Frequency regulation in islanded microgrid considering stochastic model of wind and PV

Abstract

Summary This paper addresses the method of forecasting the wind and solar power and its application to an islanded microgrid (MG) model for load frequency control. Due to high penetration of renewable energy sources, the islanded MG suffers from lower equivalent inertia. The islanded MG faces several challenges in order to ensure the stable operation by maintaining the frequency and voltage at nominal value. The supply and demand power mismatch is mainly due to continuously changing solar irradiance, fluctuating wind speed, variable inertia, and load fluctuations. The intermittent nature of RESs can significantly affect the system stability; hence, the challenge lies in accurate forecasting of power from the renewable energy sources (RESs) so that a proactive arrangement is made available for compensation of active power or frequency variations. The forecasting will determine the correct estimate of power availability so that the power reserves can be activated prior to large variations in active power affecting the stability of the MGs. To address these challenges, a stochastic model of wind and solar has been developed using “Time series modeling” of the data obtained from Charanka Solar Park under Gujarat Energy Development Agency, India. Wind and solar power availability are forecasted using autoregressive integrated moving average (ARIMA) method including the seasonality factor. The proportional and integral (PI) controller is used for regulating the frequency fluctuations caused due to intermittency in the output of RESs and load power. Various load patterns are applied to the MG model to analyze its load frequency behavior along with variations in secondary sources.

Distributed energy storage system‐based nonlinear control strategy for hybrid microgrid power management included wind/PV units in grid‐connected operation

“…The control inputs' dynamics in (38) to (41) are appended to the control inputs due to IOFL in (28) as depicted in the detailed structure of the proposed control technique in Figure 6. As evident from this figure, the DC link voltage variations are considered for all three proposed controllers.…”

“…To reach more effective control inputs with a globally stable operation for the considered hybrid microgrid, the control inputs in (28) were incorporated with the components achieved by Lyapunov theory-based stability analysis. The total energy due to the errors of the control inputs in (28) can be stated by the Lyapunov function E e ucd ; e ucq ; e uPV ; e uLB À Á…”

“…18 In Xiao et al, 19 using a unified detection strategy, two droop-based and improved virtual impedance-based control techniques have been proposed for a hybrid DC/AC microgrid to reduce circulating current and offer a power-sharing deviation performance. In addition, other challenges including power flow control, 24 DC capacitor voltage balancing technique, 25 power quality with nonlinear loads, 26 bidirectional interlinking converters, 27 frequency regulation with stochastic model, 28 generalized droop-based compensator, 29 multiple subgrids, 30 and generation-storage coordination 31 have been investigated within the microgrid structure. 20 Moreover, a hybrid DC/AC microgrid has been applied to control multiple electric vehicle (EV) storages through the control strategies of the power-droop and voltage-droop methods combined with a distributed coordination strategy.…”

“…21 In Asghar et al 22 and Zheng et al, 23 two islanded and grid-connected microgrids have been considered, respectively, in which control techniques based on intelligent fuzzy logic and power follow-up control have been designed. In addition, other challenges including power flow control, 24 DC capacitor voltage balancing technique, 25 power quality with nonlinear loads, 26 bidirectional interlinking converters, 27 frequency regulation with stochastic model, 28 generalized droop-based compensator, 29 multiple subgrids, 30 and generation-storage coordination 31 have been investigated within the microgrid structure.…”

Nonlinear backstepping control for PMSG wind turbine used on the real wind profile of the Dakhla‐Morocco city

“…For these reasons, governments are moving towards investing in the production of renewable energies to ensure sustainable development. 1 The renewable energy sector is becoming more and more competitive, 2,3 and the growth of wind energy technology is considered the fastest in the world. 4 Although wind energy is the most widespread for electricity generation, however, scientific research does not stop asking critical questions in this area.…”