Research On Phase-shifting High Frequency Link Matrix Three-phase Inverter And Parallel Tecnology

With the continuous development of distributed generation,the research on inverter has become more and more intensive.Because of small size,low noise,and high-frequency isolation,high-frequency link matrix inverter has been widely studied.The problem of current commutating has always been a technical problem that restricts their development.Therefore,the problem of the safe commutation of the matrix converter were studied in this paper,and the topology and modulation strategy was analyzed for achieving the safe commutation of the matrix converter.In this paper,the method of suppressing voltage spikes was analyzed firstly,and a topology is proposed that is a high frequency link matrix three-phase three-leg inverter with a clamp diode and resonance inductor introduced in the previous stage.The clamp diode can clamp the voltage of the transform and the switch tube,which can reduce the voltage stress of the switch tube.The introduction of resonant inductance can achieve soft switching of the front-stage switch tube.In order to solve the commutation problem of matrix inverters,an integrated phase-shift modulation strategy is proposed based on the de-re-coupling idea,and the modulation principle and working process are analyzed in detail.The problem of the synchronization between the front and back stage drives was solved by the integration of modulation,the natural commutation of the matrix converter is realized.By adopting phase shift control,the soft switching of the partial switching tube of the post-stage matrix converter is realized,and the integrated modulation adopted at the same time will make the switching tube within a safe range during hard switching,reducing the switching loss of the circuit.On this basis,the fourth bridge leg is added to the proposed topology.In order to achieve the natural commutation of the four-leg matrix inverter,the first three legs and the fourth bridge leg are independently controlled in this topology.The proposed integrated phase-shift modulation is adopted the first three bridge legs,and the independent control is adopted the fourth bridge leg.Problem of unbalanced output voltage under unbalanced operating conditions is solved in the topology.Secondly,the parallel control of the high-frequency link matrix three-phase inverter is studied in this paper.Establishes the mathematical model of the matrix inverter based on the decoupling concept,and analyzes and designs the closed loop PI regulator.In order to realize the load power equally divided between the inverters of the parallel system,the applicability and limitations of the droop control are analyzed,and the droop control under the order is used to study the parallel system.Finally,the feasibility of the proposed topology and the effectiveness of the modulation method are verified by building simulation models and experimental platforms,and the operational stability of the proposed three-phase three-leg inverter parallel system is verified by experiments.