Research And Design Of Single-phase Power Quality Analyzer Based On DSP

At first,the thesis introduces the standards of electric power quality and research status of power quality analyzer both at home and abroad. Plan and design of system is proposed bases on them.We discuss the design method of this instrument both with regard to hardware and software in detail.At last,some actual system test has been done.Based on the actual situation of electric power quality monitoring and processing,the system can be divided into the data sampling module,DSP minimum system,human-computer interaction module and communication module in hardware according to the modular designing ideas.The designing process of every module is expounded at the aspect of module function and element selecting.The data acquisition part designs the phase locked frequency doubling module to control A/D to sample the electric current and voltage in synchrony.In order to make the sampled current and voltage to reach the range that can be sampled, the signal conditioning circuit is used for changing it,which is constituted by mutual inductor and OPAMP.The displaying part adopts the Large-scale dot-matrix LED which is produced by TRULY Company. The keyboard is used to achieve the function of data inputting and command transmission.In software,the main program and the subprogram mainly accomplish the work of system initialized configuration,interruption sampling,data analysis and data transmission.In order to increase the readability and portability of the software,we adopt the C language to achieve the main program and the relevant interrupt service program.The data analysis consists of the virtual value,power and power factor (PF) calculation and harmonic analysis.In order to monitor the electric fence parameter timely,we utilize the mixing program to achieve the arithmetic of data processing.At the same time,the thesis emphasizes how to utilize the eCAN controller in the TMS320F2812 to design CAN bus interface module and CAN bus software module of the system .The analyzer can not only monitor the voltage,current, frequency and power of the electric fence timely,it also can do harmonic analysis more than 50 times.The test results show that the electric power quality analyzer can satisfy the up-to-date requirement of power quality monitoring.It also has advantages of system stability,good real-time performance,high reliability,small volume,low cost and of great practical value.