Quantitative Damping Calculation and Compensation Method for Global Stability Improvement of Inverter-Based Systems

TL;DR

This paper introduces a quantitative method for calculating and applying damping compensation to improve the global stability of inverter-based systems, addressing broadband oscillations and small-signal stability issues.

Contribution

It presents a novel damping calculation algorithm based on the nodal admittance model and an adaptive damping strategy with output current feedforward control.

Findings

The proposed method effectively enhances system damping and stability.

Simulations and experiments confirm the method's effectiveness.

The approach provides a clear guideline for damping compensation in inverter systems.

Abstract

Small-signal stability issues-induced broadband oscillations pose significant threats to the secure operation of multi-inverter systems, attracting extensive research attention. Researches revealed that system instability is led by the lacking of positive damping, yet it has not been clearly specified how much the exact amount of damping compensation required to sufficiently ensure system global stability. This paper presents a feasible solution for quantitative damping calculation and compensation to enhance the global stability of inverter-based systems. First, based on the system nodal admittance model, a quantitative damping calculation algorithm is presented, which can suggest the required damping compensation as well as compensation location for sufficient stability improvement. Then, we propose a specific AD with output current feedforward control strategy, which make the AD be quasi-pure resistive and can effectively enhance system damping efficiency. Finally, a testing system with three inverters is used as case study, showing that the proposed method provides a promising solution to efficiently enhance the global stability improvement of inverter-based systems. Simulations and experiments validate the proposed method.