A Synchronous Generator Based Diesel-PV Hybrid Micro-grid with Power Quality Controller

 

ABSTRACT:

This paper presents an isolated microgrid, with synchronous generator(SG) based diesel generation (DG) system in combination with solar photo-voltaic(PV). The DG supplies power to the load directly, and a battery supported voltage source converter (VSC) is connected in shunt at point of common coupling (PCC). The PV array is connected at DC-link of the VSC through a boost converter. A high order optimization based adaptive filter control scheme is used for maintaining the quality of PCC voltages and source currents. This controller makes the waveform free of distortion, removes errors due to unbalances, corrects the power factor and makes the source current smooth sinusoidal, irrespective of the nature of load. MATLAB/Simulink based simulation results demonstrate satisfactory performance of the given system.

KEYWORDS:

  1. Battery
  2. Diesel generator
  3. LMF
  4. Power quality
  5. PV

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

 

 

Fig. 1 System model

 EXPECTED SIMULATION RESULTS:

 

 Fig. 2 Steady State Response of DG-PV micro-grid

Fig. 3 Dynamic Response of DG-PV micro-grid

CONCLUSION:

An isolated SG based DG and PV hybrid micro-grid has been presented here, with a battery suppported VSC connected at PCC. Three-phase adaptive control is used for power quality improvement through VSC. The given system and control have been simulated in MATLAB/Simulink environment and results demonstrate their satisfactory performance in both steady state and dynamic conditions.

REFERENCES:

[1] G. Shafiullah et al., “Meeting energy demand and global warming by integrating renewable energy into the grid,” in 22nd Australasian Universities Power Engg. Conf. (AUPEC), pp. 1–7, Bali, 2012.

[2] M. Milligan et al., “Alternatives No More: Wind and Solar Power Are Mainstays of a Clean, Reliable, Affordable Grid,” IEEE Power & Energy Mag., vol. 13, no. 6, pp. 78–87, Nov.-Dec. 2015.

[3] L. Partain and L. Fraas, “Displacing California’s coal and nuclear generation with solar PV and wind by 2022 using vehicle-to-grid energy storage,” IEEE Photovoltaic Specialist Conf., pp. 1–6, LA, 2015.

[4] Daniel E. Olivares et al., “Trends in Microgrid Control,” in 2015 IEEE Trans. Smart Grid, vol. 5, no.4, pp. 1905–1919, July, 2014.

[5] Z. Zavody, “The grid challenges for renewable energy An overview and some priorities,” IET Seminar on Integrating Renewable Energy to the Grid, pp. 1–24, London 2014.

Real Time Control of an Active Power Filter under Distorted Voltage Condition

ABSTRACT:

This paper, presents three phase shunt active filter under distorted voltage condition, the active power filter control is based on the use of self-tuning filter (STF) for reference current generation and on space vector PWM for generation of pulses. The dc capacitor voltage is controlled by a classical PI controller. The diode rectifier feed RL load is taken as a nonlinear load. The self-tuning filter allows extracting directly the voltage and current fundamental components in the axis without phase locked loop (PLL) under distorted voltage condition. The experiment analysis is made based on working under distorted voltage condition, and the total harmonic distortion of source current after compensation .Self tuning filter based extraction technique is good under distorted voltage conditions. The total harmonic distortion (THD) of source current is fully reduced. The effectiveness of the method is theoretically studied and verified by experimentation.

KEYWORDS:

  1. active power filters
  2. dSPACE1104
  3. real time
  4. STF
  5. SVM

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 

Figure 1. Active Power Filter

 EXPECTED SIMULATION RESULTS:

 

 Figure 2. The source voltage

Figure 3. The load current

Figure 4. Source current

Figure 5. Filter current and its reference

Figure 6. The DC voltage

Figure 7. Load current’s harmonic spectrum

Figure 8. Source current’s harmonic spectrum

CONCLUSION:

A modified pq theory control technique applied to a three-phase Shunt Power Filter is proposed. The appropriate control strategy for removing harmonics caused by non-linear loads is developed. The main advantage of the proposed method is its simplicity (no PLL circuit needed) and its efficiency in non-ideal voltage condition. The use of SVPWM method allows to the inverter to fellow its reference accurately which increase the performance of the active filter. The experiment results show the efficiency of the proposed method in terms of harmonic reduction as shown in Figure12, the THD obtained by the new control technique has been drastically reduced.

REFERENCES:

[1] N. Mariun, A. Alam, S. Mahmod, and H. Hizam, “Review of control strategies for power quality conditioners”, in Power and Energy Conference, 2004. PECon 2004. Proceedings. National, 2004, pp. 109– 115.

[2] G. W. Chang and C. M. Yeh, “Optimisation-based strategy for shunt active power filter control under non-ideal supply voltages”, IEE Proceedings – Electric Power Applications, vol. 152, no. 2, p. 182, 2005.

[3] S. George and V. Agarwal, “A DSP Based Optimal Algorithm for Shunt Active Filter Under Nonsinusoidal Supply and Unbalanced Load Conditions”, Power Electronics, IEEE Transactions on, vol. 22, no. 2, pp. 593 –601, Mar. 2007.

[4] M. I. M. Montero, E. R. Cadaval, and F. B. Gonzalez, “Comparison of Control Strategies for Shunt Active Power Filters in Three-Phase Four-Wire Systems”, Power Electronics, IEEE Transactions on, vol. 22, no. 1, pp. 229 –236, Jan. 2007.

[5] M. Abdusalam, P. Poure, and S. Saadate, “Hardware implementation of a three-phase active filter system with harmonic isolation based on self-tuning-filter”, in IEEE Power Electronics Specialists  Conference, 2008. PESC 2008, 2008, pp. 2875–2881.,

Three-Phase Shunt Active Power Filter for Power Improvement Quality using Sliding Mode Controller

ABSTRACT:

In this paper, experimental study of Sliding Mode Controller (SMC) DC bus voltage of three phase shunt active power filter (APF), to improve power quality by compensating harmonics and reactive power required by nonlinear load is proposed. The algorithm used to identify the reference currents is based on the Self Tuning Filter (STF). For generation of the pulse switching of the IGBTs inverter the hysteresis current controller is used, implemented into an analogue card. Finally, various experimental results are presented under steady state and transient conditions.

KEYWORDS:

  1. Shunt Active Power Filter (APF)
  2. Total Harmonic Distortion (THD)
  3. Sliding Mode Controller (SMC)
  4. Self Tuning Filter (STF)

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 

Fig. 1: The basic compensation principle of the shunt APF.

 EXPECTED SIMULATION RESULTS:

 

 

Fig. 2. Experimental APF results: load current iL (A), filter current iF (A)

and source current iS (A). Ch1 to Ch4 scale: 5 A/div. Time scale: 20 ms/div.

 

Fig. 3. Experimental APF results: load current iL (A), filter current iF (A),

source current iS (A) and source voltage Vs (V). Ch1 and Ch3 scale: 5 A/div;

Ch2 scale: 100 V/div;Ch4 scale: 80 V/div; Time scale: 10 ms/div.

Figure 4. Experimental APF results : load current iL(A), filter current iF(A) ,

source current iS(A) and DC voltage Vdc(V). Ch1,Ch3 and Ch4 scale: 10

A/div. Ch2 scale: 100 V/div. Time scale: 20 ms/div.

Figure 5. Experimental APF results: DC voltage Vdc (V) and DC reference

voltage V*dc (V). Ch1 and Ch2 scale: 100 V/div. Time scale: 1s/div

CONCLUSION:

The control of the shunt Active Power Filter was divided in three parts, the first one realized by the dSPACE system to generate the reference currents, the second one achieved by an analogue card for the switching pattern generation, implementing a hysteresis current controller and the third party use a sliding mode controller SMC. A SMC controlled shunt active power filter has been studied to improve the power quality by compensating both harmonics and reactive power requirement of the nonlinear load. The performance of the SMC controller has been developed in real time process and successfully tested in the laboratory The results of experiment study of APF control technique presented in this paper are found quite satisfactory to eliminate harmonics and reactive power components from utility current. The shunt APF presented in this paper for the compensation of harmonic current components in non-linear load was effective for harmonic isolation and keeping the utility supply line current sinusoidal. The validity of this technique was proved on the basis of experiment results. The APF is found effective to meet IEEE- 519-1992 standard recommendations on harmonics levels.

REFERENCES:

[1] Chaoui; J.P.Gaubert; F.Krim; G.Champenois, “PI Controlled Threephase Shunt Active Power Filter for Power Quality Improvement” A. “Electric Power Components and Systems, 1532-5016, Volume 35, Issue 12, 2007, Pages 1331 – 1344.

[2] D. Benatous, R. Abdessemed, “Digital voltage control of AC/DC PWM Converter with improved power factor and supply current ”, Journal of electric machines and power systems, Taylor and francis, 2000.

[3] G. A. Capolino, A. Golea, H. Henao, “Système de réduction des perturbations réseau pour commande vectorielle ”, Proc. Colloque SEE Perturbations Réciproques des Convertisseurs et des Réseaux, Nantes, 6 juillet 1992.

[4] M. Abdusalam, P. Poure and S. Saadate,’’ A New control scheme of hybrid active filter using Self-Tuning Filter,’’ POWERENG, International Conference on Power Engineering , Energy and Electrical Drives, Setubal Portugal,12-14 April (2007).

[5] M. Abdusalam, P. Poure and S. Saadate, « Study and experimental +6validation of harmonic isolation based on Self-Tuning-Filter for threephase active filter ». ISIE, IEEE International Symposium on Industrial Electronics, Cambridge, UK, (2008).

 

Performance Improvement of Active Power Filters based on P-Q and D-Q Control Methods under Non-Ideal Supply Voltage Conditions

ABSTRACT:

In this paper, we investigate the effect of unbalanced and distorted supply voltages on the performance of active power filters that are based on the well-known p-q and d-q control methods. Our analysis shows that the harmonic suppression performance of the p-q and d-q control methods deteriorates when non-ideal sources are used. We propose the use of a self tuning filter (STF) with the p-q theory or d-q method as a way of alleviating the detrimental effects of non-ideal supply voltages. Simulation results show that the proposed method can improve the performance of active power filters under non-ideal voltage conditions.

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 

 Fig.1.Block diagram of simulated APF

 EXPECTED SIMULATION RESULTS:

 

 Fig.2 Three phase balanced and undistorted (ideal) source voltage

Fig.3. Supply currents with p-q method under case 1. (THDi=2.1%)

Fig.4. Supply currents with d-q method under case 1. (THDi=2.07)

Fig.5. Distorted and unbalanced source voltages for case 2.

 

Fig.6. Supply currents with p-q method under case 2.

Fig.7. Supply currents with d-q method under case 2.

Fig.8. Supply currents with STF based p-q method under case 3.

Fig.9. Supply currents with STF based d-q method under case 3.

 CONCLUSION:

In this paper, we consider the effect of an unbalanced and distorted supply on the performance of the well-known p-q theory and d-q methods for active power filters. The ability of these methods to combat current harmonics deteriorates significantly when a non-ideal supply voltage is used. A modification to the p-q and d-q methods is then proposed for alleviating the effects of an imperfect supply. This involves the use of a self-tuning filter (STF) with p-q theory and the d-q method. We show that the total harmonic distortion of source current (THDi) can be reduced by up to around 2.30 % with the use of a STF under non-ideal voltage conditions. In addition, our comparative results show that an STFbased d-q method performs better than an STF-based p-q theory.

REFERENCES:

[1] W. Mack Grady, S. Santoso, “Understanding power system harmonics“, IEEE Power Eng. Rev. 21 (November (11)) (2001) 8-11.

[2] S. Biricik, O. C. Ozerdem “Investigation of Switched Capacitors Effect on Harmonic Distortion Levels and Performance Analysis with Active Power Filter“, Przeglad Elektrotechniczny, ISSN 0033-2097, R. 86 NR 11a/2010, pp 13-17.

[3] S. Buso, L. Malesani, P. Mattavelli, “Comparison of current control techniques for active filter applications,” Industrial Electronics, IEEE Transactions on , vol.45, no.5, pp.722-729, Oct 1998.

[4] H. Akagi, Y. Kanazawa, A. Nabae, “Generalized Theory of the Instantaneous Reactive Power in Three-Phase Circuits“, IPEC’83- Int. Power Electronics Conf., Tokyo, Japan, 1983, pp. 1375-1386.

[5] M. Asadi, A. Jalilian, H. F. Farahani, “Compensation of Unbalanced Non Linear Load and neutral currents using stationary Reference Frame in Shunt Active Filters,” Harmonics and Quality of Power (ICHQP), 2010 14th International Conference on, vol., no., pp.1-5, 26-29 Sept. 2010.

Multiple – Input Bidirectional DC -DC Power Converter with Renewable Energy Source

 

ABSTRACT:

A novel multiple–input converter with bidirectional power flow capability is proposed in this paper. By using bidirectional power flow approch, not only the buck mode but also the boost mode of operation can be possible. Moreover, by establishing single power converter for different sources we can reduce the components and so the size of overall system and cost can be reduced. In this topology independent of voltage level interconnection of voltage sources can be possible. One of the source used is solar panel which holds the predominant place for satsfying the futur enegry demand. In fuel cell vehicles different sources which having unequal voltage rating is needed with bidirectional power flow. Thus the proposed topology finds application in fuel cell vehicles (FCVs)/hybrid electric vehicles (HEVs).The operation principle, theoretical analysis, and design of the proposed converter are presented in this paper. Simulation results are used to verify both the exactness and feasibility of the proposed converter.

KEYWORDS:

  1. DC –DC power converter
  2. Multiple input converter

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Functional block diagram of a FCV system

 EXPECTED SIMULATION RESULTS:

 

 Fig. 2. Simulation result of mode E inductor currents, voltages and dc link current

Fig. 3. Simulation result of mode F inductor currents, voltages and

dc link current

Fig. 4. Simulation result of mode G inductor currents, voltages and

dc link current

 CONCLUSION:

This paper has proposed a multiple-input bidirectional dc–dc converter to interface more than two sources of power/energy operating at different voltage levels. The converter can be operated either in buck mode or boost mode in either directions of power flow. It is possible to control the power flow between each pair of sources independently when more than two sources are active. This paper gives detailed analysis and operation of the converter for various modes. In each mode, the relationship between the sources is derived which assists in the implementation of the controller. Simulations are done with three sources. Results obtained from these systems have been presented and match very well with the analytically expected waveforms. This converter not only finds application in FCVs but also can be utilized in distributed energy resources, smart grid and microgrid, battery management systems, etc., where more than two dc sources need to be interfaced with bidirectional power flow capability

REFERENCES:

[1] S. Aso, M. Kizaki, and Y. Nonobe, “Development of hybrid fuel cell vehicles in Toyota,” in Proc. IEEE PCC, 2007, pp. 1606–1611

[2] K. Rajashekhara, “Power conversion and control strategies for fuel cell vehicles,” in Proc. IEEE IECON, 2003, pp. 2865–2870.

[3] C. Chan, “The state of the art of electric and hybrid vehicles,” Proc. IEEE, vol. 90, no. 2, pp. 247-275, Feb. 2002

[4] B. Ozpineci, L. M. Tolbert, D. Zhong, “Multiple input converters for fuel cells,” in proc. Industry Applications Conference, 2004, vol. 2, pp. 791-797, 3-7 Oct. 2004

[5] Y.M. Chen, Y.C. Liu, and S.H. Lin, “Double-input PWM DC-DC converter for high/low voltage sources,” 25th International Telecommunications Energy Conference, 19-23 Oct. 2003, pp. 27–32.

Three-Phase For-Wire Shunt Active Filter With Unbalanced loads

 

ABSTRACT:

The electrical power quality at low voltage alternative networks became a serious concern because of the increased use of nonlinearloads and pollutants. This work is to improve the quality of electric current in such networks. Four-Wire Shunt Active Filter is studied; deferent loads (balanced and unbalanced) are discussed. We propose to identify harmonic and reactive currents at the base of Self-Tuning-Filters, which proved very good filtering performance, either in transient or steady state. The simulations demonstrate the importance of this work in harmonic filtering and reactive power compensation.

KEYWORDS:

  1. Shunt Active Filter (SAF)
  2. Total Harmonic Distortion(THD)
  3. Self-Tuning-Filter (STF)
  4. Unbalanced loads

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 

 Fig. 1. Block diagram of the APF

EXPECTED SIMULATION RESULTS:

 

 Fig.2 Simulation results of STFs under three balanced loads:

(a) Supply and loads currents, (b) 1st phase filter current, (c) Neutral currents,

(d) Harmonic current spectre of 1st phase load, (e) Harmonic current spectre of 1st phase of supply

 

 Fig.3 Simulation results under three unbalanced loads:

(a) Source and loads currents, (b) Neutral currents, (c) Filter currents,(d) Harmonic currentspectres of loads,(e) Harmonic current spectres of supply

                          

Fig.4 Supply voltage and current (phase 1)

CONCLUSION:

In this paper we have presented a new tree-phase for-wire active power filter based on STF extraction, to identifyharmonic current and reactive power. The objective was to improve the dynamic of identification method and also selectivity. The advantages of this filter are: STFs don’t introduce any displacement between input and output, at the fundamental pulsation. Good dynamic,and high selection of fundamental signal. Their selectivity is improved by reducing K. They can filtrate the voltages that are used to calculate instantaneous powers, to identify perturbation, and so PLL is not used. This method reduces the complexity of the control scheme and consequently facilitates the digital implementation of the control system. Those results demonstrate the good performances of the proposed control.

REFERENCES:

[l] M. Abdusalam, P. Poure,S. Saadate, “Hardware Implementation of a Three-PhaseActive Filter System with HarmonicIsolationBased on Self-Tuning-Filter”, IEEE. Power Electronics Specialists Conference, Aug. 2008, pp. 2276-2278.

[2] M. Abdusalam, P. Poure, S. Saadate, “A New Control Method of Hybrid Active Filter to Eliminate the 5th and 7th Harmonic Frequency Using Self-Tuning-Filter in the Feedforward Loop”. IREE, International Review of Electrical Engineering, Feb. 2008, pp. 65-72.

[3] A Ghamri, M.T Benchouia, A.Golea.,Sliding-mode Control Based Three-phase Shunt Active Power Filter: Simulation and Experimentation; Electric Power Components and Systems Journal, 2012, 40( 4): 383-398.

[4] M. Abdusalam, P. Poure, S. Saadate, “A New ControlScheme of Hybrid Active Filter Using Self-Tuning Filter”, POWERENG, International Conference on Power Engineering , Energy and Electrical Drives, Setubal Portugal,April. 2007, pp. 12-14.

[5] M.C. Benhabib, S. Saadate, “ New Control Approach for Four-Wire Active Power FilterBasedon the Use of Synchronous Reference Frame”,Elsevier B.V. Electric Power Systems Research 73,Nov. 2004, pp. 353–362. .

Real-time control of shunt active power filter under distorted grid voltage and unbalanced load condition using self-tuning filter

 

ABSTRACT:

In this paper, an alternative control method is proposed to improve the harmonic suppression efficiency of the activepower filter in a distorted and an unbalanced power system to compensate for the perturbations caused by the unbalanced nonlinear loads. The proposed method uses a self-tuning filter (STF) to process the grid voltage in order to provide a uniform reference voltage to obtain the correct angular position of the phase locked loop. Moreover, the required compensation currents are obtained by implementing another STF in the transformed set of currents in order to separate the fundamental and the harmonic currents. This allows the calculation of a precise reference current for the unbalanced, the non-linear and the variable load conditions. The proposed control method gives an adequate compensating current reference even for a nonidealvoltage and unbalanced current conditions. The real-time control of the filter under the distorted and the unbalanced power system is developed in an RT-LAB real-time platform. The results obtained in the software-in-the-loop configuration are presented to verify the effectiveness of the proposed control technique.

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1 Block diagram of the APF and the proposed control method

 EXPECTED SIMULATION RESULTS:

 

Fig. 2 Voltage and the current waveforms

a Ideal grid voltage

b Non-ideal (distorted and unbalanced) grid voltage

c Load currents under the ideal grid voltage

d Load currents under the non-ideal grid voltage

 

Fig. 3 Compensation of the grid current harmonics by using the conventional dq method

a Under the ideal voltage

b Under the non-ideal voltage, and by using the conventional pq method

c Under the ideal voltage

d Under the non-ideal voltage

Fig. 4 Compensation of the grid current harmonics

a By using the STF-based pq theory under the ideal voltage

b By using the STF-based pq theory under the ideal voltage

c By using the proposed method under the ideal voltage

d By using the proposed method under the non-ideal voltage

 CONCLUSION:

In this paper, the design of a control method that generates thecorrect reference current signal in order to satisfy the requirements of a harmonic suppression and a reactive power compensation, for the unbalanced non-linear load combinations under the case of the non-ideal grid voltageconditions have been discussed. An alternate method is proposed where two STF are applied to manage the distorted and the unbalanced voltage and current. In the proposed method, the distorted and the unbalanced voltages are first processed by using the STF to determine the correct angular positions. Then, a second STF is used toextract the balanced load current waveforms. This methodeliminates the need for additional low-pass or high-pass filtering when extracting the harmonic components from the fundamental. A step-by-step performance study, in a real-time environment, shows that the proposed control technique is able to generate the proper compensating reference current during the steady state and the dynamic load change conditions under the distorted and the unbalanced grid voltage conditions.

REFERENCES:

1 Sasaki, H., Machida, T.: ‘A new method to eliminate AC harmoniccurrents by magnetic flux compensation-considerations on basic design’, IEEE Trans. Power Appar. Syst., 1971, PAS-90, (5), pp. 2009–2019

2 Gyugyi, L., Strycula, E.C.: ‘Active AC power filters’. Proc. IEEE Ind. Appl. Ann. Meeting, 1976, vol. 19-C, pp. 529–535

3 Singh, B., Al-Haddad, K., Chandra, A.: ‘A review of active filters for power quality improvement’, IEEE Trans. Ind. Electron., 1999, 46, (5), pp. 960–971

4 Mariun, N., Alam, A., Mahmod, S., Hizam, H.: ‘Review of control strategies for power quality conditioners’. National Power and Energy Conf. Proc., PECon 2004, 29–30 November 2004, pp. 109–115

5 Akagi, H., Kanazawa, Y., Nabae, A.: ‘Instantaneous reactive power compensators comprising switching devices without energy storage components’, IEEE Trans. Ind. Appl., 1984, IA-20, (3), pp. 625–630

Fuzzy logic controller for five-level shunt active power filter under distorted voltage conditions

 

ABSTRACT:

 In this paper, a five-level inverter is used as a shunt active power filter (APF), taking advantages of the multilevel inverter such as low harmonic distortion and reduced switching losses. It is used to compensate reactive power and eliminate harmonics drawn from a diode rectifier feeding a RL load under distorted voltage conditions. The active power filter control strategy is based on the use of self tuning filters (STF) for reference current generation and a fuzzy logic current controller. The use of STF instead of classical extraction filters allows extracting directly the voltage and current fundamental components in the a-J3 axis without phase locked loop (PLL). This study is divided in two parts. The first one deals with the harmonic isolator which generates the harmonic reference currents. The second part focuses on the generation of the switching pattern of the inverter by using a fuzzy logic controller applied and extended to a five level shunt APF. The MA TLAB Fuzzy Logic Toolbox is used for implementing the fuzzy logic control algorithm. The obtained results show that, the proposed shunt active power filter controller has produced a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.

KEYWORDS:

  1. Active filter
  2. Harmonics isolator
  3. Distorted voltage conditions
  4. Self-tuning filter
  5. Fuzzy logic control and PWM control

 SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

Fig1.power system configuration

 EXPECTED SIMULATION RESULTS:

 

Fig. 2. Supply voltage Vs waveform

Fig. 3. Supply current Is waveform without filtering.

Fig. 4. Supply current Is waveform with filter.

Fig. 5. Active filter current If

Figure 6. APF output voltage Vab (line to line) for a five-level with PDPWM

Fig. 7. DC voltage of the condensers Vdc

CONCLUSION:

This paper has discussed the control and performance improvement of a shunt active power filter under distorted voltage conditions, using a fuzzy logic controller for a five level shunt active power filter based on the optimization of the reference current generation and using a modified version of the p-q theory and PDPWM to generate switching signals. Simulation results have shown high performances in reducing harmonics and power factor correction. The use of the Self-tuning filter leads to satisfactory improvements since it perfectly extracts the harmonic currents under distorted conditions. With the fuzzy logic control, the active filter can be adapted easily to more severe constraints, such as unbalanced conditions. In addition, results have demonstrated the major advantages of using STF and fuzzy logic controller in filter control. The Five-level APF provides numerous advantages such as improvement of supply current waveform, less harmonic distortion and possibilities to use it in high power applications. As final conclusion, the obtained results showed that, the proposed active power filter controller have provided a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.

REFERENCES:

[I] H. Akagi, “Trend in active power line conditioners,” IEEE Trans Power Electronics, vol.9, pp.263-268, August 1994.

[2] H.-K. Chiang, B.-R. Lin, K.-T. Yang, and K.-W.Wu, “Hybrid active power filter for power quality compensation,” IEEE Power Electronics and Drives Systems,voL2, pp.949-954, 2005.

[3] X. Wanfang, L. An, and W. Lina, “Development of hybrid active power filter using intelligent controller, ” Autom. Electric Power Syst. Vo1.27, pp.49-52,2003.

[4] O. Vodyakho, T. Kim, S. Kwak, ‘Three-level inverter based active power filter for the three-phase, four-wire system,” IEEE Power Electronics Specialists Conference, pp. 1874-1880,2008.

[5] G.W. Chang, C.M. Yeh, “Optimization-based strategy for shunt active power filter control under non-ideal supply voltages, ” lEE Electric Power Applications, voL152, pp.182-190, March 2005.

Using “STF-PQ” Algorithm and Hysteresis Current Control in Hybrid Active Power Filter to Eliminate Source Current Harmonic

ABSTRACT:

According to importance of power quality in power network, improvement of compensator equipment and ways of efficiency increasing can reduces destroyer effect on network. Active power filters as more importance and finance in network and industrial has depended detector algorithm and switching technique. This paper presents a novel algorithm (STF-PQ). This algorithm base on harmonic extract is divided into two parts as feedback loop and feed forward loop. Then, the hysteresis current control has been used to produce the switching pattern. A comparison between PWM and hysteresis current control has been performed that shows the efficiency and simplicity of hysteresis current control. Simulation of this filter has been done in Matlab/Simulink to prove the good performance of STF-PQ and hysteresis current control in hybrid filters.

KEYWORDS:

  1. Hybrid active power filters
  2. Self tuning filter
  3. Hystrsis current control
  4. Matlab/Simulink

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 

 

Fig.1 Parallel hybrid active filter configuration

 EXPECTED SIMULATION RESULTS:

 

 

Fig.2 simulation Results

CONCLUSION:

According to development of power systems in industrial such as UPS, speed control of electrical machine, electrical furnace, computers and non-linear load that cause increasing of harmonic in network, Undesirable effect of harmonic is one of power transfer problem. This is why of standard codifying on THD limitation. Thus, it is necessary to detect and remove it until under permit limit. In this paper a novel algorithm of “STF-PQ” has been proposed to detect harmonics in power system. Then hysteresis current control has been used to make the reference current due to its simplicity and high accuracy. The comparison between PWM and hysteresis proves that use of PWM has more complexity and calculation to generate pulses. Simulation results show the efficiency of this power filter in harmonic elimination.

REFERENCES:

[1] J. C. Das,” Passive filters- Potentialities and limitations” IEEETransactions on industry applications, vol. 40, pp. 345-362, (2004).

[2] Park, J-h. Sung and K. Nam,” A New parallel hybrid filter configuration minimizing active filter size” IEEE/PESC Ann. Meeting Conf, vol. 1, pp.400-405 (1999)

[3] B. N. Singh, Bhim Singh, A. Chandra and K. Al-Haddad,” Digital implementation of new type of hybrid filter with simplified control strategy” Conference Proceeding IEEE-APEC 99., vol 1, pp. 642- 648 (1999)

[4] H. Fujita, and H. Akagi,” A practical approach to harmonic compensatreion in power systems-Series connection of passive and shunt active filters,” IEEE Trans. Ind. Appl, vol 27, pp. 1020-1025 (1991)

[5] Michael John Newman, Daniel Nahum Zmood , Donald Grahame Holmes,” Stationary Frame Harmonic Reference Generation for Active Filter Systems”, IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 38, NO. 6, NOVEMBER/DECEMBER 2002

 

The Benefit of Harmonics Current Using a New Topology of Hybrid Active Power Filter

 

ABSTRACT:

 This paper presents a new idea to benefit of eliminated harmonics current by using a new topology of hybrid active power filter (HAPF) to compensate harmonics current to be sinusoidal in order to feed some loads. The design and simulation of a new three phase HAPF circuit using a shunt active power filter (APF) connected in parallel with a capacitor (C) line of a (LC) low pass filter (LPF) has been submitted.

The first aim of the new circuit is to use the LPF as a path to pass the fundamental frequency (50 Hz) current and eliminate other high order frequencies, while APF compensates high order frequencies and compensate reactive power of the circuit. The second aim is to benefit from the modified wave in the high frequency branch of LPF to use it as a useful power in order to feed different loads. In addition, With this topology, the resonance problem (which usually happens between LPF and the system) will disappear because of using of APF in the high frequency branch.

The control circuit has been designed based on the instantaneous reactive power theory. A Clarke transformation equations and hysteresis current controller have been used in the HAPF’s design. The proposed circuit has provided a good harmonic elimination, total harmonic distortion (THD) reduced, reactive power compensation and a reasonable sinusoidal waveform.

KEYWORDS:

  1. Harmonics Elimination
  2. Hybrid Active Power Filter
  3. Active Power Filter
  4. Passive Filters
  5. Total Harmonic Distortion

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 

Fig. 1. New proposed HAPF

 EXPECTED SIMULATION RESULTS:

 

Fig. 2. C-branch’s current before adding APF

Fig. 3. Source current before filtering

Fig. 4. Source current after filtering

Fig. 5. The current of resistive load after filtering

 CONCLUSION:

This paper has presents a new topology of three phase HAPF. The system has been designed, tested and simulated by Matlab- Simulink program in three steps; firstly, without using filters, secondly, with LC low pass filter, finally, using LPF in combine with APF which represent HAPF. After a comparison between the values of total harmonic distortion (THD%) in three aforementioned circuits, the results of the simulation confirmed the effectiveness of the proposed HAPF because of the big decreasing in the THD value and high rate elimination of the harmonics. The proposed HAPF offers a reactive power compensation for the circuit because of using shunt APF. Consequently, the power quality of the circuit will improve. This paper has submit a new idea to benefit of eliminated harmonic current in the C-branch of LPF through using APF in shunt with C-branch of LPF and compensate high frequency currents in order to use it as a power supply to feed different loads. In this research, a resistive load has been presented as an invested load. However, in practical life lighting bulbs can be used as loads.

REFERENCES:

[1] C. Francisco, Harmonics and power systems. CRC press, 2006.

[2] B. Singh, B. N. Singh, A. Chandra, K. Al-Haddad, A. Pandey, and D. P. Kothari, “A review of three-phase improved power quality ac-dc converters,” Industrial Electronics, IEEE Transactions on, vol. 51, no. 3, pp. 641–660, 2004.

[3] L. Gyugyi and E. C. Strycula, “Active ac power filters,” in Proc. IEEE/IAS Annu. Meeting, vol. 19, 1976, pp. 529–535.

[4] L. Czarnecki, “An overview of methods of harmonic suppression in distribution systems,” in Power Engineering Society Summer Meeting, 2000. IEEE, vol. 2, 2000, pp. 800–805.

[5] A. Nassif, W. Xu, and W. Freitas, “An investigation on the selection of filter topologies for passive filter applications,” Power Delivery, IEEE Transactions on, vol. 24, no. 3, pp. 1710–1718, July 2009.