A Tribrid Energy Storage System for Frequency Support with Stage-Specific Control in a Complex Interconnected Power System with Hvdc Link

Abstract

The shift from hazardous fossil fuels to renewable energy has resulted in reduced inertia and poor frequency control within electrical power systems. Energy storage systems (ESS) have been proposed as a compelling solution for improved frequency stability in a reduced inertia power system. The adoption of different ESS types contributing to frequency support presents a control challenge. Controllers contributing to a specific frequency response stage are referred to as stage-specific control and are proposed. The control scheme consisted of a Supercapacitor Energy System (SCES) contributing to the inertia response stage, an Electrical Vehicle (EV) contributing to the supplementary control loop, and a Battery Energy Storage System (BESS) contributing to the inertia and supplementary control loop. Secretary Bird Optimization Algorithms (SBOA) were proposed for optimizing the control parameters. Evaluation of the control was carried out on a power system design based on a Malaysia-Thailand interconnected system considering a monopolar HVDC tie line. The simulation focused on the effects of the ESSs in Malaysia’s region and the propagating effect in Thailand’s region. Six cases were assessed with different types of loads and RE power mix. The system showed effectiveness in reducing frequency Nadir, oscillation, and settling time while in Thailand the improvement was to the oscillatory component of the frequency response. Standard deviation calculation shows an average of 80.13%, 71.80%, and 53.72% in Malaysia’s frequency, tie line power, and Thailand’s frequency respectively. The research shows the importance of the configuration of ESSs contributing to frequency support.

Keywords: Tribrid Energy Storage System, Frequency Support, Electric Vehicles (EV), Super-capacitor Energy System (SCES), Battery Energy Storage System (BESS)