Hybrid Shunt Active Filter Offering Unity PowerFactor and Low THD at Line Side with Reduced Power Rating

ABSTRACT:  

This paper present analysis of hybrid active power filter with synchronous reference frame control algorithm. The proposed topology consist of active power filter and passive power filter are connected in shunt with the mains feeding a nonlinear load. The shunt passive power filter is tuned to eliminate most dominate 5th order load current harmonic. The shunt active power filter is used compensate all other higher order load current harmonics. This approach help toreduce the overall rating of shunt active power filter, and maintain unity power factor at line side with low THD, which makes system more economical for industrial usage. Detail design steps for 5th order tuned filter is also discussed and results are presented. The proposed shunt active power filter is also tested for dynamic loading condition. Hardware results for the verification of proposed control algorithm is also presented and discussed.

KEYWORDS:

  1. Hybrid Active Filter
  2. Passive Filter
  3. Total Harmonic Distortion
  4. Synchronous Reference Frame
  5. Unity Power Factor

 SOFTWARE: MATLAB/SIMULINK

 CIRCUIT DIAGRAM:

Fig. 1: Main Power Circuit Diagram of HAPF

 EXPECTED SIMULATION RESULTS:

 

Fig. 2: Simulation Result ofSPPF (a) Phase-A Output Load Current

without Compensation (b) Phase-A Source Current with Compensation

(c) Phase-A 5th Order Harmonic Current

(d) Phase-A Source Voltage and Source Current

Fig. 3: FFT Curve ofSPPF (a) FFT of Output Load Current without

Compensation (b) FFT o f Source Current with Compensation

Fig. 4: Simulation Result of SAPF Under Fixed Load (a) Phase-A Output

Load Current without Compensation (b) Phase-A Source Current after

Compensation (c) D C Bus Voltage Across Capacitor (d) Phase-A Actual

Compensating Current (e) Phase-A Source Voltage and Source Current

Fig. 5: Simulation Result ofSAPF under Dynamic Load (a) Phase-A

Output Load Current without Compensation (b) Phase-A Source Current

after Compensation (c) Phase-A Actual Compensating Current (d) DC

Bus Voltage Across Capacitor

Fig. 6: Hysteresis Controller Results (a) Reference and Actual

Compensating Currents of Phase-A (b) Line-Line Voltage of lnverter

Fig.7: FFT Curve of Source Current after Compensation by using SAPF

under Fixed Load (b) under Dynamic Load

Fig. 8: Simulation Result ofHAPF(a) Phase-A Load Current without

Compensation,(b) Phase-A Source Current with Compensation,

(c) Phase-A Phase Voltage and Current, (d) DC Link Voltage oflnverter,

(e) Phase-A Actual Compensating Current

Fig. 9: Simulation Result ofHAPF (a) Three Phase Output Load

Current, (b) Three Phase Load Current, (c) Three Phase Source Current,

(d) FFT Curve of Source Current with Compensation

CONCLUSION:

 This paper analyze the performance and simulation of hybrid active power filter (HAPF). Through the simulation analysis, this paper verified the mitigation of harmonic, to achieve unity power factor with reduced rating of SAPF. Proposed control technique is able to give fast dynamic response during variable load condition, which demonstrate the robustness of controllers. The proposed topology is an effort to provide cost effective solution for harmonic elimination in various industrial application

REFERENCES:

[I] B. Singh, V. Verma, A. Chandra and K. AI-Haddad ” Hybrid filter for power quality improvement” IEEE proc. Gener. Transm. Distrib. , Volume:152, No.3 , May 2005.

[2] J. Arrillaga and N. R. Watson, Power System Harmonics, 2nd ed. Hoboken, NJ: Wiley, 2003

[3] B. Singh, K. AI-Haddad, and A. Chandra, ” A reviewof active filter for power quality improvement,” IEEE Trans. Ind. Electron. , Vol. 46, nO.5 pp. 960-971 , Oct.l999.

[4] H. Akagi, ” Active harmonic filters” Proc. IEEE, vol. 93, no. 12, pp.2128-2141 , Dec. 2005.

[5] K. K. Shyu, M. Yang, Y.M. Chen, and Y.F.Lin, “Model reference Adaptive control design for a shunt active po we filter systems,” TEEE Trans. Tnd. Electron., vol. 55, no. 1, pp. 97-106, Jan. 2008.

A Highly Efficient and Reliable Inverter Configuration Based Cascaded Multi-Level Inverter for PV Systems

ABSTRACT:  

This paper presents an improved Cascaded Multi-Level Inverter (CMLI) based on a highly efficient and reliable configuration for the minimization of the leakage current. Apart from a reduced switch count, the proposed scheme has additional features of low switching and conduction losses. The proposed topology with the given PWM technique reduces the high-frequency voltage transitions in the terminal and common-mode voltages. Avoiding high-frequency voltage transitions achieves the minimization of the leakage current and reduction in the size of EMI filters. Furthermore, the extension of the proposed CMLI along with the PWM technique for 2m+1 levels is also presented, where m represents the number of Photo Voltaic (PV) sources.

The proposed PWM technique requires only a single carrier wave for all 2m+1 levels of operation. The Total Harmonic Distortion (THD) of the grid current for the proposed CMLI meets the requirements of IEEE 1547 standard. A comparison of the proposed CMLI with the existing PV Multi-Level Inverter (MLI) topologies is also presented in the paper. Complete details of the analysis of PV terminal and common-mode voltages of the proposed CMLI using switching function concept, simulations, and experimental results are presented in the paper.

KEYWORDS:
  1. Cascaded multi-level inverter
  2. Leakage current
  3. Common-mode voltage
  4. Terminal voltage

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

 

Fig. 1. Proposed five-level grid-connected CMLI with PV and parasitic elements.

EXPECTED SIMULATION RESULTS:

 

Fig. 2. Simulation results of proposed five-level CMLI showing the waveforms of : (a) output voltage vuv; (b) grid current iac; (c) terminal voltage vxg; (d) terminal voltage vyg; (e) terminal voltage vzg; (f) leakage current ileak; (g) common-mode voltage vcm.

Fig. 3. Proposed five-level CMLI integrated with MPPT. The subplots give waveforms of : (a) voltage VPV1; (b) voltage VPV2; (c) current IPV1; (d) current IPV2; (e) power PPV1; (f) power PPV2; (g) resultant modulation index ma; (h) output power POUT; (i) modified reference wave vref_modified; (j) inverter output voltage vab.

CONCLUSION:

 In this paper, an improved five-level CMLI with low switch count for the minimization of leakage current in a transformerless PV system is proposed. The proposed CMLI minimizes the leakage current by eliminating the high-frequency transitions in the terminal and common-mode voltages. The proposed topology also has reduced conduction and switching losses which makes it possible to operate the CMLI at high switching frequency.

Furthermore, the solution for generalized 2m+1 levels CMLI is also presented in the paper. The given PWM technique requires only one carrier wave for the generation of 2m+1 levels. The operation, analysis of terminal and common-mode voltages for the CMLI is also presented in the paper. The simulation and experimental results validate the analysis carried out in this paper. The MPPT algorithm is also integrated with the proposed five-level CMLI to extract the maximum power from the PV panels. The proposed CMLI is also compared with the other existing MLI topologies in Table V to show its advantages.

REFERENCES:

[1] Y. Tang, W. Yao, P.C. Loh and F. Blaabjerg, “Highly Reliable Transformerless Photovoltaic Inverters With Leakage Current and Pulsating Power Elimination,” IEEE Trans. Ind. Elect., vol. 63, no. 2, pp. 1016-1026, Feb. 2016.

[2] W. Li, Y. Gu, H. Luo, W. Cui, X. He and C. Xia, “Topology Review and Derivation Methodology of Single-Phase Transformerless Photovoltaic Inverters for Leakage Current Suppression,” IEEE Trans. Ind. Elect., vol. 62, no. 7, pp. 4537-4551, July 2015.

[3] J. Ji, W. Wu, Y. He, Z. Lin, F. Blaabjerg and H. S. H. Chung, “A Simple Differential Mode EMI Suppressor for the LLCL-Filter-Based Single-Phase Grid-Tied Transformerless Inverter,” IEEE Trans. Ind. Elect., vol. 62, no. 7, pp. 4141-4147, July 2015.

[4] Y. Bae and R.Y.Kim, “Suppression of Common-Mode Voltage Using a Multicentral Photovoltaic Inverter Topology With Synchronized PWM,” IEEE Trans. Ind. Elect., vol. 61, no. 9, pp. 4722-4733, Sept. 2014.

[5] N. Vazquez, M. Rosas, C. Hernandez, E. Vazquez and F. J. Perez-Pinal, “A New Common-Mode Transformerless Photovoltaic Inverter,” IEEE Trans. Ind. Elect., vol. 62, no. 10, pp. 6381-6391, Oct. 2015.

Development of 10kW Three-Phase Grid Connected Inverter

 

ABSTRACT:

In this paper, modeling, simulation and experimental study of a 10kW three-phase grid connected inverter are presented. The mathematical model of the system is derived, and characteristic curves of the system are obtained in MATLAB with m-file for various switching frequencies, dc-link voltages and filter inductance values. The curves are used for parameter selection of three-phase grid connected inverter design. The parameters of the system are selected from these curves, and the system is simulated in Simulink. Modeling and simulation results are verified with experimental results at 10kW for steady state response, at 5kW for dynamic response and at −3.6 kVAr for reactive power. The inverter is controlled with Space Vector Pulse Width Modulation technique in d-q reference frame, and dSPACE DS1103 controller board is used in the experimental study. Grid current total harmonic distortion value  and efficiency are measured 3.59% and 97.6%, respectively.

KEYWORDS:

  1. Grid Connected Inverter
  2. Inverter Modeling
  3. Space Vector Pulse Width Modulation
  4. Total Harmonic Distortion

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Block diagram of the grid connected inverter.

EXPECTED SIMULATION RESULTS:

 

Fig. 2. THD variation of the grid current for Vdc = 650 V.

Fig. 3. THD variation of the grid current for fsw = 3 kHz.

Fig. 4. THD variation of the grid current for fsw = 9 kHz.

Fig. 5. Three-phase grid currents and voltage for fsw = 3 kHz.

Fig. 6 d-q components of the grid current for fsw = 3 kHz

Fig. 7. Three-phase grid currents and voltage for fsw = 9 kHz

Fig. 8. d-q components of the grid current for fsw = 9 kHz.

Fig. 9. d-q components of grid current.

 CONCLUSION:

In this study, performance of a 10kW three-phase grid connected inverter is investigated for various filter inductance values, DC-link voltages and switching frequencies. The system is modeled in m-file, thus characteristic curves of the inverter are obtained for different parameters. The THD values of grid current for 3 kHz and 9 kHz with 650V DC-link voltage are 10.22%and 3.41%. For verification of the modeling results, the system is simulated in Simulink. The control algorithm is implemented in Embedded Matlab Function in the simulation. The results are compared at 3 kHz and 9 kHz switching frequency, and modeling results are verified with simulation results that are 10.22% are 3.44%. In order to verify the modeling and simulation results, a laboratory prototype that is controlled by dSPACE DS1103 control board is realized. In the experimental study, THD values are measured as 10.68 and 3.59%. Furthermore, dynamic response and reactive power generation capability of the inverter are presented. The experimental results verify the modeling and simulation results. This verification shows that the system can be designed for various system and control parameters using the design curves. The study is realized for 10kW power but it is possible to obtain the characteristic curves for differen power values. According to results, the switching frequency or filter inductance value should be high to meet THD limit. Furthermore, efficiency is another important performance indicator. The efficiency at rated power and the european efficiency of the inverter is 97.6% and 97.2%  at 9 kHz.

REFERENCES:

[1] F. Blaabjerg, M. Liserre and K. Ma: “Power Electronics Converters for Wind Turbine Systems”, IEEE Transactio on Industry Applications, vol.48, pp. 708-719, 2012.

[2] F. Blaabjerg, Z. Chen, S.B. and Kjaer: “Power Electronics as Efficient Interface in Dispersed Power Generation Systems”, IEEE Transactions on Power Electronics, vol. 19,  pp. 1184-1194, 2004.

[3] J.M. Carrasco, L.G. Franquelo, J.T. Bialasiewicz, E. Galvan, R.C.P. Guisado, M.A.M. Prats, J.I. Leon and N.M. Alfonso:  “Power-Electronic Systems for the Grid Integration   of Renewable Energy Sources: A Survey”, IEEE Transactions  on Industrial Electronics, vol. 53, pp. 1002-1016, 2006.

[4] C. Ramonas and V. Adomavicius: “Research of the Converte  Possibilities in the Grid-tied Renewable Energ  Power Plant”, Elektronika IR Elektrotechnika, vol. 19, pp  37-40, 2013.

[5] D. Meneses, F. Blaabjerg, O. Garcia and J.A. Cobos: “Review and Comparison of Step-Up Transformerless Topologies for Photovoltaic AC-Module Application”, IEEE  Transactions on Power Electronics, vol. 28, pp. 2649-2663,  2013.

Simulation and Comparison of SPWM and SVPWM Control for Three Phase Inverter

ABSTRACT:

A voltage source inverter is commonly used to supply a three-phase induction motor with variable frequency and variable voltage for variable speed applications. A suitable pulse width modulation (PWM) technique is employed to obtain the required output voltage in the line side of the inverter. The different methods for PWM generation can be broadly classified into Triangle comparison based PWM (TCPWM) and Space Vector based PWM (SVPWM). In TCPWM methods such as sine-triangle PWM, three phase reference modulating signals are compared against a common triangular carrier to generate the PWM signals for the three phases. In SVPWM methods, a revolving reference voltage vector is provided as voltage reference instead of three phase modulating waves. The magnitude and frequency of the fundamental component in the line side are controlled by the magnitude and frequency, respectively, of the reference vector. The highest possible peak phase fundamental is very less in sine triangle PWM when compared with space vector PWM. Space Vector Modulation (SVM) Technique has become the important PWM technique for three phase Voltage Source Inverters for the control of AC Induction, Brushless DC, Switched Reluctance and Permanent Magnet Synchronous Motors. The study of space vector modulation technique reveals that space vector modulation technique utilizes DC bus voltage more efficiently and generates less harmonic distortion when compared with Sinusoidal PWM (SPWM) technique. In this paper first a model for Space vector PWM is made and simulated using MATLAB/SIMULINK software and its performance is compared with Sinusoidal PWM. The simulation study reveals that Space vector PWM utilizes dc bus voltage more effectively and generates less THD when compared with sine PWM.

KEYWORDS:

  1. PWM
  2. SVPWM
  3. Three phase inverter
  4. Total harmonic distortion

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Figure-1. Block diagram of SPWM inverter fed induction motor.

EXPECTED SIMULATION RESULTS:

Figure-2a. Response of line voltage in SPWM.

Figure-3. Response of line voltage in SPWM.

Figure-4a. Response of line current in SPWM.

Figure-5b. Response of line current in SPWM.

Figure-6. Response of rotor speed in SPWM.

Figure.7. Response of torque in SPWM.

Figure-8. Response of line voltage in SVPWM.

Figure-9. Response of line current in SVPWM.

Figure-10. Response of rotor speed in SVPWM.

Figure-11. Response of torque in SVPWM.

 CONCLUSION:

Space vector Modulation Technique has become the most popular and important PWM technique for Three Phase Voltage Source Inverters for the control of AC Induction, Brushless DC, Switched Reluctance and Permanent Magnet Synchronous Motors. In this paper first comparative analysis of Space Vector PWM with conventional SPWM for a two level Inverter is carried out. The Simulation study reveals that SVPWM gives 15% enhanced fundamental output with better quality i.e. lesser THD compared to SPWM. PWM strategies viz. SPWM and SVPWM are implemented in MATLAB/SIMULINK software and its performance is compared with conventional PWM techniques. Owing to their fixed carrier frequencies cfin conventional PWM strategies, there are cluster harmonics around the multiples of carrier frequency. PWM strategies viz. Sinusoidal PWM and SVPWM utilize a changing carrier frequency to spread the harmonics continuously to a wideband area so that the peak harmonics are reduced greatly.

REFERENCES:

Zhenyu Yu, Arefeen Mohammed, Issa Panahi. 1997. A Review of Three PWM Techniques. Proceedings of the American Control Conference Albuquerque, New Mexico. pp. 257-261.

  1. G. Holmes and T. A. Lipo. 2003. Pulse Width Modulation for Power Converters: Principles and Practice. M.E. El-Hawary, Ed. New Jersey: IEEE Press, Wiley- Interscience. pp. 215-313.
  2. Erfidan, S. Urugun, Y. Karabag and B. Cakir. 2004. New Software implementation of the Space Vector Modulation. Proceedings of IEEE Conference. pp.1113-1115.
  3. Rathnakumar, J. Lakshmana Perumal and T. Srinivasan. 2005. A New software implementation of space vector PWM. Proceedings of IEEE Southeast conference. pp.131-136.
  4. Hariram and N. S. Marimuthu. 2005. Space vector switching patterns for different applications- A comparative analysis. Proceedings of IEEE conference. pp. 1444-1449.

Design and Analysis of an On-Board Electric Vehicle Charger for Wide Battery Voltage Range

ABSTRACT:

The scarcity of fossil fuel and the increased pollution leads the use of Electric Vehicles (EV) and Hybrid Electric Vehicles (HEV) instead of conventional Internal Combustion (IC) engine vehicles. An Electric Vehicle requires an on-board charger (OBC) to charge the propulsion battery. The objective of the project work is to design a multifunctional on-board charger that can charge the propulsion battery when the Electric Vehicle (EV) connected to the grid. In this case, the OBC plays an AC-DC converter. The surplus energy of the propulsion battery can be supplied to the grid, in this case, the OBC plays as an inverter. The auxiliary battery can be charged via the propulsion battery when PEV is in driving stage. In this case, the OBC plays like a low voltage DC-DC converter (LDC). An OBC is designed with Boost PFC converter at the first stage to obtain unity power factor with low Total Harmonic Distortion (THD) and a Bi-directional DC-DC converter to regulate the charging voltage and current of the propulsion battery. The battery is a Li-Ion battery with a nominal voltage of 360 V and can be charged from depleted voltage of 320 V to a fully charged condition of 420 V. The function of the second stage DC-DC converter is to charge the battery in a Constant Current and Constant Voltage manner. While in driving condition of the battery the OBC operates as an LDC to charge the Auxiliary battery of the vehicle whose voltage is around 12 V. In LDC operation the Bi-Directional DC-DC converter works in Vehicle to Grid (V2G) mode. A 1KW prototype of multifunctional OBC is designed and simulated in MATLAB/Simulink. The power factor obtained at full load is 0.999 with a THD of 3.65 %. The Battery is charged in A CC mode from 320 V to 420 V with a constant battery current of 2.38 A and the charging is switched into CV mode until the battery current falls below 0.24 A. An LDC is designed to charge a 12 V auxiliary battery with CV mode from the high voltage propulsion battery.

KEYWORDS:

  1. Bi-directional DC-DC converter
  2. Boost PFC converter
  3. Electric vehicle
  4. Low voltage DC-DC converter
  5. Vehicle-to-grid

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 

Fig 1. Block Diagram of Power distribution in EV

EXPECTED SIMULATION RESULTS:

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

Fig 2.Simulated Results of Charging operation of the propulsion battery (a)Voltage and (b)Current in Beginning Point(c)voltage and (d)current in Nominal Point (e)voltage and (f)current in Turning Point(g)voltage and (h)current in End Point

Fig 3. DC link voltage and current during G2V operation (The current is multiplied by 100 for batter visibility)

Fig 4.Voltage and Current of Auxiliary battery during charging

(Current is multiplied by 10 for better visibility)

 CONCLUSION:

The second stage of OBC i.e. DC-DC converter is essential as it regulates the battery voltage and current. The most common method of charging Li-Ion batteries i.e. CC/CV mode charging is obtained by using a DC-DC converter in this chapter. The Battery is charged from 320 V to 420 V in a CC manner with a constant current of 2.38 A and further in a CV manner by keeping the battery voltage fixed at 420 V. The designed DC-DC converter supports Bi-directional power flow and the V2G mode of operation is simulated with the V2G controller, a new concept of LDC is designed here by utilizing the OBC to charge in Auxiliary battery from the propulsion battery. A single stage controller is developed in order to maintain a desired voltage across the Auxiliary battery.

REFERENCES:

[1] a. Emadi and K. Rajashekara, “Power Electronics and Motor Drives in Electric, Hybrid Electric, and Plug-In Hybrid Electric Vehicles,” IEEE Trans. Ind. Electron., vol. 55, no. 6, pp. 2237–2245, 2008.

[2] M. Yilmaz and P. T. Krein, “Review of charging power levels and infrastructure for plug-in electric and hybrid vehicles,” 2012 IEEE Int. Electr. Veh. Conf. IEVC 2012, vol. 28, no. 5, pp. 2151–2169, 2012.

[3] H. Wang, S. Dusmez, and A. Khaligh, “Design and analysis of a full-bridge LLC-based PEV charger optimized for wide battery voltage range,” IEEE Trans. Veh. Technol., vol. 63, no. 4, pp. 1603–1613, 2014.

[4] P. Maheshwari, Y. Tambawala, H. S. V. S. K. Nunna, and S. Doolla, “A review of plug-in electric vehicles charging: Standards and impact on the distribution system,” Power Electronics, Drives and Energy Systems (PEDES), 2014 IEEE International Conference on. pp. 1–6, 2014.

[5] S. K. Sul and S. J. Lee, “Integral battery charger for four-wheel drive electric vehicle,” IEEE Trans. Ind. Appl., vol. 31, no. 5, pp. 1096–1099, 1995.

Comparative Analysis of 6, 12 and 48 Pulse T-STATCOM

2016, IEEE 

ABSTRACT: This paper presents the performance and comparative analysis of Static Synchronous Compensator (STATCOM) based on 6, 12 and 48-pulse VSC configuration. STATCOM is implemented for regulation of the voltage at the Point of Common Coupling (PCC) bus which has time-variable loads. The dq decoupled current control strategy is used for implementation of STATCOM, where modulation index M and phase angle ø are varied for achieving voltage regulation at the PCC bus. The 6, 12 and 48-pulse configurations are compared and analyzed on the basis of Total Harmonic Distortion (THD) and time response parameters such as rise time, maximum overshoot and settling time. The simulation of various configurations of STATCOM is carried out using power system block-set in MATLAB/Simulink platform.

KEYWORDS:

  1. FACTS
  2. STATCOM
  3. Decoupled current control system
  4. Voltage Sourced Converter
  5. Total Harmonic Distortion

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 

Fig.1:Single line diagram of STATCOM.

 EXPECTED SIMULATION RESULTS:

 

 

Fig. 2: PCC bus voltage-VM for 6, 12 and 48 pulse STATCOM respectively.

Fig. 3: q-axis STATCOM current-ishq for PI controller of 6, 12 and 48 pulse STATCOM respectively.

Fig. 4: d-axis STATCOM current-ishd for PI controller of 6, 12 and 48 pulse STATCOM respectively.

a: Dc capacitor voltage-Vdc

b: Active power of loads-PL

c: Reactive power-Qstat

                                d: Active power-Pstat

Fig. 5: Vdc, PL, Qstat and Pstat for 48 pulse STATCOM respectively.

CONCLUSION:

In this paper, for voltage regulation and dynamic power flow control a 48-pulse ±100 MVA two-level GTO STATCOM has been modeled and simulated using decoupled current control strategy. By varying the modulation index (M) and phase angle (ɸ) between PCC bus voltage and STATCOM voltage, voltage regulation at the PCC bus is achieved. The THD and various time response parameters of 6, 12 and 48 pulse STATCOM are compared. The results show that THD of output voltage of 48 pulse STATCOM is less than 5%, which satisfies the IEEE 519 standard. Hence, there is no need of active filter. Also, 48 pulse STATCOM has better transient response as compared to 6, 12 pulse STATCOM.

REFERENCES:

[1] K. Padiyar, FACTS controllers in power transmission and distribution. New Age International, 2007.

[2] K. K. Sen and M. L. Sen, Introduction to FACTS controllers: theory, modeling, and applications. John Wiley & Sons, 2009, vol. 54.

[3] A. Edris, “Facts technology development: an update,” IEEE Power engineering review, vol. 20, no. 3, pp. 4–9, 2000.

[4] El-Moursi and A.M. Sharaf, “Novel controllers for the 48-pulse vscstatcom and ssscfor voltage regulation and reactive power compensation,” IEEE Transactions on Powersystems, vol. 20, no. 4, pp. 1985–1997, 2005.

[5] N. G. Hingorani and L. Gyugyi, Understanding FACTS: concepts and technology of flexible AC transmission systems. Wiley-IEEE press, 2000.

Modeling of 18-Pulse STATCOM for Power System Applications

ABSTRACT:

 A multi-pulse GTO based voltage source converter (VSC) topology together with a fundamental frequency switching mode of gate control is a mature technology being widely used in static synchronous compensators (STATCOMs). The present practice in utility/industry is to employ a high number of pulses in the STATCOM, preferably a 48-pulse along with matching components of magnetics for dynamic reactive power compensation, voltage regulation, etc. in electrical networks. With an increase in the pulse order, need of power electronic devices and inter-facing magnetic apparatus increases multi-fold to achieve a desired operating performance. In this paper, a competitive topology with a fewer number of devices and reduced magnetics is evolved to develop an 18-pulse, 2-level + 100MVAR STATCOM in which a GTO-VSC device is operated at fundamental frequency switching gate control. The inter-facing magnetics topology is conceptualized in two stages and with this harmonics distortion in the network is minimized to permissible IEEE-519 standard limits. This compensator is modeled, designed and simulated by a Sim Power Systems tool box in MATLAB platform and is tested for voltage regulation and power factor correction in power systems. The operating characteristics corresponding to steady state and dynamic operating conditions show an acceptable performance.

KEYWORDS:

  1. Fast Fourier transformation
  2. Gate-turn off thyristor
  3. Magnetic
  4. STATCOM
  5. Total harmonic distortion
  6. Voltage source converter

SOFTWARE: MATLAB/SIMULINK

MATLAB MODEL:

Fig. 1 MATLAB model of ±100MVAR 18-pulse STATCOM

EXPECTED SIMULATION RESULTS:

Fig. 2 Three phase instantaneous voltage(va , vb, vc) and current (ia, ib, ic) with 75MW 0.85pf lagging load when V* sets at 1.0pu, 1.03pu and 0.97pu

Fig. 3 Operating characteristics in voltage regulation mode for 70MW, 0.85pf(lag) load

Fig. 4 Voltage(va) spectrum in capacitive mode

Fig. 5. Voltage spectrum (va) in inductive mode.

Fig. 6. Current (ia) spectrum in capacitive mode.

Fig. 7. Current spectrum (ia) in inductive mode.

Fig. 8 Operating characteristics for unity power factor (upf) Correction in var control mode for 75MW, 0.85pf(lag) load

Fig. 9. Voltage harmonics(va) spectrum for upf correction.

Fig. 10 Current harmonics(ia) spectrum for upf correction

Fig. 11 Operating characteristics following 10% load injection at the instant of 0.24s in voltage regulation mode on 70MW, 0.85pf(lag) load

Fig. 12 Voltage harmonics (va) spectrum after load variation

Fig. 13. Current harmonics (ia) spectrum after load variation.

Fig. 14 Operating characteristics in var control mode for incremental Load variation of 10% at the instant of 0.24s on an initial load of 70MW, 0.85pf(lag)

Fig. 15 Voltage harmonics (va) spectrum after the load injection

Fig. 16. Current harmonics (ia) spectrum after the load injection.

CONCLUSION:

A new 18-pulse, 2-level GTO-VSC based STATCOM with a rating of + 100MVAR, 132kV was modeled by employing three fundamental 6-pulse VSCs operated at fundamental frequency gate switching in MATLAB platform using a Sim Power Systems tool box. The inter-facing magnetics have evolved in two stage sinter- phase transformers (stage-I) and phase shifter (stage-II), and with this topology together with standard PI-controllers, harmonics distortion in the network has been greatly minimized to permissible IEEE-519 standard operating limits [9]. The compensator was employed for voltage regulation, power factor correction and also tested for dynamic load variation in the network. It was observed from the various operating performance characteristics which emerged from the simulation results that the model satisfies the network requirements both during steady state and dynamic operating conditions. The controller has provided necessary damping to settle rapidly steady states for smooth operation of the system within a couple of cycles. The proposed GTO-VSC based 18-pulse STATCOM seems to provide an optimized model of competitive performance in multi-pulse topology.

REFERENCES:

[1] Colin D. Schauder, “Advanced Static VAR Compensator Control System,” U.S. Patent 5 329 221, Jul. 12, 1994.

[2] Derek A. Paice, “Optimized 18-Pulse Type AC/DC, or DC/AC Converter System,” U.S. Patent 5 124 904, Jun. 23, 1992.

[3] Kenneth Lipman, “Harmonic Reduction for Multi-Bridge Converters,” U.S. Patent 4 975 822, Dec. 4, 1990.

[4] K.K. Sen, “Statcom – Static Synchronous Compensator: Theory, Modeling, And Applications,” IEEE PES WM, 1999,Vol. 2, pp. 1177 –1183.

[5] Guk C. Cho, Gu H. Jung, Nam S. Choi, et al. “Analysis and controller design of static VAR compensator using three-level GTO inverter,” IEEE Transactions Power Electronics, Vol.11, No.1, Jan 1996, pp. 57 –65.

Design and Analysis of an On-Board Electric Vehicle Charger for Wide Battery Voltage Range  

ABSTRACT:

The scarcity of fossil fuel and the increased pollution leads the use of Electric Vehicles (EV) and Hybrid Electric Vehicles (HEV) instead of conventional Internal Combustion (IC) engine vehicles. An Electric Vehicle requires an on-board charger (OBC) to charge the propulsion battery. The objective of the project work is to design a multifunctional on-board charger that can charge the propulsion battery when the Electric Vehicle (EV) connected to the grid. In this case, the OBC plays an AC-DC converter. The surplus energy of the propulsion battery can be supplied to the grid, in this case, the OBC plays as an inverter. The auxiliary battery can be charged via the propulsion battery when PEV is in driving stage. In this case, the OBC plays like a low voltage DC-DC converter (LDC). An OBC is designed with Boost PFC converter at the first stage to obtain unity power factor with low Total Harmonic Distortion (THD) and a Bi-directional DC-DC converter to regulate the charging voltage and current of the propulsion battery. The battery is a Li-Ion battery with a nominal voltage of 360 V and can be charged from depleted voltage of 320 V to a fully charged condition of 420 V. The function of the second stage DC-DC converter is to charge the battery in a Constant Current and Constant Voltage manner. While in driving condition of the battery the OBC operates as an LDC to charge the Auxiliary battery of the vehicle whose voltage is around 12 V. In LDC operation the Bi-Directional DC-DC converter works in Vehicle to Grid (V2G) mode. A 1KW prototype of multifunctional OBC is designed and simulated in MATLAB/Simulink. The power factor obtained at full load is 0.999 with a THD of 3.65 %. The Battery is charged in A CC mode from 320 V to 420 V with a constant battery current of 2.38 A and the charging is switched into CV mode until the battery current falls below 0.24 A. An LDC is designed to charge a 12 V auxiliary battery with CV mode from the high voltage propulsion battery.

KEYWORDS:

  1. Bi-directional DC-DC converter
  2. Boost PFC converter
  3. Electric vehicle
  4. Low voltage DC-DC converter
  5. Vehicle-to-grid.

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig 1 Block Diagram of Power distribution in EV

EXPECTED SIMULATION RESULTS:

 

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

Fig 2 Simulated Results of Charging operation of the propulsion battery (a)Voltage and (b)Current in Beginning Point(c)voltage and (d)current in Nominal Point (e)voltage and (f)current in Turning Point(g)voltage and (h)current in End Point

Fig 3 DC link voltage and current during G2V operation (The current is multiplied by 100 for batter visibility)

Fig 4 Voltage and Current of Auxiliary battery during charging (Current is multiplied by 10 for better visibility)

 CONCLUSION:

An On-Board Electric Vehicle charger is designed for level 1 charging with a 230 V input supply. Different stages of an OBC is stated and the challenges are listed. The developments have been implemented to overcome key issues. A two stage charger topology with active PFC converter at the front end followed by a Bi-directional DC-DC converter is designed. The active PFC which is a Boost converter type produces less than 5 % THD at full load. Moreover, the PFC converter is applicable to wide variation in loads. The detailed design of the power stage, as well as the controller, is discussed with the simulated results.

A second stage DC-DC converter is designed and simulated for the charging current and voltage regulation. The converter performs very precisely by charging the propulsion battery in CC/CV mode over a wide range of voltage. A V2G controller has been developed for the DC-DC converter in order to supply power to the grid from the propulsion battery. A new Low-Voltage DC-DC converter is proposed to charge the Auxiliary battery via the propulsion battery utilizing the same OBC. The battery voltage and current waveforms are presented and the performance of the designed converter is verified.

REFERENCES:

[1] “No Title,” https://en.wikipedia.org/wiki/Electric_vehicle. .

[2] S. S. Williamson, Energy management strategies for electric and plug-in hybrid electric vehicles. Springer, 2013.

[3] a. Emadi and K. Rajashekara, “Power Electronics and Motor Drives in Electric, Hybrid Electric, and Plug-In Hybrid Electric Vehicles,” IEEE Trans. Ind. Electron., vol. 55, no. 6, pp. 2237–2245, 2008.

[4] M. Yilmaz and P. T. Krein, “Review of charging power levels and infrastructure for plug-in electric and hybrid vehicles,” 2012 IEEE Int. Electr. Veh. Conf. IEVC 2012, vol. 28, no. 5, pp. 2151–2169, 2012.

[5] H. Wang, S. Dusmez, and A. Khaligh, “Design and analysis of a full-bridge LLC-based PEV charger optimized for wide battery voltage range,” IEEE Trans. Veh. Technol., vol. 63, no. 4, pp. 1603–1613, 2014.

 

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

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. Passive Filters
  4. Total Harmonic Distortion

SOFTWARE: MATLAB/SIMULINK

BLCOK DIAGRAM

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:

  • Francisco, Harmonics and power systems. CRC press, 2006.
  • 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.
  • Gyugyi and E. C. Strycula, “Active ac power filters,” in Proc. IEEE/IAS Annu. Meeting, vol. 19, 1976, pp. 529–535.
  • 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.
  • 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.

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.