Research On Three-Phase Load Balance System

As electric energy plays an increasingly important role in the development of the national economy and social progress,the demand for power quality has gradually increased.In China's three phase four wire low voltage distribution network,the three-phase load imbalance problem not only seriously affects the normal production and life,but also threatens the stability of the power system.In this paper,a three-phase load balancing system with on-line load power supply is developed for the unbalanced three-phase load.The current situation of three-phase unbalanced voltage distribution network in China,the cause and harm of unbalanced three phase load,and the methods of controlling three phase unbalance at home and abroad are introduced first;And on the basis of those,the overall design scheme of the dual CPU system with STM32 MCU and DSP as the core is proposed;Through the detailed description of three phase load balancing algorithm,such as three phase unbalance calculation,symmetrical component method and hybrid base FFT algorithm,the basic theory of system monitoring the power grid signal and phase change is explained;In terms of system hardware,through the design of hardware circuit,the selection of components and communication between modules,the role of STM32 and DSP in the system,and the principle that the system completes the commutation of load power and interlocks avoids interphase short circuit fault is explained;In terms of system software,the paper mainly discusses the design of the main program,the use of various system algorithms for power network signal analysis,and the driver of communication module are discussed;Each module of the three-phase load balancing system is simulated and debugged,with the use of simulation software such as Multisim and MATLAB/Simulink.Through the analysis of the simulation results,the system can be proved to be able to exchange load power quickly,reliably and reasonably,so that the low voltage distribution network can run in a relatively balanced state.