scholarly journals Passive Reactive Power Compensators for Improving the Sustainability of Three-Phase, Four-Wire Sinusoidal Systems Supplied by Unbalanced Voltages

2021 ◽  
Vol 13 (20) ◽  
pp. 11134
Author(s):  
Elisa Peñalvo-López ◽  
Vicente León-Martínez ◽  
Joaquín Montañana-Romeu ◽  
Javier Cárcel-Carrasco
Keyword(s):  
Carbon Dioxide ◽  
Power Systems ◽  
Carbon Dioxide Emissions ◽  
Reactive Power ◽  
Distribution Networks ◽  
Industrial Applications ◽  
Energy Losses ◽  
Capacitor Banks ◽  
Three Phase ◽  
Zero Sequence

Compensation of reactive power is necessary in power systems due to economical, energetic, and environmental reasons. Reactive power increases energy power losses and carbon dioxide emissions in distribution lines and power transformers. However, capacitor banks used in most industrial applications do not significantly reduce energy losses in lines and transformers when supply voltages and loads are unbalanced and therefore do not fully improve the sustainability of distribution networks. This fact is explained in this paper using positive-, negative-, and zero-sequence reactive power components in three-phase, four-wire sinusoidal power systems supplied with unbalanced voltages. Likewise, several devices have also been developed for the compensation of the total reactive power and, specifically, for each of its components in these power systems. Comparing the effectiveness of these reactive compensators and other well-known passive compensators as capacitor banks on the sustainability improvement of the electrical installation of an actual industry, reductions between 20% and 100% in energy losses and carbon dioxide emissions, caused by circulation of reactive currents in transformer and lines, can be expected depending on the type of compensator used.

scholarly journals A Novel Load-Balancing Method and Device by Intelligent Grouping Compound Switches-Based Capacitor Banks Shunt Compensation

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Qiuye Sun ◽  
Jianguo Zhou ◽  
Xinrui Liu ◽  
Jun Yang
Keyword(s):  
Load Balancing ◽  
Reactive Power ◽  
Distribution Networks ◽  
Compensation Method ◽  
Positive Sequence ◽  
Capacitor Banks ◽  
Component Theory ◽  
Symmetrical Component ◽  
Unbalanced Load ◽  
Zero Sequence

A novel compensator topology is proposed for three-phase unbalanced loads in the distribution networks. The negative and zero sequence compensation networks are proposed using delta-connected and star-connected capacitor banks. The compensation networks are paralleled with the unbalanced load to achieve a perfect balancing of active power and a complete compensation of reactive power of the unbalanced load. Intelligent grouping compound switches are implemented to control the capacitors, where, therefore, each capacitor can be switched between phases or phase and ground. Wireless sensors are also applied to acquire the load quantities. The compensation method proposed is based on symmetrical component theory. In addition, the load compensation based on instantaneous symmetrical component theory with positive sequence online extraction is proposed under unbalanced and distorted source voltages. The proposed load-balancing method and device are applied to Liaoning, Neimenggu, and Jilin provinces. The application results are provided to validate the performance of the proposed compensator topology and compensation method.

scholarly journals Smart Meter Data-based Three-Stage Algorithm to Calculate Power and Energy Losses in Low Voltage Distribution Networks

2019 ◽  
Author(s):  
Gheorghe Grigoras ◽  
Bogdan-Constantin Neagu
Keyword(s):  
Reactive Power ◽  
Low Voltage ◽  
Distribution Network ◽  
Distribution Networks ◽  
Energy Losses ◽  
Smart Meter ◽  
Smart Meters ◽  
Three Phase ◽  
Third Stage ◽  
Power And Energy

In the paper, an improved smart meter data-based three-stage algorithm to calculate the power/energy losses in the three-phase low voltage (LV) distribution networks was proposed. In the first stage, an loading procedure of input data was built, being able to work simultaneously with files containing the active and reactive power profiles provided by smart meters and typical profiles associated to consumers without smart meters, based on the energy consumption categories, day type (weekend and working), and season type, knowing the daily energy indexes, in the second stage, a structure vectors-based algorithm was implemented to recognize the network topology, and in the third stage, an improved version of forward/backward sweep-based algorithm was proposed to calculate fast the power/energy losses to three-phase LV distribution networks in balanced and unbalanced regime. A real LV rural distribution network from a pilot zone belonging to a Distribution Network Operator (DNO) from Romania was used to verify the accuracy of the proposed algorithm. The results were compared with those obtained using the DigSilent PowerFactory Professional Software, the MAPE being by 0.94%.

scholarly journals Optimal Sizing and Placement of Capacitor Banks in Distribution Networks Using a Genetic Algorithm

Electricity ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 187-204
Author(s):  
Gian Giuseppe Soma
Keyword(s):  
Genetic Algorithm ◽  
Electricity Market ◽  
Distribution Systems ◽  
Reactive Power ◽  
Electricity Consumption ◽  
Distribution Networks ◽  
Optimal Placement ◽  
Capacitor Banks ◽  
Control Pattern ◽  
Definition Of

Nowadays, response to electricity consumption growth is mainly supported by efficiency; therefore, this is the new main goal in the development of electric distribution networks, which must fully comply with the system’s constraints. In recent decades, the issue of independent reactive power services, including the optimal placement of capacitors in the grid due to the restructuring of the electricity industry and the creation of a competitive electricity market, has received attention from related companies. In this context, a genetic algorithm is proposed for optimal planning of capacitor banks. A case study derived from a real network, considering the application of suitable daily profiles for loads and generators, to obtain a better representation of the electrical conditions, is discussed in the present paper. The results confirmed that some placement solutions can be obtained with a good compromise between costs and benefits; the adopted benefits are energy losses and power factor infringements, taking into account the network technical limits. The feasibility and effectiveness of the proposed algorithm for optimal placement and sizing of capacitor banks in distribution systems, with the definition of a suitable control pattern, have been proved.

scholarly journals A new approach to three-phase asynchronous motor model for electric power system analysis

2021 ◽  
Vol 12 (4) ◽  
pp. 2083
Author(s):  
Laura Collazo Solar ◽  
Angel A. Costa Montiel ◽  
Miriam Vilaragut Llanes ◽  
Vladimir Sousa Santos
Keyword(s):  
Power Systems ◽  
Reactive Power ◽  
Mechanical Load ◽  
Asynchronous Motor ◽  
Electrical Power ◽  
Variable Load ◽  
Electrical Power Systems ◽  
Active And Reactive Power ◽  
Voltage Variation ◽  
Three Phase

In this paper, a new steady-state model of a three-phase asynchronous motor is proposed to be used in the studies of electrical power systems. The model allows for obtaining the response of the demand for active and reactive power as a function of voltage and frequency. The contribution of the model is the integration of the characteristics of the mechanical load that can drive motors, either constant or variable load. The model was evaluated on a 2500 kW and 6000 V motor, for the two types of mechanical load, in a wide range of voltage and frequency, as well as four load factors. As a result of the evaluation, it was possible to verify that, for the nominal frequency and voltage variation, the type of load does not influence the behavior of the powers and that the reactive power is very sensitive to the voltage variation. In the nominal voltage and frequency deviation scenario, it was found that the type of load influences the behavior of the active and reactive power, especially in the variable load. The results demonstrate the importance of considering the model proposed in the simulation software of electrical power systems.

VOLTAGE LEVEL CONTROL IN WEAK DISTRIBUTION NETWORKS WITH DG BY USING HYBRID REACTIVE POWER COMPENSATIONS

2016 ◽  
Vol 78 (5-9) ◽  
Author(s):  
Piyadanai Pachanapan
Keyword(s):  
Rural Areas ◽  
Reactive Power ◽  
Voltage Control ◽  
Cost Effective ◽  
Distribution Networks ◽  
Test System ◽  
Level Control ◽  
Voltage Level ◽  
Capacitor Banks ◽  
Dynamic Voltage

The hybrid reactive power compensations, using capacitor banks and distribution static compensator (DSTATCOM) in the coordinated manner, are introduced to enhance voltage level control performances in weak distribution networks with the increasing of distributed generation (DG), such as in the rural areas. While the conventional compensation using capacitor banks gives the poor dynamic voltage control, these hybrid compensations are the cost effective solution which can deal with both under-and over-voltage changes, either short- or long duration voltage variations. The dynamic voltage control performances are demonstrated under various operating scenarios using the test system implemented in DIgSILENTPowerFactory. The simulation results showed that this approach can improve voltage controllability in weak distribution networks with DG effectively.  

A New Method of Three-Phase Unbalanced Load Harmonic Current Detection

2014 ◽  
Vol 1070-1072 ◽  
pp. 726-730
Author(s):  
Hong Zheng ◽  
Yun Zhang ◽  
Jun Huang ◽  
Zhe Yu Wang
Keyword(s):  
Reactive Power ◽  
Detection Algorithm ◽  
Phase System ◽  
Instantaneous Reactive Power Theory ◽  
Three Phase ◽  
Unbalanced Load ◽  
Zero Sequence ◽  
New Type ◽  
Leakage Error ◽  
Improved Algorithm

The extensive usage of power electronic equipments makes harmonic problem increasingly serious. In unbalanced three-phase system, traditional p-q, d-q method ignores the zero sequence currents, resulting in zero sequence harmonic leakage error. This article is based on the basic principle of instantaneous reactive power theory, it proposes a new type of harmonic detection algorithm, this algorithm does not need phase-locked loop nor do a matrix transformation, and can effectively avoid the zero order harmonic leakage error caused by coordinate transformation.In the end, using Matlab/Simulink environment to build models of traditional algorithm and improved algorithm .Through comparison, the simulation result shows that the improved algorithm is more accurate and more effective than the traditional one.

Harmonic Analysis of Three-phase Fixed Capacitor–thyristor Controlled Reactor under Balanced and Unbalanced Conditions

2018 ◽  
Vol 7 (1) ◽  
pp. 67
Author(s):  
Jayababu Badugu ◽  
Y. P.Obulesu ◽  
Ch. Saibabu
Keyword(s):  
Power Systems ◽  
Harmonic Analysis ◽  
Reactive Power ◽  
High Reliability ◽  
Voltage Waveform ◽  
Current Harmonics ◽  
Three Phase ◽  
Harmonic Filter ◽  
Harmonic Pollution ◽  
Thyristor Controlled Reactor

Three-phase Fixed Capacitor Thyristor Controlled Reactor is widely used for reactive power compensation in power systems because of reduced cost and high reliability.  The problem with FC-TCR is that to generate current harmonics when it is partially conducting. When this harmonic current is interacted with system impedance, voltage waveform will distorted. This harmonic pollution is undesirable in power systems. Therefore, it is important to know the harmonic behaviour of three-phase FC-TCR before they can be used in a power system network. This paper presents the harmonic analysis of three-phase FC-TCR operating under balanced and unbalanced conditions. This analysis is useful to design the harmonic filter to reduce the harmonic pollution in power systems.The proposed work is implemented in MATLAB environment.

Zero-Sequence Current Control of Modular Active Power Filter for High Power Three-Phase Three-Wire Electrical Networks

2006 ◽  
Vol 7 (3) ◽  
Author(s):  
Benhabib Choukri ◽  
Poure Philippe ◽  
Saadate Shahrokh
Keyword(s):  
High Power ◽  
Control Strategy ◽  
Reactive Power ◽  
Active Power ◽  
Current Control ◽  
Electrical Networks ◽  
Three Phase ◽  
Zero Sequence ◽  
Power Capability ◽  
Averaged Model

Since the development of the first control strategy for the active power filters (APF) introduced by H. Akagi [H. Akagi, Y. Kanazawa,A. Nabae, Generalized theory of the instantaneous reactive power in three-phase circuits, in: Proceedings of International Power Electronics Conference, Tokyo, Japan (1983) 1375–1386.], many efforts have been concentrated to improve their performances. However, when electrical networks supplies high current non-linear loads, a single inverter-based APF has limited power capability. In this paper, we studied parallel operation achieving high power level. More particularly, we examined a modular APF based on two three-phase inverters. This structure allows zero-sequence current circulating through the inverters, as demonstrated by using averaged modelling of the APF. To solve this problem and based on previous averaged model, we proposed a new optimal control strategy, suppressing the zero-sequence circulating current. Simulation results validate the proposed control.

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