Data Driven Learning Control With The Applications In Power Inverter

In the dissertation,data driven learning control design methods are inves-tigated to deal with output voltage harmonic problems in power inverter systems.Three-channel composite controller is studied to address uncertainties and external disturbances of inverter systems.Meanwhile,multi-inverter voltage and current cooperative control in microgrids is also taken into consideration.The main contents and contributions of this work are summarized as follows:1.Linear phase learning control based on digital filter techniques is proposed for the power inverters to address output voltage tracking and harmonic restraining problem.In this work,the closed-loop learning system stability conditions are obtained by analyzing the disturbance-to-output and reference-to-output closed-loop system transfer functions,and a stabilized controller is achieved by utilizing the linear phase characteristic of the digital filter.The leaning control method with a filter in positive feedback channel is designed for the applications in inverter engineering to restrain the error accumulation in the period domain.The simulations show that lower total harmonic distortion and higher output voltage precision are obtained under the proposed inverter learning control method.2.Learning control with the information selection mechanism is proposed to address the aperiodic disturbances in inverter systems.In the work,the periodic features of error is analyzed using the root mean square of output voltage error,and aperiodic disturbances in learning components are restrained by a appointed error fluctuation threshold.The extended state observer is introduced to estimate and compensate the aperiodic distur-bances,and the performance of the observer estimating different frequency disturbances is analyzed.For the convenience of being applied in engineering,the learning controller is reduced to a unit positive feedback component only including one filter,and learning parameters can be tuned by the cut-off frequency of the filter.3.A three-channel composite controller,including feedforward learning,distur-bance rejection and basic feedback components,is designed to address the uncertainties and external disturbances in inverter engineering,and the stability of this combined con-troller is proved.The cut-off frequency of the filter and the bandwidth of the observer and basic controller are combined to propose a one-parameter tuning method of the com-posite controller.The hardware experiments demonstrate that the uncertainties and dis-turbances can be restrained effectively by the three-channel composite controller,and a low sensitivity for parameters perturbation and external disturbances of inverter systems is obtained.4.A integrated voltage and current dual-loop cooperative control scheme is pro-posed for multi-inverter control problems in microgrids under a cyber-physical system framework,and voltage precise tracking and current sharing are achieved.In this work,voltage learning control with the synchronizing signal generator is designed to implement the phase synchronization of sinusoidal output voltage among distributed units.The cur-rent consensus regulator is designed using the nonlinear combination of local and neigh-bours instantaneous current data to achieve current sharing.A current consensus strategy under the communication constraints is proposed by utilizing neighbours historical cur-rent data to reduce the effect of network bandwidth.By the simulations,the proposed multi-inverter cooperative control scheme is verified.