Advantages of digitalization in grid restoration

2020 ◽  
Vol 68 (9) ◽  
pp. 790-803
Author(s):  
W. H. Wellßow ◽  
P. Hinkel ◽  
M. Zugck ◽  
C. Dumas ◽  
S. Hilgers ◽  
...  

AbstractIn Germany, the installed capacity of renewables exceeds the maximum load by far and the transmission task has changed from high-wind locations in the north to the economically strong south. In addition, the system inertia is reduced due to the decommissioning of large power stations. This leads to a higher probability of blackouts and a challenging restoration process. Operation during restoration differs strongly from normal. Besides other effects, the grid frequency is very sensitive to active power imbalances. An accurate power forecast of re-supplied feeders is required to estimate dynamic frequency deviations. Models for cold load pick-up (CLPU) and fluctuating renewable energy sources (RES) infeed are presented. For the coordination between Transmission system operators (TSO) and Distribution system operators (DSO) a clear and structured process is proposed to minimize the communication effort. Power system restoration (PSR) simulations are carried out and the results are presented.

2020 ◽  
Vol 209 ◽  
pp. 05015
Author(s):  
Dmitry Nogovitsyn ◽  
Zinaida Sheina ◽  
Ludmila Sergeeva

The article presents the results of expeditionary reconnaissance surveys of minor rivers in the Yana basin that allowed for the first time to estimate the installed capacity of seasonal micro-hydroelectric power stations for power supply to remote isolated localities. Works on the study of the hydrological characteristics of minor rivers in the territory under consideration have not been carried out before. For the first time, reliable information about the hydrological regime of rivers was obtained. This is primarily water consumption and the longitudinal grade of watercourse being the basis for making a decision on the location, determining the capacity of micro-power plants, as well as choosing the necessary hydroelectric equipment.


2020 ◽  
pp. 28-37
Author(s):  
Oleksandra V. Kubatko ◽  
Diana O. Yaryomenko ◽  
Mykola O. Kharchenko ◽  
Ismail Y. A. Almashaqbeh

Interruptions in electricity supply may have a series of failures that can affect banking, telecommunications, traffic, and safety sectors. Due to the two-way interactive abilities, Smart Grid allows consumers to automatically redirect on failure, or shut down of the equipment. Smart Grid technologies are the costly ones; however, due to the mitigation of possible problems, they are economically sound. Smart grids can't operate without smart meters, which may easily transmit real-time power consumption data to energy data centers, helping the consumer to make effective decisions about how much energy to use and at what time of day. Smart Grid meters do allow the consumer to track and reduce energy consumption bills during peak hours and increase the corresponding consumption during minimum hours. At a higher level of management (e.g., on the level of separate region or country), the Smart Grid distribution system operators have the opportunity to increase the reliability of power supply primarily by detecting or preventing emergencies. Ukraine's energy system is currently outdated and cannot withstand current loads. High levels of wear of the main and auxiliary equipment of the power system and uneven load distribution in the network often lead to emergencies and power outages. The Smart Grid achievements and energy sustainability are also related to the energy trilemma, which consists of key core dimensions– Energy Security, Energy Equity, and Environmental Sustainability. To be competitive in the world energy market, the country has to organize efficiently the cooperation of public/private actors, governments, economic and social agents, environmental issues, and individual consumer behaviors. Ukraine gained 61 positions out of 128 countries in a list in 2019 on the energy trilemma index. In general, Ukraine has a higher than average energy security position and lower than average energy equity, and environmental sustainability positions. Given the fact that the number of renewable energy sources is measured in hundreds and thousands, network management is complicated and requires a Smart Grid rapid response. Keywords: economic development, Smart Grid, electricity supply, economic and environmental efficiency.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1967
Author(s):  
Gaurav Kumar Roy ◽  
Marco Pau ◽  
Ferdinanda Ponci ◽  
Antonello Monti

Direct Current (DC) grids are considered an attractive option for integrating high shares of renewable energy sources in the electrical distribution grid. Hence, in the future, Alternating Current (AC) and DC systems could be interconnected to form hybrid AC-DC distribution grids. This paper presents a two-step state estimation formulation for the monitoring of hybrid AC-DC grids. In the first step, state estimation is executed independently for the AC and DC areas of the distribution system. The second step refines the estimation results by exchanging boundary quantities at the AC-DC converters. To this purpose, the modulation index and phase angle control of the AC-DC converters are integrated into the second step of the proposed state estimation formulation. This allows providing additional inputs to the state estimation algorithm, which eventually leads to improve the accuracy of the state estimation results. Simulations on a sample AC-DC distribution grid are performed to highlight the benefits resulting from the integration of these converter control parameters for the estimation of both the AC and DC grid quantities.


Electronics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 55
Author(s):  
Busra Uzum ◽  
Ahmet Onen ◽  
Hany M. Hasanien ◽  
S. M. Muyeen

In order to meet the electricity needs of domestic or commercial buildings, solar energy is more attractive than other renewable energy sources in terms of its simplicity of installation, less dependence on the field and its economy. It is possible to extract solar energy from photovoltaic (PV) including rooftop, ground-mounted, and building integrated PV systems. Interest in rooftop PV system applications has increased in recent years due to simple installation and not occupying an external area. However, the negative effects of increased PV penetration on the distribution system are troublesome. The power loss, reverse power flow (RPF), voltage fluctuations, voltage unbalance, are causing voltage quality problems in the power network. On the other hand, variations in system frequency, power factor, and harmonics are affecting the power quality. The excessive PV penetration also the root cause of voltage stability and has an adverse effect on protection system. The aim of this article is to extensively examines the impacts of rooftop PV on distribution network and evaluate possible solution methods in terms of the voltage quality, power quality, system protection and system stability. Moreover, it is to present a comparison of the advantages/disadvantages of the solution methods discussed, and an examination of the solution methods in which artificial intelligence, deep learning and machine learning based optimization and techniques are discussed with common methods.


2021 ◽  
Vol 22 (1) ◽  
pp. 113-127
Author(s):  
Mulualem Tesfaye ◽  
Baseem Khan ◽  
Om Prakash Mahela ◽  
Hassan Haes Alhelou ◽  
Neeraj Gupta ◽  
...  

Abstract Generation of renewable energy sources and their interfacing to the main system has turn out to be most fascinating challenge. Renewable energy generation requires stable and reliable incorporation of energy to the low or medium voltage networks. This paper presents the microgrid modeling as an alternative and feasible power supply for Institute of Technology, Hawassa University, Ethiopia. This microgrid consists of a 60 kW photo voltaic (PV) and a 20 kW wind turbine (WT) system; that is linked to the electrical distribution system of the campus by a 3-phase pulse width modulation scheme based voltage source inverters (VSI) and supplying power to the university buildings. The main challenge in this work is related to the interconnection of microgrid with utility grid, using 3-phase VSI controller. The PV and WT of the microgrid are controlled in active and reactive power (PQ) control mode during grid connected operation and in voltage/frequency (V/F) control mode, when the microgrid is switched to the stand-alone operation. To demonstrate the feasibility of proposed microgrid model, MATLAB/Simulink software has been employed. The performance of fully functioning microgrid is analyzed and simulated for a number of operating conditions. Simulation results supported the usefulness of developed microgrid in both mode of operation.


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