Analysis of Reactive Power Curve Optimization during Low Voltage Ride-Through in New Energy Sources

In the context of the same initial operating conditions and fault conditions in the system, the requirements for the reactive power curve of the new energy power station during low voltage ride-through are studied based on the principle of following the same steady-state voltage drop value of the new energy power source and synchronous power source with the same capacity. The article first introduces the low-voltage ride-through control structure of the wind turbine generator, and then describes the power control of the machine-side converter under different wind speeds. Secondly, a mathematical model of the wind turbine generator/thermal power equivalent external transmission system is established to analyze the effect of active and reactive power on the voltage at the point of grid connection. The PV curve is used to compare the voltage stability margin and flexibility of the wind turbine generator/thermal power node. Based on the established mathematical model, the reactive power curve of the wind turbine generator during low voltage ride-through is optimized. The Matlab simulation verification shows that after the optimization of the reactive power curve, the steady-state voltage drop values of the new energy power source and synchronous power source can be maintained consistent. This is conducive to controlling the voltage influence range of the new energy field station after a fault occurs.