A non-polar high-voltage DC contactor arc extinguishing system for increasing the creepage distance

Abstract

This utility model discloses an arc-extinguishing system for a non-polar high-voltage DC contactor that increases creepage distance. It includes an arc-extinguishing shroud, a pair of magnets installed parallel to each other inside the shroud, and a base plate sleeved on the upper end of the shroud. A pair of stationary contacts are welded inside the base plate. The arc-extinguishing shroud has irregularly shaped elongated slots extending horizontally along its length, forming a W-shaped profile. The segments are connected by right-angle bends. By designing the arc-extinguishing shroud and using these irregularly shaped elongated slots, the creepage distance between the stationary contacts is effectively increased, ensuring the insulation performance of the product after short-circuit or electrical life tests.

Description

Technical Field

[0001] This utility model belongs to the field of contactor technology, specifically relating to an arc extinguishing system for a non-polar high-voltage DC contactor that increases creepage distance. Background Technology

[0002] After completing the high-current resistive electrical life test at 270V DC, the existing arc-extinguishing structure suffers from material loss and carbon buildup due to the continuous switching of the moving and stationary contacts inside the arc-extinguishing structure cavity under load. In addition, the creepage distance between the stationary contacts is insufficient. As a result, the insulation resistance between the stationary contacts decreases significantly after the test, failing to meet the user's safety requirements and high-cycle reliability requirements.

[0003] Chinese invention patent CN111916311A discloses a high-voltage DC contactor with two sets of normally open contacts. The high-voltage DC contactor with two sets of normally open contacts solves the creepage distance problem in multi-contact systems through spatial layout reconfiguration. Chinese invention patent CN119340134A discloses an arc-extinguishing structure for a DC contactor. This patent focuses on solving the problem of metal particle deposition generated when the high-voltage DC contactor is disconnected. These deposits significantly reduce the surface resistance of the insulating material, resulting in a shortened effective creepage distance. Summary of the Invention

[0004] The purpose of this invention is to provide an arc-extinguishing system for a non-polar high-voltage DC contactor that increases creepage distance.

[0005] The technical solution of the present invention:

[0006] A non-polar high-voltage DC contactor arc extinguishing system for increasing creepage distance includes an arc extinguishing chamber, a pair of magnets installed in parallel inside the arc extinguishing chamber, a base plate sleeved on the upper end of the arc extinguishing chamber, and a pair of static contacts welded inside the base plate.

[0007] The arc-extinguishing shroud has an irregularly shaped elongated groove inside, which extends horizontally along the arc-extinguishing shroud, presenting an overall "W"-shaped zigzag outline, with each segment connected by a right-angle turn.

[0008] Preferably, the arc-extinguishing shroud has a pair of mounting grooves inside, and the upper end of the mounting grooves is provided with a circular protrusion.

[0009] Preferably, the base plate has a pair of mounting holes, the inner end face of the mounting holes of the base plate contacts the outer end of the ring of the arc extinguishing cover, and the ring of the arc extinguishing cover is inserted into the mounting holes of the base plate to realize the installation of the two.

[0010] Preferably, the lower end of the static contactor is inserted into the mounting groove of the arc-extinguishing cover, and the upper end is snapped onto the base plate.

[0011] Preferably, the pair of magnets have the same N-pole orientation and comparable magnetic strength, and the height of the magnets is greater than the height of the stationary contact inside the arc-extinguishing shroud.

[0012] Preferably, when the arc extinguishing system is connected to current, the creepage distance between the stationary contact and the arc extinguishing shroud is calculated along the irregularly shaped long slot.

[0013] Preferably, the arc-extinguishing shroud is made of plastic, the base plate is made of ceramic, and the stationary contact is made of copper.

[0014] The beneficial effects of this invention are:

[0015] By designing the arc-extinguishing chamber with an irregularly shaped elongated groove, the creepage distance between stationary contacts is effectively increased, ensuring the insulation performance of the product after short circuit or electrical life tests. Simultaneously, the arc-extinguishing chamber is made of plastic compression molding, resulting in low manufacturing costs, excellent arc-extinguishing effect, and significantly improved reliability over high life cycle durations. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the magnet installation in this utility model;

[0017] Figure 2 This is a schematic diagram of the arc extinguishing system in this utility model;

[0018] Figure 3 This is a schematic diagram of the creepage distance between the main contacts of the positive arc extinguishing system with the left stationary contact connected to the current in this utility model;

[0019] Figure 4 This is a schematic diagram of the creepage distance between the main contacts of the negative arc extinguishing system with the left stationary contact connected to the current in this utility model.

[0020] Figure 5 This is a schematic diagram of the arc-extinguishing shield in this utility model;

[0021] In the diagram: 1-magnet, 2-stationary contact, 3-base plate, 4-arc extinguishing cover. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, it should not be construed that the scope of the subject matter of the present invention is limited to the following embodiments. Any modifications, substitutions and alterations made based on ordinary technical knowledge and conventional means in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0023] See Figure 1 The arc-extinguishing chamber 4 has a roughly rectangular shape when projected onto the horizontal plane. Magnets 1 are installed in slots within the two long walls of the arc-extinguishing chamber 4, with the two magnets 1 placed parallel to each other, their N-pole orientations aligned, and their magnetic strengths comparable. The height of the magnets 1 must be greater than the height of the stationary contact within the arc-extinguishing chamber to utilize the magnetic field of the magnets to achieve arc extinguishing.

[0024] See Figure 2 The stationary contact 2 and the base plate 3 are connected together by welding. During installation, it is only necessary to insert the two rings at the upper end of the arc extinguishing cover 4 into the circular holes of the base plate 3 to achieve the installation.

[0025] See Figure 3 When the left stationary contact is connected to a positive current, under the corresponding magnetic field generated by magnet 1, the arc generated by the two stationary contacts when the current is connected moves towards the center of the arc extinguishing system under the action of Lorentz force. The arc is eventually extinguished by rapid cooling under the action of the arc extinguishing gas. For high-voltage DC contactors with a high lifespan, under long-term load switching, carbon deposits easily accumulate on the inner wall of the arc extinguishing chamber due to the ablation of the moving and stationary contacts, which can easily cause insufficient creepage distance between the stationary contacts, resulting in substandard insulation and withstand voltage. Through this arc extinguishing system, a longer creepage distance between the stationary contacts, through structural design, can meet the requirements of comparable electrical lifespan in both forward and reverse directions, and the insulation and withstand voltage capabilities are highly reliable. See the creepage distance diagram below. Figure 3 The image on the right.

[0026] See Figure 4 When the right stationary contact is connected to a positive current, the corresponding magnetic field generated by the magnet causes the arc generated by the two stationary contacts when the current is applied to move towards the two short wall ends of the arc-extinguishing system under the action of the Lorentz force. The arc is eventually extinguished rapidly by the arc-extinguishing gas. For high-voltage DC contactors with a high lifespan, under long-term load switching, carbon deposits caused by the ablation of the moving and stationary contacts can easily adhere to the inner wall of the arc-extinguishing chamber. This can also easily cause insufficient creepage distance between the stationary contacts and the arc-extinguishing chamber, resulting in inadequate insulation and withstand voltage. In severe cases, both stationary contacts may fail to be properly insulated from the arc-extinguishing chamber, ultimately causing the two stationary contacts to conduct through the arc-extinguishing chamber. With this arc-extinguishing system, a relatively long creepage distance is designed between the stationary contacts and the short wall ends of the arc-extinguishing chamber to ensure comparable electrical lifespan in both forward and reverse directions, while maintaining high reliability in insulation and withstand voltage. A schematic diagram of the creepage distance is shown below. Figure 4 The image on the right.

[0027] Reference Figure 5 The arc-extinguishing chamber 4 has an irregularly shaped elongated groove extending horizontally along it, forming a W-shaped profile. The segments are connected by right-angle bends. When the arc-extinguishing system is connected to current, the creepage distance between the stationary contact 2 and the arc-extinguishing chamber 4 is calculated along the irregularly shaped elongated groove. The magnet is made of a highly magnetic material, the stationary contact is made of copper with excellent conductivity, the arc-extinguishing chamber is made of plastic resistant to high-temperature arc erosion and with excellent insulation properties, and the base plate is made of ceramic with good strength and insulation properties.

[0028] The above provides a detailed description of the arc-extinguishing system for a non-polar high-voltage DC contactor that increases creepage distance, as provided by this utility model. Specific examples have been used to illustrate the structure and working principle of this utility model. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that those skilled in the art can make various improvements and modifications to this utility model without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this utility model.

Claims

1. An arc-extinguishing system for a non-polar high-voltage DC contactor that increases creepage distance, characterized in that: Includes an arc-extinguishing hood (4), a pair of magnets (1) installed in parallel inside the arc-extinguishing hood (4), a base plate (3) sleeved on the upper end of the arc-extinguishing hood (4), and a pair of static contacts (2) welded inside the base plate (3); The arc-extinguishing cover (4) has an irregularly shaped long groove inside. The irregularly shaped long groove extends along the horizontal direction of the arc-extinguishing cover (4) and presents a W-shaped broken line outline. The segments are connected by right-angle turns.

2. The arc-extinguishing system for a non-polar high-voltage DC contactor with increased creepage distance according to claim 1, characterized in that: The arc-extinguishing cover (4) has a pair of mounting slots inside, and the upper end of the mounting slots is provided with a circular protrusion.

3. The arc-extinguishing system for a non-polarized high-voltage DC contactor with increased creepage distance according to claim 1, characterized in that: The base plate (3) has a pair of mounting holes. The inner end face of the mounting hole of the base plate (3) contacts the outer end of the ring of the arc extinguishing cover (4). The ring of the arc extinguishing cover (4) is inserted into the mounting hole of the base plate (3) to realize the installation of the two.

4. The arc-extinguishing system for a non-polar high-voltage DC contactor with increased creepage distance according to claim 1, characterized in that: The lower end of the static contact (2) is inserted into the mounting groove of the arc extinguishing cover (4), and the upper end is snapped onto the base plate (3).

5. The arc-extinguishing system for a non-polar high-voltage DC contactor with increased creepage distance according to claim 1, characterized in that: The pair of magnets (1) have the same N-pole orientation and comparable magnetic strength, and the height of the magnets (1) is greater than the height of the stationary contact (2) inside the arc-extinguishing cover (4).

6. The arc-extinguishing system for a non-polarized high-voltage DC contactor with increased creepage distance according to claim 1, characterized in that: When the arc extinguishing system is connected to the current, the creepage distance between the stationary contact (2) and the arc extinguishing cover (4) is calculated along the irregular long strip groove.

7. The arc-extinguishing system for a non-polarized high-voltage DC contactor with increased creepage distance according to claim 1, characterized in that: The arc-extinguishing cover (4) is made of plastic, the base plate (3) is made of ceramic, and the stationary contact (2) is made of copper.

Images