Analysis on the Application of Reactive Power Compensation Technology in Electrical Automation

This paper introduces in detail the reactive power compensation technology and its characteristics, to reduce the loss of reactive power compensation technology 1N power distribution system and the electrical automation, improve the utilization rate, and realize the control of the voltage amplitude in the system network, voltage stability of power distribution system, has carried on the system analysis to reduce failure of the harmonic current to the power supply system and other functions. And the paper in-depth study on the application of reactive power compensation technology in electrical automation from the reactive compensation technology, substation and distribution line reactive power compensation, power users of reactive power compensation and other aspects.

Design to conditioning circuits of dynamic compensation of reactive power in the intelligence voltage controller

The paper introduces one design idea that making use of SCM to control Real-timely the dynamic compensation of reactive power.Firstly,design one Circuit to Sample the voltage and current,and by these datas we can easily calculate the power factor,and Voltage controller in the microcontroller to determine whether input the compensation capacitance according to the size of power factor,the paper also analyzes the principle of capacitance compensation and calculation method. Dynamic compensation for the entire process is quick and accurate.

The design and simulation of TCR(thyristor control reactor) reactive power compensation system based on Arene

Inevitably, the question of reactive power compensation was aroused by applied of power electronics. Based on the study of the instantaneous reactive power theory, the designs of TCR(thyristor control reactor) thyristor control reactor reac- tive power compensation system and TCR single closed loop strategy was pro- posed. In addition, as digital simulation software, Arene was applied to simulate the Jining coal mine No.2 system. The simulation results validate that the design is effective to improve power factor and stabilization of the system.

Reactive Power Compensation and Harmonic Suppression for Power Supply System of HT-7U Superconductive Tokamak

In this paper, a strategy for the reactive power compensation and harmonic suppression of the power supply system in HT-7U superconductive Tokamak is proposed. The optimized approach is given in the parameters design for passive filter. Also a controlling method with fast response time and good accuracy is put forward for the compensator, which is more suitable for the dynamic load.

Microcontroller Control of Reactive Power Compensation for Growing Industrial Loads

Many industrial installations in developing countries start-up as small factories, without regard for the need of compensation of reactive power, leading to significant financial losses in the long term. By improving the power factor, the customer can reduce its power demand and potentially increase efficiency of their equipment. A PIC microcontroller is used to switch capacitor banks to compensate for the reactive power. In order to determine the size of the capacitor bank needed, the microcontroller calculates the phase difference between the voltage and the current. The results obtained based on the lagging power factor for three test loads show an improvement in the power factor from 0.52 to 0.96 under different test load conditions.

Fuzzy Decision Method Applied in Action of Reactive Power Compensation Devices in Wind System

Frequent occurrence of large-scale cascading trip-off of wind turbine raises the concern about the decision process of ordered control of reactive power compensation devices. The theory of fuzzy multi-attribute decision making is adopted to ascertain the action sequence of reactive power compensation devices. First, a set of evaluation indexes including control sensitivity, regulation margin, response time, response level and cost is set up, and fuzziness of the proposed qualitative indexes is introduced to make them comparable to the proposed quantitative indexes. Then a method to calculate fuzzy weight of each index is put forward for evaluating relative importance of the proposed indexes. Finally, the action sequence of reactive power compensation devices is determined through the theory of fuzzy compromise decision making. The case study shows that the proposed method is effective to obtain the action sequence of reactive power compensation device which correspond to experience.

Optimal Reactive Power Compensation of Distribution Network to Prevent Reactive Power Reverse

The capacitive reactive power reversal in the urban distribution grid is increasingly prominent at the period of light load in the last years.In severe cases,it will endanger the security and stability of power grid.This paper presents an optimal reactive power compensation method of distribution network to prevent reactive power reverse.Firstly,an integrated reactive power planning(RPP)model with power factor constraints is established.Capacitors and reactors are considered to be installed in the distribution system at the same time.The objective function is the cost minimization of compensation and real power loss with transformers and lines during the planning period.Nodal power factor limits and reactor capacity constraints are new constraints.Then,power factor sensitivity with respect to reactive power is derived.An improved genetic algorithm by power factor sensitivity is used to solve the model.The optimal locations and sizes of reactors and capacitors can avoid reactive power reversal and power factor exceeding the limit.Finally,the effectiveness of the model and algorithm is proven by a typical high-voltage distribution network.

Research on the Technology of Low Voltage Intelligent Reactive Compensation

In order to improve the power factor of the circuit, the article takes STM32 as core circuit to development reactive power compensation controller for low voltage intelligent reactive compensation. Circuit can detect electricity distribution network parameters, and send messages to mobile phone via SMS text messages by TC35 module, remote control compensation capacitor configuration parameters. Circuit with a flexible, reliable, convenient and practical features. This paper analyzes the structure of the controller hardware and software, and describes the hardware schematic circuit diagram and software diagram of the controller. Controller with integrated control, maximize the use of compensating equipment to improve grid power quality.

The Actuality and Development Trend of Var Compensation for Distribution System

Effective reactive power compensation is very important to the safe,economical and high quality running of power system.The principle and characteristic of several main reactive power compensation devices were analyzed and compared in details, and the development trend and application prospect were viewed.

Design and Analysis of the Poloidal Field Grid Power Supply System for the HT-7 Tokamak

This paper reports a new project - the poloidal field （PF） grid power supply system to replace the ac flywheel generator power supply system on the basis of the present running parameters of the HT-7 poloidal field and the short-circuit capacity of our transformer substation. The designed parameters of the PF grid power supply system have been verified to meet the requirements of the heating field （HF） and the vertical field （VF）. In the meantime, in order to reduce the disturbance to the local power grid, the device of reactive power and harmonic current compensation has been added. Experimental results have confirmed the feasibility of the PF grid power supply system. Compared with the ac flywheel generator, the PF grid power supply system has the advantages of lower noise, precise control, convenient maintenance, simple operation and cost savings.

The Development of Network based Composite Power quality Regulation Device

First, the paper analyzes the advantages and disadvantages of all kinds of reactive power compensation technology, and then proposes a principle and integrated control strategy of the composite operation of TSC and SVG, also the paper designs and develops the main controller of Network based composite power quality regulation device, based on RTDS, the real-time digital simulation model of The Device is established, and finally the prototype of the device is developed with the function of filter and split-phase compensation. The main controller determines the cooperative operation of both TSC and SVG, and the switching strategy of TSC. The simulation result in RTDS can verify the precision of the measure system and the validity of the control logic, the prototype has finished the type test according to the national standard.

A Case Study Survey of the Impact of the Inductive Loads on Power Quality

Power quality is a complex term that is defined by the legislation, but also as an obligation of the supplier and customer. The customer must return the negative effects of its consumers （taking reactive power, harmonic generation, phase unbalance） down to the prescribed limits. This primarily refers to the presence of non-linear consumers, leading to distortion of the basic parameters of voltage and current, in steady or transient conditions, and therefore the deformation of waveform. One way to reduce the negative feedback effects, especially with inductive loads, is the reactive energy compensation. The paper presents one of the solution for reactive power compensation, applied on the pumping station of public company ＂Waterworks and Sewerage---Bar＂, Bar.

Reactive Power in One-phase Circuits with Periodical Voltages - Reactive Power Compensation

The article states about reactive power compensation methods for circuits with non-sinusoidal voltages. An basic introduction to reactive power theory has been given, together with the optimal capacitance selection theory. There have been presented selected theories application in order to compensate the reactive power in one-phase circuits. The measurement results before the compensation have been discussed and measurement results after compensation of an actual object supplied from an non-sinusoidal voltage source were presented. The algorithms of optimal capacity selection were given, which connected in parallel to the circuit with inductive character will cause current root-mean-square value minimization. The measurement results after applying the reactive power minimization algorithm have shown improvement in compensation of strongly nonlinear receivers supplied with distorted signals.

Enhancement of Distributed Generation by Using Custom Power Device

Wind energy （WE） has become immensely popular for distributed generation （DG）. This case presents the monitoring, modeling, control, and analysis of the two-level three-phase WE based DG system where the electric grid interfacing custom power device （CPD） is controlled to perform the smart exchanging of electric power as per the Indian grid code. WE is connected to DC link of CPD for the grid integration purpose. The CPD based distributed static compensator, i.e. the distributed static synchronous compensator （DSTATCOM）, is utilized for injecting the wind power to the point of common coupling （PCC） and also acts against the reactive power demand. The novel indirect current control scheme of DSTATCOM regulates the power import and export between the WE and the electric grid system. It also acts as a compensator and performs both the key features simultaneously. Hence, the penetration of additional generated WE power to the grid is increased by 20% to 25%. The burden of reactive power compensation from grid is reduced by DSTATCOM. The modeling and simulation are done in MATLAB. The results are validated and verified.

Reactive Power Problem and Solutions: An Overview

This article presents a comprehensive review for the dilemma of reactive power flow, while addressing different proposed remedy strategies: conventional and most update solutions. Robust analytical expressions were utilized to exploit the functionality of the proposed solutions and to show clearly the relation between the reactive power and control variables. The article, moreover, proposes a simple, innovative and robust analysis for static performance of the STATCOM. This approach shows clearly the advantages of the STA-TCOM in regulating reactive power and maintaining load voltage level within presumable limits. The approach, furthermore, reveals explicitly via analytical expressions the impact of the STATCOM operation on different aspects of the power system under concern.

Parameter Test and Analysis for Dynamic Compensation Devices in Wind Power Farms

The dynamic reactive power compensation equipment in Jiuquan Wind Power Base of above 10 GW consists of three different types of compensation devices, including： static var generator （SVG）, thyristor controlled compensator （TGR） and magnetically controlled reactor （MGR）. The lack of experimental verification of performance is not conducive to voltage/var management or full utilization of device capaci- ties. In order to solve the above problems, the compensation device performance test was performed. The test items and procedures were selected based on related national standards with the consideration for different grid structures and wind farm operation modes. The testing contents included dynamic regulating range, active power loss, dynamic response time, and harmonic voltage level. Three types of compensation devices installed in different wind farms, namely SVG, TCR and MCR, were chosen and tested. The performances were compared and analyzed according to the field test results.

Energy Efficiency of Reactive Dynamic Compensators

A parameter that allows an evaluation of power quality transmitted, or distributed, between energy source and the final user is electric system power factor. Among other aspects, a bigger power factor, close to unit value, relieves operational conditions of lines and cables, besides, it improves feeder＇s voltage behavior. Due to load variation along the day, the dynamic compensation of power factor allows maintaining this parameter close to the ideal. This paper brings a study about a reactive dynamic compensator based on the voltage control in a capacitive element, varying the reactive energy in accordance with the system demand, everything from the energy efficiency point of view. In distribution systems, the losses due to this variable compensation can be lower than in other compensation methods and also the voltage presents a better behavior, justifying its application.

Optimal Sizing of Capacitor Bank for Increasing Substation Capacity of Mamou

In order to increase the available power of the electrical energy distribution station and improve the voltage profile of the distribution lines, the use of shunt capacitor banks is indicated. The main results obtained during this study are: a reduction in subscribed power from 14913.978 kVA to 14010.100 kVA, a reduction in the transformer load rate from 99.4% to 93.4%, a reduction in reactive power called from 5481.729 kVAr to 481.729 kVAr, an increase in the active power transported by the substation from 8505.062 kW to 8962.323 kW, a reduction in the voltage drop from 4.8% to 3.9%, an increase in the power available at the secondary of the transformer station at full load from 13950 kW to 14700 kW and an annual electrical energy saving of 339943.48 kWh of electrical energy, therefore fuel savings and a reduction in CO2 and SO2 emissions due to this energy saving will be achieved. The installation of capacitor banks for optimization of reactive energy allowed a reduction in the current called therefore a reduction in the absorbed power: 14153.061 kVA, i.e. a reduction of 903.876 kVA. It is therefore essential that energy players are convinced of the need to install capacitors to reduce or even eliminate their reactive energy bill. This is necessarily accompanied by an investment by Electricité De Guinée by setting up active and reactive energy meters but also by implementing pricing in line with the reduction in the transfer of reactive energy in the network.

含电动汽车和光伏的配电网演化动态博弈调度策略

针对大规模电动汽车的无序充电行为可能导致电网出现的三相不平衡问题,基于演化动态博弈模型,提出一种考虑三相负荷平衡和光伏消纳的电动汽车充电调度策略。首先,基于电动汽车接入时段的主观性以及光伏出力和负荷的不确定性,引入游牧集群和定居集群之间的演化动态博弈方程;然后,考虑用户侧和电网侧双方利益关系,设计以最小化电动汽车充电费用、三相负荷不平衡度和无功需求为目标的调度优化模型;最后,通过对某商业区配电网算例进行仿真求解,对比分析三相有功曲线、三相无功曲线以及荷电状态曲线的变化趋势。算例结果表明,该调度策略可有效降低三相不平衡度,满足无功补偿的需求以及改善用户充电成本。

无功补偿与储能集成系统中H桥级联型功率变换器相内SoC快速均衡

无功补偿与储能集成系统应用于风、光电站具有经济性,其中H桥级联型功率变换器具有低功率因数运行特点,提升其相内SoC均衡速度有助于提升电池安全和储能系统容量利用率。在调制约束下,考虑相内SoC均衡中电压无功分量的叠加,分析不同功率因数时功率单元的SoC均衡能力。基于分析,提出相内SoC的快速均衡方法,设计均衡控制电压有功分量叠加方法,充分利用功率单元的SoC均衡能力。基于各功率单元叠加的电压有功分量设计相应单元的无功分量叠加方法,提升功率单元的SoC均衡能力。仿真分析验证了相内SoC快速均衡控制的有效性。