scholarly journals A Model Predictive Control for the Dynamical Forecast of Operating Reserves in Frequency Regulation Services

Forecasting ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 228-241
Author(s):  
Pavlos Nikolaidis ◽  
Harris Partaourides
Keyword(s):  
Power Systems ◽  
Real Time ◽  
Renewable Energy Sources ◽  
Great Accuracy ◽  
Frequency Regulation ◽  
Feed Forward Neural Network ◽  
Reserve Requirements ◽  
Model Control ◽  
Regulation Services ◽  
System Frequency

The intermittent and uncontrollable power output from the ever-increasing renewable energy sources, require large amounts of operating reserves to retain the system frequency within its nominal range. Based on day-ahead load forecasts, many research works have proposed conventional and stochastic approaches to define their optimum margins for reliability enhancement at reasonable production cost. In this work, we aim at delivering real-time load forecasting to lower the operating-reserve requirements based on intra-hour weather update predictors. Based on critical predictors and their historical data, we train an artificial model that is able to forecast the load ahead with great accuracy. This is a feed-forward neural network with two hidden layers, which performs real-time forecasts with the aid of a predictive model control developed to update the recommendations intra-hourly and, assessing their impact and its significance on the output target, it corrects the imposed deviations. Performing daily simulations for an annual time-horizon, we observe that significant improvements exist in terms of decreased operating reserve requirements to regulate the violated frequency. In fact, these improvements can exceed 80% during specific months of winter when compared with robust formulations in isolated power systems.

scholarly journals Modeling Vehicles to Grid as a Source of Distributed Frequency Regulation in Isolated Grids with Significant RES Penetration

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 720 ◽  
Author(s):  
Neofytos Neofytou ◽  
Konstantinos Blazakis ◽  
Yiannis Katsigiannis ◽  
Georgios Stavrakakis
Keyword(s):  
Power Systems ◽  
Electric Vehicles ◽  
Renewable Energy Sources ◽  
Rapid Development ◽  
Frequency Regulation ◽  
Charging Station ◽  
Battery Capacity ◽  
Regulation Services ◽  
Primary Frequency ◽  
The Impact

The rapid development of technology used in electric vehicles, and in particular their penetration in electricity networks, is a major challenge for the area of electric power systems. The utilization of battery capacity of the interconnected vehicles can bring significant benefits to the network via the Vehicle to Grid (V2G) operation. The V2G operation is a process that can provide primary frequency regulation services in the electric network by exploiting the total capacity of a fleet of electric vehicles. In this paper, the impact of the plug-in hybrid electric vehicles (PHEVs) in the primary frequency regulation is studied and the effects PHEVs cause in non-interconnected isolated power systems with significant renewable energy sources (RES) penetration. Also it is taken into consideration the requirements of users for charging their vehicles. The V2G operation can be performed either with fluctuations in charging power of vehicles, or by charging or discharging the battery. So an electric vehicle user can participate in V2G operation either during the loading of the vehicle to the charging station, or by connecting the vehicle in the charging station without any further demands to charge its battery. In this paper, the response of PHEVs with respect to the frequency fluctuations of the network is modeled and simulated. Additionally, by using the PowerWorld Simulator software, simulations of the isolated power system of Cyprus Island, including the current RES penetration are performed in order to demonstrate the effectiveness of V2G operation in its primary frequency regulation.

scholarly journals A secondary option market design for reserve procurement by renewable energy sources.

2021 ◽  
Author(s):  
Reza Ghaffari
Keyword(s):  
Power Generation ◽  
Power Systems ◽  
Real Time ◽  
Wind Power ◽  
Large Scale ◽  
Renewable Energy Sources ◽  
Wind Power Generation ◽  
Reliable Operation ◽  
Actual Load ◽  
Balancing Services

Wind power generation is uncertain and intermittent accentuating variability. Currently in many power systems worldwide, the total generation-load unbalance caused by mismatch between forecast and actual wind power output is handled by automatic governor control and real-time 5-minute balancing markets, which are operated by the independent system operators for maintaining reliable operation of power systems. Mechanisms such as automatic governor control and real-time 5-minute balancing markets are in place to correct the mismatch between the load forecast and the actual load. They are not designed to address increased uncertainty and variability introduced by large-scale wind power or solar power generation expected in the future. Thus, large-scale wind power generation with increased uncertainty and intermittency causing variability poses a techno-economic challenge of sourcing least cost load balancing services (reserve).

scholarly journals Evaluation of DFIGs’ Primary Frequency Regulation Capability for Power Systems with High Penetration of Wind Power

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6178
Author(s):  
Changgang Li ◽  
Zhi Hang ◽  
Hengxu Zhang ◽  
Qi Guo ◽  
Yihua Zhu ◽  
...  
Keyword(s):  
Power Systems ◽  
Wind Power ◽  
Frequency Control ◽  
Frequency Regulation ◽  
Continuous Increase ◽  
Factors Affecting ◽  
Doubly Fed ◽  
Primary Frequency ◽  
Regulation Model ◽  
System Frequency

Accompanying the continuous increase in wind power penetration, the power system inertia is reduced, and the system frequency regulation performance deteriorates. Wind turbine generators are required to participate in primary frequency regulation (PFR) to support system frequency. Here, the PFR capability of the widely-used doubly-fed induction generator (DFIG) is evaluated to estimate the participation of the DFIG in system frequency control. The frequency regulation model of the DFIG is established and briefly discussed. The equivalent PFR droop coefficient is then deduced from the model using a small signal increment method to evaluate the DFIG’s PFR capability. Key factors affecting the equivalent droop coefficient are studied, and the droop control is optimized to keep the equivalent droop coefficient in the desired range. The proposed method is verified utilizing a provincial power grid model of China.

scholarly journals Application of Synchrophasor Measurements for Improving Situational Awareness of the Power System

2018 ◽  
Vol 55 (2) ◽  
pp. 3-10
Author(s):  
A. Obushevs ◽  
A. Mutule
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Real Time ◽  
Situational Awareness ◽  
Renewable Energy Sources ◽  
Electric Power System ◽  
Energy Sources ◽  
Scada Systems

Abstract The paper focuses on the application of synchrophasor measurements that present unprecedented benefits compared to SCADA systems in order to facilitate the successful transformation of the Nordic-Baltic-and-European electric power system to operate with large amounts of renewable energy sources and improve situational awareness of the power system. The article describes new functionalities of visualisation tools to estimate a grid inertia level in real time with monitoring results between Nordic and Baltic power systems.

scholarly journals Real-Time Flexibility Assessment for Power Systems with High Wind Energy Penetration

Mathematics ◽  
2021 ◽  
Vol 9 (17) ◽  
pp. 2056
Author(s):  
Anna Glazunova ◽  
Evgenii Semshikov ◽  
Michael Negnevitsky
Keyword(s):  
Power Systems ◽  
Wind Energy ◽  
Real Time ◽  
Renewable Energy Sources ◽  
Electric Circuit ◽  
Critical Issue ◽  
Electric Power System ◽  
Electricity Production ◽  
High Wind ◽  
Operational Conditions

To reduce the reliance on fossil fuel-based generation, many countries expand the use of renewable energy sources (RES) for electricity production. The stochastic and intermittent nature of such sources (i.e., wind and solar) poses challenges to the stable and reliable operation of the electric power system (EPS) and requires sufficient operational flexibility. With continuous and random changes in the EPS operational conditions, evaluating the system flexibility in a standardized manner may improve the robustness of planning and operating procedures. Therefore, the development of fast algorithms for determining system flexibility is a critical issue. In this paper, the flexibility of the EPS with high wind energy penetration is calculated in real time. In this context, the EPS flexibility is understood as the ability of the system to maintain a balance under irregular and short-term active power variations during a specified time by using the flexibility resources. The EPS flexibility calculation relies on a deterministic method developed to qualitatively and quantitatively assess the EPS readiness to changes in load. Accurate wind power forecasts and the observance of the electric circuit law when solving the optimization problem allow for determining the actual value of the EPS flexibility during a considered time.

Grid Stabilization with Decentralized Controllable Loads using Fuzzy Control and Droop Characteristics

2014 ◽  
Vol 15 (4) ◽  
pp. 357-365 ◽  
Author(s):  
Michael Palmer ◽  
Masato Tachibana ◽  
Tomonobu Senjyu ◽  
Toshihisa Funabashi ◽  
Ahmed Y. Saber ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Heat Pump ◽  
Renewable Energy Sources ◽  
Resource Depletion ◽  
Economic Benefits ◽  
Water Heater ◽  
Water Heaters ◽  
Distributed Generators ◽  
System Frequency

Abstract In recent years, the amount of distributed generators in the power grid has increased. Most of these distributed generators are renewable energy facilities using wind turbine generators or photovoltaic power systems. The increase in distributed generators is mostly due to environmental issues, growing concern of resource depletion, and economic benefits for residents and homeowners. Along with the increase in distributed generators, all-electric apartment buildings and residential homes with electric vehicles are on the rise. This trend is beneficial for both the environment and the residents; however, the fluctuating power from renewable energy sources and unstable loads causes fluctuations in grid frequency and distributed voltage which become problematic. This paper presents a methodology to control system frequency and distributed voltage using distributed controllable loads such as the heat pump water heater (HP) and large capacity batteries such as those of the electric vehicle (EV). By applying a power consumption controller using decentralized control for heat pump water heaters and droop characteristics for batteries, fluctuations of grid frequency and voltage are suppressed to a desired value. In order to verify the effectiveness of the proposed system, MATLAB/Simulink is used for simulations.

scholarly journals Advantages of Applying Large-Scale Energy Storage for Load-Generation Balancing

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3093
Author(s):  
Dawid Chudy ◽  
Adam Leśniak
Keyword(s):  
Energy Storage ◽  
Power Systems ◽  
Large Scale ◽  
Unit Commitment ◽  
Renewable Energy Sources ◽  
Frequency Regulation ◽  
The Cost ◽  
Further Development ◽  
Proper Operation ◽  
Load Generation

The continuous development of energy storage (ES) technologies and their wider utilization in modern power systems are becoming more and more visible. ES is used for a variety of applications ranging from price arbitrage, voltage and frequency regulation, reserves provision, black-starting and renewable energy sources (RESs), supporting load-generation balancing. The cost of ES technologies remains high; nevertheless, future decreases are expected. As the most profitable and technically effective solutions are continuously sought, this article presents the results of the analyses which through the created unit commitment and dispatch optimization model examines the use of ES as support for load-generation balancing. The performed simulations based on various scenarios show a possibility to reduce the number of starting-up centrally dispatched generating units (CDGUs) required to satisfy the electricity demand, which results in the facilitation of load-generation balancing for transmission system operators (TSOs). The barriers that should be encountered to improving the proposed use of ES were also identified. The presented solution may be suitable for further development of renewables and, in light of strict climate and energy policies, may lead to lower utilization of large-scale power generating units required to maintain proper operation of power systems.

scholarly journals Optimal Distribution Coefficients of Energy Resources in Frequency Stability of Hybrid Microgrids Connected to the Power System

Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1591
Author(s):  
Mohsen Arzani ◽  
Ahmadreza Abazari ◽  
Arman Oshnoei ◽  
Mohsen Ghafouri ◽  
S.M. Muyeen
Keyword(s):  
Power Systems ◽  
Frequency Control ◽  
Renewable Energy Sources ◽  
Distribution Coefficients ◽  
Power Grids ◽  
Energy Resources ◽  
Frequency Regulation ◽  
Transient Effects ◽  
Operational Conditions ◽  
Optimal Control Scheme

The continuous stability of hybrid microgrids (MGs) has been recently proposed as a critical topic, due to the ever-increasing growth of renewable energy sources (RESs) in low-inertia power systems. However, the stochastic and intermittent nature of RESs poses serious challenges for the stability and frequency regulation of MGs. In this regard, frequency control ancillary services (FCAS) can be introduced to alleviate the transient effects during substantial variations in the operating point and the separation from main power grids. In this paper, an efficient scheme is introduced to create a coordination among distributed energy resources (DERs), including combined heat and power, diesel engine generator, wind turbine generators, and photovoltaic panels. In this scheme, the frequency regulation signal is assigned to DERs based on several distribution coefficients, which are calculated through conducting a multi-objective optimization problem in the MATLAB environment. A meta-heuristic approach, known as the artificial bee colony algorithm, is deployed to determine optimal solutions. To prove the efficiency of the proposed scheme, the design is implemented on a hybrid MG. Various operational conditions which render the system prone to experience frequency fluctuation, including switching operation, load disturbance, and reduction in the total inertia of hybrid microgrids, are studied in PSCAD software. Simulation results demonstrate that this optimal control scheme can yield a more satisfactory performance in the presence of grid-following and grid-forming resources during different operational conditions.

scholarly journals Grid-Following Mode Operation of Small-Scale Distributed Battery Energy Storages for Fast Frequency Regulation in a Mixed-Source Microgrid

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7710
Author(s):  
Amir Hussain ◽  
Wajiha Shireen
Keyword(s):  
Real Time ◽  
Renewable Energy Sources ◽  
Synchronous Generator ◽  
Frequency Instability ◽  
Power Converter ◽  
Rate Of Change ◽  
Frequency Regulation ◽  
Small Scale ◽  
Power Imbalance ◽  
Battery Energy

As the share of power converter-based renewable energy sources (RESs) is high, a microgrid, in islanded mode, is more vulnerable to frequency instability due to (1) sudden power imbalance and (2) low inertia. One of the most common approaches to address this issue is to provide virtual inertia to the system by appropriately controlling the grid-side converter of the RESs. However, the primary frequency controller (PFC) presented in this paper focuses on the fast compensation of power imbalance without adding inertia to the system. The proposed method is based on estimating the real-time power imbalance caused by a disturbance and compensating it using multiple small-scale distributed battery energy storage systems (BESSs). The power imbalance is estimated by observing the initial rate of change of frequency (RoCoF) following a disturbance. Based on the estimated power imbalance and the rating of the BESSs, the reference power for the BESSs is determined. The BESSs are controlled in grid-following mode to compensate for the power imbalance. The performance of the proposed PFC is verified using a Typhoon real-time simulator for various scenarios and is compared with the conventional virtual synchronous generator (VSG) controller.

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