17 / 2024-03-26 08:32:51

Medium voltage vacuum circuit breaker kinematic chain design with spring actuator

VACUUM CIRCUIT BREAKER, SPRING ACTUATOR, KINEMATIC CHAIN, MECHANICAL CHARACTERISTIC, ENERGY DISTRIBUTION, RESIDUAL ENERGY

The spring charged actuators are generally used as the operating mechanism for the medium voltage vacuum circuit breakers. Through appropriate kinematic chain, the energy stored in the operating mechanism is converted into linear movement to move the moveable contact of the vacuum interrupters in a circuit breaker. Through the kinematic chain, the operating mechanism drives the contact to complete the desired closing and opening operations. During the closing and opening operations, the opening spring, the closing spring, and the contact spring act together to drive the kinematic chain to achieve the desired mechanical travel characteristics. For reliable operation of the circuit breaker the balance between the energy available in the operating mechanism and the energy spent in various part of the kinematic chain is of importance.

This paper will discuss the theoretical basis of energy distribution in the design of kinematic chain, and the design process and evaluation method of a new kinematic chain design and put forward a calculation method for the energy balance.  With the same operating mechanism different kinematic chain design can provide different energy distribution. Appropriate kinematic chain design can improve the energy distribution and the mechanical travel characteristics of the circuit breaker such as overtravel, contact bounce and rebound.

Based on the new designed 40.5kV vacuum circuit breaker with spring actuator, the article introduces the theoretical calculation of kinematic chain design and its influence on the mechanical characteristics of circuit breaker closing and opening, analyzes in detail the distribution relationship between the spring energy and load in closing and opening operation, and verifies the mechanical endurance and making & breaking performance of the circuit breaker with the new mechanism and kinematic chain design through testing on samples.

This paper will also discuss in detail about the energy available in the operating mechanism and the kinematic chain design process based on the mechanical travel characteristics requirement for the circuit breaker and the energy balance calculation, the method was verified with new product samples.