Space Vector PWM Algorithm Research Articles

Digital control system design and analyses of a 3-phase bearingless induction motor

The overall conguration of a magnetic suspension decoupling control system is designed to realize the reliable digital control of a 3-phase bearingless induction motor whose rotor windings are not pole-specic. Based on a digital signal processor complementary metal-oxide semiconductor chip, the digital control hardware and software systems are analyzed and designed. In this paper, the calculation and regulation of the motor rotational speed, correction and regulation methods of the radial displacements, calculation and compensation algorithms of the unilateral magnetic pulls, induction compensation algorithm of the eective suspension control current, current regulation, and space-vector pulse width modulation algorithms, are presented in detail. The experimental results verify the feasibility and practicability of the designed decoupling digital control system of the 3-phase bearingless induction motor.

Relationship between two‐level space‐vector pulse‐width modulation and carrier‐based pulse‐width modulation in the over‐modulation region

For low voltage motor drive applications, in order to enhance the utilisation rate of dc bus voltage and extend the operating boundary of induction motors, the modulation index is often extended from the linear modulation region to the over-modulation region. The relationship between two-level space-vector pulse-width modulation (SVPWM) and carrier-based pulse-width modulation (CBPWM) in the linear modulation region has been widely investigated and it was shown that the conventional SVPWM is a special type of CBPWM algorithm with zero sequence components injection. On the basis of that, this study focuses on investigating their relationship in the over-modulation region. Firstly, the superposition principle is adopted to analyse the features of SVPWM algorithm in the over-modulation region. Second, the modulating functions of CBPWM equivalent to SVPWM in the over-modulation modes I and II are derived, respectively, which are on the basis of the CBPWM regular sampling rule. Theoretical analysis shows that SVPWM is a special type of CBPWM algorithm not only in the linear modulation region but also in the over-modulation region, which provides a bidirectional bridge for the transformation between SVPWM and CBPWM in the full modulation region. Finally, the validity and effectiveness of the theoretical analysis are verified by simulation and experimental results.

Application of SVPWM Convertor in the Distributed Wind Power System

The capacity of good input/output characteristics and energy bi-directional flow was required for excitation power in distributed wind power system. This paper analyzed the basic principle of voltage and current double closed loop control strategy, and expounded voltage space vector pulse width modulation (SVPWM) technology based on the topological structure of three-phase voltage convertor. It also established the SVPWM algorithm and the convertor model in the Matlab/Simulink, and conducted the simulation research for the distributed wind excitation power supply with this algorithm. The theory analysis and simulation results indicated that this SVPWM convertor is feasibility and superiority in this field.

A Neural Network Based Space-Vector PWM Controller for Motor Drive

This paper proposed an artificial neural network (ANN) based space vector pulse width modulation (SVPWM) for motor drive which fully covers the undermodulation and overmodulation regions. A neural network has the advantage of very fast implementation of an SVPWM algorithm that can increase the converter switching frequency, particularly when a dedicated application-specific integrated circuit chip is used in the modulator. Finally, in the environment of MATLAB/Simulink with the Neural Network Toolbox builds the simulation model of system with proposed ANN-SVPWM controller. The simulation results show that the performances of the motor drive with artificial-neural-network-based SVPWM are excellent.

A New SVPWM Dead-Time Compensation Strategy for Low Speed Direct-Drive Motor

Traditional space vector pulse-width modulation (SVPWM) algorithm included complex calculations like triangle functions and square root, which increased execution time of the program. A novel SVPWM algorithm calculating modulation functions of three phases through stationary αβ components of reference voltage vectors was proposed here to solve the problem, which was composed of only simple four arithmeticoperations. The method simplified traditional SVPWM and improved real-time performance of digital control system. However, dead-time effect still existed in novel SVPWM algorithm. And it will lead to distortions of low speed direct-drive PMSM phase currents, brought increase of speed fluctuation, resulted in unstable operating of servo system. This paper analyzed details of error voltage vectors led by dead-time effect, researched relationship between error voltage vectors and polarities of three phase currents, and put forward a novel dead-time compensation strategy that decreased influence of zero current clamping. Simulation results showed that this strategy can effectively compensate effects of dead-time error voltage vector and improve wave forms of phase currents, which increased operating performance of low speed direct-drive PMSM.

Space Vector PWM With Reduced Common-Mode Voltage for Five-Phase Induction Motor Drives Operating in Overmodulation Zone

This study presents a space vector pulsewidth modulation algorithm for five-phase converters operating in the overmodulation region that forbids the use of zero vectors, covering the whole overmodulation range and providing minimum <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> - <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i> voltages. Avoiding zero vectors reduces the content of low-order current harmonics and, at the same time, reduces the common-mode voltage (CMV) by 40%. The method is first implemented using medium and large voltage space vectors, showing good performance in terms of current harmonic content. Then, the algorithm is applied to the case when four large vectors are used, further reducing the peak-to-peak CMV by 80% and still demonstrating a satisfactory performance. Both methods are experimentally compared to existing overmodulation algorithms obtaining better current quality and lower peak-to-peak CMV.

FPGA Based Optimized Discontinuous SVPWM Algorithm for Three Phase VSI in AC Drives

The discontinuous space vector pulse width modulation (SVPWM) has well-known that can reduce switching losses. By simplifying the thermal management issues, the discontinuous SVPWM can potentially reduce the inverter size and cost. However, using the modulation due to different time interval equations for each sector can introduce glitches at the points when the sector is changed. The more main problem, it can increase unwanted harmonic content and current ripple. Consider the decrease in switching losses associated with discontinuous modulation allows the system to utilize a higher switching frequency, this paper present high frequency switching of optimized discontinuous SVPWM based on FPGA to overcome the problems above. The proposed SVPWM has been successfully implemented by using APEX20KE Altera FPGA to drive on a three phase inverter system with 1.5 kW induction machine as load. The results have proved that the method can reduce harmonic content and current ripple without glitches. DOI : http://dx.doi.org/10.11591/ijpeds.v3i1.735

Simulation and an experimental investigation of SVPWM technique on a multilevel voltage source inverter for photovoltaic systems

This paper presents a space vector pulse width modulation (SVPWM) control for a three-phase five-level diode clamped multilevel inverter (DCMLI) for photovoltaic (PV) systems. SVPWM algorithm uses a simple mapping to generate gate signals for the inverter. The location of the reference vector and time are easily determined. The maximum power point tracking (MPPT) is capable of extracting maximum power from PV array connected to each DC link voltage level. The MPPT algorithm is solved by fuzzy logic controller. A digital design of a generator SVPWM using hardware description language (VHDL) is proposed and implemented on a field programmable gate array (FPGA). This is done to achieve high dynamic performance with low total harmonic distortion (THD). Simulation and experimental results are given to verify the implemented SVPWM control in terms of THD. The results are compared with conventional sinusoidal pulse width modulation (SPWM) in terms of lower THD is obtained. Finally, the implementation on a FPGA is tested in a laboratory with a real prototype using a three-level three-phase voltage source inverter. Experimental results are presented to verify the effectiveness and accuracy of the proposed system. This scheme can be easily extended to an n-level inverter for PV system.

A Vector Space Decomposition Based Space Vector PWM Algorithm for a Three-Level Seven-Phase Voltage Source Inverter

This paper presents a novel modulation strategy for a seven-phase three-level inverter, aimed at variable-speed drive applications. Developed space vector pulsewidth modulation (SVPWM) strategy is based on vector space decomposition (VSD) approach and an analysis of multidimensional space vector projections in mutually orthogonal planes. The algorithm represents an extension of a recently developed five-phase three-level SVPWM algorithm and is considerably more complex, due to the existence of three mutually orthogonal planes in a seven-phase system. The difficulties of generalization of space vector strategies, which stem from the nature of the multiphase systems, are highlighted. Increasing the number of phases from five to seven increases the number of switching states from 35 = 243 to 37 = 2187 and the number of orthogonal planes from two to three. This considerably affects the complexity of the offline calculations. However, the final implementation of the algorithm is simple. Developed SVPWM algorithm is compared to an equivalent carrier-based strategy and it is shown that they yield identical performance. The complexity of the algorithms for real-time implementation is compared. Simulation and experimental results, obtained using neutral-point clamped inverter, verify the theoretical developments.

Space vector pulse‐width modulation algorithm and DC‐side voltage control strategy of three‐phase four‐switch active power filters

A space vector pulse-width modulation (SVPWM) algorithm and a DC-side voltage control strategy for three-phase four-switch shunt active power filters are proposed. The basic principle of three-phase four-switch inverters to output three-phase balanced voltages is investigated in detail. Based on an advanced coordinate transformation, the proposed algorithm ensures basic voltage vectors to be right on the coordinate axes of αβ-coordinate system, which has the advantages of less computation and higher accuracy than the traditional. It synthesises zero vectors by equalising the duration time of two basic voltage vectors, which are equivalent in amplitude and opposite in phase, to simplify control logic and decrease harmonics of output voltages. To stabilise the DC bus voltage and balance the DC-side capacitor voltages, a DC-side voltage control strategy is presented. The former objective is obtained by controlling the active partition of the output currents, and the latter one by adapting the direct partition of phase C output current. An overall control method combining the proposed SVPWM algorithm with the DC-side voltage control strategy is presented. Experimental results have shown the validity and feasibility of the proposed algorithm and strategy.

Improved space vector PWM algorithm for three-level voltage source inverter in overmodulation region

In high power high performance AC drive industrial applications, multilevel inverters have established their importance, as they can synthesise output waveform with improved harmonic spectrum. In this paper, an improved synchronisation and symmetrical SVPWM algorithm is proposed for three-level inverter in overmodulation region for better utilisation of DC bus and to reduce harmonic distortion. The performance analysis of the proposed algorithm is compared with SHEPWM and STPWM for three-level voltage source inverter in terms of THD of line voltage and motor current along with fundamental component of the line voltage. It is shown that the proposed algorithm gives improved results compared to SHEPWM and STPWM algorithms. The algorithm is also verified experimentally on a constant v/f drive fed from IGBT-based voltage source inverter using Motorola power PC (MPC8240) based embedded controller.

FPGA based multilevel cascaded inverters with SVPWM algorithm for photovoltaic system

This paper presents the control for three-phase multilevel cascaded H-bridge inverter for photovoltaic (PV) system. The maximum power point tracking (MPPT) is capable of extracting maximum power from the PV array connected to each DC link voltage level. The MPPT algorithm is solved by perturbation and observation method (P&O). Space vector pulse width modulation (SVPWM) algorithm uses a simple mapping to generate gate signals for the inverter. The location of the reference vector and time are easily determined. The adjustments of modulation index and phase angles are synthesized onto field programmable gate array (FPGA) by means of hardware description language (VHDL). A digital design of the generator SVPWM using VHDL is proposed and implemented on FPGA. This is done to achieve high dynamic performance with low total harmonic distortion (THD). Simulation and experimental results are given to verify the implemented SVPWM control for PV system in terms of THD.

Synchronized SVPWM Algorithm for the Overmodulation Region of a Low Switching Frequency Medium-Voltage Three-Level VSI

In high-power applications, the output voltage of a voltage source inverter (VSI) must be synchronized with its fundamental component in order to eliminate subharmonics. With proper selection of switching states, it is possible to obtain synchronization and symmetry in the space vector pulse width modulation (SVPWM) algorithm. This paper presents an improved three-level SVPWM algorithm for the overmodulation region, which guarantees synchronization, half-wave symmetry, quarter-wave symmetry, and three-phase symmetry for all integer values of the pulse number. The proposed synchronized SVPWM algorithm is experimentally verified. The performance of the proposed algorithm is compared with other conventional algorithms. The comparative results prove that the consideration of synchronization and various symmetry results in better performance of the VSI.

Development of a Grid-Connected Wind Generation System With a Modified PLL Structure

This paper presents the development of a single-phase grid-connected wind energy conversion system (WECS) that uses a modified PLL. The WECS development is based on the use of the low cost 30 MIPS Digital Signal controller (DSC) dsPIC30f3011. The modified single-phase PLL is based on the PQ theory, where a lag structure based on an integrator is proposed instead of a conventional lag structure. The voltage source inverter (VSI) is driven by a Space Vector Pulse Width Modulation (SVPWM). The maximum power transfer is achieved by using a Maximum Power Point Tracking (MPPT) algorithm based on the steepest ascent method. The tasks related to the SVPWM algorithm, the PLL, the MPPT algorithm, and the monitoring of the DC voltage were successfully implemented in the DSC.

Space Vector PWM Technique for a Three-to-Five-Phase Matrix Converter

Variable-speed multiphase (more than three phases) drive systems are seen as serious contenders to the existing three-phase drives due to their distinct advantages. Supply to the multiphase drives is invariably given from a voltage source inverter. However, this paper proposes an alternative solution for supplying multiphase drive system using a direct ac-ac converter called a matrix converter. This paper proposes the pulsewidth modulation (PWM) algorithm for the matrix converter topology with three-phase grid input and five-phase variable-voltage and variable-frequency output. The PWM control technique developed and presented in this paper is based on space vector approach. This paper presents the complete space vector model of the three-to-five-phase matrix converter topology. The space vector model yield 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> total switching combinations which reduce to 243 states considering the imposed constraints, out of which 240 are active and 3 are zero vectors. However, for space vector PWM (SVPWM) implementation, only 90 active and 3 zero vectors can be used. The SVPWM algorithm is presented in this paper. The viability of the proposed solution is proved using analytical, simulation, and experimental approaches.

Design of New Frequency Converter Based on TMS320LF2407A

In order to improve voltage utilization ratio and dynamic performance of frequency converter, this paper presents a digital frequency converter design scheme based on digital signal processor TMS320LF2407A and the theory of space vector pulse width modulation (SVPWM) technology, provides its detailed design measures of software and hardware and SVPWM algorithm realization methods. The experimental results prove that this new frequency converter has simple structure, high control precision, higher voltage utilization ratio, better dynamic and static property.

A General Space Vector PWM Scheme for Multilevel Inverter

This paper introduces a simple space vector PWM algorithm for a cascaded multilevel inverter. The scheme determines the location of the reference vector easily. It uses space state equation to get the value of vector. A cascaded thirteen-level inverter is used to explain the scheme. The scheme can be easily extended to n-level inverter. It is applicable to cascaded multilevel high voltage inverter and cascaded active compensation device. The result of simulation verifies that the scheme is useful in improving utilization of the direct current (dc) link voltage and reducing THD.

Simple and Novel Hybrid Random PWM Algorithm for DTC-Induction Motor Drive for Reduced Acoustical Noise

A simple and novel hybrid random PWM algorithm for direct torque controlled induction motor drive for reduced acoustical noise and harmonic distortion is presented in this paper to reduce the complexity of the classical space vector approach. The proposed algorithm is developed by using the imaginary switching times, which does not require angle and sector information. In order to get the randomization effect, the proposed algorithm uses discontinuous pulsewidth modulation maximum (DPWMMAX) algorithm in conjunction with the space vector pulsewidth modulation (SVPWM) algorithm. The harmonic analysis of the two switching sequences is carried out and by comparing each other in each sampling time interval, the proposed algorithm selects a suitable switching sequence. In the proposed algorithm by changing the factor  , the switching sequences of SVPWM and DPWMMAX algorithms are generated. The proposed PWM algorithm uses 0127 and 721 sequences when  value takes 0.5 and 0 respectively. As the zero state time is varied randomly according to the operating sequence, randomization effect will occur, which results in reduced dominating harmonics and hence gives reduced acoustical noise. To validate the proposed PWM algorithm, the numerical simulation studies have been carried out and results are presented and compared. The simulation results confirm the effectiveness of the proposed algorithm.

Simplified multilevel space vector pulse-width modulation scheme based on two-level space vector pulse-width modulation

A novel simplified multilevel space vector pulse-width modulation (SVM) scheme is proposed based on the two-level SVM. The voltage vectors with same amplitude and phase angle are applied to the various power units of cascaded multilevel inverter (CMLI), and the refresh times of various vectors are delayed in order, thus the corresponding multilevel output voltage waveform is formatted. During every sampling period, only the on-times of main and auxiliary voltage vectors of one-stage unit are calculated based on a two-level SVM algorithm, so the computational complexity is independent on the unit-cascaded number. Then the algorithm is simplified, and the expandability is enhanced. The simulation and experimental results prove the validity and feasibility of the novel scheme.

A new simplified SVPWM algorithm based on modified carrier signal

This paper presents a simplified algorithm of space vector pulse width modulation (SVPWM) for a two-level three-phase inverter, which can operate in undermodulation and overmodulation modes. In other simplifications founded in literature, the reference voltages are modified and compared with a triangular carrier to estimate the switching states of the inverter. However, this paper proposes the modification of the carrier signal instead of the references. This procedure reduces the number of mathematical operations and increases the execution speed of SVPWM algorithm in DSPs or FPGAs. The reference voltages are sinusoidal, even for overmodulation mode. Simulation and experimental results proves that the proposed simplification produces the same switching patterns than conventional SVPWM, is simpler and is faster than other simplifications.