基于脉冲宽度调制整流的电流互感器取电策略

Current transformer power taking strategy based on pulse width modulation rectification

针对母线低电流时取能不足、启动电流大的问题,提出基于脉冲宽度调制整流电路的大功率在线取能方法。利用控制回路调节整流输入阻抗,使其在母线低电流时与电流互感器内阻匹配以输出最大功率,在母线大电流时改变阻抗稳定输出功率。文中建立了CT取电装置的等效模型,分析了电源最大功率输出条件,搭建了整流电路输入阻抗控制回路,为取电装置的制作提供了理论基础。利用Simulink搭建取电装置的模型进行仿真,结果表明,在母线电流较低时,利用该方法可以取得更大的功率且可以在母线电流宽范围波动时稳定运行。

In view of the insufficient power taking and high starting current when the bus is in the state of low current,a high⁃power on⁃line power taking method based on pulse width modulation(PWM)rectification circuit is proposed.The control loop is used to adjust the rectification input impedance to make it match with the internal resistance of current transformer(CT)to output the maximum power when the bus is in the state of low current,while change the impedance to stabilize the output power when the bus is in the state of high current.The equivalent model of CT power taking device is established,the maximum power output condition of the power supply is analyzed and the input impedance control loop of the rectification circuit is established,which provide the theoretical basis for the manufacture of the power taking device.Simulink is used to build the power taking model to perform simulation.The simulation results show that the method can achieve more power when the bus current is low and can operate stably when the bus current fluctuates in a wide range.