Concerted voltage frequency control and superconducting magnetic energy storage operation using optimal adaptive model predictive control for improved frequency response of power system

Abstract

SummaryActive power equilibrium is analogous to frequency control. A hypothesis of maintaining this balance with voltage regulation is slightly less instinctive, notwithstanding the contribution it can make to the overall stability of the power system. This idea in synergism with the utilization of superconducting magnetic energy storage (SMES) technology in a colossal multi‐machine power network, is exercised in this paper. The main focus of this work is to make a small‐rated SMES more providential in large power systems with the aid of voltage frequency control (VFC). This study proposes an adaptive model predictive control (AMPC) equipped small capacity SMES as well as VFC operation, to ensure load frequency control of a wind power penetrated system. While assuming the plant as an autoregressive discrete mode system with exogenous input, the determination of both the plant model and controller parameters are effectuated online using a recursive least squares (RLS) identification algorithm. Detailed mathematical modeling of SMES is presented in addition to the discrete mode automatic generation control (d‐AGC) and governor dead band non‐linearity at the synchronous power source ends. A compact doubly fed induction generator (DFIG) model architecture harmonizing the maximum power point tracking (MPPT) mode using the standard two‐dimensional look‐up table with turbine characteristics is also discussed. Simulations in MATLAB/Simulink domain reveals a percentage improvement of 82.6% in the frequency nadir under load disturbance with the proposed VFC‐SMES scheme. Furthermore, an average percentage improvement of 82% in peak frequency deviations under turbulent wind scenario is attained. These results are validated in real‐time, employing the real‐time digital simulator OPAL‐RT (OP4510).