| Summary: | Due to new energy electric vehicle market developing rapidly, a series of energy supply problems in the charging system urgently need to be solved. The two subsystems of this new energy photovoltaic charging station system are studied respectively. Firstly, the topology equivalent circuit diagram of a three-level pulse width modulation rectifier is proposed. And a simplified space vector pulse width modulation algorithm is applied to the control of the current inner loop and voltage outer loop of three-level AC/DC. A three-level bidirectional DC/DC converter was introduced, its power characteristics and implementation conditions of soft switching were analyzed, and a phase shift modulation method was proposed to achieve its intelligent control. The results indicate that in the dynamic performance analysis of the simplified space vector pulse width modulation algorithm, the phase of phase A current and voltage are in a synchronous state before and after adding a load. After adding the load, the A-phase voltage remained stable at 300V, but its maximum current increased from 80A to 150A. At the same time, the maximum value of three-phase current suddenly changed from 80A to 150A after the load was added, and subsequently stabilized at about 150A. In the power characteristic experiment of a three-level bidirectional DC/DC converter, when the set current Iset is positive, the current value of the input current IinF of the primary bridge arm stabilizes at 11.5A around 0.025 seconds. When the set current Iset is negative, the current value of the input current IinF of the primary bridge arm stabilizes at −11.5A around 0.020s. This shows that the three-level bidirectional DC/DC converter can convert the photovoltaic system’s output voltage to the voltage requirements on DC side of the inverter. The three-level AC/DC and three-level bidirectional DC/DC converters used in this study have significant performance advantages, providing reliable technical support for the photovoltaic charging station technology of modern new energy electric vehicles.
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