Effect of Load Ratio Parameter on Electric Spring Performance for Critical Bus Voltage Stabilization

The electric spring (ES) is a flexible power electronic device utilized in power system to enhance voltage stability through reactive power compensation. When connected in series with a non-critical load (NCL), ES and NCL forms a smart load (SL), which is then connected in parallel with the critical load (CL). By adjusting the output voltage and the active power of NCL through reactive power compensation, ES stabilizes the voltage of CL. In addition, an advantage of ES is its ability to dynamically adapt to the fluctuating generation of renewable energy, without the need for prior load demand determination. This feature makes ES suitable for widespread application at various nodes in the power grid, effectively accommodating unpredictable renewable energy generation. However, existing research has primarily focused on voltage and frequency regulation of ES, with limited consideration given to the associated NCL and CL. Therefore, this paper aims to analyze the impact of the load ratio (CL to NCL) on the performance of ES in voltage stabilization. Mathematical model of ES is derived for analysis, then simulations are conducted using MATLAB/Simulink to validate the voltage control of ES under different load ratios.