Virtual Inertia Control-Based Model Predictive Control for Microgrid Frequency Stabilization Considering High Renewable Energy Integration

Abstract

Renewable energy sources (RESs), such as wind and solar generations, equip inverters to connect to the microgrids. These inverters do not have any rotating mass, thus lowering the overall system inertia. This low system inertia issue could affect the microgrid stability and resiliency in the situation of uncertainties. Today's microgrids will become unstable if the capacity of RESs become larger and larger, leading to the weakening of microgrid stability and resilience. This paper addresses a new concept of a microgrid control incorporating a virtual inertia system based on the model predictive control (MPC) to emulate virtual inertia into the microgrid control loop, thus stabilizing microgrid frequency during high penetration of RESs. The additional controller of virtual inertia is applied to the microgrid, employing MPC with virtual inertia response. System modeling and simulations are carried out using MATLAB/Simulink ® software. The simulation results confirm the superior robustness and frequency stabilization effect of the proposed MPC-based virtual inertia control in comparison to the fuzzy logic system and conventional virtual inertia control in a system with high integration of RESs. The proposed MPC-based virtual inertia control is able to improve the robustness and frequency stabilization of the microgrid effectively.

Virtual Inertia Control Application to Enhance Frequency Stability of Interconnected Power Systems with High Renewable Energy Penetration

“…During the deviation of frequency, the proposed virtual inertial control will deliver the desired power to the i-th area, as follows [12][13][14]27]:…”

“…Recently, considerable research has been proposed regarding virtual inertia control designs [5][6][7][8][9][10][11][12][13][14]. Reference [8] compared the dynamic characteristics of VSG and droop control methods to imitate inertia in the power system.…”

“…Reference [11] proposed the integration of DC microgrids as virtual synchronous machines into the power system/utility grid. Reference [12] proposed model predictive control technique-based virtual inertia control to improve the stability performances of microgrids. Almost 100% of grid-connected renewable energy systems [13] have proposed the robust virtual inertia control as a means to support the frequency stability of microgrids.…”

An Approach to Improve the Penetration of Sustainable Energy Using Optimal Transformer Tap Control

“…The reactive power sensitivity can be expressed as ∂Q ∂t : Reactive power sensitivity following tap adjustment (2) Equation (1) can be expanded into the equations that define the changes in active power (P) and reactive power (Q) at both ends of the transformer following the tap adjustment and then the change in V of the i-th bus based on the changes made in P and Q by applying the chain rule.…”

“…The increase in renewable energy is making the operation of power systems more difficult due to the variability of renewable energy that changes power generation according to changes in nature [2]. Furthermore, if the proportion of renewable energy is too high, it may cause instability in power systems.…”