Academic literature on the topic 'INTERCONNECTED MULTI AREA'

To enhance the quality of output power from regional interconnected power grid and strengthen the stability of overall system, a hybrid energy storage system (HESS) is applied to traditional multi-area interconnected power system to improve the performance of load frequency control. A novel topology structure of interconnected power system with the HESS is proposed. Considering the external disturbances of the system and the interconnected factors between each control area, the dynamic mathematical model of each area in the new topology is established in the form of state-space equation. Combining the state feedback robust control theory with linear matrix inequality (LMI) theory, the controller is designed to calculate how much power the HESS should provide to power grid in real time, according to the load change of system. Taking the four-area interconnected power system as study object, the simulation results obtained by MATLAB prove that the application of HESS can well improve the frequency stability of multi-area interconnected system and the H∞ robust controller proposed in this paper is effective.

Most of the existing results for load frequency control of multi-area interconnected power systems can only be obtained when the norm of the aggregated uncertainties is bounded by a positive constant. This condition is difficult to achieve in real multi-area interconnected power systems. In this paper, a new load frequency control (LFC) for multi-area interconnected power systems is developed based on a decentralised adaptive double integral sliding mode control technique where the above limitation is eliminated. First, an adaptive gain tuning law is adopted to estimate the unknown upper bound of the aggregated uncertainties. Second, a double integral sliding surface based adaptive sliding mode controller is proposed to improve the transient performance of the closed loop system. Simulation results show that the proposed control law results in shortening the frequency’s transient response, avoiding the overshoot, rejecting disturbance better, maintaining required control quality in the wider operating range, and being more robust to uncertainties as compared to some existing control methods.

With the rapid increase of photovoltaic (PV) penetration and distributed grid access, photovoltaic generation (PVG)-integrated multi-area power systems may be disturbed by more uncertain factors, such as PVG, grid-tie inverter parameters, and resonance. These uncertain factors will exacerbate the frequency fluctuations of PVG integrated multi-area interconnected power systems. For such system, this paper proposes a load frequency control (LFC) strategy based on double equivalent-input-disturbance (EID) controllers. The PVG linear model and the multi-area interconnected power system linear model were established, respectively, and the disturbances were caused by grid voltage fluctuations in PVG subsystem and PV output power fluctuation and load change in multi-area interconnected power system. In PVG subsystems and multi-area interconnected power systems, two EID controllers add differently estimated equivalent system disturbances, which has the same effect as the actual disturbance, to the input channel to compensate for the impact of actual disturbances. The simulation results in MATLAB/Simulink show that the frequency deviation range of the proposed double EID method is 6% of FA-PI method and 7% of conventional PI method, respectively, when the grid voltage fluctuation and load disturbance exist. The double EID method can better compensate for the effects of external disturbances, suppress frequency fluctuations, and make the system more stable.

In an interconnected multi-area power system, Load Frequency Control (LFC) is a main challenging problem. This paper presents the Fractional Order Proportional Integral (FOPI) controller for an interconnected two-area power system, wherein each area has multi-source power systems. The gains of the proposed controller are being optimized by Lion Algorithm (LA), utilizing an integral square error (ISE) criterion, to develop the proposed Lion with Levy Update-based FOPI controller (LLUFOPI). The proposed LA schedules the gain of the LLUFOPI controller by achieving the least possible error. Hence, the LLUFOPI controller assures better LFC in the two-area interconnected power system. The performance of the proposed controller is assessed by considering the practical constraints in power system such as Generation Rate Constraints (GRC), communication delay, AC/DC link, step load variation and Capacitive Energy Storage (CES) device. Finally, the simulation results show that the LLUFOPI controller provides a well- optimized gain that is 89% higher than the other algorithms with better stability. The Integral Square Error (ISE) value of the proposed controller is 81.1% lesser than the other algorithms. Better LFC in the two-area multi-source-interconnected power system is hence achieved with minimum ISE.