scholarly journals Features of autonomous and parallel operation of an asynchronous generator with a network of endless power in the current stage of EPS development

2021 ◽  
Vol 289 ◽  
pp. 07019
Author(s):  
Yunus Bobojonov ◽  
Tolqin Alibekova ◽  
Asror N Sultonov ◽  
Polat Quwatbaev ◽  
Atabek Ismandiyarov
Keyword(s):  
Reactive Power ◽  
Active Power ◽  
Electric Power System ◽  
Power Network ◽  
Parallel Operation ◽  
Asynchronous Machines ◽  
Reliable Source ◽  
Asynchronous Generator ◽  
Infinite Power ◽  
Current Stage

The article describes the use of asynchronous machines in generator mode to provide power to threephase consumers, as well as the features of autonomous and parallel operation of an asynchronous generator with an infinite power network. The use of static sources of reactive power allows widespread introduction of an asynchronous generator in the electric power system as a reliable source of active power.

Reactive Power Optimization Problem Research Based on Node-Voltage-Based and Branch-Current-Based Hybrid Electric Power Network Equations

2012 ◽  
Vol 614-615 ◽  
pp. 751-760
Author(s):  
Guo You Wang ◽  
Xi Lin Zhang ◽  
Yu Shi ◽  
Yang Liu ◽  
Cheng Min Wang ◽  
...  
Keyword(s):  
Electric Power ◽  
Computational Efficiency ◽  
Optimization Problem ◽  
Reactive Power ◽  
Power Optimization ◽  
Electric Power System ◽  
Power Network ◽  
Reactive Power Optimization ◽  
Hybrid Electric ◽  
Node Voltage

The electric power system is a specific example among various networks in nature and human society, in which the network flow models and arithmetic can be applied. The node-voltage-based and branch-current-based hybrid electric power network equations are established in this paper, and the reactive power optimization problem is modeled based on the established network equations. It is respectively solved while the reactive power optimization problem is decomposed as two sub-problems, among which a sub-problem is described by quadric minimum cost flow model and another one is expressed by a linear equations. Thereby, the complexity and dimensions of reactive power optimization problem are distinctly reduced due to the two decomposed sub-problems are easy to solve. It is proved that found optimal solution is closed to global by the computational efficiency analysis. The case study is made at IEEE-30 system and it is indicated that proposed approach could improve the computational efficiency of reactive power optimization problem by comparing with traditional optimal power flow arithmetic.

scholarly journals Modeling and Simulation of the Anticipated Effects of the Synchronous Condenser on an Electric-Power Network with Participating Wind Plants

2018 ◽  
Vol 10 (12) ◽  
pp. 4834 ◽  
Author(s):  
Famous Igbinovia ◽  
Ghaeth Fandi ◽  
Ibrahim Ahmad ◽  
Zdenek Muller ◽  
Josef Tlusty
Keyword(s):  
Electric Power ◽  
Power Plants ◽  
Reactive Power ◽  
Short Circuit ◽  
Assessment Method ◽  
Active Power ◽  
Power Network ◽  
Electricity Grid ◽  
Systematic Assessment ◽  
Synchronous Condenser

Installing a synchronous condenser (SC) onto an electricity grid can assist in the areas of reactive power needs, short-circuit strength, and, consequently, system inertia and guarantees better dynamic voltage recovery. This paper summarizes the practical potential of the synchronous condenser coordinated in an electric-power network with participating wind plants to supply reactive power compensation and injection of active power at their point of common coupling; it provides a systematic assessment method for simulating and analyzing the anticipated effects of the synchronous condenser on a power network with participating wind plants. A 33-kV power line has been used as a case study. The results indicate that the effect of the adopted synchronous condenser solution model in the MATLAB/Simulink environment provides reactive power, enhances voltage stability, and minimizes power losses, while the wind power plants provide active power support with given practical grid rules.

scholarly journals The Reactive Power Support Strategy based on Dual-loop Control for Three-phase Grid-connected Inverter

2020 ◽  
Vol 182 ◽  
pp. 02011
Author(s):  
WAN Qian ◽  
Xia Chengjun ◽  
Azeddine Houari ◽  
Zhao Xue ◽  
Xia Chengjun ◽  
...  
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Active Power ◽  
Electric Power System ◽  
Pv System ◽  
Loop Control ◽  
Pv Array ◽  
Three Phase

Renewable energy sources (RESs) generally connected with electric power system via power electronic interface. This paper presents a reactive power and voltage (Q/V) control strategy of three-phase photovoltaic (PV) system to offering reactive power based on the typical dual-loop control topology. It is worth mentioning that control strategy can support reactive power when a low voltage fault occurs in AC bus without additional compensation device. With the help of the decoupling control, the PV array can generate active power as much as possible in variable external solar radiation conditions. The voltage of PV arrays is adopted as the objective, which on account of the easy availability and controllability of voltage, to control output active power. Besides, accurately modeling process from a PV cell to PV array is described in the beginning to acquire the P-V and V-I characteristics of PV arrays, which promote the designment of Q/V control.

scholarly journals Compensation of Reactive Power and Unbalanced Power in Three-Phase Three-Wire Systems Connected to an Infinite Power Network

2019 ◽  
Vol 10 (1) ◽  
pp. 113 ◽  
Author(s):  
Pedro A. Blasco ◽  
Rafael Montoya-Mira ◽  
José M. Diez ◽  
Rafael Montoya ◽  
Miguel J. Reig
Keyword(s):  
Linear Systems ◽  
Reactive Power ◽  
Current System ◽  
Positive Sequence ◽  
Power Network ◽  
Negative Sequence ◽  
Three Phase ◽  
Network Losses ◽  
Infinite Power

The compensation of an electrical system from passive compensators mainly focuses on linear systems where the consumption of charges does not vary significantly over time. In three-phase three-wire systems, when the network voltages are unbalanced, negative-sequence voltages and currents appear, which can significantly increase the total apparent power supplied by the network. This also increases the network losses. This paper presents a method for calculating the compensation of the positive-sequence reactive power and unbalanced powers caused by the negative-sequence line currents using reactive elements (coils and/or capacitors). The compensation is applied to three-phase three-wire linear systems with unbalanced voltages and loads, which are connected to an infinite power network. The method is independent of the load characteristics, where only the line-to-line voltages and line currents, at the point where compensation is desired, need to be known in advance. The solution obtained is optimal, and the system observed from the network behaves as one that only consumes the active power required by a load with a fully balanced current system. To understand the proposed method and demonstrate its validity, a case study of a three-phase three-wire linear system connected to an infinite power network with unbalanced voltages and currents is conducted.

scholarly journals A review of voltage and reactive power control algorithms in medium voltage distribution networks

2021 ◽  
Vol 897 (1) ◽  
pp. 012016
Author(s):  
S Šantaras
Keyword(s):  
Distributed Generation ◽  
Power Loss ◽  
Reactive Power ◽  
Heuristic Algorithms ◽  
Distribution Networks ◽  
Active Power ◽  
Control Methods ◽  
Power Network ◽  
Medium Voltage ◽  
Distributed Generators

Abstract Current power network was built in mind that there will be mostly one-way power transmission, but as there is increasing penetration of distributed generation (DG), power network evolves and changes. Thereof old control strategies and algorithms used in power distribution do not fully utilize ever evolving power network in ensuring minimum active power loses, best distribution power generation for optimal voltage and frequency control. The main objective of this paper is review and comparison of heuristic algorithms in medium-voltage (MV) distribution networks with high distributed generation (DG) penetration. The specific goal is integrating reviewed algorithms in distributer power network control to minimise power loss, control active and reactive power flow between transmission and distribution power networks and utilization of current power network structure with growing number distributed generation penetration and thus minimizing required cost for its upgrade. Due to complexity of different power network structures and control methods used in managing it, algorithms are reviewed used in ensuring fast and reliable calculations by guaranteeing as minimum active power loss as possible and by improving power system performance over existing centralised as well as decentralised control methods. For both control methods distributed generators requires to be endowed with communication capabilities, as it is effective in driving the voltages within the admissible intervals and, additionally, it exploits the cooperation among the distributed generators and controllers to reach power network objectives of minimal power loss, voltage stability as mentioned before.

A New Method for Online Steady-State Power Flow Calculation in Electric Power System

2013 ◽  
Vol 816-817 ◽  
pp. 1090-1093 ◽  
Author(s):  
Hai Bao ◽  
Xin Huang ◽  
Ling Wang ◽  
Gang Liu
Keyword(s):  
Power Flow ◽  
Reactive Power ◽  
Active Power ◽  
Electric Power System ◽  
New Method ◽  
Power Measurement ◽  
Power Flow Calculation ◽  
Flow Calculation ◽  
Measuring Accuracy ◽  
The Given

Owing to the given variables are measurable in online power flow calculation, the electrical variables of higher measuring accuracy should be chosen for calculation. Currently the theory of reactive power is deficient and several methods for reactive power measurement are briefly introduced in this paper. The inaccuracy of those methods is pointed out by the relevant references in non-sinusoidal conditions. The measuring accuracy of Active power directly obtained by voltage and current is the same as that of voltage and current. For increasing the accuracy of online power flow calculation, a method substituting voltage magnitude for reactive power is proposed in this paper. The new method eliminates the effects resulted from inaccurate reactive power measurement. The simulation results on software MATPOWER verify the correctness and rationality of the new method.

Improving the efficiency of oilfield electric power distribution

2019 ◽  
pp. 79-87
Author(s):  
Yu. F. Yu. F. Romaniuk ◽  
О. V. Solomchak ◽  
М. V. Hlozhyk
Keyword(s):  
Power Distribution ◽  
Reactive Power ◽  
Power Transmission ◽  
Transmission Efficiency ◽  
Active Power ◽  
Oil Field ◽  
Total Power ◽  
Simultaneous Increase ◽  
Active Load ◽  
Step Down

The issues of increasing the efficiency of electricity transmission to consumers with different nature of their load are considered. The dependence of the efficiency of the electric network of the oil field, consisting of a power line and a step-down transformer, on the total load power at various ratios between the active and reactive components of the power is analyzed, and the conditions under which the maximum transmission efficiency can be ensured are determined. It is shown by examples that the power transmission efficiency depends not only on the active load, but also largely on its reactive load. In the presence of a constant reactive load and an increase in active load, the total power increases and the power transmission efficiency decreases. In the low-load mode, the schedule for changing the power transmission efficiency approaches a parabolic form, since the influence of the active load on the amount of active power loss decreases, and their value will mainly depend on reactive load, which remains unchanged. The efficiency reaches its maximum value provided that the active and reactive components of the power are equal. In the case of a different ratio between them, the efficiency decreases. With a simultaneous increase in active and reactive loads and a constant value of the power factor, the power transmission efficiency is significantly reduced due to an increase in losses. With a constant active load and an increase in reactive load, efficiency of power transmission decreases, since with an increase in reactive load, losses of active power increase, while the active power remains unchanged. The second condition, under which the line efficiency will be maximum, is full compensation of reactive power.  Therefore, in order to increase the efficiency of power transmission, it is necessary to compensate for the reactive load, which can reduce the loss of electricity and the cost of its payment and improve the quality of electricity. Other methods are also proposed to increase the efficiency of power transmission by regulating the voltage level in the power center, reducing the equivalent resistance of the line wires, optimizing the loading of the transformers of the step-down substations and ensuring the economic modes of their operation.

scholarly journals Improving Power Quality by a Four-Wire Shunt Active Power Filter: A Case Study

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1951
Author(s):  
Mihaela Popescu ◽  
Alexandru Bitoleanu ◽  
Mihaita Linca ◽  
Constantin Vlad Suru
Keyword(s):  
Power Quality ◽  
Quality Indicators ◽  
Reactive Power ◽  
Control Method ◽  
Active Power Filter ◽  
Active Power ◽  
Current Control ◽  
Shunt Active Power Filter ◽  
Power Filter ◽  
Unbalanced Load

This paper presents the use of a three-phase four-wire shunt active power filter to improve the power quality in the Department of Industrial Electronics of a large enterprise from Romania. The specificity is given by the predominant existence of single-phase consumers (such as personal computers, printers, lighting and AC equipment). In order to identify the power quality indicators and ways to improve them, an A-class analyzer was used to record the electrical quantities and energy parameters in the point of common coupling (PCC) with the nonlinear loads for 27 h. The analysis shows that, in order to improve the power quality in PCC, three goals must be achieved: the compensation of the distortion power, the compensation of the reactive power and the compensation of the load unbalance. By using the conceived three-leg shunt active power filter, controlled through the indirect current control method in an original variant, the power quality at the supply side is very much improved. In the proposed control algorithm, the prescribed active current is obtained as a sum of the loss current provided by the DC voltage and the equivalent active current of the unbalanced load. The performance associated with each objective of the compensation is presented and analyzed. The results show that all the power quality indicators meet the specific standards and regulations and prove the validity of the proposed solution.

scholarly journals Using Energy Storage Inverters of Prosumer Installations for Voltage Control in Low-Voltage Distribution Networks

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1121
Author(s):  
Rozmysław Mieński ◽  
Przemysław Urbanek ◽  
Irena Wasiak
Keyword(s):  
Energy Storage ◽  
Control Strategy ◽  
Reactive Power ◽  
Low Voltage ◽  
Storage System ◽  
Distribution Networks ◽  
Energy Storage System ◽  
Voltage Regulation ◽  
Active Power ◽  
Total Power

The paper includes the analysis of the operation of low-voltage prosumer installation consisting of receivers and electricity sources and equipped with a 3-phase energy storage system. The aim of the storage application is the management of active power within the installation to decrease the total power exchanged with the supplying network and thus reduce energy costs borne by the prosumer. A solution for the effective implementation of the storage system is presented. Apart from the active power management performed according to the prosumer’s needs, the storage inverter provides the ancillary service of voltage regulation in the network according to the requirements of the network operator. A control strategy involving algorithms for voltage regulation without prejudice to the prosumer’s interest is described in the paper. Reactive power is used first as a control signal and if the required voltage effect cannot be reached, then the active power in the controlled phase is additionally changed and the Energy Storage System (ESS) loading is redistributed in phases in such a way that the total active power set by the prosumer program remains unchanged. The efficiency of the control strategy was tested by means of a simulation model in the PSCAD/EMTDC program. The results of the simulations are presented.

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