Residual Current Circuit Breaker Detection Device Development

Accidents are frequently occurred due to the improper use of electrical equipments, poor quality of device or some deficients of the device applied in line in daily life. Residual current circuit breaker (RCCB) is a kind of important low-voltage electrical protection appliance which can provide a protection from elecric shock or leakage. Thus the improvement of RCCB's reliability means the enhancement of its efficiencc in personnel safty ensurance and avoiding the accidents such as fire initiated by electric leakage. The quality and performance of RCCB is affectted by those factors such as component, external environment, temperature, production technology, design technology. This paper presents a device which can be used to determine the performance of RCCB in order to improve the product's reliability by detecting its residual current operation properities.The device this paper presents is based on direct digital frequency synthesis (DDS) which is developed rapidly and with widely application currently. PIC16F877 is also adopted as processor, and the design of its control parts, generation and adjusting parts of detection current, current detection parts, man-machine interface and some other hardware parts are also included. Furthermore, the software design overall idea with the consideration of the characteristics of residual current operation properities is provided and programmed in C language for the precise simulation of residual current, also with the detection and display of RCCB operation time and limiting non-actuating time. Closed-loop control mode is applied for the further reduction of system errors and improvement of system stability and precision. And its software is with PID (proportional integral derivative) algorithm in order to regulate the output current's amplitude accurately. Brief introduction of the debugging process and the result of experiment and anlysis are given in the end of this design process.With the anlysis of experiment results, it can be concluded that this devcie is qualified for the detection of the residual current circuit breaker operation properities, and it show with the advantages of high precision, high stability and programmable comparing with traditional one.