Robust operating strategy for voltage and frequency control in a non-linear hybrid renewable energy-based power system using communication time delay

Abstract

Nowadays modern power systems are of interconnected type having both conventional and renewable generation sources. Integration of renewable sources in these modern power systems causes serious stability issues specifically fluctuations of frequency and voltage are one of the major problems. So, to maintain the power quality we need to confront these issues of frequency and voltage fluctuations caused by the intermittent nature of renewable sources such as wind and solar. Addressing these challenges requires advanced control strategies based on real-time monitoring. In this paper, a sine cosine algorithm (SCA) tuned optimal dual mode PI controller with derivative control (DM-PI-DC) is proposed to mitigate frequency and voltage fluctuations. The investigated system comprises two areas having traditional power plants as well as renewable sources while taking into consideration the influence of communication time delays (CTDs). Confrontation of frequency fluctuation is handled by the load frequency control (LFC) loop and regulation of voltage in the power system is accomplished by the automatic voltage regulation (AVR) loop. In order to model a real system, the physical limitations of the power system are also taken into consideration. To manage the power flow, an interline power flow controller (IPFC) is incorporated and to keep the system stable during contingencies redox flow batteries (RFBs) are added to the system. Moreover, to evaluate the competence of the suggested controller it undergoes testing by variable loading, and also the comparison of performance is carried out with the advanced controllers. The detailed analysis showcases that the proposed controller demonstrates an oscillation-free response in 3.3 s whereas other controllers settle in 3.8 s, 6.45 s, 6.2 s, and 3.7 s. Moreover, the proposed controller achieves a 33.33 % improved response, particularly in terms of undershoot. The findings further show that the presented control strategy ensures power quality addressing all the key challenges.