逆变式等离子切割电源双闭环控制策略-中国电机工程学报.PDF

第31 卷 第9 期 中 国 电 机 工 程 学 报 Vol.31 No.9 Mar.25, 2011 2011 年3 月25 日 Proceedings of the CSEE ©2011 Chin.Soc.for Elec.Eng. 15 文章编号：0258-8013 (2011) 09-0015-08 中图分类号：TM 46 文献标志码：A 学科分类号：470·40 逆变式等离子切割电源双闭环控制策略 刘宝其，段善旭，李勋，赵耕，刘邦银 (华中科技大学电气与电子工程学院，湖北省 武汉市 430074) Double Closed Loop Control Strategy for Plasma Cutting Inverter LIU Baoqi, DUAN Shanxu, LI Xun, ZHAO Geng, LIU Bangyin (College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei Province, China) ABSTRACT: This paper proposed a double closed loop 0 引言 control strategy composed of inner voltage-loop and external 大功率空气等离子切割电源通常采用移相全 current-loop with a current-reference feedforward link, which was based on the output voltage and current characteristics of 桥变换电路，并采用非接触式引弧方式以减小割炬 the non-contact arc ignition and cutting process in an air 损耗。移相全桥变换电路实现了后级电路与电网的 plasma cutting inverter. An equivalent mathematical model of 隔离，保证了切割操作的安全，并利用电路本身的 the cutting inverter was built up, then frequency domain 寄生参数很方便实现了软开关技术，变换器效率 analysis and designing work for the double closed loop 高，满足大功率切割电源的输出要求[1-3] 。切割电源 controller was put up also. Simulations and experiments were 呈现垂直陡降的输出恒流外特性。待机空载时，变 given to verify that the proposed control method shows fast 换器工作于电压源模式，空载电压一般高于150V ， response, small overshoot, strong adaptation and high steady precision, which overcomes the drawbacks of