Voltage directional vector control strategy improvement and mathematical modeling method

The invention discloses a voltage directional vector control strategy improvement and mathematical modeling method. According to the method, in a main circuit model of a photovoltaic grid-connected inverter, a series inductance, a shunt capacitor and a port transformer are connected onto the AC output side of the inverter and form an equivalent LCL (lower control limit) filter circuit; three-phase voltage on line side and the three-phase current on line side are collected and then are put into VOC (variable output circuit) control algorithm for correlation operations. The mathematical modeling method takes the three-phase current on the side of the network as an inner ring of a control system to realize double closed loop control of the system. The mathematical modeling method further adopts the voltage space-vector PMW (pulse width modulation) method to realize voltage-direction-based vector control of the grid-connected inverter. Based on the voltage directional vector control strategy improvement and mathematical modeling method in RTDS (real time digital system) simulation modeling, corresponding improvement is performed on the control algorithm, and a corresponding SVPWM (space vector pulse width modulation) control module is built on RTDS/RSCAD, so the flexible and diversified control manners are achieved and the inverter can be in four-quadrant operation.