What are the opening speed and closing speed of VS1 vacuum circuit breaker and their impact on the vacuum circuit breaker?

The opening speed and closing speed of the VS1 vacuum circuit breaker should be explained as the average speed. These parameters are often found in the factory test report of the vacuum circuit breaker. So what is the opening speed and what is the closing speed? Gate speed, what impact does it have on vacuum circuit breakers? Which speed range is the best for the vacuum circuit breaker? Let’s take a look at these questions together.

The opening speed of VS1 vacuum circuit breaker usually refers to the average opening speed when the contacts move apart. Since the opening speed directly affects the recovery speed of the dielectric strength between the contacts after the current crosses zero, if the recovery speed of the dielectric strength between the contacts is less than the transient recovery voltage after the arc is extinguished, the arc will re-ignite.

In order to prevent arc re-ignition and shorten arcing time, vs1 vacuum circuit breaker must have a fast enough opening speed. The opening speed mainly depends on the rated voltage. When the rated voltage and contact opening distance are constant, the fluctuation range of the opening speed depends on the breaking current and the nature of the load. When the breaking current is large, the opening speed should also be large. When the capacitor current is broken, due to the high recovery voltage, in order to reduce the probability of re-ignition, the opening speed should also be large. However, the higher the opening speed, the better. When the opening speed is too high, the vibration (bounce and bounce) during operation will be more serious, and the impact on the vacuum interrupter bellows will be more serious, and it may even be damaged in advance. The bellows causes air leakage in the arc extinguishing chamber. At the same time, the vibration of the whole machine will become greater, which can easily cause damage to the parts of the whole machine. Therefore, appropriate selection must be made based on the working tasks of the vs1 vacuum circuit breaker. The opening speed of 12 kVvs1 vacuum circuit breaker is usually 0.8~1.2 m/s, which can be increased to 1.5m/s if necessary. In fact, during the short circuit breaking process, the biggest impact on the breaking capacity is the initial opening speed, that is, the initial opening speed. Therefore, for some large-capacity vs1 vacuum circuit breakers and 40.5 kV voltage level vs1 vacuum circuit breakers, the vs1 vacuum is usually determined by measuring and assessing the speed just after the point of separation or the speed within the reference stroke of 2 to 6 mm after the contact point is just divided. Opening speed characteristics of circuit breaker.

vs1 vacuum circuit breaker opening stroke curve. The stroke of contact movement between speed point A and speed point C is the average opening speed. The speed at speed point A is the rigid opening speed. The stroke of contact movement between speed point A and speed point B is the rigid opening speed. Reference stroke speed 2 mm after the dividing point.

The closing speed of vs1 vacuum circuit breaker usually refers to the average closing speed when the contacts are closed and moving. Since the insulation capacity of the vacuum interrupter is relatively high at the rated opening distance, the closing speed of the vs1 vacuum circuit breaker is correspondingly lower than the closing speed. However, in order to improve the short-circuit current closing ability, the vs1 vacuum circuit breaker must also have a certain closing speed to reduce the electrical wear caused by pre-breakdown of the contacts during the short-circuit closing process and avoid contact welding. However, an excessively high closing speed will increase the closing work of the operating mechanism, causing closing bounce and increasing the closing impact force that the vs1 vacuum circuit breaker receives during each closing operation, reducing the service life of the vacuum arc extinguisher. . The closing speed of the 12 kV vacuum switch is usually 0.4~0.7 m/s. Depending on the work tasks, it can be 0.8~1.2 m/s when necessary. In fact, during the short-circuit closing process, the speed of the contact just-close point is the most important only when the contact pre-breakdown occurs. Therefore, some large-capacity vs1 vacuum circuit breakers usually measure and assess the just-close speed or the contact just-close point. The speed within the first 2~6 mm reference stroke is used to determine the closing speed characteristics of the vacuum switch.

The closing stroke of vs1 vacuum circuit breaker is shown in the figure. The stroke of contact movement between speed point A and speed point C is the average closing speed. The speed at speed point A is the rigid closing speed. The stroke of contact movement between speed point A and speed point B is the rigid closing speed. Reference stroke speed 2mm before conjunction.