泵系统电动机效率的测量方法

为了实现泵驱动电动机效率的测量,推导了电动机能量关系式,结果表明,电动机效率与电动机的输入功率和运行电流有关,并得到电动机运行效率计算公式.取6组不同型号的三相异步电动机,引用其标准测试数据进行理论验证,读取电动机输入功率与运行电流,结合电动机运行效率表达式,计算出电动机运行效率,并与电动机实际效率对比.计算结果表明,计算效率与电动机实际运行效率值的相对偏差在1.8%之内,精度较高.为进一步证明方案可靠性,设计了离心泵试验台进行试验验证,通过调节水泵阀门开度控制电动机端负载,得到不同工况下的电动机运行参数,再结合推导公式即可得到电动机运行效率,试验结果表明计算效率与试验效率值最大相差1.06%,基本吻合.与一般测试方法相比,该方案只需在电动机运行时读取其输入功率及电流,即可快速准确地计算出运行效率,而不需要测量其他数据,也不需停机测量,极大提高了测量效率.

Measuring method of motor efficiency of pump system

The energy relationship of motor was derived to measure the the efficiency of the pump motor. The results show that the motor efficiency is related to the input power and running current of the motor. The calculation formula of motor operating efficiency was obtained. The standard test data of six different types of three-phase asynchronous motor were used to conduct a theoretical verification. The input power and running current of the motor were adopted in the calculation of operating efficiency, and compared with the the actual efficiency of the motor. The results show that the overall error between the calculation efficiency and the actual operating efficiency of the motor is less than 1.8%. To further prove the reliability of the scheme, the centrifugal pump test bench was designed to verify the test. The motor end load was controlled by adjusting the pump valve opening degree to obtain the motor calculation efficiency under different working conditions. The test results show that the error between calculation efficiency and the test efficiency value is less than 1.06%. Compared with the general test method, the program can calculate the operating efficiency quickly and accurately by reading its input power and current while the motor is running, without measuring other data or stopping the measurement, which greatly improves measurement efficiency.