高频融冰激励电源及其控制策略的研究

Study on high frequency ice-melting excitation source and control strategy

高频激励融冰是一种新型输电线路融冰方法,利用覆冰在高频电场下电介质和高频电流的集肤效应的共同作用对线路进行融冰,高频融冰激励电源是该融冰技术的关键装置。文中研究了一种5 kHz高频融冰激励电源,通过逆变模块并联实现系统大容量的输出。常规SPWM较难实现高频率的输出,利用了载波相移技术产生逆变器开关的驱动信号,降低开关的工作频率,提高电源的输出频率。提出了一种电压电流双闭环加环流抑制的控制策略,电压外环保证电压稳定输出,电流内环采用电感电流反馈,改善了系统的动态响应,环流抑制环抑制各模块间的环流,提高了模块的功率分配均匀度。仿真验证了激励电源的设计和控制方法的可行性。

Ice-melting with high frequency excitation is a new method of ice-melting for transmission lines. The icing is a loss dielectric under high frequency electric field. The ice is melted by loss dielectric heat and the skin effect of high frequency current. High frequency ice-melting excitation device is the key device of the ice-melting technology. In this paper,the large capacity output of system in a 5 kHz high frequency ice-melting excitation device is realized by parallel inverter modules. The conventional SPWM is more difficult to achieve high frequency output. A drive signal of the inverter switches is generated through using CPS-SPWM technique,thus reducing the switching frequency of the switch,and improving the output frequency of the system. A control strategy of double-loop and circulation current suppression is put forward,the output voltage loop ensures a stable output voltage and the current loop improves the system dynamic response by using inductor current feedback. The circulation current suppression restrains the circulation current between modules,and the uniformity of the power distribution module is improved. The simulation results validate the feasibility of the design of the device and the control method of excitation source.