Abstract For the application requirements of voltage, current and power monitoring in Urban rail vehicles, the paper design a power quality monitoring system which consists of embedded power quality detection device and data processing module. The power quality detection device integrates the module of transformer and rectifier and the module of Hall current sensor to achieve real-time detection of AC voltage and current; the detection device is able to display parameters such as voltage, current and power in real time by the LCD display module; the detection device realizes real-time output and real-time recording of measurement data through the UART and SD memory card respectively. The paper gives the theoretical derivation of harmonic analysis based on DFT algorithm. Combined with the three-phase voltage measurement data of the device, taking the test of the three-phase voltage monitoring relay module in the air-conditioning cabinet as an example, the paper introduces the harmonic detection method based on DFT. The application case shows that the power quality monitoring system has met application requirements and can be applied in AC detection environment with voltage not higher than three-phase 400V by customized design.
2020, Vol. 21 
