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

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

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.