The Design Of Automatic Voltage Control Unit Based On STM32

Automatic Voltage Control System (AVC) is an important mean to ensure thequality of voltage and the reasonable distribution of reactive power flow in the grid. Itis significant for the stability of the grid and the security operation of the powerequipment. The automatic voltage control system has a two-layer structure whichincludes AVC master station and AVC sub-station. The main role of the AVCsub-station is to upload information and execute the reactive power control commandfrom the master station to ensure the stability and effective functioning of the grid.Based on this situation, the measurement&control unit that applied in the AVCsub-station is designed.In this article, the lower machine of AVC sub-station is mainly researched andthe hardware and software proposal is developed. In the hardware design, we use themodular proposal. The hardware circuits have7modules which include the maincontrol module, AC input module,4-20mA DC input/output module and switchinput/output module. In this7modules, we mainly analysis the main control moduleand the AC input module that based on the energy measurement chip CS5484. In thesoftware design, based on the functional requirements, we have5software modulesinclude LwIP module, GPS module,4-20mA module and switch module. In this5modules, we mainly analysis the program of the LwIP module, GPS module and the4-20mA module.Based on the hardware and software proposal above, we develop themeasurement&control unit and use the standard AC signal source and4-20mA DCsource with the error of0.05%and1%to measure it. The measurement result showsthat the has a high precision, the voltage and current measurement error is less than0.2%, the power measurement error is less than0.4%and the4-20mA measurementerror is less than0.4%. This measurement&control unit is well meet the requirementof the measurement accuracy and it has a low cost, rich feature and flexibleconfiguration to meet the requirement of numbers of occasions.