Research On Intelligent Sectional Switch Controller With Distributed Power Supply

Traditional power systems around the world are facing problems such as low energy efficiency,environmental pollution and fossil fuel depletion.Due to the advantages of low pollution,low energy consumption and effective solution of energy crisis,distributed power supply is now plugged into the power grid at a rate of increase.However,the power grid will be transformed into a complex active distribution network by the integration of distributed generators,and the previous fault location technology is no longer applicable.In this context,a subsection switch controller is designed.Besides realizing the basic protection function of the subsection switch,it also realizes the function of "four remote" and fault location.Firstly,the sampling principle of electric parameters is analyzed,inter-phase shortcircuit fault,single-phase grounding fault judgment principle and fault location principle are introduced.The idea of fault location algorithm is to construct the network description matrix according to the network topology structure and power flow direction,construct the fault information matrix based on the uploaded fault information when the fault occurs,obtain the fault judgment matrix through two matrix operations,and locate the fault interval.Secondly,hardware and software are designed.The main control chip adopts ARM chip LPC1778,and the hardware design consists of power module,high-speed sampling module,real-time clock module,display and key module,switch input and switch output module,communication module and handheld remote control module.The communication module includes GPRS,Ethernet,ZigBee and RS-232 serial port communication.Software design includes driver program of function module,protection function program of controller,human-computer interaction function program and communication program of four modes.Finally,software and hardware debugging.Hardware debugging is to check whether the subsection switch controller can work properly.The purpose of software debugging is to check whether the subsection switch controller can realize functions as required,including bottom driver debugging,high-speed sampling debugging,human-computer interaction debugging,communication debugging,protection function and fault location debugging.The experimental results show that the data sampling error is within 0.5% and the action time error is within 50 ms.According to the electric data uploaded by the subsection switch controller,the control center can accurately locate faults after processing.