LOCAL REACTIVE POWER CONTROL IN A LOW-VOLTAGE MICROGRID USING A 4th-ORDER IIR FILTER

• Дата: 2025
• Автори: Blinov, I., Trach, I., Miroshnyk , V.
• Формат: Стаття
• Мова: Українська
• Опубліковано: Institute of Renewable Energy National Academy of Sciences of Ukraine 2025
• Теми: voltage control; reactive power; load; microgrid; recursive filter; IIR – Infinite Impulse Response.
• Онлайн доступ: https://ve.org.ua/index.php/journal/article/view/574
• Назва журналу: Vidnovluvana energetika

This study analyzes and compares existing methods for regulating reactive power in a low-voltage microgrid (MV) model characterized by a predominance of the active component of transmission line resistances and connected to a medium-voltage distribution network (MV), utilizing reactive power from renewable energy sources (RES) and energy storage systems (ESS) with inverters. Special attention is given to the local reactive power regulation mode at the output of the distribution transformer, particularly the compensation of reactive power for loads. A key aspect of the study is the in-depth analysis and classification of reactive power parameters in low-voltage microgrids, which are characterized by significant variability in power consumption and a limited number of loads. For the first time, results of the autocorrelation function calculation are presented for this type of microgrid with 10-second quantization intervals for 8 residential houses, revealing the dynamics of reactive power. High autocorrelation (in the range of [0.889, 1.0]) was established over a short interval of 4 cycles, while low autocorrelation was observed over intervals of 15 cycles. The reactive power of the load was classified as a process with "short memory." Based on the findings regarding consumption properties derived from empirical data, a new method of CIIR4 reactive power regulation for the studied network is justified and developed, using a 4th order recursive filter (IIR – Infinite Impulse Response) in a control system with a delay of 1 cycle. The use of "memory" of the filter to a depth of 4 cycles of the previous input signal, adapted to the characteristic properties of the autocorrelation function of the regulated signal, is proposed. During optimization, the stability criterion of the control system was taken into account. An important aspect of the obtained novelty is the optimization of filter parameters by minimizing the mean square error, specifically the reactive power at the output of the distribution transformer. This ensures high compensation efficiency for the specific consumption dynamics of low-voltage microgrids. The method is implemented under conditions of limited information transmission speed regarding the magnitude of the error. The study utilized real data on load fluctuations from a group of residential buildings, collected over weekly time intervals in an operational network with 10-second quantization intervals. An example of the results of optimizing the parameters of the IIR regulator, obtained by minimizing the mean square error in the time domain, is presented. The analysis of the obtained results confirms a high level of reactive power compensation for the loads of low-voltage microgrids and stability of the proposed control system.