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Due to the uneven geographical distribution between load and wind power, currently it is difficult to integrate the large-scale wind power into the State Grid in China. There are significant wind curtailments for wind farms due to system restrictions. This paper proposes a new way of utilizing wind power, i.e. in-situ consumption, as an alternative to the costly development of long-distance transmission...
Demand response (DR) has proved to be an inevitable part of the future grid. Much research works have been reported in the literature on the benefits and implementation of DR. However, little works have been reported on the impacts of DR on dynamic performance of power systems, specifically on the load frequency control (LFC) problem. This paper makes an attempt to fill this gap by introducing a DR...
One of the challenges in future energy systems is the massive use of high power converters that decouple new energy sources from the AC power grid, disabling natural frequency response. This situation decreases the total system inertia affecting the ability of power system to overcome system frequency's disturbances. It has been established by the wind power industry a controller to enable inertial...
Automatic generation control (AGC) is regularly used to maintain frequency stability and quality in multi-area power system. As each of control areas intend to achieve the best economy during AGC regulation, a concept of optimally economic AGC in a distributed manner arises and is required to investigate. Game theory provides a natural framework for such a kind of problems. Since different control...
Inertia issues due to increased use of modern wind turbines (WTs) have gained increased attention during the last years, especially in isolated power systems with limited frequency control capabilities. Therefore, different control strategies to allow inertial response from WTs have been proposed, either by considering deloaded operation or by using part of the kinetic energy stored in the blades...
The shortcoming of conventional power system operation is manifest: economic dispatch (ED) only optimizes generation schedule periodically, and any power change of distributed generators or system loads can make the power outputs of the generating units deviate from the optimality. To this end, a distributed real-time ED approach is introduced, which integrates ED and secondary frequency control,...
The inertia of the power system is reduced in the presence of Renewable Energy Sources (RESs) due to their low or even no contribution in the inertial response as it is inherently available in the Synchronous Machines (SMs). The total inertia of the grid becomes unknown or at least uncertain following outage of SMs during cascading events. Therefore, the active power deficit following the disturbance/s...
Recent trends of rising demands of electricity for supporting critical infrastructure have led to increasing interest in microgrids. Microgrids hold the promise of being the reliable and economically viable electric system which can greatly improve the efficiency, resiliency and eco-friendliness of future smart grid. Recently, several techniques have been proposed to managing microgrids. In this paper,...
Future distribution networks with high penetration of renewable resources and energy storage can provide ancillary services such as frequency regulation. This study proposes a secondary frequency control scheme based on aggregated active distribution networks. The proposed method is based on hierarchical coordinated control of bidirectional controlled energy storages under islanding situations. The...
The frequency thresholds in the classical Under Frequency Load Shedding (UFLS) are constant and prespecified independent of event scale and place. Furthermore, almost all of recent LS schemes are based on System Frequency Response method to estimate the active power deficit using initial frequency gradient following the event; a method that may no longer be valid in the presence of renewable energy...
Distributed feedback linearization control schemes are proposed for the stability of microgrids in the islanded mode. Utilizing frequency readings of the synchronous generators in the microgrid, the distributed controllers affect the operation of fast-acting energy storage systems for an efficient transient frequency stability after the occurrence of a disturbance in the islanded-mode microgrid. Numerical...
The Grid Friendly™ Appliance (GFA) controller, developed at Pacific Northwest National Laboratory, was originally designed to autonomously switch off appliances by detecting under-frequency events. In this paper, the feasibility of using the GFA controller to provide primary frequency response is investigated. In particular, the impacts of an important design parameter, i.e., curtailing frequency...
A reliable and economic/environmental smart grid (SG) has been a major focus area for modern power system design, which is threatened by the renewable resource penetration and load fluctuation. This paper presents a reliable and economic load frequency control (LFC) strategy based on model predictive control (MPC) to allocate active power set points for different generators by considering units' economic...
An embedded HVDC system is a HVDC link connected in parallel with an AC transmission line or a mashed AC system. This paper proposes a control strategy cooperating with conventional d-q vector control for embedded HVDC system. The novel control method employs frequency features at two terminal stations to eliminate power oscillation. Dynamic simulation models are constructed in PSCAD platform to compare...
Power sharing between angle-droop controlled inverter-based sources largely depends on the line impedances and choice of droop coefficients. Simple power correction methods such as set-point correction and droop coefficient modification work satisfactorily for specific network topologies and require only limited amount of communication. However, their performance can be inadequate for microgrids with...
High penetration of wind generation causes concerns regarding the frequency stability if wind plants do not provide inertial response. Extensive research has been conducted to investigate the design of controller to facilitate wind plants to provide synthetic inertia. However, the economic value of synthetic inertia provision from wind plants has not yet been understood. This paper develops a methodology...
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