Parallel Connection of Voltage Inverters Stability Analysis

This paper considers an easy-to-use method for stability calculation in a parallel inverter connection system with sinusoidal output voltage on a single load. It is assumed that there is no connection between inverter control systems. The phase is synchronized and the amplitude is equalized using the feedback of active and reactive power components at the inverter output. The calculation is based on the widely used Nyquist stability criterion. Expressions are given for frequency and amplitude control loops corresponding to this criterion application and considering the parameters of both inverters and the load. The obtained results allow for calculating and synthesizing control systems with sufficient ease and accuracy for practical use.