直流污秽试验系统试验电源控制策略的研究

Research of the Control Strategy for D.C Power Source Used in Artificial Pollution Test

人工直流污秽试验中,染污绝缘子的泄漏电流持续时间长、波动和峰值大。试验电源的输出性能直接关系到污秽试验结果的可靠性,需要采取恰当的控制策略提高电源的跟随性和抗扰性。为研制符合国标输出性能参数要求的直流污秽试验系统,本文在定量研究晶闸管触发角变化与电源输出性能参数关系的基础上,提出了一种基于单片机控制的晶闸管反馈控制策略,并开发了快速调压控制系统。控制系统由保护、采样、同步、隔离和触发等模块组成,单片机通过比较电压整定值与实际输出电压值之间的偏差,由偏差值决定晶闸管的导通及触发角。经Simulink仿真及低压模拟试验的验证,应用本文所提策略控制的试验电源的输出性能参数远高于国标对相对电压降、相对电压过冲和纹波因数等参数的要求。

The leakage current of the contaminated insulator lasts long and has a very high peak in the artificial pollution test. The right control strategy can ensure the stabilization of the test power source which affects the result of the artificial pollution test. In this paper,we putted forward a new control strategy on the basic of a research between the trigger angle of the SCR and the output characteristic of the test power source. We also made a control system under the control strategy. The control system controlled by the single chip computer was consists of protection,sampling,in-phase,isolation,and trigger. The computer controlled the SCR by the difference of the input voltage and the output voltage. The output characteristic is up to the mustard of the National Standard in the simulation and simulated artificial pollution test.