Research On Online Monitoring Method Of Motor System Energy Consumption Under Variable Frequency Power Supply

The important works on efficiency estimation of Variable Frequency Motor System is accurate online measurement of the losses of the motor and its drive system. Due to the output voltages of the inverter carries enormous harmonics, the accurate measurement of the electrical quantity and the interference problem is obvious on the practical engineering, the test system even can't work normally in severe cases. In order to meet the need of monitoring the loss of the Variable Frequency Motor System, this thesis systematically study energy efficiency assessment of Variable Frequency Motor System is accurate with the method of the theoretical analysis, on-site test and experimental study, the main works are as below.1) Based on the operating principle of Industry Inverter, we analyzed the characteristic of the electrical quantity of the motor terminal supplied by inverter and power grid, respectively. Then the note of the online test of output power, harmonic, voltage and current of the inverter is presented. The notes can serve the research of online test of loss of the Variable Frequency Motor System.2) Based on the operating principle of Industry Inverter, we analyzed the characteristic of the electrical quantity of the motor terminal supplied by inverter and power grid, respectively. Then the note of the online test of output power, harmonic, voltage and current of the inverter is presented. Those notes can serve the research of online test of loss of the Variable Frequency Motor System.3) Preliminary developed a set of the online test instrument, which is used to measure the energy efficiency of Variable Frequency Motor System on a thermal power plant, of Variable Frequency Motor System. So far, the operating result is very good, and this provided a strong foundation on energy efficiency assessment of the Variable Frequency Motor System.