The Design Of The Portable Circuit Breaker Operation Power Supply

The operation voltage test and the mechanical property test are the most direct way to reflect the mechanical properties of the high voltage circuit breaker. And the operation power supply of the circuit breaker is the key to the above experiments. The output voltage of the rectification models is much lower than the open circuit ones. Both the average voltage drop and the instantaneous voltage drop have a very important impact on the properties of the high voltage circuit breaker. In addition, for that both the operation voltage test and the mechanical property test are carried out under high voltages, the power supply must be able to sustain a high electromagnetic interference. In this paper, a new operation power supply high voltage circuit breaker which has a better load regulation property, smaller ripples, stronger anti-jamming and better man-machine interface is proposed. The paper is arranged as the following:First, the present status and the drawbacks of the circuit breaker operation power supply are analyzed. According to the test requirements of the high voltage circuit breaker, the function allocation and the parameters are defined.Second, on the basis of the high frequency switching power supply, the global structural block diagram of the circuit breaker power supply is presented. The main circuit is analyzed detailedly and the input rectifier and filter circuit, the design of the transformer, the output rectifier and filter circuit are presented and discussed.Then, MCU with PWM IC TL494 to control the power supply is presented. The functional module of the power supply is composed of MCU, TL494, driving and amplifying circuit, protecting circuit, D/A transfer circuit, LCD, keyboard input circuit and auxiliary power supply circuit etc.Last, according to the above design, the circuit breaker operation power supply prototype is produced and tested. The experimental results verified that the design of this circuit breaker operation power supply is logical, lower ripple coefficient and friendly man machine interface.