摘要
为了达到交流电子负载实时跟踪模拟负载参考电流的目的,参考Delta变换器的工作条件,通过对交流电子负载三角波调制方式和滞环控制方式工作特性的理论分析,对比了两种方式的优缺点:三角波调制方式的开关频率固定,电流跟踪误差在三角波幅值之内,低频时电流跟踪精度较差,放大器增益有限,电流误差开关周期平均值不为0,易产生低次谐波,含有三角波同频及其倍频谐波,当电流误差波形斜率高于三角波斜率时,比较器会出现多个相交比较点,导致很高的开关频率;而滞环电流控制电流响应快,但谐波丰富,不利于滤波。推导得出了滞环宽度和开关频率的函数关系,提出了一种固定开关频率的滞环控制方式,并通过仿真计算验证了该控制方式的优越性。
In order to enable the AC electronic load to track down the analog load reference current in real time, re-ferring to the working conditions of Delta convertor, the advantages and disadvantages of hysteresis control and triangu-lar wave control were compared by analyzing the two methods theoretically.The triangular wave control had fixed switc-hing frequency,and the current-tracking error is within the amplitude of the triangular wave .The current-tracking precision was very low at low frequency.The amplifier gain was limited, the average value in switching period of the current error was not zero, and the low order harmonic was liable to result, containing triangle frequency and its doub-le frequency harmonic.When the current error slope was higher than the triangular wave slope , multiple intersecting comparison points would appear in the comparator, resulting in a high switching frequency.Hysteresis current control responded fast, but had rich harmonics, which was not conducive to filtering.Based on the derived function relation-ship between the hysteresis band and the switching frequency, a kind of hysteresis control method with fixed switching frequency was proposed, and the superiority of the control was verified by simulation experiments.
出处
《电测与仪表》
北大核心
2014年第23期73-78,共6页
Electrical Measurement & Instrumentation
基金
国家自然科学基金资助项目(50977091)
国防科技重点实验室基金项目(9140C870103120C87028)
关键词
电子负载
三角波控制
滞环控制
固定频率
环宽
electronic load, triangular wave control, hysteresis control, fixed frequency, hysteresis band
