Electrified locking device for static contact baffle plate of switch cabinet

Abstract

The utility model provides a switch cabinet static contact baffle plate live locking device, which belongs to the field of power distribution systems and comprises a circuit breaker handcart, a voltage relay YJ, an intermediate relay KA, an air switch QF and a locking electromagnet RL. A normally open contact YJ1 of the voltage relay YJ is connected in series with a normally closed contact KA1 of the intermediate relay KA and then is connected into a power supply loop of the locking electromagnet RL; a normally-closed auxiliary contact Q1 of the circuit breaker handcart and a working position auxiliary contact S1 of the circuit breaker handcart are connected in parallel and then are connected in series to a coil loop of the intermediate relay KA, and a power loop of the voltage relay YJ, a power loop of the latching electromagnet RL and the coil loop of the intermediate relay KA are finally connected to positive and negative output terminals of the air switch QF. When a static contact or a bus of the switch cabinet is electrified, the static contact isolation baffle plate is locked and cannot be opened, and an electrified part is isolated to prevent people from electric shock.

Description

Technical Field

[0001] The utility model relates to the technical field of power distribution systems, in particular to a live locking device for a static contact baffle of a switch cabinet. Background Art

[0002] At present, the indoor AC metal-enclosed switchgear used in various power supply and distribution systems is a common complete set of power distribution equipment for 3.6-12kV three-phase AC power supply systems, equipped with circuit breaker trolleys, and is mainly used in power supply systems of power plants, power distribution of working enterprises, secondary transformation and transmission of power systems, and starting of large high-voltage motors, etc., with control, protection, monitoring and other functions. For this kind of switch cabinet equipped with a circuit breaker trolley, when the circuit breaker trolley is pulled out of the cabinet for inspection and maintenance, the staff habitually inspects and maintains various parts in the cabinet. At this time, the upper static contact in the cabinet is usually in a live state. After the circuit breaker trolley is pulled out of the cabinet door, the live parts are automatically isolated by the movable baffle, but the staff can move the movable baffle with a slight lift, causing a contact accident. In recent years, such electric shock accidents are common. Due to the high voltage level, discharge usually occurs without touching the live parts, resulting in electric shock accidents, which are extremely harmful. For workers with higher professional qualities, the probability of electric shock is relatively small, but if we want to fundamentally eliminate such accidents, we still need to achieve inherent safety of switch cabinets to improve safety. Utility Model Content

[0003] The technical problem to be solved by the utility model is how to improve the safety of isolating live static contacts in a high-voltage switch cabinet.

[0004] The utility model solves the above technical problems through the following technical solutions: a switch cabinet static contact baffle live locking device, including a circuit breaker trolley, a voltage relay YJ, an intermediate relay KA, an air switch QF and a locking electromagnet RL, a normally open contact YJ1 of the voltage relay YJ and a normally closed contact KA1 of the intermediate relay KA are connected in series and then connected to the power supply circuit of the locking electromagnet RL, a normally closed auxiliary contact Q1 of the circuit breaker trolley and a working position auxiliary contact S1 of the circuit breaker trolley are connected in parallel and then connected in series to the coil circuit of the intermediate relay KA, and the power supply circuit of the voltage relay YJ, the power supply circuit of the locking electromagnet RL, and the coil circuit of the intermediate relay KA are finally connected to the positive and negative output terminals of the air switch QF.

[0005] The utility model utilizes common components such as voltage relay YJ, intermediate relay KA, locking electromagnet RL, etc., and cooperates with auxiliary contacts of the switch cabinet body to realize the situation that when the static contact or busbar of the switch cabinet is energized, the static contact isolation baffle is locked so that it cannot be opened, thereby isolating the energized parts to prevent people from getting electric shock.

[0006] Preferably, the circuit breaker trolley is located in the switch cabinet and the secondary plug is not unplugged, the locking electromagnet RL shall not be energized, and the static contact baffle is unlocked.

[0007] Preferably, the high-voltage busbar is energized and the circuit breaker trolley is moved out of the cabinet, the locking electromagnet RL is energized, and the static contact baffle is locked.

[0008] Preferably, the high-voltage busbar is energized, the circuit breaker trolley is located in the test position, and the secondary plug is unplugged, the locking electromagnet RL is energized, and the static contact baffle is locked.

[0009] Preferably, the high-voltage busbar of the switch cabinet is powered off, the locking electromagnet RL loses power, and the static contact baffle is unlocked.

[0010] Preferably, the normally closed auxiliary contact Q1 of the circuit breaker trolley is located inside the circuit breaker trolley.

[0011] Preferably, the circuit breaker trolley working position auxiliary contact S1 is located in the circuit breaker switch cabinet or in the circuit breaker trolley.

[0012] Preferably, the acquisition circuit of the voltage relay YJ is connected in parallel to the lower port of the secondary side fuse of the voltage transformer in the secondary terminal room in the cabinet, or is connected in parallel to the electric energy metering circuit, or is connected in parallel to the relay protection circuit.

[0013] Preferably, the static contact of the switch cabinet comprises an upper static contact and a lower static contact, and the upper static contact and the lower static contact are both located on the inner side of the switch cabinet body.

[0014] Preferably, both ends of the baffles of the upper stationary contact and the lower stationary contact are installed in the switch cabinet through guide rails, and the locking electromagnet RL is located on the side of the guide rail on one side of the baffle of the upper stationary contact.

[0015] The advantages provided by the utility model are:

[0016] The utility model utilizes common components such as voltage relay YJ, intermediate relay KA, locking electromagnet RL, etc., and cooperates with auxiliary contacts of the switch cabinet body to realize that when the static contact or busbar of the switch cabinet is energized, the static contact isolation baffle is locked so that it cannot be opened, thereby isolating the energized parts to prevent people from getting electric shock, greatly improving the safety of the equipment, reducing the risk of electric shock for workers, and transforming the switch cabinet into an intrinsically safe device. Combined with the operating characteristics of the circuit breaker trolley in the switch cabinet, the auxiliary contacts of the circuit breaker trolley itself and the auxiliary contacts in the switch cabinet are used to flexibly control the locking circuit to achieve both production and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The circuit diagram of the switch cabinet static contact baffle live locking device provided by the embodiment of the utility model adopts the voltage relay YJ;

[0018] Figure 2 A schematic diagram of the position of the locking electromagnet RL in the live locking device for the static contact baffle of the switch cabinet provided by the embodiment of the utility model;

[0019] Figure 3 The switch cabinet static contact baffle live locking device provided by the embodiment of the utility model adopts a circuit diagram of a high-voltage live display HL. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the utility model more clear, the technical solution of the utility model is clearly and completely described below in combination with specific embodiments and with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, but not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] like Figure 1 As shown, this embodiment provides a switch cabinet static contact baffle live locking device, including a circuit breaker trolley, a voltage relay YJ, an intermediate relay KA, an air switch QF and a locking electromagnet RL. The normally open contact YJ1 of the voltage relay YJ and the normally closed contact KA1 of the intermediate relay KA are connected in series and then connected to the power supply circuit of the locking electromagnet RL. The normally closed auxiliary contact Q1 of the circuit breaker trolley and the working position auxiliary contact S1 of the circuit breaker trolley are connected in parallel and then connected in series to the coil circuit of the intermediate relay KA. The power supply circuit of the voltage relay YJ, the power supply circuit of the locking electromagnet RL, and the coil circuit of the intermediate relay KA are all connected to the positive and negative output terminals of the air switch QF.

[0022] When the circuit breaker is in the open state, the circuit breaker trolley normally closed auxiliary contact Q1 is closed. When the circuit breaker trolley is in the working position, the circuit breaker trolley working position auxiliary contact S1 is closed. The air switch QF is the control power branch air switch in the switch cabinet. The circuit breaker trolley normally closed auxiliary contact Q1 is located in the circuit breaker trolley body, and is connected to the locking circuit through the secondary plug connected to the secondary circuit of the circuit breaker and the secondary circuit of the switch cabinet. The circuit breaker trolley working position auxiliary contact S1 is located in the switch cabinet, and can also be located inside the circuit breaker trolley body and connected to the locking circuit through the secondary plug.

[0023] Voltage relay YJ is connected in parallel to the lower port of the secondary fuse of the voltage transformer in the secondary terminal room of the cabinet, or in parallel to the electric energy metering circuit, or in parallel to the relay protection circuit. It is used to collect live signals and is equipped with a special circuit breaker or fuse to prevent short circuit on the secondary side of the voltage transformer caused by circuit fault.

[0024] The state of the locking loop is divided into the following four situations:

[0025] 1. When the circuit breaker trolley is inside the switch cabinet, and the secondary plug has been inserted into the circuit breaker trolley. At this time, the circuit breaker trolley has four states: ① the test position open state, ② the working position open state, ③ the working position closed state, and ④ the circuit breaker trolley is in the process of swinging from the test position to the working position. In state ①, the normally closed auxiliary contact Q1 of the circuit breaker trolley is closed, and the auxiliary contact S1 of the working position of the circuit breaker trolley is disconnected, then the intermediate relay KA is energized, the normally closed contact KA1 is disconnected, and the locking electromagnet RL is de-energized, that is, the static contact baffle is unlocked; in state ②, the normally closed auxiliary contact Q1 of the circuit breaker trolley is closed, and the auxiliary contact S1 of the working position of the circuit breaker trolley is closed, then the intermediate relay KA is energized, the normally closed contact KA1 is disconnected, and the locking electromagnet RL is de-energized, that is, the static contact baffle is unlocked; In state ③, the normally closed auxiliary contact Q1 of the circuit breaker trolley is disconnected, and the auxiliary contact S1 of the circuit breaker trolley working position is closed, then the intermediate relay KA is energized, the normally closed contact KA1 is disconnected, and the locking electromagnet RL loses power, that is, the static contact baffle is unlocked; in state ④, the normally closed auxiliary contact Q1 of the circuit breaker trolley is closed, and the auxiliary contact S1 of the circuit breaker trolley working position is disconnected, then the intermediate relay KA is energized, the normally closed contact KA1 is disconnected, and the locking electromagnet RL loses power, that is, the static contact baffle is unlocked. In summary: as long as the circuit breaker trolley is located in the switch cabinet and the secondary plug has been inserted into the circuit breaker trolley, regardless of whether the high-voltage busbar of the switch cabinet is energized, the locking electromagnet RL will not be energized, and the static contact baffle will be unlocked.

[0026] 2. When the high-voltage busbar of the switch cabinet is energized and the circuit breaker trolley is moved out of the cabinet, the small busbar on the secondary side of the PT located on the top of the cabinet is energized, and the voltage relay YJ receives the voltage signal and operates, and the normally open contact YJ1 is closed, preparing for the operation of the locking electromagnet RL. Since the circuit breaker trolley has been removed from the cabinet, the normally closed auxiliary contact Q1 of the circuit breaker trolley and the auxiliary contact S1 of the working position of the circuit breaker trolley must be disconnected, the intermediate relay KA loses power, and the normally closed contact KA1 is closed, so the locking electromagnet RL is energized, and the static contact baffle is in a locked state. In summary: when the high-voltage busbar is energized and the circuit breaker trolley is moved out of the cabinet, the static contact baffle 100 is locked. If Figure 2 As shown, the static contact baffle 100 cannot be moved at will, so as to prevent the live parts from being exposed, thereby preventing the operator from getting an electric shock.

[0027] 3. When the high-voltage busbar of the switch cabinet is energized, and the circuit breaker trolley is in the test position and the secondary plug is unplugged, the PT secondary side small busbar located in the top of the cabinet is energized, then the voltage relay YJ receives the voltage signal and operates, and its normally open contact YJ1 is closed, and the locking electromagnet RL is ready to operate. Since the circuit breaker trolley is in the test position and the secondary plug is unplugged, the circuit breaker trolley normally closed auxiliary contact Q1 connected to the electromagnet RL control circuit through the secondary plug is disconnected, and the circuit breaker trolley working position auxiliary contact S1 is also disconnected, then the intermediate relay KA loses power, and the normally closed contact KA1 is closed, so the locking electromagnet RL is energized, and the static contact baffle is in a locked state.

[0028] 4. When the high-voltage busbar of the switch cabinet is powered off. From the above, it can be seen that at this time, regardless of whether the circuit breaker trolley in the switch cabinet is closed, moved out of the cabinet, or the secondary plug is unplugged, the voltage relay YJ loses power, the normally open contact YJ1 is disconnected, and the locking electromagnet RL is in a power-off state, that is, the static contact baffle is in an unlocked state. In summary: when the high-voltage busbar of the switch cabinet is powered off, the static contact is unlocked.

[0029] As mentioned above: 1. As long as the circuit breaker trolley is in the switch cabinet and the secondary plug is inserted into the circuit breaker trolley, that is, the circuit breaker trolley is in hot standby or cold standby state, regardless of whether the high-voltage busbar is energized, the static contact baffle is unlocked, and as the position of the circuit breaker trolley changes, the static contact baffle is still in the unlocked state, and the static contact baffle can be moved at will. This design is because at this time, the operator cannot touch the static contact due to the obstruction of the circuit breaker trolley and the cabinet door, and there is no need to lock the static contact baffle. At the same time, it also meets the requirement that the static contact baffle cannot be locked when the circuit breaker trolley enters the working position from the test position, and while meeting the actual use needs and ensuring the safety of the operators, it also avoids the reduction of the service life of the locking electromagnet due to long-term power-on. 2. When the high-voltage busbar is energized and the circuit breaker trolley is moved out of the cabinet, the static contact baffle is locked to protect the safety of the operators. 3. When the high-voltage busbar of the switch cabinet is energized, the circuit breaker trolley is in the test position and the secondary plug is unplugged, the static contact baffle is locked. This design is because the operator has opened the switch cabinet door at this time, and the circuit breaker trolley is ready to be moved out of the cabinet or to carry out necessary maintenance work when the circuit breaker trolley is in this state. In order to ensure the safety of the operators, the static contact baffle must be locked. 4. When the high-voltage busbar is powered off, no matter what position the circuit breaker trolley is in or what state the secondary plug is in, the static contact baffle is unlocked, and the operators can further inspect and maintain the switch cabinet body and static contacts. At this time, since the high-voltage busbar is not energized, there is no safety hazard for the operators.

[0030] In special circumstances, when the static contact baffle must be unlocked, the air switch QF is disconnected to de-energize the entire control circuit to unlock the static contact baffle.

[0031] The utility model utilizes common components such as voltage relay YJ, intermediate relay KA, locking electromagnet RL, etc., and cooperates with auxiliary contacts of the switch cabinet body to realize the situation that when the static contact or busbar of the switch cabinet is energized, the static contact isolation baffle is locked so that it cannot be opened, thereby isolating the energized parts to prevent people from getting electric shock.

[0032] By adding common electrical components, the live locking function of the static contacts of the switch cabinet is realized, which improves the safety factor of the equipment. It can completely eliminate the incidents of casualties caused by touching the live static contacts in the power system, avoid the hidden dangers of electric shock inside the switch cabinet, greatly improve the safety of the equipment, reduce the risk of electric shock for workers, and transform the switch cabinet into an intrinsically safe device. Combined with the operating characteristics of the circuit breaker trolley in the switch cabinet, the auxiliary contacts of the circuit breaker trolley itself and the auxiliary contacts in the switch cabinet are used to flexibly control the locking circuit to achieve both production and maintenance.

[0033] The static contact of the switch cabinet of the utility model comprises an upper static contact and a lower static contact, both of which are located on the inner side of the switch cabinet. When the circuit breaker trolley is pulled out of the cabinet, the upper static contact is energized and the lower static contact is not energized.

[0034] Both ends of the isolation baffles of the upper static contact and the lower static contact are installed in the switch cabinet through guide rails. The locking electromagnet RL is located on the side of the guide rail on one side of the isolation baffle of the upper static contact. When the locking electromagnet RL is energized, the end of the locking electromagnet RL extends out to block the isolation baffle of the upper static contact from moving upward.

[0035] The utility model adopts the method of collecting the secondary voltage of the voltage transformer by the voltage relay to judge whether the busbar has electricity, and is suitable for power supply systems with voltage transformers, such as Figure 1 As shown. The high-voltage live display HL can also be used to replace the voltage relay YJ. Specifically, in the circuit diagram, the voltage relay YJ is replaced by the high-voltage live display HL, and the normally open contact YJ1 of the voltage relay YJ is replaced by the normally open contact HL1 of the high-voltage live display HL. This is suitable for bus sections with a single unit or without voltage transformers, such as Figure 3 shown.

[0036] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A switch cabinet static contact baffle live locking device, Features: It includes a circuit breaker trolley, a voltage relay YJ, an intermediate relay KA, an air switch QF and a locking electromagnet RL. The normally open contact YJ1 of the voltage relay YJ and the normally closed contact KA1 of the intermediate relay KA are connected in series and then connected to the power supply circuit of the locking electromagnet RL. The normally closed auxiliary contact Q1 of the circuit breaker trolley and the working position auxiliary contact S1 of the circuit breaker trolley are connected in parallel and then connected in series to the coil circuit of the intermediate relay KA. The power supply circuit of the voltage relay YJ, the power supply circuit of the locking electromagnet RL and the coil circuit of the intermediate relay KA are finally connected to the positive and negative output terminals of the air switch QF.

2. The switch cabinet static contact baffle live locking device according to claim 1, Features: The circuit breaker trolley is located in the switch cabinet and the secondary plug is not unplugged, the locking electromagnet RL shall not be energized, and the static contact baffle shall be unlocked.

3. The switch cabinet static contact baffle live locking device according to claim 1, Features: When the high-voltage busbar is energized and the circuit breaker trolley is moved out of the cabinet, the locking electromagnet RL is energized and the static contact baffle is locked.

4. The switch cabinet static contact baffle live locking device according to claim 1, Features: When the high-voltage busbar is energized, the circuit breaker trolley is in the test position, and the secondary plug is unplugged, the locking electromagnet RL is energized and the static contact baffle is locked.

5. The switch cabinet static contact baffle live locking device according to claim 1, Features: The high-voltage busbar of the switch cabinet is powered off, the locking electromagnet RL loses power, and the static contact baffle is unlocked.

6. The switch cabinet static contact baffle live locking device according to claim 1, Features: The normally closed auxiliary contact Q1 of the circuit breaker trolley is located inside the circuit breaker trolley.

7. The switch cabinet static contact baffle live locking device according to claim 1, Features: The circuit breaker trolley working position auxiliary contact S1 is located in the circuit breaker switch cabinet or in the circuit breaker trolley.

8. The switch cabinet static contact baffle live locking device according to claim 1, Features: The acquisition circuit of the voltage relay YJ is connected in parallel to the lower port of the secondary side fuse of the voltage transformer in the secondary terminal room in the cabinet, or in parallel to the electric energy metering circuit, or in parallel to the relay protection circuit.

9. The switch cabinet static contact baffle live locking device according to claim 1, Features: The static contacts of the switch cabinet include an upper static contact and a lower static contact, and both the upper static contact and the lower static contact are located on the inner side of the switch cabinet body.

10. The switch cabinet static contact baffle live locking device according to claim 9, Features: Both ends of the baffles of the upper stationary contact and the lower stationary contact are installed in the switch cabinet through guide rails, and the locking electromagnet RL is located on the side of the guide rail on one side of the baffle of the upper stationary contact.

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