Study And Design Of Intelligent Residual Current Protective Device Development System

Residual current circuit breaker is an important kind of low-voltage protective device, which is widely used in low voltage distribution power grid. With the development of smart power grids, residual current circuit breaker is continuously put forward new requirements. In order to shorten the development cycle of the residual current circuit breaker, realize the new function expansion and the module development in the laboratory environment, upgrade each function module and realize redevelop, designing an intelligent residual current protective device development system has the important significance.Firstly, the development situation of residual current protection technology and residual current operated circuit breaker is introduced, and the working principles of intelligence residual current protection device development system are researched.The theoretical research of residual current protection and the causes and method of eliminating dead zone of residual current are discussed. The principles of protection for many current and voltage faults are analyzed.Secondly, the hardware circuit of the system is designedand and the system is modular in design of hardware circuit, including power module, residual current protection module, voltage protection module, current protection module, communication module, control module, control module, and the keyboard and display module.Thirdly, intelligent residual current protective device development system auxiliary function modules are designed. It includs the time measurement module which is based on AT89C52 micro controller, function signal generator module and voltage-controlled gain amplifier modules in order to achieve operating time measurements and generate waveforms and adjust waveform amplitude. The auxiliary function modules provide the necessary support for intelligent residual current protective device development system.Finally, the intelligent residual current protective device development system and its auxiliary function modules are tested. The output waves of the residual current protection module, voltage protection module, the current protection module, power modules, function signal generator module and voltage-controlled gain amplifier module are tested,and the communication modules, intelligent control module, the control system peripheral circuit module, and alarm buttons and display module and the trip module,etc, are verified. And the results show that the system can meet the design requirements.