Linearization Equivalent Model Study of IIDG Fault Output with Low Current Limiting

Inverter-interfaced distributed generator is more and more widely used in power systems, which makes the nonlinear characteristics of power systems more and more significant. The inverter-interfaced distributed generator with different control strategies and control goals has different nonlinear fault characteristics. This paper analyses the fault output characteristics of inverter-interfaced distributed generator based on the grid-following and grid-forming control strategies and the control goals of suppressing negative sequence current, active power fluctuation and reactive power fluctuation. Based on the least-squares method, the linearization equivalent of the inverter-interfaced distributed generator fault output with low current-limiting multiplier is proposed. Validation demonstrates that the linearization equivalent model is suitable for the equivalent calculation of the fault output of inverter-interfaced distributed generator with different control strategies and control goals under different fault types, and has a faster computational performance than the non-linearized model.