基于Modbus的变电站多点电能质量监测

摘要

The power quality monitoring and the division of the responsibility of the substation and distribution networks are widely concerned.To study the multi-point detection technology of power quality in the key node equipment of the substation,based on DSP28335,a power quality parameter acquisition and conditioning circuit is designed,as well as the calculation methods of the main power quality parameters.The parameters such as voltage and current harmonics,imbalance and power factor are extracted.Combined with the test data,the power quality problems are analyzed and forecasted.Based on the harmonic power flow localization method,the direction of the harmonic source is judged by calculating the polarity of harmonic power of PQU,and then the harmonic distribution is determined by the source side multi-point PQU detection value.The communication protocol based on Modbus RTU protocol is designed,and the power quality monitoring and evaluation software of host computer is established by means of ForceControl software.%变电站及其所在配网的电能质量监测与责任定位区分问题引起各方广泛关注,旨在研究变电站中关键节点设备处电能质量多点检测技术.基于DSP28335设计了电能质量参数采集和调理电路,设计了主要电能质量参数计算方法,实现了对电压和电流谐波、不平衡度、功率因数等参数提取.结合检测数据,对电能质量问题进行分析和预警,并基于谐波功率潮流定位方法,通过计算电能质量检测点PQU处谐波功率极性,判断谐波源方向,再结合源侧多点检测数值,确定谐波分布情况.设计了基于ModbusRTU协议的上下位机通信协议,借助力控组态软件建立上位机电能质量监测与评估软件.