scholarly journals A Machine Learning-Based Communication-Free PV Controller for Voltage Regulation

2021 ◽  
Vol 13 (21) ◽  
pp. 12208
Author(s):  
Shabib Shahid ◽  
Saifullah Shafiq ◽  
Bilal Khan ◽  
Ali T. Al-Awami ◽  
Muhammad Omair Butt

Due to the recent advancements in the manufacturing process of solar photovoltaics (PVs) and electronic converters, solar PVs has emerged as a viable investment option for energy trading. However, distribution system with large-scale integration of rooftop PVs, would be subjected to voltage upper limit violations, unless properly controlled. Most of the traditional solutions introduced to address this problem do not ensure fairness amongst the on-line energy sources. In addition, other schemes assume the presence of communication linkages between these energy sources. This paper proposes a control scheme to mitigate the over-voltages in the distribution system without any communication between the distributed energy sources. The proposed approach is based on artificial neural networks that can utilize two locally obtainable inputs, namely, the nodal voltage and node voltage sensitivity and control the PV power. The controller is trained using extensive data generated for various loading conditions to include daily load variations. The control scheme was implemented and tested on a 12.47 kV feeder with 85 households connected on the 220 V distribution system. The results demonstrate the fair control of all the rooftop solar PVs mounted on various houses to ensure the system voltage are maintained within the allowed limits as defined by the ANSI C84.1-2016 standard. Furthermore, to verify the robustness of the proposed PV controller, it is tested during cloudy weather condition and the impact of integration of electric vehicles on the proposed controller is also analyzed. The results prove the efficacy of the proposed controller.

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6532
Author(s):  
Vahab Rostampour ◽  
Thom S. Badings ◽  
Jacquelien M. A. Scherpen

We present a Buildings-to-Grid (BtG) integration framework with intermittent wind-power generation and demand flexibility management provided by buildings. First, we extend the existing BtG models by introducing uncertain wind-power generation and reformulating the interactions between the Transmission System Operator (TSO), Distribution System Operators (DSO), and buildings. We then develop a unified BtG control framework to deal with forecast errors in the wind power, by considering ancillary services from both reserves and demand-side flexibility. The resulting framework is formulated as a finite-horizon stochastic model predictive control (MPC) problem, which is generally hard to solve due to the unknown distribution of the wind-power generation. To overcome this limitation, we present a tractable robust reformulation, together with probabilistic feasibility guarantees. We demonstrate that the proposed demand flexibility management can substitute the traditional reserve scheduling services in power systems with high levels of uncertain generation. Moreover, we show that this change does not jeopardize the stability of the grid or violate thermal comfort constraints of buildings. We finally provide a large-scale Monte Carlo simulation study to confirm the impact of achievements.


Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Yinuo Huang ◽  
Licheng Wang ◽  
Kai Wang

Distributed rooftop photovoltaic (PV) generators prospered distributed generation (DG) in recent years. Certain randomness of rooftop PV connection may lead to significant PV power imbalance across three phases, especially in low-voltage distribution systems. Due to interphase line coupling, traditional Var compensation methods which typically have competent voltage regulation performance may become less effective in such PV imbalance scenarios. In this paper, the limitation of traditional Var compensation methods in voltage regulation with unbalanced PV power integration is demonstrated and comprehensively analyzed. After describing the voltage regulation challenge, based on the voltage sensitivity analysis, it is revealed that PV power unbalanced level together with equivalent mutual impedance among phase conductors has a significant impact on the effectiveness of traditional Var compensation methods on voltage regulation. On this basis, to improve the performance of voltage regulation methods, some suggestions are proposed for both current system operation and future distribution system planning. Numerical studies demonstrate the effectiveness of the proposed suggestions. Future rooftop PV integration in LV systems can benefit from this research.


2018 ◽  
Vol 27 (05) ◽  
pp. 1830002 ◽  
Author(s):  
C. Subramani ◽  
K. R. Ramanand

The current energy scenario in the world considering the overconsumption of fossil fuels as well as its disastrous impact on environment calls for the promotion of renewable resources to take part in the growth towards sustainable development. With the penetration of such intermittent renewable energy sources into the existing grid, it not only enhanced the capability of the grid but also posed challenges regarding system stability. A practical solution to these problems by means of a new technological concept called “electric springs” is presented in this paper which enhances the system stability and provides voltage regulation for the same. Reviewing the various analyses, control methodologies as well as applications regarding the electric spring provides the confidence to further analyze its scope in large-scale power distribution system.


2020 ◽  
Vol 12 (23) ◽  
pp. 9844
Author(s):  
Maximilian Borning ◽  
Larissa Doré ◽  
Michael Wolff ◽  
Julian Walter ◽  
Tristan Becker ◽  
...  

To mitigate global warming, the European Union aims at climate neutrality by 2050. In order to reach this, the transportation sector has to contribute especially, which accounts for about a quarter of the European greenhouse gas emissions. Herein, electricity-based fuels are a promising approach for reducing emissions. However, a large-scale deployment of electricity-based fuels has a significant impact on the power system due to high electricity demand and the requirement to use renewable energy sources in order to be sustainable. At the same time, this fuel production could offer additional flexibility for the power system. This article investigates the opportunities and challenges of electricity-based fuels and flexible electricity-based fuel production for the European power system. In a literature analysis, the pivotal role of electricity-based fuels for climate neutrality is confirmed. To analyze the impact of flexible fuel production, European power market simulations for the year 2035 are conducted. Results indicate that flexibilization leads to an increased integration of electricity based on renewable energy sources as well as reductions in both carbon dioxide emissions and total operational costs of the power system. However, very high flexibility levels also benefit high-emission power plants and may even lead to increased emissions.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 992
Author(s):  
Phi-Hai Trinh ◽  
Il-Yop Chung

Distributed energy resources (DERs), including renewable energy resources (RESs) and electric vehicles (EVs), have a significant impact on distribution systems because they can cause bi-directional power flow in the distribution lines. Thus, the voltage regulation and thermal limits of the distribution system to mitigate from the excessive power generation or consumption should be considered. The focus of this study is on a control strategy for DERs in low-voltage DC microgrids to minimize the operating costs and maintain the distribution voltage within the normal range based on intelligent scheduling of the charging and discharging of EVs, and to take advantage of RESs such as photovoltaic (PV) plants. By considering the time-of-use electricity rates, we also propose a 24-h sliding window to mitigate uncertainties in loads and PV plants in which the output is time-varied and the EV arrival cannot be predicted. After obtaining a request from the EV owner, the proposed optimal DER control method satisfies the state-of-charge level for their next journey. We applied the voltage sensitivity factor obtained from a load-flow analysis to effectively maintain voltage profiles for the overall DC distribution system. The performance of the proposed optimal DER control method was evaluated with case studies and by comparison with conventional methods.


Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6413
Author(s):  
Feng-Chang Gu ◽  
Hung-Cheng Chen

Large-scale wind farms in commercial operations have demonstrated growing influence on the stability of an electricity network and the power quality thereof. Variations in the output power of large-scale wind farms cause voltage fluctuations in the corresponding electrical networks. To achieve low-voltage ride-through capability in a doubly fed induction generator (DFIG) during a fault event, this study proposes a real-time reactive power control strategy for effective DFIG application and a static synchronous compensator (STATCOM) for reactive power compensation. Mathematic models were developed for the DFIG and STATCOM, followed by the development of an indirect control scheme for the STATCOM based on decoupling dual-loop current control. Moreover, a real-world case study on a commercial wind farm comprising 23 DFIGs was conducted. The voltage regulation performance of the proposed reactive power control scheme against a fault event was also simulated. The simulation results revealed that enhanced fault ride-through capability and prompt recovery of the output voltage provided by a wind turbine generator could be achieved using the DFIG along with the STATCOM in the event of a three-phase short-circuit fault.


2013 ◽  
Vol 724-725 ◽  
pp. 1344-1349
Author(s):  
Zhen Fu Zhang ◽  
Xiao Qing Huang ◽  
Bo Xiao

Large-scale adoption of electric vehicles may impose impact on grid. In order to formulate the appropriate scheme of time-of-use (TOU) to lower the adverse effect of charging load on the power grid, it is necessary to analyze the impact of the peak-valley period partition on the load curve of distribution system with electric vehicles. The electric vehicle charging load model considering TOU was built according to the statistics of the driving habits. Several scenarios were set according to different period partitions and the changes of the load at start time of valley period, numerical value and moment of peak load and peak-valley differences were analyzed with the Monte Carlo simulation method under those scenarios. The simulation results show that the farther between the time instant of peak load and start moment of valley period the less impact it has on load curve of distribution system.


Author(s):  
Silvia Tasnim ◽  
Md. Jashim Uddin ◽  
Synthia Tahsin ◽  
Khairul Anam

— The penetration of Electric Vehicle (EV) on the distribution network has been increased worldwide and this has also boosted up the impacts on power system performance affecting voltage profile, voltage sensitivity factor, harmonics, overloading, increased grid loss resulting in reduced efficiency and power quality. A coordinated charging schedule can reduce this stress on the power grid and show significant improvement of network parameters. In this study, by simulating through Power Factory built-in MV/LV distribution test system, the impact of increasing EV on the distribution system has been analyzed and a simple approach of charging schedule for a centralized charging station has been proposed that will minimize the deteriorating impacts on connected distribution system due to EV charging.


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