中文摘要：

超声波电动机电流精确测试对研究提高其输出效率有重要作用。为克服传统测试方法灵敏度不高、发热严重、系统不灵活等问题，提出基于闭环磁通门技术的超声波电机电流测试系统，传感器采用LEM公司的电流传感器CAS6-NP，搭建完整软硬件系统。利用商用60型行波型超声波电动机对整个系统进行测试，灵敏度为3．307V／A，适合长时间测试，未发现明显温升。

英文摘要：

Current measurement with high precision is of great importance for the research of improving the efficiency of USM. Traditional method of current monitor is not precise, the temperature of the sensor was high and the system was not flexible. Current monitor system special for USM based on closed-loop fluxgate technique was proposed. Sensor type was LEM CAS6-NP, and related software and hardware module were set up. Experiments with commercial 60 TRUSM show sen- sitivity of the current test system is 3. 307 V/A. And it is suitable for long time monitor, and temperature of the sensor does not increase a lot.