Performance Investigation of Shunt Hybrid Active Power Filter With A Synchronous Reference Frame BasedController

ABSTRACT:  

This paper presents a novel synchronous reference frame based (SRF) control strategy for shunt hybrid active power filter (SHAPF). The control strategy includes a direct current control (DCC) and an indirect current control (ICC) strategy. SHAPF can achieve harmonic compensation and dynamic reactive power compensation with the proposed controller. In this proposed method, as distinct from studies in literature, dynamic reactive power compensation and dc link voltage control is realized with ICC and harmonic current compensation is realized with DCC. Also, the proposed controller provides a variable SHAPF dc link voltage which is adjusted according to the reactive power compensation requirements in order to decrease the switching losses of converter and achieve power savings. The performance of proposed controller is verified with experimental results.

KEYWORDS:

  1. Active Power Filter (APF)
  2. Harmonics
  3. Reactive Power Compensation
  4. Direct Current Control
  5. Indirect Current Control

 SOFTWARE: MATLAB/SIMULINK

 CIRCUIT DIAGRAM:

Fig. 1. Power Circuit Diagram of SHAPF

 EXPECTED SIMULATION RESULTS:

(a)

(b)

Fig.2. Reactive Power Trend (a) and Current Harmonic Spec. (b) of Case I

(a)

(b)

Fig.3. Reactive Power Trend (a) and Current Harmonic Spec. (b) of Case II

CONCLUSION:

 This paper presents a SRF based controller approach for SHAPF. In proposed control method, DCC strategy is preferred for harmonic compensation control to maintain superior dynamic and steady state performance on the compensation of low order harmonics. ICC strategy is used for the reactive power compensation controller and the dc link voltage controller to simplify the controller and provide a successful performance without being affected by dynamic changes in active and reactive current components. Additionally, the dc link voltage is determined with adaptive to the reactive power demand of load by the proposed control method. By the help of this ability, the switching losses of SHAPF is decreased by keeping only required voltage level on dc link. The proposed control method is applied on the laboratory prototype of SHAPF. The steady state and dynamic performance of controller is verified with the experimental results.

REFERENCES:

[1] H. Fujita and H. Akagi, “A practical approach to harmonic compensation in power systems-series connection of passive and active filters,” IEEE Trans. Ind. Appl., vol. 27, no. 6, pp. 1020–1025, 1991.

[2] H. Akagi, “Active and hybrid filters for power conditioning,” ISIE’2000. Proc. 2000 IEEE Int. Symp. Ind. Electron. (Cat. No.00TH8543), vol. 1, 2000.

[3] H. Fujita, T. Yamasaki, and H. Akagi, “A hybrid active filter for damping of harmonic resonance in industrial power systems,” IEEE Trans. Power Electron., vol. 15, no. 2, pp. 215–222, Mar. 2000.

[4] S. Srianthumrong and H. Akagi, “Medium-voltage transformerless ac/dc power conversion system consisting of a diode rectifier and a shunt hybrid filter,” IEEE Trans. Ind. Appl., vol. 39, no. 3, pp. 874–882, May 2003.

[5] R. Inzunza and H. Akagi, “A 6.6-kV Transformerless Shunt Hybrid Active Filter for Installation on a Power Distribution System,” IEEE Trans. Power Electron., vol. 20, no. 4, pp. 893–900, Jul. 2005.

MATLAB-Simulink Model Based Shunt Active Power Filter Using Fuzzy Logic Controller to Minimize the Harmonics

ABSTRACT:

The issue of value electrical vitality gave to the clients has emerged. This is because of the expanding nearness in system of nonlinear loads.They establish a consonant contamination wellspring of the system, which produce numerous aggravations, and exasperate the ideal task of electrical types of gear. This work, proposed an answer for take out the sounds presented by the nonlinear burdens. It displays the investigation and reenactment utilizing Matlab Simulink of a active power filter (APF) repaying the sounds and receptive power made by nonlinear loads in unfaltering and in drifters. The convenience of the reenactment way to deal with APF is shown , have a superior power quality knowledge utilizing Matlab Simulink so as to grow new fuzzy logic controller based dynamic power channel.

 

 BLOCK DIAGRAM:

Figure 1 Block diagram of Basic Active Power Filter

EXPECTED SIMULATION RESULTS:

 

 Fig. 2 Three phase voltage and current waveform with non linear load

 Fig.3 THD analysis of three phase voltage waveform with nonlinear load

 Fig.4 Three phase voltages and current waveform with shunt active power filter with connected fuzzy logic controller

 Fig.5 THD analysis of voltages with shunt active power filter using fuzzy logic controller

 

 CONCLUSION:

The paper exhibits the utilization of the fuzzy logic controller to control the repaying voltage. The Mamdani max-min approach is utilized for the fluffy induction and the defuzzification technique, separately. The structure of info and yield enrollment for the fluffy rationale controller is essential for the framework execution. The reproduction results demonstrate that the fuzzy logic controller gives a decent execution to control the remunerating voltage of shunt dynamic power channel. The %THD of the voltages at PCC point can be pursued the IEEE Std. 519-1992.

 

Compensation Of Voltage Sag And Harmonics By Dynamic Voltage Restorer Without Zero Sequence Blocking

ABSTRACT:

Dynamic Voltage Restorer (DVR) is a power electronic gadget to protection delicate stress from voltage hang. Regularly, delicate burdens are electronic-based gadgets which create music. This paper presents soft polar based DVR as voltage hang restorer and sounds compensator without zero succession blocking. Research exhibited in this paper utilizes d-q-0 pivot technique considering of the estimation of unbiased hub, in light of the fact that the strategy works great if the impartial hub esteem is zero. Result demonstrates that this strategy can repay voltage sag and harmonics with a pay blunder of 0.99%. Utilizing this technique, DVR may lessen voltage THD from 10.22% to 0.66%.

 BLOCK DIAGRAM:

 

 Fig.1 Dynamic voltage restorer

EXPECTED SIMULATION RESULTS:

 

 Fig. 2 Distorted voltages at bus C

Fig. 3 Voltage at bus C after DVR

Fig.4 70% sag at bus C caused by phase-phase-ground fault

Fig.5 70% sag at bus C (caused by phase-phase- ground fault) restored by DVR

CONCLUSION:

The reproduction of a DVR utilizing MATLAB has been introduced. Recreation results demonstrate that DVR can reestablish both the voltage droop and voltage sounds. The proficiency and viability in voltage hang rebuilding and voltage sounds remuneration appeared by the DVR makes it an intriguing force quality gadget contrasted with other custom power gadgets. Under typical condition, DVR can diminish voltage THD from 10.22 % to 0.66%. What’s more, utilizing the proposed strategy, DVR can reestablish hilter kilter voltage droop without zero blocking transformer. The normal mistake of DVR voltage list remuneration is 0.99. voltage sag and harmonics.

aThree-Phase Transformerless Shunt Active Power Filter with Reduced Switch Count for Harmonic Compensation in Grid-Connected Applications

ABSTRACT:

Shunt active power filter is the preeminent solution against nonlinear loads, current harmonics and power quality problems. APF topologies for harmonic compensation use numerous high-power rating components and are therefore disadvantageous. Hybrid topologies combining low-power rating APF with passive filters are used to reduce the power rating of voltage source inverter. Hybrid APF topologies for high-power rating systems use a transformer with large numbers of passive components. In this paper, a novel four-switch two-leg VSI topology for a three-phase SAPF is proposed for reducing the system cost and size. The proposed topology comprises a two-arm bridge structure, four switches, coupling inductors, and sets of LC PFs. The third leg of the three-phase VSI is removed by eliminating the set of power switching devices, thereby directly connecting the phase with the negative terminals of the dc-link capacitor. The proposed topology enhances the harmonic compensation capability and provides complete reactive power compensation compared with conventional APF topologies. The new experimental prototype is tested in the laboratory to verify the results in terms of total harmonic distortion, balanced supply current, and harmonic compensation, following the IEEE-519 standard.

KEYWORDS:

  1. Harmonics
  2. hybrid topology
  3. nonlinear load
  4. power quality (PQ)
  5. Transformerless inverter
  6. Grid-connected system

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Proposed transformerless APF system

EXPECTED SIMULATION RESULTS:

 Fig. 2. Steady state operation of the proposed SAPF a) Utility voltage (THDv=4%) b) Utility current (THDi=4.1%) c) Load current (THDi=30.1%) d) Compensating filter current.

Fig. 3. a) DC voltage (50V/div). b) Filter current (100A/div) at filter switched ON (t=0.15).

Fig. 4. Starting performance of the proposed SAPF. a) Utility voltage (THDv=4%) b) Utility current (THDi=4.1%) c) Load current (THDi=30.1%) d) Compensating current at switched ON.

Fig. 5. a) On-state and Off-state APF operations. b) Zoom image of utility line current (𝒊𝑺𝒂𝒃𝒄) at 5th and 7th order harmonics.

Fig. 6. Dynamic performance with the R-L load step-change waveforms of the proposed SAPF.

 CONCLUSION:

In this paper, a novel three-phase reduced switch count and transformer-less APF circuit, operating with the function of active filtering and enhanced reactive power compensation. The main point of the proposed APF circuit topology, which uses a two-leg bridge structure and only four IGBT power devices in the three-phase power converter. Compared with the other existing topologies, the elimination of the transformer and minimum active and passive component contributes to a significant reduction in the manufacturing cost, volumetric size and weight. The proposed APF system is more robust, efficient and stable to improve the feasibility and harmonic propagation of the power distribution system. A detail analysis of the both the active filter inverter and passive filter, including the reactive power capability and filtering characteristics has been presented. The series LC tuned PF at the 5th and 7th order harmonic frequencies improves the harmonic mitigation performance. However, the series ac coupling inductors can overcome the fixed reactive power compensation caused by the defined value of the LC filter. The control algorithm can ensure the regulated sinusoidal voltage, phase amplitude, and low THD in the power distribution system, along with dc-link voltage control. The experimental and simulation results have verified the feasibility of the proposed APF topology and its excellent performance in terms of both transient and steady states responses to compensate selectively either the reactive power compensation, as well as in damping out the current harmonic distortion. Furthermore, the proposed APF system based on transformerless and power switching device reduced count configuration could be used in extensive applications, such as the grid-connected power converters, grid interfaced distributed energy sources, and so on.

REFERENCES:

[1] S. D. Swain, P. K. Ray, and K. B. Mohanty, “Improvement of Power Quality Using a Robust Hybrid Series Active Power Filter,” IEEE Transactions on Power Electronics, vol. 32, pp. 3490-3498, 2017.

[2] A. Javadi, A. Hamadi, L. Woodward, and K. Al-Haddad, “Experimental Investigation on a Hybrid Series Active Power Compensator to Improve Power Quality of Typical Households,” IEEE Transactions on Industrial Electronics, vol. 63, pp. 4849-4859, 2016.

[3] W. U. Tareen, S. Mekhilef, M. Seyedmahmoudian, and B. Horan, “Active power filter (APF) for mitigation of power quality issues in grid integration of wind and photovoltaic energy conversion system,” Renewable and Sustainable Energy Reviews, vol. 70, pp. 635-655, 4// 2017.

[4] J. Solanki, N. Fröhleke, and J. Böcker, “Implementation of Hybrid Filter for 12-Pulse Thyristor Rectifier Supplying High-Current Variable-Voltage DC Load,” IEEE Transactions on Industrial Electronics, vol. 62, pp. 4691-4701, 2015.

[5] L. Asiminoaei, C. Lascu, F. Blaabjerg, and I. Boldea, “Performance Improvement of Shunt Active Power Filter With Dual Parallel Topology,” IEEE Transactions on Power Electronics, vol. 22, pp. 247-259, 2007.

Neuro Fuzzy based controller for Power Quality Improvement

International Conference on Computational Intelligence and Communication Networks, 2015

ABSTRACT: Use of power electronic converters with nonlinear loads leads to power quality problems by producing harmonic currents and drawing reactive power. A shunt active power filter provides an elegant solution for reactive power compensation as well as harmonic mitigation leading to improvement in power quality. However, the shunt active power filter with PI type of controller is suitable only for a given load. If the load is varied, the proportional and integral gains are required to be fine tuned for each load setting. The present study deals with hybrid artificial intelligence controller, i.e. neuro fuzzy controller for shunt active power filter. The performance of neuro fuzzy controller over PI controller is examined and tabulated. The salvation of the problem is extensively verified with various loads and plotted the worst case out of them for the sustainability of the neuro fuzzy controller.

 

KEYWORDS:

  1. Active Power Filter
  2. Neuro Fuzzy Controller
  3. Back Propagation Algorithm
  4. Soft Computing

 

SOFTWARE: MATLAB/SIMULINK

 

BLOCK DIAGRAM:

Fig 1. Schematic Diagram of Shunt Active Power Filter

  

EXPECTED SIMULATION RESULTS:

   

Fig 2. (a) Waveform of Load Current, Compensating Current, Source

Current and Source Voltage for Case V of Table1 (1kVA with α=60o) and

(b) Waveform of Source Voltage and in phase Source Current of Fig. (a) Reproduced

 

CONCLUSION:

The application of hybrid artificial intelligence technique on shunt active power filter is proved to be an eminent solution for the mitigation of harmonics and the compensation of reactive power. The hybrid artificial intelligence used here is the neuro fuzzy controller. It takes the linguistic inputs as a fuzzy logic controller and it adapts any situation in between the running of the program as the neural network. The simulation results states that the active power filter controller with neuro fuzzy controllers have been seen to eminently minimize harmonics in the source current when the load demands non sinusoidal current, irrespective of whether the load is fixed or variable when compared to PI Controller. Simultaneously, the power factor at source also becomes the unity, if the load demands reactive power. The neuro fuzzy controller is far superior to the PI controller for all the loads. In the present work, a range of values of the load is considered to robustly test the controllers. It has been demonstrated that neuro fuzzy controller offers more acceptable results over the PI controller. The neuro fuzzy controller, therefore, significantly improves the performance of a shunt active power filter.

 

REFERENCES:

  • Laszlo Gyugyi, “Reactive Power Generation and Control by Thyristor Circuits”, IEEE Transactions on Industry Applications, vol. IA-15, no. 5, September/October 1979.
  • Akagi, Y. Kanazawa, and A. Nabae, “Instantaneous reactive power compensators comprising switching devices without energy storage components,” IEEE Transaction Industrial Applications, vol. IA-20, pp. 625-630, May/June 1984.
  • Z. Peng, H. Akagi, and A. Nabae, “A study of active power filters using quad series voltage source pwm converters for harmonic compensation,” IEEE Transactions on Power Electronics, vol. 5, no. 1, pp. 9–15, January 1990.
  • Conor A. Quinn, Ned Mohan, “Active Filtering of Harmonic Currents in Three-phase, Four-Wire Systems with Three-phase and Single-phase Non-Linear Loads”, IEEE-1992.
  • A. Morgan, J. W. Dixon, and R. R. Wallace, “A three-phase active power filter operating with fixed switching frequency for reactive power and current harmonic compensation,” IEEE Transactions on Industrial Electronics, vol. 42, no. 4, pp. 402–408, August 1995.

PSO – PI Based DC Link Voltage Control Technique for Shunt Hybrid Active Power Filter

2016 IEEE

ABSTRACT: In power systems, the intensive use of nonlinear loads causes several power quality problems such as current harmonic pollution. In order to reduce the current harmonic pollution, the shunt hybrid active filter (SHAPF) is the best solutions effectively. In shunt hybrid active filter systems SHAPFs, the design of dc link controller is a significant and challenging task due to its impact on the performance and stability of the overall system. The main contribution of this paper is that the particle swarm optimization (PSO) algorithm is applied gains for PI controller which can result in the improved response in terms of response time and overshoot. In proposed control method, the performance results of harmonic compensation are satisfactory. Theoretical analyses and simulation results are obtained from an actual industrial network model in PSCAD. The simulation results are presented for proposed system in order to demonstrate that the harmonic compensation performance meets the IEEE-519 standard.

KEYWORDS

  1. DC link controller
  2. Harmonics
  3. Particle swarm optimization
  4. Power quality
  5. PSCAD
  6. Shunt hybrid active power filter

SOFTWARE: MATLAB/SIMULINK

 CIRCUIT DIAGRAM:

Figure 1. SHAPF Power System

 EXPECTED SIMULATION RESULTS

 

Figure 2 Comparison of PI, PID and PSO based PI controller for DC link

Control

Figure 3 Three phase Source Voltages, Load – M-SHAPF – Source

Currents, SHAPF DC link Voltage

Figure 4 Source -Load-M-SHAPF active power, Source -Load-M-SHAPF

reactive power

 CONCLUSION

The intensive use of nonlinear loads causes several power quality problems such as current harmonic pollution. In order to reduce the current harmonic pollution, the shunt hybrid active filter (SHAPF) is the best solution effectively. In shunt hybrid active filter systems (SHAPF)s, the design of dc link controller is a significant and challenging task due to its impact on the performance and stability of the overall system. On account of the limitations between existing literatures, the purpose of this paper is that PSO algorithm has been proposed to adapt the dc link controller gains of the SHAPF. In this paper, the particle swarm optimization (PSO) algorithm is applied gains for PI controller which can result in the improved response in terms of response time and overshoot. In proposed control method, the performance results of harmonic compensation are satisfactory. Theoretical analyses and simulation results are obtained from an actual industrial network model in PSCAD. The simulation results are presented for proposed system in order to demonstrate that the harmonic

REFERENCES

[1] B. Soudan and M. Saad, “An evolutionary dynamic population size PSO implementation,” in Information and Communication Technologies: From Theory to Applications, 2008. ICTTA 2008. 3rd International Conference on, 2008, pp. 1–5.

[2] J. Kennedy, “Particle swarm optimization” IEEE International Conference on Neural Network , pp. 1942 – 1948 , 1995. doi: 10.1109/ICNN.1995.488968.

[3] Chien-Hung Liu and Yuan-Yih Hsu, “Design of a Self-Tuning PI Controller for a STATCOM Using Particle Swarm Optimization,” IEEE Transactions on Industrial Electronics, vol. 57, no. 2, pp. 702– 715, Feb. 2010.

[4] J. Turunen, M. Salo and H. Tuusa, “Comparison of three series hybrid active power filter topologies”, 11th International Conference on. Harmonics and Quality of Power, pp. 324–329, Sept. 2004. doi: 10.1109/ICHQP.2004.1409375.

[5] M. A. Mulla, C. Rajagopalan, A. Chowdhury,”Compensation of three-phase diode rectifier with capacitive filter working under unbalanced supply conditions using series hybrid active power filter”, IET Power Electronics, vol.7, (6), pp. 1566–1577, 2014, doi: 10.1049/iet-pel.2013.0605.

Harmonics Reduction And Power Quality Improvement By Using DPFC

 

ABSTRACT:

The DPFC is derived from the unified power-flow controller (UPFC). The DPFC can be considered as a UPFC with an eliminated common dc link. The active power exchange between the shunt and series converters which is through the common dc link in the UPFC is now through the transmission lines at the third-harmonic frequency. The DPFC employs the distributed concept, in which the common dc-link between the shunt and series converters are eliminated and three-phase series converter is divided to several single-phase series distributed converters through the line. According to the growth of electricity demand and the increased number of non-linear loads in power grids harmonics, voltage sag and swell are the major power quality problems. DPFC is used to mitigate the voltage deviation and improve power quality. Simulations are carried out in MATLAB/Simulink environment. The presented simulation results validate the DPFC ability to improve the power quality.

KEYWORDS:

  1. Load flow control
  2. FACTS
  3. Power Quality
  4. Harmonics
  5. Sag and Swell Mitigation
  6. Distributed Power Flow Controller
  7. Y–Δ transformer

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. DPFC configuration

EXPECTED SIMULATION RESULTS:

 

Fig 2. three phase voltage sag waveform without DPFC

 

Fig. 3 three phase voltage sag waveform with DPFC

 Fig.4 3-ϕ load current swell waveform without DPFC

Fig.5 Mitigation of 3-ϕ load current swell with DPFC

             

Fig.6 Total harmonic distortion of load voltage without DPFC

.Fig.7 Total harmonic distortion of load voltage with DPFC

 CONCLUSION:

This paper has presented a new concept called DPFC. The DPFC emerges from the UPFC and inherits the control capability of the UPFC, which is the simultaneous adjustment of the line impedance, the transmission angle, and the bus voltage magnitude. The common dc link between the shunt and series converters, which is used for exchanging active power in the UPFC, is eliminated. This power is now transmitted through the transmission line at the third-harmonic frequency. The series converter of the DPFC employs the DFACTS concept, which uses multiple small single-phase converters instead of one large-size converter. The reliability of the DPFC is greatly increased because of the redundancy of the series converters. The total cost of the DPFC is also much lower than the UPFC, because no high-voltage isolation is required at the series-converter part and the rating of the components of is low. To improve power quality in the power transmission system, the harmonics due to nonlinear loads, voltage sag and swell are mitigated. To simulate the dynamic performance, a three-phase fault is considered near the load. It is shown that the DPFC gives an acceptable performance in power quality improvement and power flow control.

 REFERENCES:

[1] S.Masoud Barakati Arash Khoshkbar sadigh and Mokhtarpour.Voltage Sag and Swell Compensation with DVR Based on Asymmetrical Cascade Multicell Converter North American Power Symposium (NAPS),pp.1-7,2011.

[2] Zhihui Yuan, Sjoerd W.H de Haan, Braham Frreira and Dalibor Cevoric “A FACTS Device: Distributed Power Flow Controller (DPFC)” IEEE Transaction on Power Electronics, vol.25, no.10, October 2010.

[3] Zhihui Yuan, Sjoerd W.H de Haan and Braham Frreira “DPFC control during shunt converter failure” IEEE Transaction on Power Electronics 2009.

[4] M. D. Deepak, E. B. William, S. S. Robert, K. Bill, W. G. Randal, T. B. Dale, R. I. Michael, and S. G. Ian, “A distributed static series compensator system for realizing active power flow control on existing power lines,” IEEE Trans. Power Del., vol. 22, no. 1, pp. 642–649, Jan. 2007.

[5] D. Divan and H. Johal, “Distributed facts—A new concept for realizing grid power flow control,” in Proc. IEEE 36th Power Electron. Spec. Conf. (PESC), 2005, pp. 8–14.

Harmonics Reduction And Power Quality Improvement By Using DPFC

 

ABSTRACT:

The DPFC is derived from the unified power-flow controller (UPFC). The DPFC can be considered as a UPFC with an eliminated common dc link. The active power exchange between the shunt and series converters which is through the common dc link in the UPFC is now through the transmission lines at the third-harmonic frequency. The DPFC employs the distributed concept, in which the common dc-link between the shunt and series converters are eliminated and three-phase series converter is divided to several single-phase series distributed converters through the line. According to the growth of electricity demand and the increased number of non-linear loads in power grids harmonics, voltage sag and swell are the major power quality problems. DPFC is used to mitigate the voltage deviation and improve power quality. Simulations are carried out in MATLAB/Simulink environment. The presented simulation results validate the DPFC ability to improve the power quality.

KEYWORDS:

  1. Load flow control
  2. FACTS
  3. Power Quality
  4. Harmonics
  5. Sag and Swell Mitigation
  6. Distributed Power Flow Controller
  7. Y–Δ transformer

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. DPFC configuration

EXPECTED SIMULATION RESULTS:

 

Fig 2. three phase voltage sag waveform without DPFC

 

Fig. 3 three phase voltage sag waveform with DPFC

Fig.4 3-ϕ load current swell waveform without DPFC

Fig.5 Mitigation of 3-ϕ load current swell with DPFC

             

Fig.6 Total harmonic distortion of load voltage without DPFC

Fig.7 Total harmonic distortion of load voltage with DPFC

 CONCLUSION:

This paper has presented a new concept called DPFC. The DPFC emerges from the UPFC and inherits the control capability of the UPFC, which is the simultaneous adjustment of the line impedance, the transmission angle, and the bus voltage magnitude. The common dc link between the shunt and series converters, which is used for exchanging active power in the UPFC, is eliminated. This power is now transmitted through the transmission line at the third-harmonic frequency. The series converter of the DPFC employs the DFACTS concept, which uses multiple small single-phase converters instead of one large-size converter. The reliability of the DPFC is greatly increased because of the redundancy of the series converters. The total cost of the DPFC is also much lower than the UPFC, because no high-voltage isolation is required at the series-converter part and the rating of the components of is low. To improve power quality in the power transmission system, the harmonics due to nonlinear loads, voltage sag and swell are mitigated. To simulate the dynamic performance, a three-phase fault is considered near the load. It is shown that the DPFC gives an acceptable performance in power quality improvement and power flow control.

 

REFERENCES:

[1] S.Masoud Barakati Arash Khoshkbar sadigh and Mokhtarpour.Voltage Sag and Swell Compensation with DVR Based on Asymmetrical Cascade Multicell Converter North American Power Symposium (NAPS),pp.1-7,2011.

[2] Zhihui Yuan, Sjoerd W.H de Haan, Braham Frreira and Dalibor Cevoric “A FACTS Device: Distributed Power Flow Controller (DPFC)” IEEE Transaction on Power Electronics, vol.25, no.10, October 2010.

[3] Zhihui Yuan, Sjoerd W.H de Haan and Braham Frreira “DPFC control during shunt converter failure” IEEE Transaction on Power Electronics 2009.

[4] M. D. Deepak, E. B. William, S. S. Robert, K. Bill, W. G. Randal, T. B. Dale, R. I. Michael, and S. G. Ian, “A distributed static series compensator system for realizing active power flow control on existing power lines,” IEEE Trans. Power Del., vol. 22, no. 1, pp. 642–649, Jan. 2007.

[5] D. Divan and H. Johal, “Distributed facts—A new concept for realizing grid power flow control,” in Proc. IEEE 36th Power Electron. Spec. Conf. (PESC), 2005, pp. 8–14.

Implementation of Adaptive Filter in Distribution Static Compensator

 

ABSTRACT:

This paper presents an implementation of an adaptive filter in a three-phase distribution static compensator (DSTATCOM) used for compensation of linear/nonlinear loads in a three-phase distorted voltage ac mains. The proposed filter, which is based on adaptive synchronous extraction, is used for extraction of fundamental active- and reactive-power components of load currents in estimating the reference supply currents. This control algorithm is implemented on a developed DSTATCOM for reactive-power compensation, harmonics elimination, load balancing, and voltage regulation under linear and nonlinear loads. The performance of DSTATCOM is observed satisfactory under unbalanced time-varying loads.

KEYWORDS

  1. Adaptive filter (AF)
  2. distribution static compensator (DSTATCOM)
  3. harmonics
  4. load balancing
  5. sinusoidal tracking algorithm
  6. voltage-source converter (VSC)

SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Fig.1. Schematic of three-leg DSTATCOM.

EXPECTED SIMULATION RESULTS:

(a)

(b)

                                                             (c)

Fig. 2. (a), (b), and (c) Various intermediate signals of the control algorithm at load injection. (a) Ch. 1 and 2: 200 V/div; Ch. 3 and 4: 20 A/div; Time axis: 50 ms/div. (b) Ch. 1, 2, 3, and 4: 20 A/div; Time axis: 20 ms/div. (c) Ch. 1, 2,3, and 4: 20 A/div; Time axis: 20 ms/div.

 Fig. 3. Steady-state performance of DSTATCOM at linear lagging PF load in PFC mode. (a) Ps. (b) PL. (c) Pc. (d) vab, isa. (e) vbc, isb. (f) vca, isc.

Fig. 4. Steady-state performance of DSTATCOM at nonlinear loads in PFC mode. (a) vab, isa. (b) vbc, isb. (c) vca, isc. (d) Harmonic spectrum of isa. (e) vab, iLa. (f) Harmonic spectrum of iLa.

Fig. 5. Dynamic performance of DSTATCOM at unbalanced linear loads. (a) vab, isa, isb, isc. (b) vab, iLa, iLb, iLc. (c) vdc, isa, iCa, iLa.

Fig. 6. Dynamic performance of DSTATCOM at unbalanced nonlinear loads. (a) vab, isa, isb, isc. (b) vab, iLa, iLb, iLc. (c) vdc, isa, iCa, iLa

Fig. 7. Steady-state performance of DSTATCOM at linear lagging PF load in ZVR mode. (a) Ps. (b) PL. (c) Pc. (d) vab, isa. (e) vbc, isb. (f) vca, isc.

Fig. 8. Steady-state performance of DSTATCOM at nonlinear load in ZVR mode. (a) vab, isa. (b) vbc, isb. (c) vca, isc. (d) Harmonic spectrum of isa. (e) Harmonic spectrum of iLa. (f) iCa. (g) Ps. (h) PL.

Fig. 9. Variation of Vt, isa, and iLa with vdc under unbalanced linear loads.

 CONCLUSION:

 A DSTATCOM has been implemented for a three-phase distribution system. An AF has been used for control of DSTATCOM. This AF has been found simple and easy to implement, and its performance has been observed satisfactory with nonsinusoidal and distorted voltages of ac mains under load variation. The performance of DSTATCOM with its AF has been demonstrated for harmonics elimination, reactivepower compensation, and load balancing with self-supporting dc link in PFC and ZVR modes. The dc-link voltage of the DSTATCOM has been also regulated to a desired value under time-varying load conditions.

 REFERENCES:

 [1] E. F. Fuchs and M. A. S. Mausoum, Power Quality in Power Systems and Electrical Machines. London, U.K.: Elsevier, 2008.

[2] H. Akagi, E. H. Watanabe, and M. Aredes, Instantaneous Power Theory and Applications to Power Conditioning. Hoboken, NJ, USA: Wiley, 2007.

[3] A. Emadi, A. Nasiri, and S. B. Bekiarov, Uninterruptible Power Supplies and Active Filters. Boca Raton, FL, USA: CRC Press, 2005.

[4] J. Jacobs, D. Detjen, C. U. Karipidis, and R. W. De Doncker, “Rapid prototyping tools for power electronic systems: Demonstration with shunt active power filters,” IEEE Trans. Power Electron., vol. 19, no. 2, pp. 500– 507, Mar. 2004.

[5] A. Ghosh and G. Ledwich, Power Quality Enhancement Using Custom Power Devices. New Delhi, India: Springer Int. Edition, 2009.

Diode Clamped Three Level Inverter Using Sinusoidal PWM

 

ABSTRACT:

An inverter is a circuit which converts dc power into ac power at desired output voltage and frequency. The ac output voltage can be fixed at a fixed or variable frequency. This conversion can be achieved by controlled turn ON & turn OFF or by forced commutated thyristors depending on applications. The output voltage waveform of a practical inverter is non sinusoidal but for high power applications low distorted sinusoidal waveforms are required. The filtering of harmonics is not feasible when the output voltage frequency varies over a wide range. There is need for alternatives. Three level Neutral Point Clamped inverter is a step towards it.

KEYWORDS:

  1. Harmonics
  2. Inverter
  3. THD
  4. PWM

 SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Figure1.Diode clamped three level inverter

EXPECTED SIMULATION RESULTS:

 

 Figure2. Upper triangular pulse width modulation

Figure3. lower triangular pulse width modulation

Figure4. three level voltage waveform

Figure5.Matlab model of three level inverter feeding induction motor

 Figure 6. stator waveform of three level inverter

 CONCLUSION:

In normal inverters odd harmonics are present which causes distortion of the output waveform. By using the “THREE LEVEL DIODECLAMPED INVERTER” we can eliminate some number of harmonics hence increasing the efficiency of the inverter.

 REFERENCES:

[1] A.Mwinyiwiwa, Zbigneiw Wolanski, ‘Microprocessor Implemented SPWM for Multiconverters with Phase-Shifted Triangle Carriers’ IEEE Trans. On Ind. Appl., Vol. 34, no. 3, pp 1542-1549, 1998.

[2] J. Rodriguez, J.S. Lai, F. Z. Peng, ’ Multilevel Inverters: A Survey of Topologies, Controls and Applications’, IEEE Trans. On Ind. Electronics, VOL. 49, NO. 4, pp. 724-738, AUGUST 2002

[3] D. Soto, T. C. Green, ‘A Comparison of High Power Converter Topologies for the Implementation of FACTS Controller’, IEEE Trans. On Ind. Electronics, VOL. 49, NO. 5, pp. 1072-1080, OCTOBER 2002.

[4] Muhammad H. Rashid, Power Electronics: Circuits, Devices and Applications, Third edition, Prentice Hall of India, New Delhi, 2004.

[5] Dr. P. S. Bimbhra, Power Electronics, Khanna Publishers, Third Edition, Hindustan Offset Press, New Delhi-28, 2004.