Proposed Space Vector Modulation Research Articles

Hybrid matrix converter for grid connected multiphase wind generation

ABSTRACT This paper presents a novel multiphase hybrid matrix converter topology dedicated to grid-connected five-phase wind generation. The proposed converter, named Five-phase Ultra-Sparse Series Z-source Matrix Converter (FUSSZMC), aims to facilitate the integration of the five-phase wind turbine generators. This is done by taking into account the improvement of the injected power quality and allowing the fixed output converter voltage level to that of the grid, thanks to the use of the series Z-source, under the variable voltage magnitude of the wind turbine generator, which depends on the wind speed. The proposed space vector modulation as a control strategy for FUSSZMC was detailed, where it was demonstrated that a suitable use of both large and small current vectors improves the input current waveforms. The global model of the proposed system was tested by simulation under Matlab/Simpowersys environment. The obtained results demonstrate clearly the advantages of using FUSSZMC and its modulation strategie. These benefits includea good input and output current waveforms, as reflected by the obtained total harmonic distortion (THD) values, that fall within the range prescribed by international standards. Additionally, FUSSZMC is capable of operating with unity input power factor, regulating input voltages and improving the quality of injected power into the grid.

Design and Xilinx Virtex-field-programmable gate array for hardware in the loop of sensorless second-order sliding mode control and model reference adaptive system–sliding mode observer for direct torque control of induction motor drive

This article aims first to propose an improved space vector modulation–direct torque control in order to enhance the induction motor performance using: (1) a super-twisting controller and (2) a novel model reference adaptive system based on a sliding mode observer. Second, due to the complexity of the suggested control algorithm, this article deals also with a hardware implementation on a field-programmable gate array board. Indeed, the field-programmable gate array is mainly chosen to reduce the execution time, thanks to its parallel processing which significantly improves the quality of the control system by reducing the sampling period, and consequently the delays in the control loop. Besides, the super-twisting controller is proposed to enhance the speed regulation loop which is a second-order sliding mode control technique that uses a continuous control law to prevent the chattering phenomenon induced by the first-order sliding mode control technique. Moreover, the high performance control requires information about the rotor speed which can be obtained by a sensor. Generally, the use of the speed sensor increases the system cost and size, and reduces its system reliability. Therefore, a combination between a model reference adaptive system observer and a sliding mode observer is suggested for speed estimation and overcoming the sensitivity of the classical model reference adaptive system observer against uncertainties and stator resistance variations. The performance of the proposed space vector modulation--direct torque control--super-twisting controller with the model reference adaptive system--sliding mode observer algorithm of an induction motor is verified through simulation, hardware co-simulation and experimental validation utilizing a field-programmable gate array Virtex-5-ML507 board. The performance of the suggested sensorless control method is compared also with other recent published schemes.

Modulation Technique for Modified Active Quasi-Z-Source Inverter with Common-Mode Voltage Reduction

In Z-source topologies, a high-amplitude common-mode voltage can occur when shoot-through states are inserted. In this study, a new space vector pulse-width modulation for an active quasi-Z-source topology is proposed to operate at a high modulation index and reduce the common-mode voltage to one-third of the DC-link voltage. Moreover, the quality of the output voltage is improved by operation with a high modulation index and decreasing the switching loss of the H-bridge switches. The detailed operating principles of the active quasi-Z-source topology using the proposed space vector modulation (SVM) method are presented. A simulation model was built, and an experimental prototype was verified to correct the theoretical analysis.

Space-vector modulation for three-phase indirect matrix converters to reduce common-mode voltage

This paper presents a space vector modulation strategy for a three-phase indirect matrix converter to reduce the common-mode voltage and maintain the output performance. To reduce the peak value of the common-mode voltage to 57.7% of the input phase voltage, three active voltage vectors are used to generate the desired output voltage with arbitrary amplitude and frequency, instead of using both active and zero voltage vectors as in the traditional space vector modulation strategy. Although the common-mode voltage is reduced, the output waveform quality of the three-phase indirect matrix converter deteriorates due to the absence of the zero voltage vectors. To overcome this problem, the proposed space vector modulation strategy is redesigned to control the rectifier stage of the indirect matrix converter by utilizing three active current vectors instead of two as usual. Consequently, the constant average dc-link voltage is achieved, which can improve the output performance in terms of the output voltage and current harmonic distortion. The simulation is implemented by PSIM software and experimental results are provided to verify the effectiveness of the proposed space vector modulation strategy.

Coupled Three-Phase Converter Concept and an Example: A Coupled Ten-Switch Three-Phase Three-Level Inverter

The bridge arms of traditional three-phase multilevel converters are independent of each other; thus, more active switches and passive diodes are required. In order to reduce the number of devices, a coupled three-phase converter architecture, which is suitable for both dc-ac and ac-dc converters, is presented. Based on this architecture, a ten-switch three-phase three-level (10S-3P-3L) inverter is proposed in this article. The proposed topology employs only ten active switches and no additional diodes, which helps to cut size, weight, and costs of system. The proposed space vector modulation enables 10S-3P-3L inverter to operate full modulation indexes. A comparison between the proposed inverter with some existing topologies in terms of device voltage and current stresses, conduction loss, switching loss, and other parameters is made to highlight its excellent performance. Moreover, the experimental results from a 3-kW experimental prototype reveal that the proposed inverter offers superior power quality.

Analysis and Reduction of Stator Copper Losses in Three-phase Four-switching Inverter-fed SPMSM Drives Using Space Vector Pulse-width Modulation

In consideration of cost reduction, three-phase four-switch (TPFS) converters are applied in permanent magnet synchronous motor/generator (PMSM/G) drive application. However, the reduced number of active vectors has a negative influence on the signal waveform and the stator copper losses. With respect to the stator copper loss reduction, the root-mean-square (RMS) value of the stator copper loss ripple is chosen as a performance criterion in this paper. It is proved in this paper that the stator current ripple plays a more important role than the equivalent resistance in the copper loss ripples by double Fourier integral analysis. Thus, the RMS value of the stator current ripple can be applied as an analytical approach to evaluate the stator harmonic copper losses of the two proposed space vector modulation (SVM). Consequently, the proposed SVM strategy realizes the high-frequency stator copper loss ripple reduction. The experimental results demonstrate the validation of the proposed analysis.

Space vector modulation‐included commutation method for voltage source‐type isolated three‐phase/single‐phase matrix converter

This paper proposes a control strategy for voltage source‐type isolated AC/DC matrix converter. In this paper, differences of control strategy between a current source‐type and a voltage source‐type isolated AC/DC matrix converter are discussed by using instantaneous space vector diagrams. In addition, a commutation scheme of the voltage source‐type isolated matrix converter is proposed. The operation of proposed space vector modulation and commutation method is confirmed by the simulation results. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Control Strategy for Single-Phase Transformerless Three-Leg Unified Power Quality Conditioner Based on Space Vector Modulation

The unified power quality conditioner (UPQC) is known as an effective compensation device to improve PQ for sensitive end-users. This paper investigates the operation and control of a single-phase three-leg UPQC (TL-UPQC), where a novel space vector modulation method is proposed for naturally solving the coupling problem introduced by the common switching leg. The modulation method is similar to the well-known space vector modulation widely used with three-phase voltage source converters, which thus brings extra flexibility to the TL-UPQC system. Two optimized modulation modes with either reduced switching loss or harmonic distortion are derived, evaluated, and discussed, in order to demonstrate the flexibility brought by the space vector modulated TL-UPQC. Simulations and experimental results are presented to verify the feasibility and effectiveness of the proposed space vector modulation approach as well as two mentioned modulation modes.

Digital Implementation of DSVPWM Control for EV fed through Impedance Source Inverter

<p>In this paper, a new space vector modulation technique is proposed for speedcontrol of Induction Motor using Z-source inverter powered by a low voltage DCsource. The zero states of conventional space vector modulation is used for boosting the DC link voltage to the required level. The proposed SVM techniqueestimates the required shoot through period of the Z-source inverter to maintainthe DClink voltage constant at the desired level through capacitor voltage control.A 32 bit DSP (TMS320F28335) is used to implement the proposed space vectormodulation method. The power structure and the modulation technique is wellsuited for electric vehicle application.</p>

Control and DC-capacitor voltage balancing of a space vector-modulated five-level STATCOM

A space vector modulation (SVM)-based switching strategy for a five-level diode-clamped converter that is adapted as a static compensator (STATCOM) is presented. The main feature of the proposed SVM switching strategy is that it enables voltage-balancing of the DC capacitors, under steady-state and transient conditions, with no requirements for additional control actions or auxiliary devices. A dynamic model of the five-level STATCOM for power system studies is also developed. On the basis of the developed model, a voltage controller to regulate the DC-side voltage and a decoupled current controller to control the AC-side real and reactive power are designed. Performance of the STATCOM and the corresponding controllers are evaluated on the basis of digital time-domain simulation studies in the PSCAD/EMTDC environment. The studies demonstrate capabilities of the proposed space vector modulation (SVM) strategy to maintain voltage balance of the DC capacitors and control the STATCOM reactive power exchange for various operating conditions.

Speed Control of a Three-Phase Induction Motor Based on Robust Optimal Preview Control Theory

A synthesized method for speed control of a three-phase induction motor (IM) based on optimal preview control system theory is implemented in this article. An IM model comprises three-input variables and three-output variables that coincide with the synchronous reference frame that is implemented using the vector method. The input variables of this model are the stator angular frequency and the two components of the stator space voltage vector, whereas the output variables are the rotor angular speed and the two components of the stator space flux linkage. The objective of the synthesized control system is to achieve motor speed control, field orientation control, and constant flux control. A novel error system is derived and introduced into the control law to increase the robustness of the system. The preview feed-forward controller, which includes the desired and disturbance signals, is used to improve the transient response of the system. A space vector pulse-width modulation (PWM) control technique for voltage source-fed IM is prepared for microprocessor-based control. Spectral analysis of the output voltage is evaluated to predict the effect of the proposed space vector modulation technique on the dynamic performance of the IM. The optimal preview controlled system is implemented, and its applicability and robustness are demonstrated by computer simulation and experimental results.

A novel modulation technique for a single phase H-bridge inverter

In this paper a novel space vector modulation method for single-phase inverters is presented. Mathematical analysis, simulation and comparison of conventional sinusoidal pulse width modulation (SPWM) techniques with the proposed space vector modulation for single-phase inverter are included. These modulation techniques are compared, evaluated and classified for different single-phase applications, including deadband effects. The proposed modulation method combines the flexibility of the well-known unipolar PWM scheme for single-phase inverters result in maximum harmonic mitigation. The new technique is suitable for simple digital implementation. Experimental results, obtained by a digital signal processor (DSP) board, are included.