基于PLC的直流大容量试验控制系统设计

Design of DC Large Capacity Test Control System Based on PLC

直流开关试验系统大多采用以电网为试验电源的低压试验系统,存在试验容量较小,试品和工况相对单一,试验次数和试验时间受限,调节参数不便等缺陷,阻碍了直流开关电器的发展[1]。本文通过对直流电器的测试工作要求进行需求分析,确定了直流大容量试验控制电源的功能定位和参数要求,设计了一套基于PLC的直流大容量试验控制系统。该控制系统采用上位计算机和可编程逻辑控制器(PLC)系统的硬件构成,实现了开关电器试验的操作和程序控制。在低压直流短路试验系统中采用高压陪试品与低压选相合闸开关的组合,解决了低压直流大容量试验低压开关容量不足、短路试验电流不能显示的问题。并设计了特有的控制电源出口矩阵,以保证一套电源系统满足不同操作电压同时试验的需要。电压等级全,精度高,容量大,满足直流电器试验的需要。

Most of the DC switch test systems use low-voltage test systems with the power grid as the test power source. The defects such as small test capacity,relatively single test samples and working conditions,limited number of tests and test time,and inconvenient adjustment parameters hinder the development of DC switch appliances[1].This paper determines the functional positioning and parameter requirements of the DC large-capacity test control power supply through the analysis of the requirements of the DC electrical test work,and designs a set of PLC-based DC large-capacity test control system.The control system adopts the hardware composition scheme of the host computer and programmable logic controller(PLC)system to realize the operation and program control of the switchgear test.In the low-voltage DC short-circuit test system,the combination of the high-voltage test product and the lowvoltage phase-selective closing switch is used to solve the problems of insufficient low-voltage switch capacity and inability to display the short-circuit test current in the low-voltage DC large-capacity test.And a unique control power outlet matrix is designed to ensure that a set of power supply system can meet the requirements of simultaneous tests of different operating voltages.The voltage level is complete,the precision is high,and the capacity is large,which can meet the needs of the DC electrical test.