Dynamic stability analysis of a standalone photovoltaic microgrid on a dynamic load in a rural area.

Abstract

This paper analyzes the dynamic stability of the voltage amplitude of a photovoltaic generator feeding a dynamic load. We focused on a photovoltaic field with an output of about 20 kWp, a three-phase PWM-controlled voltage inverter and 7.5 kW three-phase induction motor (IM) driving a load for rural use. MATLAB / SIMULINK is used for the simulations. The results of the simulation on a resistive load and on a dynamic load which is the three-phase induction motor with a load torque of 40 N.m showed that the relative voltage drop is more than 12% in the transient regime and about 3% in steady state. This variation shows the instability of the system’s voltage amplitude due to lack of inertia. It is therefore essential in these types of microgrids to improve the dynamic stability of the voltage amplitude for an effective and efficient use. To do this, a first solution to this voltage instability is to hybridize the solar photovoltaic system with an inertial voltage source which is the wind source.