Research And Implementation Of Automatic Tuning Control System Of Passive Harmonic Filter Device

With the increasing time-varying load introduced in the power grid,the existing passive harmonic filter device cannot tune the harmonics in real time for the changed harmonic current,and it is difficult to meet the requirements for power harmonics of the power grid.In this paper,the existing passive harmonic filter device is optimized,and the automatic tuning control system of the passive harmonic filter device(referred to as "automatic tuning control system")is researched and implemented,supported by Wuhan Science and Technology Support Project.The optimized passive harmonic filter device can dynamically filter out harmonics when the harmonic source is degenerate and the filtering effect is optimal.The main work and achievements of this paper are as follows:(1)The hardware design of the auto-tuning control system is completed.Firstly,the design requirements of the auto-tuning control system are analyzed,the topology structure of the passive harmonic filter device of the auto-tuning control system and the main circuit design are completed;Secondly,According to the design requirements of the automatic tuning control system and the main circuit,the hardware structure of the control system is designed.Finally,the hardware circuit is designed,including hardware selection,the operating circuit,three-phase electrical parameter acquisition circuit,pulse trigger circuit,PLC input/output circuit and remote monitoring alarm circuit.(2)The study of automatic tuning control method is completed.Firstly,the switching method of the capacitor bank is studied.Secondly,according to the characteristics of the output inductance of the primary winding of the reactor and the basic structure of the BP neural network,the BP neural network model of the inductance regulation is established and the feasibility of the model is verified by simulation.Finally,the implementation steps of the automatic tuning control method are proposed.(3)The software design of the automatic tuning control system is completed.Firstly,PLC control program design is completed,including the main program,initialization program,data acquisition and processing procedures,capacitor switching program,inductance adjustment program,fault alarm program;Secondly,the man-machine interface design is completed,including the welcome interface,main menu,real-time monitoring interface,capacitor switching interface,inductance adjustment interface,and fault alarm interface.(4)The experimental study of the automatic tuning control system is completed.Firstly,the development of the auto-tuning control system is completed;secondly,the auto-tuning control system is tested and the test results are analyzed.The tests show that the study of the automatic tuning control method and the control system hardware and software design are feasible.The automatic tuning control system has a good follow-up to the change of the harmonic current,and the optimized passive harmonic filter device can dynamically filter the harmonic current when the harmonic source is time-varying,and achieves the filtering effect of controlling the changed harmonic current within the national industrial standard.