Variable speed drive with PFC front-end for three-phase induction motor

 

ABSTRACT:

 A variable frequency drive for an induction motor is proposed. The drive uses a power factor (PF) correction bridgeless single-ended primary inductor converter-controlled rectifier operating in discontinuous inductor current mode as a front-end in order to improve the input power quality and a variation of the constant volts per hertz controller, with feedback to regulate the velocity of the motor shaft. The frequency slip is measured and compensated, since the input stage. Experiments with and without load are carried out and presented. Input power quality measurements are also presented. The proposed system is effective to regulate the velocity and achieving a close to unity PF.

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1 Proposed AC–DC–AC converter

 EXPECTED SIMULATION RESULTS:

 

 

Fig. 2 Results from experiments I and II

Fig. 3 Input voltage and current waveforms and input current harmonics

a Input voltage and current waveforms, Channel 1 for current and Channel 2 for voltage. Current is measured by V–I converter with 1 V:1.6 A conversion ratio

b First 39 non-fundamental current harmonics

 CONCLUSION:

The proposal of an SEPIC converter as the front-end of single-phase to three-phase AC–DC–AC converter for an induction motor for improving the input power quality is presented. It is also shown a variation of the CVH controller to regulate the angular velocity of the motor shaft using the aforementioned topology. The controller compensates the frequency slip, due to mechanical load, since the rectifying stage. The experimental results show that the topology is effective for regulating the velocity and that the topology can achieve a close to unity PF and low THD. The computed spectrum can be used to design passive input filters and further improve the THD and the PF of the circuit.

REFERENCES:

1 Moghani, J.S., and Heidari, M.: ‘High efficient low cost induction motor drive for residential applications’. Int. Symp. Power Electronics, Electrical Drives, Automation and Motion, 2006 SPEEDAM 2006, Taormina, Italy, May 2006, pp. 1399–1402

2 Singh, S., and Singh, B.: ‘A voltage-controlled PFC Cuk converter-based PMBLDCM drive for air-conditioners’, Trans. Ind. Appl., 2012, 48, (2), pp. 832–838

3 Bist, V., and Singh, B.: ‘An adjustable-speed PFC bridgeless buck–boost converter-fed BLDC motor drive’, Trans. Ind. Electron., 2014, 61, (6), pp. 2665–2677

4 Abe, K., Haga, H., Ohishi, K., and Yokokura, Y.: ‘Fine current harmonics reduction method for electrolytic capacitor-less and inductor-less inverter based on motor torque control and fast voltage feedforward control for IPMSM’, Trans. Ind. Electron., 2017, 64, (2), pp. 1071–1080

5 APA Sabzali, A.J., Ismail, E.H., Al-Saffar, M.A., and Fardoun, A.A.: ‘New bridgeless DCM SEPIC and Cuk PFC rectifiers with low conduction losses’, Trans. Ind. Appl., 2011, 47, (2), pp. 873–881

Design of External Inductor for Improving Performance of Voltage Controlled DSTATCOM

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, 2015

ABSTRACT: A distribution static compensator (DSTATCOM) is used for load voltage regulation and its performance mainly depends upon the feeder impedance and its nature (resistive, inductive, stiff, non-stiff). However, a study for analyzing voltage regulation performance of DSTATCOM depending upon network parameters is not well defined. This paper aims to provide a comprehensive study of design, operation, and flexible control of a DSTATCOM operating in voltage control mode. A detailed analysis of the voltage regulation capability of DSTATCOM under various feeder impedances is presented. Then, a benchmark design procedure to compute the value of external inductor is presented. A dynamic reference load voltage generation scheme is also developed which allows DSTATCOM to compensate load reactive power during normal operation, in addition to providing voltage support during disturbances. Simulation and experimental results validate the effectiveness of the proposed scheme.

KEYWORDS:

  1. Distribution static compensator (DSTATCOM)
  2. Current control
  3. Voltage control
  4. Power factor
  5. Power quality

 SOFTWARE: MATLAB/SIMULINK

EQUIVALENT CIRCUIT DIAGRAM:

 

 Fig. 1. Three phase equivalent circuit of DSTATCOM topology in distribution system.

EXPECTED SIMULATION RESULTS:

Fig. 2. Voltage regulation performance of conventional DSTATCOM with resistive feeder. (a) PCC voltages. (b) Load Voltages. (c) Source currents. (d) Filter currents. (e) Load currents.

Fig. 3. Simulation results. (a) During normal operation (i)-(v). (b) During voltage sag (vi)-(x). (c) During voltage swell (xi)-(xv).

CONCLUSION:

This paper has presented design, operation, and control of a DSTATCOM operating in voltage control mode (VCM). After providing a detailed exploration of voltage regulation capability of DSTATCOM under various feeder scenarios, a benchmark design procedure for selecting suitable value of external inductor is proposed. An algorithm is formulated for dynamic reference load voltage magnitude generation. The DSTATCOM has improved voltage regulation capability with a reduced current rating VSI, reduced losses in the VSI and feeder. Also, dynamic reference load voltage generation scheme allows DSTATCOM to set different constant reference voltage during voltage disturbances. Simulation and experimental results validate the effectiveness of the proposed solution. The external inductor is a very simple and cheap solution for improving the voltage regulation, however it remains connected throughout the operation and continuous voltage drop across it occurs. The future work includes operation of this fixed inductor as a controlled reactor so that its effect can be minimized by varying its inductance.

REFERENCES:

[1] M. H. Bollen, Understanding power quality problems. vol. 3, IEEE press New York, 2000.

[2] S. Ostroznik, P. Bajec, and P. Zajec, “A study of a hybrid filter,” IEEE Trans. Ind. Electron., vol. 57, no. 3, pp. 935–942, Mar. 2010.

[3] C. Kumar and M. Mishra, “A voltage-controlled DSTATCOM for power quality improvement,” IEEE Trans. Power Del., vol. 29, no. 3, pp. 1499– 1507, June 2014.

[4] Q. Liu, L. Peng, Y. Kang, S. Tang, D. Wu, and Y. Qi, “A novel design and optimization method of an LCL filter for a shunt active power filter,” IEEE Trans. Ind. Electron., vol. 61, no. 8, pp. 4000–4010, Aug. 2014.

[5] T. Aziz, M. Hossain, T. Saha, and N. Mithulananthan, “VAR planning with tuning of STATCOM in a DG integrated industrial system,” IEEE Trans. Power Del., vol. 28, no. 2, pp. 875–885, Apr. 2013.

Design of External Inductor for Improving Performance of Voltage Controlled DSTATCOM

 

ABSTRACT:

A distribution static compensator (DSTATCOM) is used for load voltage regulation and its performance mainly depends upon the feeder impedance and its nature (resistive, inductive, stiff, non-stiff). However, a study for analyzing voltage regulation performance of DSTATCOM depending upon network parameters is not well defined. This paper aims to provide a comprehensive study of design, operation, and flexible control of a DSTATCOM operating in voltage control mode. A detailed analysis of the voltage regulation capability of DSTATCOM under various feeder impedances is presented. Then, a benchmark design procedure to compute the value of external inductor is presented. A dynamic reference load voltage generation scheme is also developed which allows DSTATCOM to compensate load reactive power during normal operation, in addition to providing voltage support during disturbances. Simulation and experimental results validate the effectiveness of the proposed scheme.

KEYWORDS:

  1. Distribution static compensator (DSTATCOM)
  2. Current control
  3. Voltage control
  4. Power factor
  5. Power quality

 SOFTWARE: MATLAB/SIMULINK

EQUIVALENT CIRCUIT DIAGRAM:

 Fig. 1. Three phase equivalent circuit of DSTATCOM topology in distribution system.

EXPECTED SIMULATION RESULTS:

 Fig. 2. Voltage regulation performance of conventional DSTATCOM with resistive feeder. (a) PCC voltages. (b) Load Voltages. (c) Source currents. (d) Filter currents. (e) Load currents.

Fig. 3. Simulation results. (a) During normal operation (i)-(v). (b) During voltage sag (vi)-(x). (c) During voltage swell (xi)-(xv).

CONCLUSION:

This paper has presented design, operation, and control of a DSTATCOM operating in voltage control mode (VCM). After providing a detailed exploration of voltage regulation capability of DSTATCOM under various feeder scenarios, a benchmark design procedure for selecting suitable value of external inductor is proposed. An algorithm is formulated for dynamic reference load voltage magnitude generation. The DSTATCOM has improved voltage regulation capability with a reduced current rating VSI, reduced losses in the VSI and feeder. Also, dynamic reference load voltage generation scheme allows DSTATCOM to set different constant reference voltage during voltage disturbances. Simulation and experimental results validate the effectiveness of the proposed solution. The external inductor is a very simple and cheap solution for improving the voltage regulation, however it remains connected throughout the operation and continuous voltage drop across it occurs. The future work includes operation of this fixed inductor as a controlled reactor so that its effect can be minimized by varying its inductance.

REFERENCES:

[1] M. H. Bollen, Understanding power quality problems. vol. 3, IEEE press New York, 2000.

[2] S. Ostroznik, P. Bajec, and P. Zajec, “A study of a hybrid filter,” IEEE Trans. Ind. Electron., vol. 57, no. 3, pp. 935–942, Mar. 2010.

[3] C. Kumar and M. Mishra, “A voltage-controlled DSTATCOM for power quality improvement,” IEEE Trans. Power Del., vol. 29, no. 3, pp. 1499– 1507, June 2014.

[4] Q. Liu, L. Peng, Y. Kang, S. Tang, D. Wu, and Y. Qi, “A novel design and optimization method of an LCL filter for a shunt active power filter,” IEEE Trans. Ind. Electron., vol. 61, no. 8, pp. 4000–4010, Aug. 2014.

[5] T. Aziz, M. Hossain, T. Saha, and N. Mithulananthan, “VAR planning with tuning of STATCOM in a DG integrated industrial system,” IEEE Trans. Power Del., vol. 28, no. 2, pp. 875–885, Apr. 2013.

A Novel Power Factor Correction Technique/or a Boost Converter

 

ABSTRACT:

The paper evolves a mechanism for improving the input power factor of an AC-DC-DC conversion system. It involves the process of shaping the input current wave to phase align with the input supply through a process of error compensation. The methodology includes cohesive formulation to arrive at nearly unity power factor and enjoy the etiquettes of output voltage regulation. The theory assuages to subscribe the benefits for the entire range of operating loads. It eliminates the use of passive components and fortifies the principles of pulse width modulation (PWM) for realizing the change in duty cycle. The MA TLAB based simulation results arbitrate the viability of the proposed approach and exhibit its suitability for use in real world applications.

 KEYWORDS:

  1. Ac-dc converter
  2. Power factor
  3. THD
  4. Voltage regulation

 SOFTWARE: MATLAB/SIMULINK

 CIRCUIT DIAGRAM:

image001

Figure 1. Power Factor Correction Control of Boost Converter

 EXPECTED SIMULATION RESULTS:

 image002

 Figure 2. Steady State Input AC Voltage and Input AC Current Waveform

image003

Figure 3. Steady State Rectified DC Voltage and Rectified DC Current Waveform

image004

Figure 4. Steady State Regulated DC Output Voltage and Regulated DC Output Current Waveform

image005

Figure 5. Power Factor Measurement of the Proposed Power Factor Correction Boost Converter

image006

Figure 6. FFT Spectrum of the AC input current of Proposed Power Factor Correction Boost Converter

image007

Figure 7. Transient response of Input AC Voltage and Input AC Current Waveform

image008

Figure 8. Transient Response of Rectified DC Voltage and Rectified DC Current Waveform

image009

Figure 9. Transient Response of Regulated DC Output Voltage and Regulated DC Output Current Waveform

image010

Figure 10. Power Factor Measurement of the Proposed Power Factor Correction Boost Converter at transient condition

CONCLUSION:

A single stage power factor correction strategy has been proposed for full bridge diode rectifier fed boost converter to support a 400W, lA DC load. The suitability of boost converter for power factor correction has been illustrated by the elimination of input capacitor filter and low output ripple factor. The formulated control design has been effectively orchestrated to correct the power factor in addition providing good voltage regulation. The transient performance has been portrayed to up-heave the strength of the control structure with an adequate output regulation and effective harmonic elimination. The control plan has been nurtured to standardize the THD level of the system that prevents the adverse effects of harmonics being injected in the grid. The exclusion of additional passive components and interleaving configuration has been fostered to reduce the size thus making it more adaptive to low cost compact electronic applications with high standards .

 REFERENCES:

[1] M. Milanovic, F . Mihalic, K. Jezernik and U. Milutinovic,” Single phase unity power factor correction circuits with coupled inductance,” Power Electronics Specialists Conference, 1992, vol.2, pp. l077-1082.

[2] M. Orabi and T Ninomiya, “Novel nonlinear representation for two stage power-factor-correction converter instability,” IEEE International Symposium on Industrial Electronics, 2003, voU, pp- 270-274.

[3] Yu Hung, Dan Chen, Chun-Shih Huang and Fu-Sheng Tsai, “Pulse-skipping power factor correction control schemes for ACIDC power converters,” Fourth International Conference on Power Engineering, Energy and Electrical Drives (POWERENG), 2013, pp-I087-1092.

[4] Lu, D.D. -C, H.H.-C. lu, V. Pjevalica, “A Single-Stage AC/DC Converter With High Power Factor, Regulated Bus Voltage, and Output Voltage,” Power Electronics, IEEE Transactions on, vo1.23, issue. I, pp. 218-228, Jan. 2008.

[5] M. Narimani and G. Moschopoulos, “A New Single-Phase SingleStage Three-Level Power Factor Correction AC-DC Converter,” Power Electronics, IEEE Transactions on , vol.27, issue.6, pp. 2888- 2899, June. 2012.