高稳定度恒流负载的设计与实现

Design and Implementation of High-stability Constant Current Load

为满足多种电源测试要求,文中设计并实现一有源恒流负载,满足不同电压、电流及功率的交、直流电源负载要求,测试设定简单,电流波形与电压波形一致,具有高稳定度。首先产生直流基准;输入交流电压桥式整流后,再通过反馈回路产生交流基准,与测试电源波形和相位一致,从而实现真正意义的阻性负载。试验测得样机直流恒流稳定度接近100%,交流恒流稳定度为99.8%。分析表明此方案可用于工程实际中对交、直流电源性能的测试。

To realize testing different kinds of power supply, this paper designed and realizes an active constant current load, which can meet the load requirements of alternating or direct current in different voltage, current and power with simple setting pat- tern, and whose waveform of its current is as same as its voltage＇s with high stability. It produced the reference of direct current, then produced that of alternating current through the feedback circuit after rectifying alternating current of power source by the full bridge, to keep the current＇s waveform and phase position staying the same as the tested power supply＇s , thus authentic different im- pedance electronic load was realized. The experimental results show that the stability of direct constant current approaches 100% , and that of alternating current is 99.8%. Analysis confirms that the design can be used in testing the performance of alternating and direct current power supply in practical engineering application.