摘要
针对数字域下传统功率计算的积分延时影响并联系统的稳定性和动态性能的问题,提出一种无积分单元的功率计算方法。该方法根据正弦信号的三要素复原信号的原理,复现电压电流信号,仅用前后两拍的数值就可以实时计算平均功率。且在负载突变后,仅需一个采样周期即可得到平均功率真实值,动态跟踪好。减小了计算延时,提高了并联系统的稳定性和动态性能,因抛弃了正余弦表,占用DSP资源少,计算量小。仿真和理论计算对比表明该方法稳态误差小于0.04%和负载突变的动态响应快。两台75kVA/50Hz的单相逆变器并联实验验证了该方法的有效性。
As the integral delay of traditional power calculation impacts the parallel inverters stability and dynamic performance in digital-domain,a method without integral unit is presented,which is based on si-nusoidal signal three-elements to reproduce the time-domain voltage and current in digital-domain. It can obtain the real-time active power and reactive power only according to the last and present values of volta-ges and currents. Moreover,it has good dynamic performance because it knows the true power value only one sampling time delay once the load step change. In addition,it occupies much smaller DSP space be-cause of the absence of sine and cosine tables and simplifies greatly power calculation process. The com-parisons of ideal value and simulation value express that the proposed method has great precision and fast dynamic response because of the steady error is smaller than 0. 04% . The experiments results show that the propose method is effective under various loads by using two 75 kVA/50 Hz inverters.
出处
《电机与控制学报》
EI
CSCD
北大核心
2010年第5期37-43,共7页
Electric Machines and Control
基金
国家自然科学基金重点项目(50737004)
关键词
并联逆变器
功率计算
正余弦表
动态响应
parallel inverters
power calculation
sine and cosine tables
dynamic response
