Effect of renewable energy-based distributed generation with power invertors on resonance at harmonic frequencies

The purpose of the article is to study the influence of distributed generation installations based on renewable energy sources using inverters on the resonance at harmonic frequencies. The function of the inverter is to convert DC voltage into AC. The inverter uses pulse width modulation (PWM) to generate a sinusoidal output current. The analysis is performed for distributed generation installations with an inverter system connected to the IEEE 13 Node Test Feeder in the Simulink graphical simulation environment. To study the phenomenon of resonance, frequency is measured during the analysis of the Fourier series expansion in order to measure voltage and current distortions at the point of general connection of the network and distributed generation. The influence of harmonics on the interaction between the distribution system and the distributed generation unit with an inverter connected to a passive LCL filter is analyzed. In order to study the effect of distributed generation integration into the distribution network, it has been decided to consider two scenarios of generating plant connection. In the first scenario, the effect of several distributed generation installations connected to different buses of the distribution network is researched. In the second scenario, the effect of several installations of the given type connected to one bus of the design circuit distribution network is studied. In addition, each of the scenarios contains four measurements with a uniform increase in the number of generating units in each measurement. The maximum permissible integration level of distributed generation units connected to the grid is assumed to be equal to 40% of the total connected load. It is based on breaking the limits of standard harmonic voltage distortion. This study also analyzes the effect of multiple distributed generators under integration and resonance at harmonic frequencies. The analysis of the influence of distributed generation installations integrated into the distribution network has been carried out with the application of an analytical comparison of the obtained (calculated) parameters of voltage non-linear distortion coefficients when modeling distributed generator operation in the network with permissible limits for these coefficients of voltage non-linear distortions in accordance with low voltage network GOST. The results of numerical experiments are presented.

distributed generation, resonance, harmonic distortions, converter, nonlinear distortion coefficient, inverter