On the issue of improving the efficiency of power systems and substantiation of reactive power compensation in electric networks

2021 ◽  
Vol 13 (4) ◽  
pp. 267-272
Author(s):  
M. M. Sultanov ◽  
A. V. Strizhichenko ◽  
I. A. Boldyrev ◽  
O. I. Zhelyaskova ◽  
E. A. Voloshin ◽  
...  
Keyword(s):  
High Voltage ◽  
Active Component ◽  
Reactive Power ◽  
Voltage Drop ◽  
Reactive Power Compensation ◽  
Power Losses ◽  
Reactive Component ◽  
Voltage Range ◽  
Electric Network ◽  
Active And Reactive Power

Reactive power in the power system negatively affects the operating mode of the electric network, additionally loading high-voltage lines and transformers, which leads to an increase in power losses, as well as to an increase in voltage drops. The influence of active and reactive power components of voltage in the network nodes is different and is overwhelmingly determined by the ratio of active and reactive components of the resistance elements of the electric system. In high-voltage networks, the reactive component of the resistance significantly exceeds the active component, and therefore the flow of reactive current through the network leads to a greater voltage drop than the flow of the active component of the current. The transfer of reactive power can lead to exceeding the normalized voltage range in the load nodes. To reduce power losses and voltage drop in the elements of the electric network, synchronous compensators (SC), static capacitor banks (SCB), static thyristor compensators (STC), controlled shunt reactors (CSR) can be used. The cost of production and transmission of active and reactive power are different, and when choosing the power of reactive power compensation means, it is necessary to take into account the costs and compare them with the resulting effect, which differs for large and small values of reactive power when this is reduced by the same amount. To assess the feasibility of application of compensatory devices, and to choose their type and locations of installation, relevant calculations are required. An empirical criterion is proposed for preliminary assessment of the technical feasibility of reactive power compensation. It enables to identify the network sections and nodes, which require reactive power compensation and should be considered in greater detail.

scholarly journals Coordinated Control of Active and Reactive Power Compensation for Voltage Regulation with Enhanced Disturbance Rejection Using Repetitive Vector-Control

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2812 ◽  
Author(s):  
Felipe J. Zimann ◽  
Eduardo V. Stangler ◽  
Francisco A. S. Neves ◽  
Alessandro L. Batschauer ◽  
Marcello Mezaroba
Keyword(s):  
Vector Control ◽  
Reactive Power ◽  
Low Voltage ◽  
Voltage Drop ◽  
Coordinated Control ◽  
Voltage Regulation ◽  
Reactive Power Compensation ◽  
Voltage Profile ◽  
Promising Alternative ◽  
Active And Reactive Power

Voltage profile is one of many aspects that affect power quality in low-voltage distribution feeders. Weak grids have a typically high line impedance which results in remarkable voltage drops. Distribution grids generally have a high R/X ratio, which makes voltage regulation with reactive power compensation less effective than in high-voltage grids. Moreover, these networks are more susceptible to unbalance and harmonic voltage disturbances. This paper proposes an enhanced coordinated control of active and reactive power injected in a distribution grid for voltage regulation. Voltage drop mitigation was evaluated with power injection based on local features, such loads and disturbances of each connection. In order to ensure disturbances rejection like harmonic components in the grid voltages, a repetitive vector-control scheme was used. The injection of coordinated active and reactive power with the proposed control algorithm was verified through simulations and experiments, demonstrating that it is a promising alternative for voltage regulation in weak and low-voltage networks subject to inherent harmonic distortion.

Algorithm of Fundamental Equivalent Susceptance of TCR Type SVC

2012 ◽  
Vol 457-458 ◽  
pp. 1047-1051 ◽  
Author(s):  
Qing Bo Meng ◽  
Gui Xiang Zhang
Keyword(s):  
Real Time ◽  
Active Component ◽  
Reactive Power ◽  
Reactive Power Compensation ◽  
Control Performance ◽  
Reactive Component ◽  
Power Theory ◽  
Instantaneous Reactive Power Theory ◽  
Instantaneous Reactive Power ◽  
Relationship Of

The paper expounds the topology of TCR type SVC and proposes the controller’s implementation. Based on instantaneous reactive power theory, the paper ascertains the overall algorithm on SVC reactive power compensation. It can be refined to three steps: the extraction of active component and reactive component of fundamental, the modeling of compensation susceptances required and the four components of fundamental, and the establishing relationship of the fundamental equivalent susceptance of TCR and the triggering angle.The control performance of the algorithm is valued on accuracy and real-time.

Reactive Power Compensation of Oilfield Distribution Systems Based on Tabu Search Algorithm

2013 ◽  
Vol 397-400 ◽  
pp. 1113-1116
Author(s):  
Xiao Meng Wu ◽  
Wang Hao Fei ◽  
Xiao Mei Xiang ◽  
Wen Juan Wang
Keyword(s):  
Power Loss ◽  
Distribution Systems ◽  
Reactive Power ◽  
Search Algorithm ◽  
Global Optimum ◽  
Reactive Power Compensation ◽  
Active Power ◽  
Voltage Profile ◽  
Voltage Range ◽  
Shunt Capacitors

In order to solve the problem in reactive power compensation of oilfield distribution systems at present, a Taboo search algorithm is proposed in this paper, by which the optimal location and size of shunt capacitors on distribution systems are determined. Then the voltage profile is improved and the active power loss is reduced. In this paper, Voltage qualified is used as objective function to search an initial solution that meets the voltage constraints so that it is feasible in practicable voltage range; then the global optimum solution can be got when taking the reduced maximum of active power loss as objective unction. The examples show that the improved algorithm is feasible and effective.

scholarly journals Active and Reactive Power Losses in Distribution Transformers

2020 ◽  
Vol 17 (1) ◽  
pp. 161-174
Author(s):  
Michal Kolcun ◽  
◽  
Anna Gawlak ◽  
Miroslaw Kornatka ◽  
Zsolt Čonka ◽  
...  
Keyword(s):  
Reactive Power ◽  
Power Losses ◽  
Active And Reactive Power ◽  
Distribution Transformers

A Procedure of Drawing up Integral Indicators for Comprehensively Estimating the Properties of Electric Power System Nodes

Vestnik MEI ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 11-18
Author(s):  
Nailia Sh. Chemborisova ◽  
◽  
Ivan D. Chernenkov ◽  
Keyword(s):  
Power System ◽  
Electric Power ◽  
Reactive Power ◽  
Voltage Regulation ◽  
Reactive Power Compensation ◽  
Electric Power System ◽  
Power Losses ◽  
System Operation ◽  
Active Power Losses ◽  
System Nodes

The problem of selecting the electric power system control nodes is studied. By performing control of these modes, matters concerned with providing reliable power supply of the required quality to consumers can be settled in the most efficient manner. As an example, a fragment of the electric power system mathematical model used in the Finist mode-setting simulator for a power system dispatch control center operator is considered, which represents a highly branched electrical network consisting of eleven 110 kV nodes, three 220 kV nodes connected with the system, and two generator nodes. A new procedure for selecting the control nodes is proposed, which takes into account a combination of different indicators having different measurement units, dimensions and scales is proposed. These indicators characterize the following properties of power system nodes: the reactive power fraction absorbed at a node, the sensitivity of voltage to reactive load variations, the number of connected power lines, and statistical indicators characterizing the change of voltage at the nodes and reactive power flows for different options of installing the reactive power compensation devices. For combined use of these indicators, they were ranked according to the efficiency of installing reactive power compensation devices in the system. For each indicator, a scale of five ranks (intervals) is set, which determine the preferences (qualitative judgments) of the researcher in evaluating the reactive power compensation devices installation efficiency at the system nodes. The highest rank (5) corresponds to the maximum efficiency, and the lowest rank (1) corresponds to the minimum efficiency. To calculate the individual (integral) priority indicator of installing reactive power compensation devices, the ranks of indicators are added together, and their sum is divided by the product of the number of ranks by the number of the used indicators (features). Based on the calculation results, the rating (location) of each node is determined, and the nodes for installing the reactive power compensation devices are selected according to their effect on ensuring the electric power system operation reliability, active power losses in the network, and voltage regulation. Thus, a new procedure is presented for determining the integral indicators for comprehensively estimating the properties of complex electric power system nodes and selecting the controlled nodes using a system of various indicators. These indicators characterize the studied nodes in terms of the efficiency of installing reactive power compensation devices to reduce active power losses in the network, voltage regulation, and ensuring the electric power system operational reliability. The validity of the results obtained in the study is confirmed by their comparison with the indicators of the balance-conductivity method, which has proven itself in solving problems connected with determining the nodes for controlling electric power system operation modes.

Reactive Power Compensation Method of HVDC Commutation Failure

2014 ◽  
Vol 536-537 ◽  
pp. 1510-1513
Author(s):  
Xiao Ming Wang ◽  
Qi Zhang ◽  
Bin Qian
Keyword(s):  
Reactive Power ◽  
Voltage Drop ◽  
Critical Value ◽  
Reactive Power Compensation ◽  
Transmission System ◽  
Critical Voltage ◽  
High Voltage Direct Current ◽  
Commutation Failure ◽  
The Difference ◽  
Bus Voltage

In the high-voltage direct current transmission system, the difference value between the landing phase voltage and DC transmission system commutation failure of the critical voltage drop value, as system occurred in the critical value of commutation failure. When commutation voltage lower than the critical value would reduce arc Angle, caused by commutation failure。Therefore, by using the method of reactive power compensation to keep converter bus voltage stability, can avoid commutation failure.

Researches on Reactive Compensation for Long-Distance and Highcapacity Hybrid Submarine Cable Lines

2012 ◽  
Vol 433-440 ◽  
pp. 2406-2410
Author(s):  
Dong Mei Sun ◽  
Jun Wen
Keyword(s):  
High Voltage ◽  
Transmission Lines ◽  
Reactive Power ◽  
High Capacity ◽  
Reactive Power Compensation ◽  
Submarine Cable ◽  
Long Distance ◽  
Power Frequency ◽  
Electro Magnetic ◽  
Cable Lines

In order to balance reactive power, reduce line losses, prevent excessive power frequency and switching over-voltage and adjust and control the line voltage etc. The long-distance and high voltage transmission lines are needed reactive power compensation. High voltage overhead transmission lines and high voltage submarine cable (including mixed-submarine) transmission lines are different, for example, the capacitance in the submarine cable lines is larger than in the conventional overhead lines. Therefore, the reactive power compensation on the EHV transmission lines which contains submarine cable lines is focus on the compensation of submarine cable lines. The reactive power compensation in 500 kV AC submarine cable interconnection project for Hainan power grid and Guangdong power grid[1], which is the first 500 kV long-distance and high-capacity sea trails interconnection project in China and which is just completed soon, is researched by Electro-Magnetic Transient Program——PSCAD/EMTDC (Power System Computer Aided Design/ Electro Magnetic Transient in DC System in this paper). The simulation results verifies that the role of shunt reactor which could absorb charging power and suppress the power frequency overvoltage for the long-distance and high-capacity hybrid submarine cable lines. The conclusions can offer references to suppress power frequency overvoltage and the reactive power compensation in extra high voltage transmission lines which is the mixed mode of overhead transmission lines and submarine cables.

Design of HTS Magnetically Controlled Saturable Reactor

2013 ◽  
Vol 380-384 ◽  
pp. 2982-2985
Author(s):  
Hong Da Dong
Keyword(s):  
High Temperature ◽  
High Voltage ◽  
Large Scale ◽  
Reactive Power ◽  
Magnetic Circuit ◽  
Reactive Power Compensation ◽  
Model Design ◽  
Power Capacity ◽  
Wide Range ◽  
Small Capacity

There are many problems for traditional reactive power compensation devices to be applied in the grid, such as discontinuous adjustment, small capacity, complex control and harmonics. This paper aims to study a high temperature superconducting magnetically controlled saturable reactor (HTS MCSR), which has a wide range of stepless adjustment. It has a good application prospect in large scale reactive power compensation devices. Based on research of theory and core structure, a shaped-cylinder core is proposed. By means of calculation of saturable reactor and analysis of algebraic and magnetic circuit model, design of 220V HTS MCSR is finished. Results of normal conductive reactor prototype and simulations verify that the range of inductance adjustment is very wide. Furthermore, conceptual design of 35kV HTS MCSR confirms its reactive power capacity is so large, therefore, it is suitable for high voltage power system.

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