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The continued expansion of renewable energy sources share in the power generation mix continues to increase the proportion of generating units and consumer systems that are connected to the network via power electronic devices. These producers - in contrast to conventional synchronous generators - and consumers do not have a rotating mass with direct coupling to the electric system, which would be...
The foreseen high penetration levels of wind energy will have serious implications on frequency stability, hence developed control methods of wind turbine and alternative technologies including energy storage should enable the provision of frequency support by wind power. Active research is ongoing to investigate the possibility of collecting and transmitting offshore wind power through low frequency...
The current and massive deployment of non-synchronous generation is degrading the inertial response in power systems. The addition of an extra control loop, the so-called synthetic inertia, can contribute in the improvement of the frequency response, through an additional power injection. In this paper, the active damping method is used to enhance both, the closed-loop current control and the synthetic...
This paper presents a model of multiple DC microgrids with battery energy storage systems and demand response capability, taking part in primary frequency regulation of electrical power system. Although DC microgrids can contribute to stability and efficiency of frequency regulation, these complex systems may cause serious stability issues due to the imperfect communication. This work presents possible...
This paper presents a frequency control mechanism for an AC system through the active and reactive power loops of a VSC-HVDC system. The proposed scheme makes use of the reactive power loop for inertia support by exploiting the voltage-power sensitivity of loads, and active power droop control has been used to provide governor-like support following the large-disturbance. The performance of the presented...
This paper presents a novel approach, which identifies a buffer zone around a given study system and replaces the external system with an equivalent. The aim is to obtain a reduced system, which is suitable for assessment of long-term voltage and frequency dynamics in the study system. First, the proposed methodology ensures that all components, which are impacting the voltage profile of the study...
To achieve expected active power balancing in the transmission network and regulate frequency in a practical way, aggregate controllable loads would be useful. Such a scheme would need to be granulated down to sub-transmission networks in which active power flows affect both frequency and bus voltage, and hence a new control method should be adopted. A control scheme is proposed for sub-transmission...
This paper aims to propose a secondary control algorithm based on Fuzzy Logic to adjust frequency and voltage in islanded microgrids. It is well-known, that, when a microgrid changes its operation from grid-connected to islanded mode, the time domain variability of the loads will change the frequency and voltage profiles of the system. In this sense, the operation of the system might become unsafe...
This paper presents some experiences concerning the testing of generating units response to frequency transient. The tests have been performed both for modeling and monitoring the compliance of the settings of the generating units with the operational requirements. A test methodology, based on mathematical modeling, is developed and proposed. The approach is intended to interfere (or disturb) less...
Load frequency control in an islanded microgrid is challenging due to the low system inertia and random power variations resulting from renewable energy sources and loads. The traditional droop control mechanism may become unstable under some conditions. To overcome this problem a new control algorithm is proposed in this paper. The necessary condition derived to ensure the frequency stability is...
This paper proposes a frequency regulation strategy applied to wind turbine generators (WTGs) in an isolated grid. In order to complement active power shortage caused by sudden load or wind speed change, an improved deloading method is proposed to solve inconsistent regulation capabilities in different speed regions and provide WTGs a certain capacity of power reserves. Considering the torque compensation...
This paper proposed new position control method with acceleration feedforward compensation under the limited control bandwidth in the position control system of the EGR valve. This method estimates the acceleration reference through analysis of the relation between position controller output and speed reference without pattern and differential. The proportional gain of the position controller and...
Renewable Energy (RE) units especially grid connected Wind and Solar PV which have no rotational inertia are effectively displacing the conventional generators and their rotating systems. This reduces both the cost of generation and environmental effects. However, this has implications on the frequency stability in that frequency dynamics become faster with low inertia. This makes frequency control...
This paper proposes a smoothing method of frequency fluctuations of power system due to the varying output of wind farms (WFs) by using High Voltage Direct Current (HVDC) transmission system. The proposed control method is designed to minimize the fluctuations of the power system frequency without any additional installation of energy storage systems such as batteries. Simulation analysis is performed...
It is of great importance to mitigate frequency fluctuation in power systems with high penetration of renewable energy sources such as wind turbines and photovoltaics. Especially, in isolated microgrids like island power systems, frequency regulation becomes more significant because the system frequency easily changes by relatively small moment of inertia. To cover the small system inertia, it is...
This paper proposes a controller for energy storage (ES) to improve damping of power system oscillation. The controller manages charge and discharge of an ES device to respond to the real-time frequency deviation measured locally to provide positive damping effects. The expected damping ratio improvement from an ES equipped with this controller is derived mathematically from a single-machine-infinite-bus...
The future in electric power supplying is characterized by huge deployment of AC and DC distributed generations (DG). The main requirement was caused by the maximum use of local energy resources in countries with advanced technologies with good cost flows, into the usable energy forms. Huge possibility has especially photovoltaic generation together with accumulation systems or with others local power...
This paper proposes a Dynamic Regulation Market Mechanism (DRMM) that results in improved financial settlements for wholesale electricity markets. The DRMM dispatches control signals at the Tertiary Control (TC) level based on a co-optimization problem that jointly optimizes energy production and reserve capacity. At the Secondary Control (SC) level the DRMM dispatches control signals using an iterative...
Power networks have to withstand a variety of disturbances that affect system frequency, and the problem is compounded with the increasing integration of intermittent renewable generation. Following a large-signal generation or load disturbance, system frequency is arrested leveraging primary frequency control provided by governor action in synchronous generators. In this work, we propose a framework...
This paper presents a feedback Takagi-Sugeno Fuzzy control in finite frequency for wind energy conversion systems (WECS) improved by artificial neural network. The wind energy conversion system model is represented by a Takagi-Sugeno fuzzy (TSF) model. The finite frequency approach is proposed to control the closed-loop system in an operating finite frequency domain. However, when the external perturbations...
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