Design And Development Of A Phasor Measurement Unit For Distribution Network

The distribution network has a large number of nodes,a broad range of network coverage,and the existence of the phenomenon such as across and cross between the lines and the lines,which are not conducive to layout the phasor measurement unit,affecting the wide-area measurement network.At present,the research of the synchronous phasor measurement system in the distribution network at home and abroad mainly focuses on the theoretical analysis and the small-scale test stage.Therefore,it is of great significance to develop a new synchronous phasor measurement device for distribution network.Firstly,the application and demand of synchronous phasor measurement technology in distribution network are discussed in this thesis,and the design of miniaturized phasor measurement unit(PMU Mini)is put forward.Secondly,the hardware circuit and the software function of the system is introduced in detail,and the relevant test is carried out after the structure design is finished.Finally,the rationality of the design,the realization of the function and the place to be improved are analyzed and discussed.The miniaturized phasor measurement unit(PMU Mini)using Cortex-M3 core microprocessor STM32F103ZET6 as the main chip,and extends 1M bytes of SDRAM to meet the needs of high-capacity data caching.The analog-to-digital converter uses the 16-bit high-performance synchronous sampling chip AD7606.The PWM wave issued by STM32 triggers the AD7606 chip to start sampling,and the data is stored in the SD card.The synchronous clock pulse(PPS)output pin of the GPS/Beidou dual mode positioning module directly control the initial start of the PWM wave,which is the original signal that achieved the data synchronization acquisition.Besides,the device is equipped with a capacitive touch screen assembly to input measure parameter and display the working status in real time;has 232&485 communication interfaces and a 925 MHz wireless communication module;uses a micro USB interface for charging.The phasor measurement unit has some distinctive features: through the touch screen operation,man-machine interaction is convenient;with modular structure AD7606 sampling board which realized the data acquisition of various channels;with local data storage,wired data transmission and wireless network functions.Compared with the PMU,PMU Mini has made great efforts to streamline the hardware structure and software functions,is a miniaturized,flexible deployment,and low-cost data synchronization acquisition system.