The operating mechanism is an important component of a high-voltage circuit breaker, consisting of an energy storage unit, a control unit, and a force transmission unit. High-voltage SF6 circuit breakers have various types of operating mechanisms, such as spring-operated mechanisms, pneumatic mechanisms, hydraulic mechanisms, and hydraulic spring mechanisms.The mechanism for separating the closing and energy storage in a circuit breaker primarily relies on a spring energy storage mechanism, where the closing spring and opening spring function separately. The following is a detailed explanation:
Spring operating mechanism
A spring-operated mechanism is a mechanical operating mechanism that uses a spring as an energy storage element. The energy storage of the spring is accomplished by a motor through a reduction gear, and maintained in the stored state by a locking system. During opening, the latch releases magnetically, the spring releases its energy, and the contact moves via a mechanical transmission unit. The spring-operated mechanism has a simple structure and high reliability. The opening and closing operations are achieved using two helical compression springs. The energy storage motor stores energy for the closing spring; during closing, part of the energy from the closing spring is used for closing, and the other part is used to store energy for the opening spring. As soon as the closing spring is released, the energy storage motor immediately stores energy for it, with a storage time not exceeding 15 seconds (the energy storage motor is an AC/DC universal motor). During operation, both the opening and closing springs are in a compressed state, and the release of the opening spring has an independent system, unrelated to the closing spring. This spring-operated mechanism has high reliability and stability, and can meet both the O-0.3 sec -CO-180 sec -CO operation cycle and the CO-15 sec -CO operation cycle. The mechanical stability test reaches 10,000 times.
Pneumatic-Spring Operating Mechanism
The pneumatic operating mechanism of the SF6 product is a type of operating mechanism that uses compressed air as power for opening the circuit breaker and a closing spring as the closing energy storage element. The compressed air is stored in the product's own compressor. During opening, the cylinder piston stores energy for the closing spring, which is then transmitted through a mechanical transmission unit to complete the opening operation. The locking system keeps the closing spring in the stored energy state. During closing, the locking mechanism releases magnetically, the spring releases energy, and the mechanical transmission unit then completes the closing operation. Therefore, this mechanism should be accurately described as a pneumatic-spring operating mechanism.
The pneumatic-spring operating mechanism has a simple structure and high reliability. The opening operation is powered by compressed air, and the valve system controlling the compressed air is a single-stage valve structure. The closing spring is a helical compression spring. During operation, the compressed air required for opening is sealed in an air tank through a control valve, while the closing spring is in a released state. Thus, closing and closing each have an independent system. The capacity of the gas storage tank is sufficient to meet the high reliability and stability of the spring operating mechanism designed in this way. It can meet the -0.3sec-CO-180sec-CO operation cycle and the mechanical stability test reaches 10,000 times.
