Reactive Power Consumption Research Articles

Distribution Grid Hosting Capacity Improvement using Reactive Power Control Optimization Algorithm of Inverter-based Photovoltaic Generation System

This paper uses a reactive power control optimization algorithm to present an inverter-based photovoltaic generation system for increasing the distribution grid host capacity. The main objective of this study is to regulate bus voltages by providing sufficient minimal reactive power consumption, which is obtained by a Particle Swarm Optimization-based optimization algorithm. A modeling study of the system network is developed using DIgSILENT PowerFactory, and the control algorithm is implemented in MATLAB. The proposed approach is efficient for various scenarios of the IEEE 13-bus test system and practical distribution network. The analysis results are compared with outcomes from other control methods, including technical and economic assessments. The performance of the proposed optimization-based power system has shown that the proposed algorithm method yielded significantly superior mitigated voltage rises and increased hosting capacity compared to those achieved by existing control methods of a specific distribution network.

Power Factor Optimization with Cos Phi Mode Trainee

The power factor cos phi measures the efficiency of using electrical power in a system. A low power factor indicates the presence of high reactive power consumption, which can lead to increased energy losses and operational costs. To overcome this problem, an effective power factor regulation system is required. This research designed and developed the Cos Phi Trainer, which operates in two modes, manual and automatic, to improve the power factor at an electrical load. The system is designed to give users a practical understanding of measuring and improving power factors by setting up compensation capacitors. In manual mode, the user directly sets the value of the capacitor used to fix the power factor. While in automatic mode, the system uses current and voltage sensors to measure the power factor value in real-time and automatically adjusts the capacitor to achieve the optimal power factor. The trainer has an easy-to-use interface and a measurement panel that displays important parameters such as current, voltage, active power, reactive power, and power factor. The test results show that the system can significantly increase the power factor in manual and automatic modes. Thus, this Cos Phi Trainer is an effective tool for training in the laboratory of Indorama Engineering Polytechnic and teaching about electrical power management and energy loss reduction in the electrical system. Keywords: Power factor, manual, active power, reactive power, trainer

Advanced Static Var Generator in the Reactive Power Automatic Compensation System of an Underground Mine with a Thyristor Hoisting Machine

In industrial plants with dynamically varying load profiles, the problem of increased charges for over-contracted reactive power consumption is very common. To eliminate these charges, reactive power compensation systems are used. This article presents a case study of an automatic reactive power compensation system in an underground mine where a thyristor hoisting machine is used. To reduce the higher current harmonics of the hoisting machine and compensate for the reactive power of the PCC (Point of Common Coupling), the main reactive power automatic compensation system and an ASVG (Advanced Static Var Generator) with a nonstandard control loop were used. The article considers aspects of the operation of the ASVG, locally with the hoisting machine, and also as a master-controlled device that is part of the reactive power automatic compensation system. This part of the article is based on measurements taken in a mine. The reactive power automatic compensation system considered in this article has been successfully implemented, improving PQ (Power Quality) and eliminating additional overcompensation charges.

Quadratic functions for efficient load balancing in the terminals of a substation of a three-phase asymmetric network with power loss reduction capabilities

This research addresses the problem of optimal load balancing in terminals of the three-phase substation by proposing three quadratic objective functions. These objective functions are formulated considering active, reactive, and apparent power consumptions aggregated at the terminals of the substation. The proposed formulation belongs to the mixed-integer quadratic models’ family, which can be solved globally with specialized mixed-integer convex tools. To evaluate the effect of load redistribution in the substation terminals, the 15- and 35-bus grids are tested using each of the proposed quadratic functions. In addition, Broyden's unbalanced power flow method is used to determine the extent of power loss reduction and enhancement of voltage profile. Numerical results confirm the effectiveness of the proposed mixed-integer quadratic model in enhancing electrical performance in three-phase asymmetric networks through load balancing at the substation terminals. After solving each quadratic function for the 15-bus grid, power losses were reduced between 12.9624% and 17.2550%, and these reductions were between 5.0771% and 7.7389% in the 35-bus grid.

Electric Network Topology Optimization with Distributed Generation using Pandapower Library

The paper describes the selection of the optimal topology for a distributed electric network with renewable energy sources. The Newton-Raphson method is used to calculate power flows, which is the basis of the Pandapower library. The library is a Python-based tool for modeling, analyzing, and optimizing electrical networks. It allows for the creation and modification of electrical schematics, calculation of power flows, determination of voltages and currents, as well as optimization of system performance. The result of the work is the determination of the optimal configuration in terms of minimizing electrical energy losses in network lines. The developed software allows for loading data on network nodes and lines, including active and reactive power consumption and generation, performing steady-state calculations with determination of losses in lines. Due to the automation of calculations, it is possible to perform calculations for all permissible network topologies and select the optimal one for the given conditions. The result of the work is the determination of the optimal configuration in terms of minimizing electrical energy losses in network lines.

Power consumption profiles of the main fans at coal mines

Purpose. To determine the main indicators of the power consumption profiles of the main ventilation fans of coal mines under the condition of regulating their performance using controlled electric drive systems based on semiconductor elements. The methods. The methods of operations research were used to analyse technological processes in terms of compliance of the actual power consumption profiles of the main fans with their expected operating modes. The methods of mathematical statistics were used to determine the statistical parameters of the electrical loading diagrams of the main ventilation fans of coal mines. Findings. A statistical analysis of typical power consumption profiles of the main fans of coal mines with different electric drive systems has been carried out: a synchronous motor with a high-voltage frequency converter, an induction motor based on the asynchronous-thyristor cascade system, and a synchronous motor with ‘classical’ rotor excitation control without semiconductor elements. The feasibility of using adjustable electric drive systems to control the performance of main ventilation fans in terms of reducing active power consumption has been confirmed. However, at the same time, the consumption of a significant amount of reactive power is shown, which is inherent for systems based on semiconductor elements, regardless of the motor type (synchronous or asynchronous). Originality. The statistical analysis of the actual daily power consumption profiles of the main fans of coal mines with different controlled electric drive systems has shown that the standard deviation of the active load does not exceed 1% of the rated power of the drive motor and does not depend on its type (synchronous or asynchronous). Practical implementation. The practical value of the work is in determining the actual consumption of reactive power by the systems of controlled electric drive based on semiconductor elements. It shows its significant level, which should be provided by appropriate filter-compensating devices on the power supply buses of the motors of the main ventilation fans.

A non-isolated PFC bridgeless SEPIC-Cuk converter with adaptive PI controller for induction motor

In general, the induction motor (IM) is extremely nonlinear in nature and frequency dependent. In most cases, the power generated by the IM has a low power factor (PF), which exhibits detrimental effect on the extent to which the whole transmission and distribution system functions. Since there exists more current harmonics as an outcome of minimized PF, the efficiency of the power system suffers due to transmission line heating and voltage distortion characteristics. Therefore, this paper proposes a power factor correction (PFC) method to overcome the aforementioned issues. Here, by the utilization of AC-DC bridgeless SEPIC-Cuk converter, the power quality is improved by reducing reactive power consumption and enabling better control of voltage and current outputs. To maintain the stable DC link voltage with reduced ripples, the adaptive proportional-integral (PI) controller is used in this work. The three-phase voltage source inverter (VSI) transitioning function is controlled by cascaded fuzzy logic (CFL) controller, which is also utilized for regulating the speed of the three-phase IM. Implementing the proposed control strategy improves power quality significantly by reducing total harmonic distortion (THD). The proposed system is simulated in the MATLAB platform and the attained outcomes, it is clear that the proposed system is highly effective.

Modeling of energy recovery processes in railway traction power supply systems

Regenerative braking of trains can provide significant energy saving and a sizeable reduction in greenhouse gas emissions. The efficiency of energy recovery can be defined using an efficiency indicator equal to the product of the free-fall acceleration and the fraction of potential energy used in the recovery. Its slope dependence is well approximated by a polynomial of the third degree. The operating conditions of the traction power supply system of the mountain pass section of the main railway were modeled. The results obtained allowed the following conclusions to arrive at: regenerative braking is accompanied by circulating currents in adjacent inter-substation areas and leads to an absolute and relative increase in electrical energy losses in the traction network; the share of active energy losses rises by several times; the energy recovery causes a change in the direction of active energy flows at traction substations with a steep increase in reactive power consumption by trains; the energy recovery produces a significant decrease in voltage on the current collectors of electric locomotives; the voltage on the section under consideration, with three trains weighing tons decreased to 23 kV due to the large reactive energy consumption. © 2024 The Authors. Published by Elsevier Ltd.

Automatic Power Factor Controller

Automatic Power Factor Controllers (APFCs) play a crucial role in modern electrical systems by ensuring efficient electrical power and improving power quality. This paper presents a comprehensive overview of the Design, implementation, and performance analysis of an APFC system. The proposed APFC system employs advanced control techniques to regulate the power factor of the electrical load, thereby minimizing reactive power consumption and optimizing overall system efficiency. The design process encompasses the selection of suitable power electronics converters, control algorithms, and sensing techniques tailored to the requirements of an application. The results demonstrate significant improvements in power quality, energy utilization, and system stability, thereby highlighting the practical relevance and applicability of the developed APFC technology.

Distributed Real-Time Feedback Optimization for Renewable Energy Sources and Vehicle-to-Grid Power Compensation of Electric Vehicle Chargers in Distribution Systems

A novel distributed feedback optimization-based controller for electric vehicle (EV) chargers and renewable energy sources (RESs) in distribution systems is proposed. The proposed controller utilizes the flexibility in EV chargers’ active and reactive power consumption to offer the desirable vehicle-to-grid services. Instead of using the conventional cascaded PI controllers, a new optimization-based approach is proposed to control RESs to track their power injection setpoints. The proposed controller formulates the control targets as a single constrained optimization problem, i.e., to minimize the critical bus voltage magnitude deviations while driving RESs to follow their power setpoints, thereby fulfilling the EV charging requirements and regulating their power outputs and bus voltage magnitudes to stay within their limits. A distributed feedback optimization-based control algorithm is designed for EV chargers and RESs to steer the system trajectories of the distribution systems towards the optimal solution of the formulated optimization problem. Simulation results show that the proposed controller can always steer the test system to the optimal solution of the optimization problem. The advantages of the real-time vehicle-to-grid power compensation of EV chargers are also demonstrated.

Operation Assessment of a Hybrid Distribution Transformer Compensating for Voltage and Power Factor Using Predictive Control

Hybrid Distribution Transformers (HDTs) offer a compelling alternative to traditional low-frequency transformers (LFTs), providing auxiliary services in addition to standard functionalities. By integrating LFTs with power converters, HDTs enhance the operational capabilities of the system. The specific configuration in which converters are connected to the transformer allows for the provision of multiple services. This can not only prevent network failures but also extend the lifespan of its components, an outcome that is highly desirable in a distribution grid. This article discusses an HDT developed to mitigate voltage fluctuations in the grid and to decrease the reactive power drawn from the secondary side of traditional LFTs. A finite-control-set model predictive control (FCS-MPC), in conjunction with linear controllers, is utilized for the effective management of the HDT converters. Two separate control loops are established to regulate voltage and reactive power on the secondary side of the transformer. Results from Hardware-in-the-Loop (HIL) testing affirm the proficiency of HDT in reducing grid voltage variations by 15% and in cutting reactive power consumption by up to 94%. The adopted control strategy and topology are demonstrated to be effective in stabilizing voltage and reactive power fluctuations while concurrently facilitating the charging of the converters’ DC link directly from the grid.

Design of Reactive Power Compensation Devices on the Base of Dynamical Simulation of Steelmaking Process

Alternative current electric arc furnaces (AC-EAF) are characterized by significant active and reactive power consumption. The operation of electric arc furnaces can cause considerable harmonic distortion and voltage fluctuations (flicker) in the electric power system due to the non-linearity of electric arc and stochastic character of arc burning. The distortion level caused by AC EAF operation depends on the stage of the steelmaking process. The novel method of design of reactive power compensation devices on the base of dynamical digital simulation of complete steelmaking process is described in the offered paper.

Increasing efficiency of induction motor by predictive control system

Standard squirrel-cage induction machine is widely used in industrial enterprises due to its advantages in terms of reliability, durability and economic efficiency. However, one of its disadvantages is that it suffers from a power dissipation factor due to its inability to balance active and reactive power consumption. Especially when the SCIM is running at no load condition or during the initial start-up, the power factor or useful operation and performance are drastically reduced. Therefore, improving the power factor of the induction machine is an actual topic for the following article, and has had some interesting solutions for several years. In this thesis, two different induction motor control algorithms (frequency converter and Predictive torque control) are included and a clear comparison between them is given. The main focus of this article is to design an induction motor control system using the two algorithms mentioned above, analyse the performance of different control methods, and experimentally verify these algorithms by comparing simulations and experimental results.

Features of Electromagnetic Processes and Force Interactions in Turbogenerators with Reactive Power Consumption

Features of Electromagnetic Processes and Force Interactions in Turbogenerators with Reactive Power Consumption

Optimal Day Ahead Active and Reactive Power Management in Residential Buildings using Particle Swarm Optimization

This paper introduces an innovative Active and Reactive Residential Building Energy Management (AR-RBEM) system, seamlessly integrated with a smart microgrid and the Electrical Power Grid (EPG) supplier. The proposed AR-RBEM computes optimal active and reactive power setpoints for each energy source over the next 24 hours based on predicted PV power generation and load consumption. The proposed strategy aims to achieve two primary objectives: minimize overall energy expenses, considering both active and reactive power consumption, and account for Energy Storage System (ESS) degradation costs. Additionally, it seeks to reduce the Peak-to-Average Ratio (PAR) and carbon emissions from the supplier’s perspective. To tackle this multi-objective problem, a metaheuristic algorithm which is Particle Swarm Optimization (PSO), is employed. To assess the effectiveness of the proposed approach, a comparative analyse is conducted, emphasizing the significance of concurrently managing active and reactive power compared to a system exclusively managing active power (A-RBEM). Both strategies are evaluated using Time of Use Tarriff (TOU) and real world data. The comparative analysis underscores the advantages of the proposed AR-RBEM, showcasing benefits in terms of cost reduction for both active and reactive power of 59,6%, a substantial 25.3% reduction in carbon emissions compared to the alternative strategy.

Influence of Temperature Rise in Stator End Region on Reactive Power Consumption Ability of Dual-Excited Synchronous Condenser

Influence of Temperature Rise in Stator End Region on Reactive Power Consumption Ability of Dual-Excited Synchronous Condenser

Investigation of transients in asynchronous generators used in microhydroelectric power plants

In this article, a study of transients in autonomous asynchronous generators used in microgenerators is carried out. This article analyzes the transients occurring in an asynchronous generator by starting an asynchronous motor by exciting an asynchronous generator using capacitor elements of reactive power consumption. To start the asynchronous generator, mechanical energy is supplied to the shaft of the asynchronous motor at a speed 5-10% higher than the nominal number of revolutions, after which the asynchronous motor starts working in generator mode and generates electricity. To launch the CASSY Lab program, the electrical parameters of an asynchronous generator were considered, as well as transients occurring in operating modes by digitally transmitting the parameters of the electrical energy generated by the generator. Starting an asynchronous generator with the help of this program, a real experimental test was also carried out to determine the sinusoidal forms of voltage and current in three phases in the yuksiz, load and overload operating modes. In the course of a real experiment, it was concluded that the improvement of transients occurring in the modes of operation of an asynchronous generator, i.e. transients during the transition from a non-loading mode of operation to a mode of operation with a load, depends on the mechanical energy transmitted to the shaft of an asynchronous generator for grinding.

Reactive power compensation and start-up energy waste reduction of linter device electric motor

In primary cotton processing enterprises, all electricity consumers, including the electricity consumption of the linter, especially the reactive power, are the compensation of the reactive power consumption. In particular, it is seen that the high power consumption of electric energy in the start time mode, which is present in all electric motors, can be eliminated through soft starts, and the effect of soft start on the device is studied.

A Novel Methodology for Reducing Excessive Reactive Power Consumption Penalties for Photovoltaic Prosumers

A Novel Methodology for Reducing Excessive Reactive Power Consumption Penalties for Photovoltaic Prosumers

Voltage Deviation Influence on Electric Sizes of Lighting Lamps

The influence of voltage deviation from the nominal value of 220 V on the illumination of incandescent lamps and arc sodium tubular lamps (HPS) is presented. It has been established that voltage deviations from the nominal value do not affect the illumination of energy-saving and LED lamps. It is shown that most of the energy-saving LED and HPS lamps used in household and street lighting in Dushanbe have a low active power factor, which, in turn, leads to an increase in reactive power consumption in the electrical network.