A Practical Approach to Determine Limiter Values of Inverter Control to Maximize Renewable Energy Penetration

Abstract

The increase in renewable-energy-based generations, such as photovoltaic and wind turbines, inevitably leads to an increase in the number and capacity of inverters connected to the power system. This also increases the voltage on the inverter-connected and adjacent buses. By absorbing reactive power appropriately, it can suppress excessive voltage and increase the potential capacity of real power. Currently, most inverters connected to the power grid are set up in a way that does not involve adjusting the voltage at the point of connection. This means that the inverter controller's limiter settings have not significantly impacted the system's stability after a fault. This article examines the impact of reactive power absorption on grid-connected inverters’ stability and limiter values’ effects on stability. Additionally, to set the limiter values for a convenient inverter controller, the causes of instability are explained in a phasor diagram, and a method for setting the limiter values using this information is explained. The stability impact analysis and limiter value setting are carried out through accurate EMT model-based simulations. The infinite bus with the equivalent impedance is used for the stability analysis and limiter values setting, and the determined values are verified on the real power system. The simulation is conducted using the power system computer-aided design and electromagnetic transient including dc.