Research On T-S Fuzzy Control Of Inverter With Wide Inductance Variation

The increasing depletion of non-renewable energy and the increasing pollution of the environment have prompted the development and utilization of new energy.Several kinds of renewable energy such as solar energy and wind energy have drawn attention from many countries from all over the world.The inverters play a crucial role in distributed power generation systems and uninterruptible power systems.And the ferrite with air gap and the magnetic core materials,which have the features of high resistivity and high magnetic permeability,have been applied in inverter as the core of inductor,which make the inverter have the advantages of low loss and high power density to improve the efficiency and to reduce the size and cost.However,the linearity of this kind of materials is rather poor,which causes the inductance of the inductor be changed by the current,especially at the high current.In addition,the change of the inductance may cause the oscillation of current and the inverter to be unstable,which may affect the performance of the system,such as the stability of control,the filtering effect,the static and dynamic effects.For the inductance value of the filter inductor has a wide range of changes during the change of inductor current,the dual buck full-bridge inverter topology is taken as the research object in this paper to study the interrelated control strategy in depth.The research status of nonlinear inductance,the inverter control algorithm and the T-S fuzzy control algorithm have been summarized.It points out that the research about the inverter with wide inductance variation is still few.In addition,the T-S fuzzy model method is especially suitable for the system which is local linear and controlled by stages.The T-S fuzzy model method is an effective tool to build a control model with a wide range of inductance variation inverter.The dual buck full-bridge inverter has been selected as the research object,and its topology and working principle have been analyzed.By analyzing the single-cycle control algorithm,it is pointed out that this algorithm is easy to be used and has the advantage of fast response,which has been widely applied in power factor correction(PFC)and the current control of grid-connected inverter.However,the single-cycle control algorithm relies heavily on the inductance parameters.If the fixed single-cycle control algorithm is still being use,the performance of the inverter will deteriorate or even fail when the inductance parameter changes with the load.The correctness of the theoretical analysis is verified by simulation.In order to solve this problem,the T-S fuzzy model is used to make the model of the inverter with wide inductance variation.According to the parallel distributed compensation strategy(PDC)of T-S fuzzy control algorithm,the single-cycle fuzzy control algorithm is proposed as the inner current loop.The inner curren t loop which is structured of single-cycle fuzzy control and the outer loop which is structured of PI control are designed as the double-loop control.In addition,the design method of the proposed algorithm and the implementation steps are given,and the simulation results is analyzed by PSIM.The results show that the proposed method can ensure a good output waveform after considering the change of the wide inductance of the filter inductor compared with the traditional fixed single-cycle control method.And the quality of the output waveform is excellent,which conform the control requirements.Finally,a dual-buck inverter prototype with a wide range of inductance is designed and fabricated using a dual-core DSP TMS320F28377D controller which has the capability of fast computing.The verification of the control algorithm based on T-S fuzzy model is completed.The method can effectively solve the problem about the influence of the wide range of the inductance of the nonlinear filter inductor on the control performance of the inverter.