Design and Simulation of Single Phase Shunt Active Power Filter using MATLAB

ABSTRACT: 

Power Quality issues are becoming a major concern of today’s power system engineers. Harmonics play significant roll in deteriorating power quality, called harmonic distortion. Harmonic distortion in electric distribution system is increasingly growing due to the widespread use of nonlinear loads. Large considerations of these loads have the potential to raise harmonic voltage and currents in an electrical distribution system to unacceptable high levels that can adversely affect the system. IEEE standards have defined limits for harmonic voltages and harmonic currents. Active power filters have been considered a potential candidate to bring these harmonic distortions within the IEEE limits. This paper deals with an active power filter (APF) based on simple control. A voltage source inverter with pulse width modulation (PWM) is employed to form the APF. A diode rectifier feeding capacitive-resistive load is considered as nonlinear load on ac mains for the elimination of harmonics by the proposed APF. MATLAB model of the scheme is simulated and obtained results are studied.

KEYWORDS:
1. Power Quality
2. THD
3. Non-linear Load
4. PWM

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Figure 1 Principle of Shunt connected SPAPF

CIRCUIT DIAGRAM:

Figure 2. Basic Circuit of Single Phase APF 

EXPECTED SIMULATION RESULTS:

Figure 3. Load Current without SPAPF

Figure 4. Load Current Harmonic Spectrum without SPAPF

Figure 5. Load Voltage without SPAPF

Figure 6. Load Current Harmonic Spectrum without SPAPF

           

Figure 7. Load Current with SPAPF

Figure 8. Load Current Harmonic Spectrum with SPAPF

Figure 9. Load Voltage without SPAPF

Figure 10. Load Voltage Harmonic Spectrum with SPAPF

CONCLUSION:

A simple control scheme of the single phase active power filter is proposed which requires sensing of one current and two voltages only. The APF results in sinusoidal unity power factor supply current. It is concluded that the reduced value of dc bus capacitor is able to give quite satisfactory operation of the APF system. The voltage controller gives fast response. The proposed APF is able to reduce THD of supply current and supply voltage below prescribed permitted limits specified by IEEE 519.

REFERENCES:

[1] D. C. Bhonsle, Dr. R. B. Kelkar and N. K. Zaveri, “Power Quality Issues-In Distribution System”, IE(I) 23rd National Convention of Electrical Engineers, Pune, November 2007 Proceedings, pp. 108-111.

[2] K. C. Umeh, A. Mohamed, R. Mohmed, “ Comparing The Harmonic Characteristics of Typical Single Phase Nonlinear Loads”, National Power Energy Conference (PECon) 2003 Proceedings, Bangi, Malaysia, pp. 383-387.

[3] Mohamed S. A. Dahidah, N. Mariun, S. Mahmod and N. Khan, “Single Phase Active Power Filter for Harmonic Mitigation in Distribution Power Lines”, National Power and Energy Conference (PECon) 2003 Proceedings, Bangi, Malaysia, pp. 359-362.

[4] Dalila Mat Said Ahmed, Abdullah asuhaimi, Mohd Zin, "Power Supply Quality Improvement: Harmonic Measurement and Simulation," National Power and Energy Conference (PECon), 2003 Proceedings, Bangi, Malaysia, pp. 352-358.

[5] C. Gopalkrishnan, K Udaykumar, T. A. Raghvendiran, "Survey of Harmonic Distortion for Power Quality Measurement and Application of Standard including Simulation," 2001, Anna University, India.

Application of Unified Power Flow Controller in Interconnected Power Systems—Modeling, Interface, Control Strategy, and Case Study

ABSTRACT:

In this paper, a new power frequency model for unified power flow controller (UPFC) is suggested with its dc link capacitor dynamics included. Four principal control strategies for UPFC series element main control and their impacts on system stability are discussed. The main control of UPFC series element can be realized as a combination of the four control functions. The supplementary control of UPFC is added for damping power oscillation. The integrated UPFC model has then been incorporated into the conventional transient and small signal stability programs with a novel UPFC-network interface. Computer tests on a 4-generator interconnected power system show that the suggested UPFC power frequency model and the UPFC- network interface method work very well. The results also show that the suggested UPFC control strategy can realize power flow control fairly well and improve system dynamic performance significantly.

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

 

Fig. 1. Transmission line with UPFC installed.

CONTROL SYSTEM:

Fig. 2. The main control and phasor diagram.

EXPECTED SIMULATION RESULTS:

Fig. 3. Plots of case 1a.

Fig. 4. Plots of case 1b.

Fig. 5. Plots of case 1c.

Fig. 6. Effects of supplementary control.

Fig. 7. Results of the suggested control scheme.

CONCLUSION:

The suggested UPFC power frequency model and the developed UPFC-network interface method work very well in the study of power system dynamics with satisfied convergence and accuracy. Four principal main control strategies are discussed and the computer tests results support the discussion conclusion very well. The constant power flow control is good for steady state control and the constant series compensation control is useful for first swing stability. The supplementary control is very efficient in damping intcrarea power oscillation. The suggested UPFC control can realize the desired control strategy flexibly and improve system dynamic performance significantly.

REFERENCES:

[1] L. Gyugyi, “Unified Power-Flow Control Concept for Flexible AC Transmission Systems,” IEE Proceedings-C, vol. 139, no. 4, pp. 323–331, July 1992.

[2] I. Papic, P. Zunko, and D. Povh, “Basic Control of Unified Power Flow Controller,” IEEE Trans. on Power Systems, vol. 12, no. 4, pp. 1734–1739, Nov. 1997.

[3] R. Mihalic, P. Zunko, and D. Povh, “Improvement of Transient Stability Using Unified Power Flow Controller,” IEEE Trans. on Power Delivery, vol. 11, no. 1, pp. 485–491, Jan. 1996.

[4] K. S. Smith, L. Ran, and J. Penman, “Dynamic Modeling of a Unifed Power Flow Controller,” IEE Proc.-Gener. Transm. Distrib., vol. 144, no. 1, pp. 7–12, Jan. 1997.

[5] M. Noroozian, L. Angquist, and M. Ghandhari, et al., “Improving Power System Dynamics by Series-connected FACTS devices,” IEEE Trans. on Power Delivery, vol. 12, no. 4, pp. 1635–1641, Oct. 1997.

High-Gain Single-Stage Boosting Inverter for Photovoltaic Applications

High-Gain Single-Stage Boosting Inverter

for Photovoltaic Applications

ABSTRACT

This paper introduces a high-gain single-stage boosting inverter (SSBI) for alternative energy generation. As compared to the traditional two-stage approach, the SSBI has a simpler topology and a lower component count. One cycle control was employed to generate ac voltage output. This paper presents theoretical analysis, simulation and experimental results obtained from a 200 W prototype. The experimental results reveal that the proposed SSBI can achieve high dc input voltage boosting, good dc–ac power decoupling, good quality of ac output waveform, and good conversion efficiency.

KEYWORDS

1.      Microinverter

2.      one cycle control (OCC)

3.      tapped inductor (TI)

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

Fig.1. Topology of the proposed SSBI.

EXPECTED SIMULATION RESULTS

                       

Fig. 2. Simulated waveforms of the proposed SSBI on the line frequency

scale.

          

Fig. 3. Simulated waveforms of the SSBI’s output voltage Vac , dc-link voltage

Vdc , and dc input source current Ig with the TI operating at the CCM–DCM

boundary (Po = Pob ).

                

Fig. 4. Simulated waveforms of the SSBI’s output voltage Vac , dc-link voltage

Vdc , and dc input source current Ig : (a) illustrating the undistorted output

voltage Vac , when SSBI is operated in deep DCM just above the minimum

power level Po > Pomin and (b) illustrating the peak-shaving distortion of the

output voltage Vac for Po < Pomin .

CONCLUSION

A high-gain SSBI for alternative energy generation applications is presented in this paper. The proposed topology employs a TI to attain high-input voltage stepup and, consequently, allows   operation from low dc input voltage. This paper presented principles of operation, theoretical analysis of continuous and discontinuous modes including gain and voltage and current stresses. To facilitate this report, two stand-alone prototypes one for 48 V input and another for 35 V input were built and experimentally tested. Theoretical findings stand in good agreement with simulation and experimental results. Acceptable efficiency was attained with low-voltage input source. The proposed SSBI topology has the advantage of high voltage stepup which can be further increased adjusting the TI turns ratio. The SSBI allows decoupled control functions. By adjusting the boost duty cycle Dbst, the SSBI can control the dc-link voltage, whereas the output waveform can be shaped by varying the buck duty cycleDbk. The ac–dc power decoupling is attained on the high-voltage dc link and therefore requires a relatively low capacitance value. The OCC control method was applied to shape the output voltage. OCC’s fast response and low sensitivity to dc-bus voltage ripple allowed applying yet smaller decoupling capacitor value, and has demonstrated low THD output for different types of highly nonlinear loads.

REFERENCES

[1] S. B. Kjaer, J. K. Pedersen, and F. Blaabjerg, “A review of singlephase grid-connected inverters for photovoltaic modules,” IEEE Trans. Ind. Appl., vol. 41, no. 5, pp. 1292–1306, Sep. 2005.

[2] D. C. Martins and R. Demonti, “Interconnection of a photovoltaic panels array to a single-phase utility line from a static conversion system,” in Proc. IEEE Power Electron. Spec. Conf., 2000, pp. 1207–1211.

[3] Q. Li and P.Wolfs, “A current fed two-inductor boost converter with an integrated magnetic structure and passive lossless snubbers for photovoltaic module integrated converter applications,” IEEE Trans. Power Electron., vol. 22, no. 1, pp. 309–321, Jan. 2007.

[4] S. B. Kjaer, J. K. Pedersen, and F. Blaabjerg, “Power inverter topologies for photovoltaic modules—A review,” in Proc. Ind. Appl. Conf., 2002, vol. 2, pp. 782–788.

[5] C. Vartak, A. Abramovitz, and K. M. Smedley, “Analysis and design of energy regenerative snubber for transformer isolated converters,” IEEE Trans. Power Electron., vol. 29, no. 11, pp. 6030–6040, Nov. 2014.

An Envelope Type (E-Type) Module Asymmetric Multilevel Inverters With Reduced Components

ABSTRACT:

This paper presents a new E-Type module for asymmetrical multilevel inverters with reduced components. Each module produces 13 levels with four unequal DC sources and 10 switches. The design of the proposed module makes some preferable features with a better quality than similar modules such as the low number of semiconductors and DC sources and low switching frequency. Also, this module is able to create a negative level without any additional circuit such as an H-bridge which causes reduction of voltage stress on switches. Cascade connection of the proposed structure leads to a modular topology with more levels and higher voltages. Selective harmonics elimination pulse width modulation (SHE-PWM) scheme is used to achieve high quality output voltage with lower harmonics. MATLAB simulations and practical results are presented to validate the proposed module good performance. Module output voltage satisfies harmonics standard (IEEE519) without any filter in output.

KEYWORDS:

1.      Asymmetric

2.      Components

3.      E-Type

4.      Multilevel inverter

5.      Power electronics

6.      Selective harmonics elimination

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1 Proposed E-Type module of multilevel inverter (a) Circuit topology

 EXPECTED SIMULATION RESULTS:

Fig.2 Output voltage and FFT analysis of proposed multilevel

CONCLUSION:

This paper presented a new multilevel inverter topology named as Envelope Type (E-Type) module which can generate 13 levels with reduced components. It can be used in high voltage high power applications with unequal DC sources. As E-Type module can be easily modularized, it can be used in cascade arrangements to form high voltage outputs with low stress on semiconductors and lowering the number of devices. Modular connection of these modules leads to achieve more voltage levels with different possible paths. It causes an improvement in the reliability of the modular inverter which enables it to use different paths in case of malfunction for a switch or a driver. The main advantage of proposed module is its ability to generate both positive and negative output voltage without any H-bridge circuit at the output of the inverter. THDv% is obtained 3.46% and 4.54% in simulation and experimental results, respectively that satisfy harmonics standard (IEEE519). Also module is tested in three frequency and under different resistive – inductive loads which results shows good performance.

REFERENCES:

[1] R. Feldman, M. Tomasini, E. Amankwah, J.C. Clare, P.W. Wheeler, D.R. Trainer, R.S. Whitehouse, "A Hybrid Modular Multilevel Voltage Source Converter for HVDC Power Transmission," IEEE Trans. Ind. Appl., vol.49, no.4, pp.1577–1588, July-Aug. 2013.

[2] M. Odavic, V. Biagini, M. Sumner, P. Zanchetta, M. Degano, "Low Carrier–Fundamental Frequency Ratio PWM for Multilevel Active Shunt Power Filters for Aerospace Applications," IEEE Trans. Ind. Appl., vol.49, no.1, pp.159–167, Jan.-Feb. 2013.

[3] Liming Liu, Hui Li, Seon-Hwan Hwang, Jang-Mok Kim, "An Energy-Efficient Motor Drive With Autonomous Power Regenerative Control System Based on Cascaded Multilevel Inverters and Segmented Energy Storage," IEEE Trans. Ind. Appl., vol.49, no.1, pp.178–188, Jan.-Feb. 2013.

[4] Yushan Liu, Baoming Ge, H. Abu-Rub, F.Z. Peng, "An Effective Control Method for Quasi-Z-Source Cascade Multilevel Inverter-Based Grid-Tie Single-Phase Photovoltaic Power System," IEEE Trans. Ind. Inform., vol.10, no.1, pp.399–407, Feb. 2014.

[5] Jun Mei, Bailu Xiao, Ke Shen, L.M. Tolbert, Jian Yong Zheng, "Modular Multilevel Inverter with New Modulation Method and Its Application to Photovoltaic Grid-Connected Generator," IEEE Trans. on Power Electron., vol.28, no.11, pp.5063–5073, Nov. 2013.

Unknown Input Observer for a Novel Sensorless Drive of Brushless DC Motors

 ABSTRACT:

In this paper, a novel motor control method is proposed to improve the performance of sensorless drive of BLDC motors. In the terminal voltage sensing method, which is a great portion of sensorless control, a precise rotor position cannot be obtained when excessive input is applied to the drive during synchronous operation mode. Especially in the transient state, the response characteristic decreases. To cope with this problem, the unknown input (back-EMF) is modelled as the additional state of system in this paper. Taking into account the disturbance adopted by the back-EMF, the observer can be obtained by an equation of the augmented system. An algorithm to detect the back-EMF of a BLDC motor using the state observer is constructed. As a result, a novel sensorless drive of BLDC motors that can strictly estimate rotor position and speed is proposed.

SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Fig. 1. Block diagram of BLDC motor drive.

EXPECTED SIMULATION RESULTS:

Fig. 2. Speed response for the start and transient state. (a) In the proposed sensorless scheme. (b) In the conventional scheme use sensor.

Fig. 3. Simulation results of the proposed sensorless scheme at 2000 (rpm). (a) Rotor speed. (b) Rotor position. (c) Phase current. (d) Line-to-line back-EMF. (e) Commutation function. (f) Commutation signal.

Fig. 4. Simulation results of the proposed sensorless scheme at 100 (rpm). (a) Rotor speed. (b) Rotor position. (c) Phase current. (d) Line-to-line back-EMF. (e) Commutation function. (f) Commutation signal.

CONCLUSION:

In this paper, the unknown input (back-EMF) is modeled as the additional state of system. Considering disturbance that is adopted by back-EMF, the observer can be obtained effectively using the equation of augmented system and estimating back-EMF. As a result, an effective algorithm to estimate rotor position and speed of motor using the state observer is proposed. Use of sensorless control method can remove problem on manufacture that is happened in circuit to detect rotor position and speed. Moreover the production of inexpensive motor controller may be possible because the additional circuit such as encoder is not necessity. In cases using the proposed sensorless control method, the start-up performance has an almost analogous transient state characteristic after forced alignment, compared with the conventional method. This method also provides useful motor control because it is possible to analyze about transient state as well as steady state unlike various sensorless control methods that have been recently proposed. In addition, it can be easily applied in industry applications requiring the low-cost style drive of BLDC motor because actual realization is very simple.

REFERENCES:

[l] T. J. E Miller, “Brushless Permanent-Magnet and Reluctance Motor Drives,” Clarendon Press, Oxford 1989.

[2] S. Ogasawara and H. Akagi, “An Approach to Position Sensorless Drive for Brushless DC Motors,” IEEE Trans. Ind. Appl., vol. 27, no. 5, pp. 928-933, Sep./Oct. 1991.

[3] J. C. Moreira, “Indirect Sensing for Rotor Flux Position of Permanent Magnet AC Motors Operating Over a Wide Speed Range,” IEEE Trans. Ind. Appl., vol. 32, no. 6, pp. 1392-1401, Nov./Dec. 1996.

[4] H. R. Andersen and J. K. Pedersen, “Sensorless ELBERFELD Control of Brushless DC Motors for Energy-Optimized Variable-Speed Household Refrigerators,” EPE Conf. Rec., vol. 1, pp. 314-318, Sep. 1997.

[5] Hyeong-Gee Yee, Chang-Seok Hong, Ji-Yoon Yoo, Hyeon-Gil Jang, Yeong-Don Bae and Yoon-Seo Park, “Sensorless Drive for Interior Permanent Magnet Brushless DC Motors,” Electric Machines and Drives Conf. Record, 1997, IEEE International 18-21 pp. TD1/3.1-TD1/3.3, May 1997.

Sensorless Brushless DC Motor Drive Based on the Zero-Crossing Detection of Back Electromotive Force (EMF) From the Line Voltage Difference

 ABSTRACT:

This paper describes a position sensorless operation of permanent magnet brushless direct current (BLDC) motor. The position sensorless BLDC drive proposed, in this paper, is based on detection of back electromotive force (back EMF) zero crossing from the terminal voltages. The proposed method relies on a difference of line voltages measured at the terminals of the motor. It is shown, in the paper, that this difference of line voltages provides an amplified version of an appropriate back EMF at its zero crossings. The commutation signals are obtained without the motor neutral voltage. The effectiveness of the proposed method is demonstrated through simulation and experimental results.

KEYWORDS:

1.      Back electromotive force (EMF) detection

2.       Brushless dc (BLDC) motor

3.      Sensorless control

4.      Zero crossing

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Block diagram of the experimental setup.

EXPECTED SIMULATION RESULTS:

Fig. 2. Phase current and speed waveform on no-load (experimental).

Fig. 3. Phase current and speed waveform on load (experimental).

Fig. 4. Phase current and speed waveform during loading transient (experimental).

Fig. 5. Phase current, virtual Hall, and real Hall sensor signal for 50% duty

ratio PWM switching.

CONCLUSION:

A simple technique to detect back EMF zero crossings for a BLDC motor using the line voltages is proposed. It is shown that the method provides an amplified version of the back EMF. Only three motor terminal voltages need to be measured thus eliminating the need for motor neutral voltage. Running the machine in sensorless mode is then proposed, in this paper, making use of the novel zero-crossing detection algorithm. While starting relies on triggering devices at the zero crossings detected using the proposed algorithm, continuous running is achieved by realizing the correct commutation instants 30◦ delay from the zero crossings. The motor is found to start smoothly and run sensorless even with load and load transients. Simulation and experimental results are shown which validate the suitability of the proposed method.

REFERENCES:

[1] K. Iizuka,H.Uzuhashi, M. Kano, T. Endo, and K.Mohri, “Microcomputer control for sensorless brushless motor,” IEEE Trans. Ind. Appl., vol. IA- 21, no. 4, pp. 595–601, May/Jun. 1985.

[2] J. Shao, D. Nolan,M. Teissier, and D. Swanson, “A novel micro controller based sensorless brushless DC (BLDC) motor drive for automotive fuel pumps,” IEEE Trans. Ind. Appl., vol. 39, no. 6, pp. 1734–1740, Nov./Dec. 2003.

[3] T.-H. Kim and M. Ehsani, “Sensorless control of BLDC motors from near-zero to high speeds,” IEEE Trans. Power Electron., vol. 19, no. 6, pp. 1635–1645, Nov. 2004.

[4] S. Ogasawara and H. Akagi, “An approach to position sensorless drive for brushless DC motors,” IEEE Trans. Ind. Appl., vol. 27, no. 5, pp. 928–933, Sep./Oct. 1991.

[5] R. C. Becerra, T. M. Jahns, and M. Ehsani, “Four-quadrant sensorless brushless ECM drive,” in Proc. IEEE APEC, Mar. 1991, pp. 202–209.