Load Frequency Control and Automatic Voltage Regulation in Four-Area Interconnected Power Systems Using a Gradient-Based Optimizer

Abstract

Existing interconnected power systems (IPSs) are being overloaded by the expansion of the industrial and residential sectors together with the incorporation of renewable energy sources, which cause serious fluctuations in frequency, voltage, and tie-line power. The automatic voltage regulation (AVR) and load frequency control (LFC) loops provide high quality power to all consumers with nominal frequency, voltage, and tie-line power deviation, ensuring the stability and security of IPS in these conditions. In this paper, a proportional integral derivative (PID) controller is investigated for the effective control of a four-area IPS. Each IPS area has five generating units including gas, thermal reheat, hydro, and two renewable energy sources, namely wind and solar photovoltaic plants. The PID controller was tuned by a meta-heuristic optimization algorithm known as a gradient-based optimizer (GBO). The integral of time multiplied by squared value of error (ITSE) was utilized as an error criterion for the evaluation of the fitness function. The voltage, frequency, and tie-line power responses of GBO-PID were evaluated and compared with integral–proportional derivative (GBO-I-PD), tilt integral derivative (GBO-TID), and integral–proportional (GBO-I-P) controllers with 5% step load perturbation (SLP) provided in each of the four areas. Comprehensive comparisons between GBO-PID and other control methodologies revealed that the proposed GBO-PID controller provides superior voltage, frequency, and tie-line power responses in each area. The reliability and efficacy of GBO-PID methodology were further validated with variations in the turbine time constant and speed regulation over a range of  ± 25%. It is evident from the outcomes of the sensitivity analysis that the proposed GBO-PID control methodology is very reliable and can successfully stabilize the deviations in terminal voltage, load frequency, and tie-line power with a shorter settling time in a four-area IPS.

Load Frequency Stabilization of Distinct Hybrid Conventional and Renewable Power Systems Incorporated with Electrical Vehicles and Capacitive Energy Storage

“…The recommended gains for the FOPIDD2 controller were established by minimizing the cost function through the squid game optimizer. The adoption of an ITSE-based cost function [33,40,49] leads to a reduction in settling time and rapid attenuation of high oscillations.…”

“…Traditional power generation systems consisted of reheat thermal (incorporating a governorturbine-reheater sub model) and hydropower generation (incorporating a penstock-droop compensation sub model). The subsequent equations illustrate the mathematical representations for reheating thermal systems and their corresponding sub-models, which consist of a governor, turbine, and re-heater [33,49].…”

Load frequency stabilization of distinct hybrid conventional and renewable power systems incorporated with electrical vehicles and capacitive energy storage

“…Traditional power generation systems consisted of reheat thermal (incorporating a governor-turbine-reheater sub model) and hydropower generation (incorporating a penstock-droop compensation sub model). The subsequent equations illustrate the mathematical representations for reheating thermal systems and their corresponding sub-models, which consist of a governor, turbine, and re-heater 33 , 48 . …”

“…The subsequent sub-models for hydroelectric power, including droop compensation, governor, and penstock, are mathematically represented by the equations listed below 48 . …”

“…The recommended gains for the FOPIDD2 controller were established by minimizing the cost function through the squid game optimizer. The adoption of an ITSE-based cost function 33 , 40 , 48 leads to a reduction in settling time and rapid attenuation of high oscillations.

Figure 4 Structure of suggested FOPIDD 2 .

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