Voltage Oriented Controller Based Vienna Rectifier for Electric Vehicle Charging Stations

ABSTRACT:

Vienna rectifiers have gained popularity in recent years for AC to DC power conversion for many industrial applications such as welding power supplies, data centers, telecommunication power sources, aircraft systems, and electric vehicle charging stations. The advantages of this converter are low total harmonic distortion (THD), high power density, and high efficiency. Due to the inherent current control loop in the voltage-oriented control strategy proposed in this paper, good steady-state performance and fast transient response can be ensured. The proposed voltage-oriented control of the Vienna rectifier with a PI controller (VOC-VR) has been simulated using MATLAB/Simulink. The simulations indicate that the input current THD of the proposed VOC-VR system was below 3.27% for 650V and 90A output, which is less than 5% to satisfy the IEEE-519 standard. Experimental results from a scaled-down prototype showed that the THD remains below 5% for a wide range of input voltage, output voltage, and loading conditions (up to 2 kW). The results prove that the proposed rectifier system can be applied for high power applications such as DC fast-charging stations and welding power sources.

KEYWORDS:

1.      Front-end converters

2.      High power applications

3.      Power factor

4.      Total harmonic distortion

5.      Vienna rectifier

6.      Voltage oriented controller

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 

Figure 1. The Proposed Electric Vehicle Charger Is Based On Vienna Rectifier With A Voc Controller (Voc-Vr) System.

EXPECTED SIMULATION RESULTS:

Figure 2. Input Current Waveform Of The Proposed Voc-Vr System With 440 V Rms In And 650 V Dc Out.

 

Figure 3. Total Harmonic Distortion Of The Proposed Voc-Vr System With 440 V Rms In And 650 V Dc Out.

 

Figure 4. Dc Output Voltage And Output Current Of The Vienna Rectifier With Voc Controller With 350 V Ac Rms Input And 650 V Dc Output Voltage.

Figure 5. Dc Output Voltage And Output Current Of The Vienna Rectifier

With Voc Controller With 350 V Ac Rms Input And 220 V Dc Output Voltage For Slow Charging Stations.

 

 

CONCLUSION:

In this research work, a three-level Vienna rectifier based on a voltage-oriented controller (VOC-VR) has been designed and experimentally tested. The proposed system has been simulated using MATLAB Simulink software targeting high power applications such as DC-fast chargers for electric vehicles. The proposed controller for Vienna rectifier focused on combining voltage-oriented controllers with the PWM method. In proposed design, the reactive and unstable active currents are counteracted by the input and output filters and Voltage Oriented Controller (VOC) with Vienna rectifier. The proposed design also guarantees a sinusoidal current at the input side with minimum ripples and distortions. The system's power factor is maintained at unity, and total harmonic distortion of the input current is kept less than 5 %, which meets the IEEE-519 standard. The benefit of the proposed controller over conventional PFC controller has been demonstrated by simulations and experimental results. Low THD, good power factor, and smaller filtering requirements make the voltage-oriented controller-based Vienna rectifier an ideal candidate in electric vehicle charging stations.

REFERENCES:

[1] F. Nejabatkhah, Y. W. Li, and H. Tian, ``Power quality control of smart hybrid AC/DC microgrids: An overview,'' IEEE Access, vol. 7, pp. 52295_52318, 2019.

[2] P. Arboleya, G. Diaz, and M. Coto, ``Unified AC/DC power flow for traction systems:Anewconcept,'' IEEE Trans. Veh. Technol., vol. 61, no. 6, pp. 2421_2430, Jul. 2012.

[3] W. Su, H. Eichi,W. Zeng, and M.-Y. Chow, ``A survey on the electrification of transportation in a smart grid environment,'' IEEE Trans. Ind. Informat., vol. 8, no. 1, pp. 1_10, Feb. 2012.

[4] I. Pavi¢, T. Capuder, and I. Kuzle, ``Value of flexible electric vehicles in providing spinning reserve services,'' Appl. Energy, vol. 157, pp. 60_74, Nov. 2015.

[5] L. Hang, H. Zhang, S. Liu, X. Xie, C. Zhao, and S. Liu, ``A novel control strategy based on natural frame for Vienna-type rectifier under light unbalanced-grid conditions,'' IEEE Trans. Ind. Electron., vol. 62, no. 3, pp. 1353_1362, Mar. 2015.

Scalar and Vector Controlled Infinite Level Inverter (ILI) Topology Fed Open-Ended Three-Phase Induction Motor

ABSTRACT:

The design and performance analysis of an open-ended three-phase induction motor, driven by an Infinite Level Inverter (ILI) with its speed control using scalar and direct vector control techniques are presented in this paper. The ILI belongs to an Active-Front-End (AFE) Reduced-Device-Count (RDC) Multi-level Inverter (MLI) topology. The fundamental structure of this inverter topology is a dc-to-dc buck converter followed by an H-bridge. This topology performs a high-quality power conversion without any shoot-through issues and reverse recovery problems. The performance of the proposed topology is validated using a resistive load. The THD of output voltage waveform obtained is 1.2%. Moreover, this topology has exhibited a high degree of dc-source voltage utilization. ILI considerably reduces the switching and conduction losses, since only one switch per phase is operated at high frequency, and other switches are operated at power frequency. The overall efficiency of the inverter is 98%. The speed control performance of the ILI topology using three-phase open-ended induction motor has been further validated through scalar and direct vector control techniques. Results obtained from simulation studies are verified experimentally.

KEYWORDS:

1.      Active-front-end

2.      Multi-level inverters

3.       Reduced-device-count

4.      Scalar and direct vector control

5.       Three-phase infinite level inverter

SOFTWARE: MATLAB/SIMULINK

SCHEMATIC DIAGRAM:

 

Figure 1. Three Phase Infinite Level Inverter Topology. Basic Structure Of The Proposed Topology Is A Buck Converter (Afe Converter) Followed By An H-Bridge. This Topology Consists Of One High-Frequency Operated Switch For Every Buck Circuit And Four Low-Frequency Operated Switches For Every H-Bridge; Hence, One Inductor And One Capacitor Per Phase.

EXPECTED SIMULATION RESULTS:

Figure 2. Simulated Waveforms Of Ili. (A) High Frequency, (B,C) Low Frequency Switching Pulses.

Figure 3. Simulated Waveforms Of Ili Using Resistive Load. Voltage And Current Wave Forms Across The Afe Converter Components. (A,B) High Frequency Switch, (C,D) Diode,(E,F) Inductor, (G,H) Capacitor,(I,J) Voltage Across Low Frequency Operating Switches.

 

Figure 4. Simulated Waveforms Of Ili Using Resistive Load. (A) Voltage Waveforms Across

The Buck Capacitor, (B) Voltage ,(C) current Wave Form Across The Load Resistance.

 

Figure5. Simulated Waveforms Of Ili Using Resistive Load. (A) Three-Phase Output Voltage Waveforms Across

The Buck Capacitor, (B) Three-Phase Output Voltage Wave Form Across The Load Resistance.

 

Figure 6. Simulated Waveforms Of (A) Third Harmonic Injection Pwm Control Implementation Logic, (B) Phase Voltage Waveform Of The Ili Using Resistive Load.

 

 

Figure 7. The Dynamic Responses Of The Simulated Output Voltage Waveforms Using V/F Control. (A) Voltage Waveform Across The Buck Capacitor, (B) Line-To-Line Voltage Across The Load.

Figure 8. The Dynamic Responses Of The Simulated Output Voltage Waveforms Using Direct Vector Control. (A,C) Voltage Waveform Across The Buck Capacitor, (B,D) Line-To-Line Voltage Across The Load.

 

Figure 9. The Simulated Output Voltage Waveforms Using Resistive Load (A) Conventional 2-Level H-Bridge Inverter, (B) 3-Level H-Bridge Inverter, (C) 5-Level Cascaded H-Bridge Mli, (D) Proposed Topology.

 CONCLUSION:

Design and analysis of the performance of an infinite level inverter driven induction motor have been discussed in this paper. ILI has been found to impart better performance to an induction motor drive. The ILI which belongs to an AFERDC- MLI topology has been tested with a resistive load and found to possess very good quality voltage and current waveforms in terms of THD. While conventional inverter topologies contain tens of percentage of THD, the topology mentioned in this paper contains a THD as low as 1.2%. Moreover, the dc- voltage requirement for generating a fixed ac-voltage output has been found to be much less than that required by other similar topologies, making the dc-source utilization better with this topology. While it is required to have a dc-voltage requirement of 677V in a conventional inverter working in sine PWM mode, the requirement of dc-voltage in the new inverter is only 338V. Use of third harmonic injection modulation scheme has also been performed using this inverter and found that the dc-source utilization can be improved further. Efficiency of inverter has also been found to be better, since only one switch per phase is operated at high frequency. All the switches in conventional inverters are operated at high frequency. Scalar and vector control of induction motor have also been performed using this topology. It has been found that the dynamic performance is better with this topology. This has been validated by accelerating and decelerating the machine with different reference speeds. Since the harmonic content in current has been very less, torque pulsations experienced by the motor would be negligible. Requirement of de-rating associated with induction motors fed by conventional inverters is not present in this case. Since there is no shoot-through menace, the chances of the inverter getting damaged is less, which results in better life and reliability of the drive system.

REFERENCES:

[1] P. Omer, J. Kumar, and B. S. Surjan, ``A review on reduced switch count multilevel inverter topologies,'' IEEE Access, vol. 8, pp. 22281_22302,Jan. 2020.

[2] J. Rodríguez, J.-S. Lai, and F. Z. Peng, ``Multilevel inverters: A survey of topologies, controls, and applications,'' IEEE Trans. Ind. Electron., vol. 49, no. 4, pp. 724_738, Aug. 2002.

[3] L. M. Tolbert, F. Z. Peng, and T. G. Habetler, ``Multilevel converters for large electric drives,'' IEEE Trans. Ind. Appl., vol. 35, no. 1, pp. 36_44, Jan./Feb. 1999.

[4] J.-S. Lai and F. Z. Peng, ``Multilevel converters_A new breed of power converters,'' IEEE Trans. Ind. Appl., vol. 32, no. 3, pp. 509_517, May 1996.

[5] S. Kouro, M. Malinowski, K. Gopakumar, J. Pou, L. G. Franquelo, B.Wu, J. Rodríguez, M. A. Pérez, and J. I. Leon, ``Recent advances and industrial applications of multilevel converters,'' IEEE Trans. Ind. Electron., vol. 57,

no. 8, pp. 2553_2580, Aug. 2010.

Performance Evaluation of Seven Level Reduced Switch ANPC Inverter in Shunt Active Power Filter with RBFNN Based Harmonic Current Generation

ABSTRACT:

One of the serious issues that a Power System faces is the Power Quality (PQ) disturbance which occur mainly because of the non-linear loads. Among these PQ disturbances, harmonics play a vital role which should to be mitigated along with reactive power compensation. In this paper, a modified seven-level boost Active-Neutral-Point-Clamped (7LB-ANPC) inverter is utilized as a Shunt Active Power Filter (SAPF). Another vital aspect of this work is to retain the link voltage across the capacitor, which is accomplished through a PI controller tuned with an Adaptive Neuro-Fuzzy Inference System (ANFIS). An adaptive instantaneous p-q theory is instigated in the direction of extracting reference current and the harmonic extraction is carried out by using Radial Basis Function Neural Network (RBFNN). Gating sequence of inverter is generated for the outputs, which are attained from ANFIS and RBFNN and thus the opposite harmonics are injected to the Point of Common Coupling (PCC) by which current harmonics are eliminated with reactive power compensation. The 7Lb-ANPC inverter has a minimized number of switching devices with low switching losses and high boosting ability. By RBFNN based reference current generation, the source current THD of 0.89% is achieved. The proposed methodology is simulated through MATLAB and in hardware by utilizing FPGA Spartan 6E.

KEYWORDS:

1.      Power Quality

2.      Shunt Active Power Filter

3.      Multi-Level Inverters

4.      Active-Neutral-Point-Clamped Inverter

5.      Radial Basis Function Neural Network

6.      Adaptive Neuro-Fuzzy Inference System

SOFTWARE: MATLAB/SIMULINK

SCHEMATIC DIAGRAM:

 

 

Figure 1 Proposed Seven-Level ANPC Circuit Diagram

EXPECTED SIMULATION RESULTS:

Figure 2: Source Voltage waveform

 

Figure 3: Load Current waveform

Figure 4: Current injected at the PCC

  

Figure 5: Source Current

 

Figure 6: DC-link voltage

 

 

Figure 7: THD waveform with the RBFNN approach

Figure 8: THD waveform with PQ theory

 CONCLUSION:

In this paper, harmonic mitigation and reactive power compensation are accomplished through a modified seven-level boost ANPC inverter, which exhibits high boosting ability with a minimized number of switches and low switching losses. The reference current generation is highlighted through the adaptive instantaneous p-q theory with RBFNN. Link voltage in the capacitor is retained by using ANFIS and which is compared by the PI controller and Fuzzy. PWM generator with a hysteresis current controller has generated the required gating sequence for the modified 7LB-ANPC inverter. A detailed comparison of modified 7LB-ANPC with the recent strategies has been carried out. The simulation results has highlighted that the proposed methodology is well suited for harmonic mitigation.

REFERENCES:

[1] P. S. Harmonics, "Power System Harmonics: An Overview," in IEEE Transactions on Power Apparatus and Systems, vol. PAS-102, no. 8, pp. 2455-2460, Aug. 1983, doi: 10.1109/TPAS.1983.317745.

[2] M. Rastogi, R. Naik and N. Mohan, "A comparative evaluation of harmonic reduction techniques in three-phase utility interface of power electronic loads," in IEEE Transactions on Industry Applications, vol. 30, no. 5, pp. 1149-1155, Sept.-Oct. 1994, doi: 10.1109/28.315225.

[3] R. Arnold, "Solutions to the power quality problem," in Power Engineering Journal, vol. 15, no. 2, pp. 65-73, April 2001, doi: 10.1049/pe:20010202.

[4] D. Graovac, V. Katic and A. Rufer, "Power Quality Problems Compensation With Universal Power Quality Conditioning System," in IEEE Transactions on Power Delivery, vol. 22, no. 2, pp. 968-976, April 2007, doi: 10.1109/TPWRD.2006.883027.

[5] B. Singh, K. Al-Haddad and A. Chandra, "A review of active filters for power quality improvement," in IEEE Transactions on Industrial Electronics, vol. 46, no. 5, pp. 960-971, Oct. 1999, doi: 10.1109/41.793345.

 

Passivity-Based Control Strategy With Improved Robustness for Single-Phase Three-Level T-Type Rectifiers

ABSTRACT:

A passivity-based control (PBC) strategy with improved robustness for single-phase three-level rectifiers feeding resistive and constant power loads (CPLs) is proposed. It is shown that the control of the rectifier can be achieved if the damping injection is applied to the grid current only. In this case, the knowledge of load resistance is required in the computation of reference grid current amplitude. Since the output voltage and load current are dc quantities, the load resistance can be estimated easily. Then, the amplitude of the reference grid current is calculated from the power balance equation of the rectifier. The transfer function from reference grid current to actual grid current is derived. The derived transfer function is analyzed under variations in the filter inductance. The results reveal that the proposed PBC offers strong robustness to variations in the filter inductance when a suitable damping gain is selected. The performances of the proposed PBC strategy under undistorted and distorted grid voltage as well as, variations in inductor are investigated via experimental studies during steady-state and transients caused by the resistive load and CPL changes. In all cases, the output voltage is regulated at the desired value, and grid current tracks its reference.

KEYWORDS:

1.      Passivity-based control

2.      Damping injection

3.      Three-level T-type rectifier

4.      Constant power load

SOFTWARE: MATLAB/SIMULINK

 SCHEMATIC DIAGRAM:

 

Figure 1. Single-Phase Three-Level T-Type Rectifier Feeding Resistive Load And Cpl.

 EXPECTED SIMULATION RESULTS:

Figure 2. Waveforms Of Grid-Voltage (Eg), Grid Current (Ig) And Its Reference (I_ G ), Five-Level Voltage (Vxy ), Output Voltage (Vdc ) And Its Reference (V _ Dc ), And Capacitor Voltages (Vc1 And Vc2) Under Undistorted Grid Voltage.

Figure 3. Waveforms Of Grid-Voltage (Eg), Grid Current (Ig) And Its Reference (I_ G ), Output Voltage (Vdc ) And Its Reference (V _ Dc ), And Capacitor Voltages (Vc1 And Vc2) Under Distorted Grid Voltage.

Figure 4. Waveforms Of Grid-Voltage (Eg), Grid Current (Ig) And Its Reference (I_ G ), Output Voltage (Vdc ) And Its Reference (V _ Dc ), And Capacitor Voltages (Vc1 And Vc2) Under Rl D 25: (A) Le < L (Le D 1:6 Mh) And &1 D 1, (B) Le < L (Le D 1:6 Mh) And &1 D 20, (C) Le > L (Le D 2:4 Mh) And &1 D 20.

 

 

Figure 5. Waveforms Of Grid-Voltage (Eg), Grid Current (Ig) And Its Reference (I_ G ), Output Voltage (Vdc ) And Its Reference (V _ Dc ), Grid Current Error (X1), Output Voltage Error (X2), And Capacitor Voltages (Vc1 And Vc2) For A Step Change In &1 From 1 To 20 When Le D L.

 

Figure 6. Waveforms Of Grid-Voltage (Eg), Grid Current (Ig) And Its Reference (I_ G ), Output Voltage (Vdc ) And Its Reference (V _ Dc ), Resistive Load Current (Ir ), And Capacitor Voltages (Vc1 And Vc2) For A Step Change In V _ Dc From 250v To 300v Under Resistive Load R D 25.

Figure 7. Waveforms Of Grid-Voltage (Eg), Grid Current (Ig) And Its Reference (I_ G ), Output Voltage (Vdc ), Resistive Load Current (Ir ), Cpl Current (Icpl), Total Load Current (Il), And Capacitor Voltages (Vc1 And Vc2) For A Step Change In: (A) R From 100 To 50, (B) Cpl From 0.625kw To 1.25kw.

  

Figure 8. Waveforms Of Grid-Voltage (Eg), Grid Current (Ig) And Its Reference (I_ G ), Output Voltage (Vdc ) And Its Reference (V _ Dc ), Cpl Current (Icpl), And Capacitor Voltages (Vc1 And Vc2) For A Step Change In V _ Dc From 250v To 300v Under Cpl.

CONCLUSION:

This paper presented a robust PBC strategy for single-phase three-level T-type rectifiers feeding resistive and constant power loads. It is pointed out that both dc output voltage and grid current of the rectifier can be controlled if the damping injection is applied to the grid current only. It is shown that the proposed PBC strategy possesses strong robustness to variations in the inductance when the damping gain is selected in accordance with the grid current transfer function magnitude. The performance of the proposed PBC strategy is investigated by experimental studies during steady-state and transients caused by the load and reference voltage changes under undistorted and distorted grid voltage conditions and variations in inductance. It is shown that the dc output voltage is regulated at its reference value, and grid current tracks its reference in all conditions, particularly under constant power load, which may endanger the stability of the system due to the negative resistance characteristic.

REFERENCES:

[1] M. P. Kazmierkowski, L. G. Franquelo, J. Rodriguez, M. A. Perez, and J. I. Leon, ``High-performance motor drives,'' IEEE Ind. Electron. Mag., vol. 5, no. 3, pp. 6_26, Sep. 2011.

[2] S. Vazquez, S. M. Lukic, E. Galvan, L. G. Franquelo, and J. M. Carrasco, ``Energy storage systems for transport and grid applications,'' IEEE Trans. Ind. Electron., vol. 57, no. 12, pp. 3881_3895, Dec. 2010.

[3] F. Blaabjerg, M. Liserre, and K. Ma, ``Power electronics converters for wind turbine systems,'' IEEE Trans. Ind. Appl., vol. 48, no. 2, pp. 708_719, Mar./Apr. 2012.

[4] X. Liu, P. C. Loh, P. Wang, and F. Blaabjerg, ``A direct power conversion topology for grid integration of hybrid AC/DC energy resources,'' IEEE Trans. Ind. Electron., vol. 60, no. 12, pp. 5696_5707, Dec. 2013.

[5] G. Wang, G. Konstantinou, C. D. Townsend, J. Pou, S. Vazquez, G. D. Demetriades, and V. G. Agelidis, ``A review of power electronics for grid connection of utility-scale battery energy storage systems,'' IEEE Trans. Sustain. Energy, vol. 7, no. 4, pp. 1778_1790, Oct. 2016.