电压型逆变器电流实时检测质量改善研究

Study on Current Measure Improvement of Voltage Inverter

交流调速系统在取消机械传感器后,其速度的估计依靠实时检测逆变器端电压、电流来完成,因而电流检测质量的好坏至关重要。良好的滤波是系统实现无速度传感器稳定运行的前提,而传统模拟和数字滤波在宽调速范围内面临难以克服的困难。为此,提出采用跟踪-微分法对逆变器电流进行滤波,并研究了跟踪-微分器各参数对滤波性能的影响。以一个4 kW普通三相异步电机为控制对象了进行仿真试验,对比分析了新旧电流检测滤波方案下的电机运行性能。分析结果表明,采用新的电流滤波方案后,调速系统在宽调速范围内均有更好的运行性能。

Speed estimation relies on the detection of inverter voltages and currents in sensorless AC speed adjustable system ,so it＇s important to detect currents well and truly.Good current filtering is the foundation of system running, but the traditional analog and digital filters are faced with insurmountable embarrassment in wide speed adjustable range.The tracking-differentiator was adopted to realize inverter current filtering and the analysis of parameters influence on filter performance was carried out.A simulative experiment of a 4 kW induction motor was done and the motor runing performance difference was compared.The experimental results demonstrate that the new currents filter has high performance in wide speed adjustable ranges.