slot 6-7, crank the handle 7 to drive the lead screw 6-6 forward, thus pushing the circuit breaker 2 from the test position to the working position. During normal operation, the handle 7 is not in the handle slot 6-7.

[0037] Figure 5 The image on the right shows the handle 7 in the inserted state. When handle 7 is inserted, handle locking buttons 6-8 pop up, locking handle 7.

[0038] The handle 7 pushes the insertion pin 6-3 upward, compressing the push mechanism return spring 6-5. The inclined surface at the top of the insertion pin 6-3 acts on the linkage roller 6-2, causing the handle position linkage rod 6-1 to move to the left. The linkage rod return spring 6-4 is stretched, and the handle position linkage rod 6-1 separates from the push mechanism handle insertion position auxiliary switch S2, thus disconnecting the push mechanism handle insertion position auxiliary switch S2.

[0039] After the push is completed, press the handle locking button 6-8 to remove the handle 7 from the handle slot 6-7. The push mechanism reset spring 6-5 resets, causing the insertion pin 6-3 to move downward. The linkage rod reset spring 6-4 resets, causing the linkage roller 6-2 to move to the right along the inclined surface at the top of the insertion pin 6-3. The handle position linkage rod 6-1 presses the push mechanism handle insertion position auxiliary switch S2, which closes and remains closed.

[0040] Reference line 8 provides a schematic diagram of the relative position of the propulsion mechanism 6 in both the pull-out and insertion states of the handle 7.

[0041] The micro switch S3 for removing components is installed inside the door frame of the circuit breaker compartment and is a normally open contact. When the front door 9 of the circuit breaker compartment is closed, the micro switch S3 for removing components is closed.

[0042] The maintenance changeover switch S4 is installed on the door of the external instrument room of the complete switchgear 1 for easy manual control by personnel.

[0043] The auxiliary switch S1 of the aircraft plug locking mechanism provides a remote signaling contact and is also in the drive circuit of motor 4-1; the other contacts are all remote signaling contacts and do not have high load-bearing capacity requirements.

[0044] To more precisely control the pressure applied by the motor 4-1, in this embodiment, the electric clamping mechanism 4 also includes a pressure sensor 4-4 positioned above the circuit breaker 2 corresponding to the pressure cover 4-3. The automatic control device 3, based on the set clamping value and in conjunction with the feedback value from the pressure sensor 4-4, performs clamping operations with different force values. The corresponding pressure sensor 4-4 is mounted on the main frame of the circuit breaker.

[0045] See Figure 6 Two sets of electric clamping mechanisms 4 are symmetrically arranged in the upper space above the working position of the circuit breaker 2 in the complete set of switchgear 1.

[0046] In the equipment, the line enters the instrument room through the secondary connector of the circuit breaker 2 and the cable tray of the complete set of switchgear 1, and is connected to the automatic control device 3, which provides triggering conditions and performs pressing and depressurizing actions.

[0047] See Figure 3 The formula for determining logical chaining in this embodiment is: Result=(SS4 OR SS3) AND SS2 AND SS1 Among them, SS1, SS2, SS3, and SS4 are the switch states of auxiliary switch S1 for the aircraft insertion locking mechanism, auxiliary switch S2 for the propulsion mechanism handle insertion position, micro switch S3 for the removal component, and maintenance switch S4, respectively. When a switch is closed, the corresponding switch state is 1, and when a switch is open, the corresponding switch state is 0. Result is the judgment result. When Result is 1, the control motor is pressed and held. When Result is 0, the control motor is lifted and held, and the pressing is released.

[0048] Figure 3 The logical connections between the automatic control device 3, auxiliary switch, motor 4-1, and AC / DC power supply are shown, but these are not actual electrical connections. In this embodiment, the automatic control device 3 is installed in the instrument room and powered by a small busbar.

[0049] The physical meaning of the logical chain judgment formula: Condition for performing the clamping operation: Result=1.

[0050] 1. Circuit breaker 2 is in the working position; this position is confirmed by the auxiliary switch S1 of the circuit breaker's locking mechanism, which needs to be in the closed state.

[0051] 2. Executable status confirmation: To adapt to two different working conditions, normal operation and maintenance, this status confirmation is performed by the auxiliary switch S2 for inserting the handle 7 of the propulsion mechanism. The switch is in the closed state after the handle 7 is pulled out.

[0052] 3. Safety Confirmation; ① To ensure reliable closure of the removable component during normal operation, the position of the micro switch S3 of the removable component is confirmed, and the switch should be in the closed state; ② To meet maintenance conditions, if the removable component is not closed, the maintenance changeover switch S4 needs to be in the closed state after confirming safety. This switch is connected in parallel with the micro switch S3 of the removable component in the trigger circuit.

[0053] 4. The equipment nodes in the above 3 points are connected in series and parallel to form a triggering circuit. Only when all 3 confirmation conditions are met can the logic interlock be established and the triggering circuit be connected. The automatic control device 3 controls the motor 4-1 to perform the pressing operation. When this operation is performed, the pressure sensor 4-4 provides real-time feedback of the force value. After the preset force value is reached, the process stops.

[0054] Condition for releasing the clamping operation: Result=0.

[0055] 1. If any one of the confirmation states during the clamping operation cannot be met, the automatic control device 3 will perform a release clamping operation.

[0056] 2. During normal operation and power failure, the release of the clamping process is mainly carried out by disconnecting the micro switch S2 at the insertion position of the push mechanism handle.

[0057] 3. After the maintenance operation is completed, the clamping process is mainly carried out by disconnecting the maintenance and replacement switch S4.

[0058] Example of operation: Normal power supply operation: 1. In accordance with the operating procedures for the complete set of high-voltage switchgear, place the circuit breaker 2 in the complete set of switchgear 1; 2. When the component is removed, the micro switch S3 is closed. 3. The circuit breaker moves from the test position to the working position, the aircraft plug locking mechanism 5 operates, and the auxiliary switch S1 of the aircraft plug locking mechanism closes; 4. Remove the propulsion mechanism handle 7, and the auxiliary switch S2 for the propulsion mechanism handle insertion position will close; 5. The automatic control device detects that the trigger circuit is conducting and executes the clamping operation; the clamping mechanism performs the clamping action, and stops when the force value returned by the pressure sensor reaches the preset value; 6. Perform the circuit breaker closing operation.

[0059] Normal power outage procedure: 1. Ensure that circuit breaker 2 is in the open state in accordance with the operating procedures of the complete set of high-voltage switchgear; 2. Insert the propulsion mechanism handle 7, and the auxiliary switch S2 for the propulsion mechanism handle insertion position is turned off; 3. When the trigger circuit is broken, the automatic control device 3 performs the decompression operation; the clamping mechanism performs the release clamping action; 4. Perform other power-off operations according to the operating procedures.

[0060] Inspection and testing of the clamping mechanism: At this time, the front door 9 of the circuit breaker compartment is in the open state, and the micro switch S3 of the removed component is disconnected.

[0061] 1. Follow the operating procedures for overhauling complete sets of high-voltage switchgear to ensure the safety of overhauling complete sets of switchgear; 2. With circuit breaker 2 in the working position, remove the propulsion mechanism handle 7 (the auxiliary switch S1 for the aircraft plug locking mechanism is closed, and the auxiliary switch S2 for the propulsion mechanism handle insertion position is closed). 3. Rotate the maintenance selector switch S4 to the maintenance position (closed), the trigger circuit is activated, and the clamping operation is performed; 4. After maintenance or testing is completed, turn the maintenance selector switch S4 to the working position (disconnected), the trigger circuit is disconnected, and the decompression operation is performed.

[0062] By performing a clamping operation, the circuit breaker 2 is clamped to a predetermined pressure value; after clamping, when the complete switchgear 1 is switching on and off with short-circuit current, the circuit breaker's sprite contacts are firmly connected, which can effectively improve the electrical life of the equipment.

Claims

1. A method for improving the electrical life of complete switchgear, characterized in that, The method includes controlling the action of the electric clamping mechanism (4) through a logic interlock judgment to clamp the handcart circuit breaker (2) and prevent the connection of the circuit breaker (2) sprite contacts from loosening; The electric pressing mechanism (4) is controlled by an automatic control device (3), which is connected to a power supply, the electric pressing mechanism (4), and an auxiliary switch. The automatic control device (3) determines the on / off state of the auxiliary switch, and performs a logical interlocking judgment based on the on / off state of the auxiliary switch to control the action of the electric pressing mechanism (4). The auxiliary switches include an auxiliary switch for the aircraft insert locking mechanism (S1), an auxiliary switch for the insertion position of the propulsion mechanism handle (S2), a micro switch for the removal component (S3), and a maintenance switch (S4). The auxiliary switch (S1) of the aircraft plug locking mechanism is controlled by the aircraft plug locking mechanism (5). The aircraft plug locking mechanism (5) and the electric pressing mechanism (4) are arranged side by side. When the aircraft plug locking mechanism (5) is locked, the auxiliary switch (S1) of the aircraft plug locking mechanism is closed. The auxiliary switch (S2) for inserting the handle of the propulsion mechanism is controlled by the handle (7). When the handle (7) is inserted into the propulsion mechanism (6), the auxiliary switch (S2) for inserting the handle of the propulsion mechanism is disconnected. The micro switch (S3) of the removable component is installed inside the door frame of the circuit breaker compartment and is a normally open contact. When the front door (9) of the circuit breaker compartment is closed, the micro switch (S3) of the removable component is closed. The maintenance changeover switch (S4) is located outside the complete switchgear (1) and is manually controlled; The formula for determining the logical chain is: Result=(SS4 OR SS3) AND SS2 AND SS1 Among them, SS1, SS2, SS3, and SS4 are the switch states of the auxiliary switch (S1) for the aircraft insertion locking mechanism, the auxiliary switch (S2) for the propulsion mechanism handle insertion position, the micro switch (S3) for the removal component, and the maintenance switch (S4), respectively. When a switch is closed, the corresponding switch state is 1, and when a switch is open, the corresponding switch state is 0. Result is the judgment result. When Result is 1, the control motor (4-1) is pressed down, and when Result is 0, the control motor (4-1) is lifted up.

2. The method for improving the electrical life of complete switchgear according to claim 1, characterized in that, The electric pressing mechanism (4) includes a motor (4-1) fixed inside the complete switchgear (1) and the space above the circuit breaker (2), a push rod (4-2) driven by the motor (4-1), and a pressure cover (4-3) set at the bottom of the push rod (4-2). The motor (4-1) drives the push rod (4-2) to press the pressure cover (4-3) onto the top of the circuit breaker (2).

3. The method for improving the electrical life of complete switchgear according to claim 2, characterized in that, The electric clamping mechanism (4) also includes a pressure sensor (4-4) installed above the circuit breaker (2) at a position corresponding to the pressure cover (4-3). The automatic control device (3) performs clamping operations with different force values ​​according to the set clamping value and in conjunction with the feedback value of the pressure sensor (4-4).

4. The method for improving the electrical life of complete switchgear according to claim 1, characterized in that, Two sets of the electric pressing mechanism (4) are symmetrically arranged.

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