Multilevel voltage source power quality conditioner

Author(s):  
R. Strzelecki ◽  
M. Jarnut ◽  
E. Kot ◽  
A. Kempski ◽  
G. Benysek
Author(s):  
Madhusmita Patro ◽  
Kanhu Charan Bhuyan

<p>Power quality has become an important factor in power systems, for consumer and household appliances. The main causes of poor power quality are harmonic currents, poor power factor, supply voltage variations etc. A technique of achieving both active current distortion compensation, power factor correction and also mitigating the supply voltage variations at load side is compensated by unique device UPQC presented in this thesis. This concept presents a multi loop based controller to compensate power quality problems through a three phase four wire unified power quality conditioner (UPQC) under unbalanced and distorted load conditions. Here the UPQC is constituted of two voltage source converters (VSC) connected via power link. The series compensator is connected to the line in series and injects the voltage and thus compensates for voltage issues; whereas the shunt compensator injects current thus compensating for current issues, and is connected in shunt to the line. The voltage injection to the line uses an injecting transformer. The injection transformer is later replaced with injection capacitors, thus eliminating the drawback of conventional UPQC. In this way a good power quality is maintained.</p>


Author(s):  
Madhusmita Patro ◽  
Kanhu Charan Bhuyan

<p>Power quality has become an important factor in power systems, for consumer and household appliances. The main causes of poor power quality are har ue of achieving active current distortion compensation, power factor monic currents, poor power factor, supply voltage variations etc. A techniq correction and also mitigating the supply voltage variations at load side is compensated by unique device UPQC presented in this thesis. This concept presents a multi loop based controller to compensate power quality problems through a three phase four wire Unified Power Quality Conditioner (UPQC) under unbalanced and distorted load conditions. Here the UPQC is constituted of two Voltage Source Converters (VSC) connected via power link. The series compensator is connected to the line in series and injects the voltage and thus compensates for voltage issues; whereas the shunt compensator injects current thus compensating for current issues, and is connected in shunt to the line. The voltage injection to the line uses an ijecting transformer. The injection transformer is later replaced with injection capacitors, thus eliminating the drawback of conventional UPQC. In this way a good power quality is maintained</p>


2012 ◽  
Vol 433-440 ◽  
pp. 6731-6736
Author(s):  
Chandrakant L. Bhattar ◽  
Vilas N. Ghate

This paper presents the new control algorithm for three-phase, four-wire distributing system using unified power quality conditioner (UPQC). The UPQC, a combination of series and shunt active filter (AF) with common dc link, is one of the best solution towards the compensation of voltage sag, swell problems and also compensate voltage flicker/imbalance, reactive power, negative sequence current and maintain zero voltage regulation (ZVR) at the point of common coupling (PCC) on distribution system. The series AF is seen by using a three-phase, three leg voltage source inverter (VSI) and the shunt AF is of a three-phase, four leg voltage source inverter (VSI). The proposed model of the UPQC is developed in the MATLAB/SIMULINK environment and the simulation results prove the power quality improvement in the system.


2021 ◽  
Vol 23 (06) ◽  
pp. 1383-1395
Author(s):  
Avanish Tripathi ◽  
◽  
Dr. Imran ◽  

Power flow in any distribution system either it is multi-bus or three feeders explain by a Generalized Unified Power Quality Conditioner i.e. GUPQC.On the one side, that is DC side is connected with the common DC link capacitor which is also coupled consecutively through 3 voltage source converters. This is the simple block realization of GUPQC. This multi feeder is explained where one feeder is controlled by a parallel compensator and the next two feeders are controlled through the proposed series compensator. This technique i.e. GUPQC makes the feeder distribution free from harmonic and voltage-current compensation etc randomly. Also, it can improve the quality of supply power given to another consumer. A vast and huge study of Simulation is helped to how MATLAB/SIMULINK is used for making this type of GUPQC. Disrupted Voltage, current, and power quality issues can be easily improved in this technique.


The network reconfiguring and compensating devices are the two different types of custom power solutions. The network reconfiguration devices consist of switchgear with current breaking, current restrict and current sending devices. The compensating device will compensate load by correcting power factor, unbalance etc. or supplied voltage quality will be improved. These devices are either connected in shunt (DSTATCOM) or in series (DVR) or a combination of both (UPQC) are the different types of custom power devices. This paper proposes compensating custom power device formed by the 3-phase, 3-level voltage source converters (VSC’s) connected one on another through a common dc link to three independent feeders distribution system, which is known as Generalised unified power quality conditioner (G-UPQC). Simulations are performed using MATLAB/SIMULINK package to mitigate current imperfections in first feeder which is connected with unbalanced and Non-linear load and voltage imperfections in the other two feeders which are connected with unbalanced and sensitive loads


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yeison Alberto Garcés Gomez ◽  
Nicolás Toro García ◽  
Fredy E. Hoyos

This paper outlines a new approach for the compensation of power systems presented through the use of a unified power quality conditioner (UPQC) which compensates impulsive and oscillatory electromagnetic transients. The newly proposed control technique involves a dual analysis of the UPQC where the parallel compensator is modelled as a sinusoidal controlled voltage source, while the series compensator is modelled as a sinusoidal controlled current source, opposed to the traditional approach where the parallel and series compensators are modelled as current and voltage nonsinusoidal sources, respectively. Also a new compensation algorithm is proposed through the application of the theory of generalized reactive power; this is then compared with the theory of active and reactive instantaneous power, orpqtheory. The results are presented by means of simulations in MATLAB-Simulink®.


2018 ◽  
Vol 1 (1) ◽  
pp. 54-66
Author(s):  
Rakan Khalil Antar ◽  
Basil Mohammed Saied ◽  
Rafid Ahmed Khalil

A new control strategy for active power filters is proposed, modeled and implemented in order to improve the power quality of a line commutated converter High voltage DC link. The ability of reactive power and harmonics reductions are generally met by using passive and active power filters. In this paper, modified active power filter with a modified harmonics pulse width modulation algorithm is used to minimize the source harmonics and force the AC supply current to be in the same phase with AC voltage source at both sending and receiving sides of a line commutated converter high voltage DC link. Therefore, it is considered as power factor corrector and harmonics eliminator with random variations in the load current. The modified harmonics pulse width modulation algorithm is applicable for active power filter based on a three-phase five-level and seven-level cascaded H-bridge voltage source inverter. Simulation results show that the suggested modified multilevel active power filters improve total harmonics distortion of both voltage and current with almost unity effective power factor at both AC sides of high voltage DC link. Therefore, modified active power filter is an effective tool for power quality improvement and preferable for line commutated converter high voltage DC link at different load conditions.


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