Space Vector Modulation Algorithm Research Articles

Methods, Techniques, and Algorithms of Synchronous Multi-Zone Modulation of Signals of Voltage Source Inverters (literature review)

This publication provides a brief overview of the results of research work in the field of developing alternative methods, schemes, and algorithms of synchronous multi-zone modulation of signals of inverters of power conversion systems with reduced switching frequency of power switches. In particular, in the mentioned researches, the basic strategies, schemes, and algorithms of synchronous multi-zone modulation have been fur-ther developed, modernized, modified, and disseminated in relation to new promising topologies of power conversion systems, including: two-inverter-based electric drives with open windings of electrical motor; drive systems based on electric motor with two stator windings; dual three-phase electric drives of symmetrical and asymmetric type; five-phase power conversion systems, powerful six-phase systems based on four inverters, and two-inverter-based and three-inverter-based photovoltaic installations with multi-winding transformer. It is shown that the developed schemes and algorithms of synchronous space-vector modulation applied for control of inverter-based systems provide continuous synchronization and symmetry of the basic voltage waveforms of systems during the whole control range. It provides minimization of even harmonics and undesirable subhar-monics (of the fundamental frequency) in spectra of the basic voltages of systems, leading to reducing of losses in systems and to increasing of its efficiency. Based on a comparative analysis of the integral spectral character-istics of the phase and line voltages of the systems, recommendations are formulated for the rational choice of schemes and algorithms of synchronous modulation for the relevant installations, depending on the modes of their operation.

Enhanced deadbeat predictive current control with novel generalized space vector modulation for five‐level inverter fed permanent magnet synchronous motor drive with reduced torque ripples and less computational burden

SummaryTraditional electric drive control methodologies, such as field oriented control (FOC) and direct torque and flux control (DTFC), predominantly rely on multiple proportional‐integral (PI) controllers that demand complex tuning. While model predictive current control (MPCC) omits PI controllers, it has inherent challenges including high computational burden and tempered dynamics. Although two‐level inverters (2LI) are prevalent in many applications, their performance wanes in high‐power applications like high performance industrial drives and marine propulsions. Multilevel inverters (MLIs) are more efficient, but combined with space vector modulation (SVM), they add computational complexity, particularly at higher levels, limiting drive sampling frequencies and causing torque ripples and harmonics, affecting performance. To address the above drawbacks, this manuscript presents a deadbeat predictive current control of five‐level inverter fed permanent magnet synchronous motor (PMSM) drive with a novel generalized SVM algorithm with reduced computational burden and improved performance. The proposed method is validated through MATLAB/Simulink‐based simulation study and experimental implementation. The results are presented and discussed. The results are compared with DTFC and MPCC where it is observed that the proposed method offers superior performance with reduced computational burden and streamlined implementation.

Space-vector Modulation Algorithms and Base Vectors of a Seven-phase Motor Winding

Space-vector Modulation Algorithms and Base Vectors of a Seven-phase Motor Winding

Моделирование динамических режимов работы электроприводов с системой векторного управления синхронным двигателем

Purpose: The purpose of the work is a comparative assessment of dynamic processes in electric drives with a vector control system for permanent magnets synchronous motors and various methods of stator voltage modulation. To achieve this purpose, a mathematical description of a synchronous motor in a rotating dq coordinate system is given, and a mathematical model of a vector control system is developed. The model of the vector control system takes into account the decoupling of stator current control loops and proposes two options for generating a current reference along the d-axis, ensuring the efficiency of energy conversion processes at rotation speeds below the nominal value, depending on the design of the motor rotor. Algorithms for scalar pulse-width and space-vector modulation of motor stator voltage for a frequency converter with a two-level autonomous voltage inverter are presented. Methods: When developing mathematical models and algorithms, methods from the theory of electric drive and the theory of automatic control have been used. The developed mathematical models and algorithms are implemented in the Matlab Simulink software package. Results: The results of modeling dynamic processes in electric drives (mechanical characteristics, stator currents, stator current total harmonic distortion) are presented, which have shown the performance of the developed models and algorithms. Practical significance: The choice of modulation type does not affect the mechanical characteristics of the electric drive, but does affect the harmonic composition of the stator current. The greatest effect from the use of space-vector modulation algorithms is manifested at reduced values of the frequency of the stator current and partial load torque on the rotor shaft.

Harmonic Current Control of OW-PMSM for Low-Voltage Traction by Nonlinear Disturbance Rejection With Improved Modulation Scheme

The open-winding permanent magnet synchronous motor (OW-PMSM) has been developed, mostly potential for low-voltage traction in electric vehicles. Yet, both the disturbance from vehicle system under driving and the motor with low-reactance (LR) feature expose the limits of traditional controllers that are prone to great current harmonics. Therefore, the current control for LR OW-PMSM becomes challenging. The main objective of this research is to provide a current harmonic control strategy for LR OW-PMSM by the nonlinear lumped disturbance observer (NLDO) combined with improved space vector modulation (SVM) scheme. The existence of nonlinear, unknown, unmodeled factors has been confirmed by current measurement and harmonic analysis in full operation range, and thus is considered in proposed controllers. The NLDO is designed for all the three axes under the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> 0 frame. The SVM algorithm is adjusted to two switching patterns in order to get widened linear voltage modulation range. In addition, in the 3-D voltage space is the possible modulation area investigated. Ultimately, the target LR OW-PMSM has been designed, prototyped, and tested. The proposed NLDO, juxtaposed with ordinary PI and deadbeat controllers, reduces current harmonics on both the motor and inverter sides, possesses high robustness, and is practical for LR motors, according to experimental results.

Improved space vector modulation algorithm of 5-level three-phase z-source based cascaded inverter

The integration of a Z-source network with a 5-Level three-phase inverter based cascaded to provide voltage step-up function is proposed in this paper. The system is controlling by an improved space vector modulation (SVM) the implantation of algorithm and innovative virtual automated solutions can be considered, very fast and very simple. The main objective of the proposed system is to achieve an output voltage twice the applied input voltage, and to eliminate the largest amount of excess harmonic. This proposed model is characterized by the ease of boosting the output voltage twice the input voltage, depending on the characteristics of the Z-source network without the need for a DC-DC rectifier. Furthermore, the proposed algorithm for this system is characterized by improving the output voltage and eliminating a large number of harmonics while greatly simplifying the calculations compared to its conventional SVM. This makes the proposed system and its algorithm an interesting alternative to classical systems and algorithms. The simulation was processed using MATLAB/Simulink. The results obtained prove and verify the effectiveness of the proposed system. From the results, of the output current total harmonic distortion (THD), it was reduced to 1.05% which is very low compared to the other algorithms in the literature.

Zero-Sequence Current Reduction Technique for Electrical Machine Emulators With DC Coupling by Regulating the SVM Zero States

In this article, a new zero-sequence current suppression technique for electrical machine emulators with reduced component count is proposed. The proposed control scheme is implemented by properly regulating the zero states in space vector modulation (SVM). It is well known that a machine emulator allows fast experimental validation of the control and design of a drive system without having a physical electrical machine, since the machine is replaced by another voltage-source converter and a three-phase inductor. However, in emulators with a coupled dc link, circulating zero-sequence current is freely developed creating additional load for the power switches. The currently available control methods require additional hardware common-mode filters to effectively reduce this current. Contrarily, the proposed SVM algorithm suppresses the zero-sequence current more effectively via direct compensation of common-mode voltage, and thus, no additional hardware filters are needed. Thus, an electrical machine emulator with less hardware requirements can be developed with the proposed control technique for being utilized in several laboratory test-bench applications. Experimental results on a 60-kW system validate the effectiveness of the proposed SVM algorithm, since the zero-sequence current amplitude has been measured to be 3.7% of the phase current or even less than this.

Synchronous Multi-Zone Modulation for Control of Inverter-Based Power Electronic Systems: Overview of Recent Research

This publication provides a brief overview of the results of recent research works by the author in the field of power electronics, carried out and published mainly in 2019–2021, and awarded with the Premium “Boris Lazarenko” of the Academy of Sciences of Moldova in the field of engineering. The methodological basis of those investigations is an original alternative method of the synchronous multi-zone space-vector modulation of signals of voltage source inverters as the main workhorses of adjustable speed electric drives and renewable energy systems. Therefore, basic strategies, schemes, and algorithms of synchronous multi-zone modulation have been further developed, modernized, modified, and disseminated for the control of novel promising topologies of power conversion systems for variable speed drives and for photovoltaic installations. It is shown that the developed schemes and algorithms of the synchronous space-vector modulation applied for control of inverter-based systems provide continuous synchronization and symmetry of the basic voltage waveforms of systems during the whole control range. It provides minimization of even harmonics and undesirable subharmonics (of the fundamental frequency) in spectra of the basic voltages of systems, leading to reducing the losses in the systems and to increasing their efficiency. Based on a comparative analysis of the integral spectral characteristics of the phase voltage of the systems, recommendations are formulated for the rational choice of schemes and algorithms of the synchronous space-vector modulation for the relevant installations, depending on the modes of their operation.

МОДЕЛИРОВАНИЕ ЭЛЕКТРОПРИВОДА ПЕРЕМЕННОГО ТОКА С АЛГОРИТМАМИ ПРОСТРАНСТВЕННО-ВЕКТОРНОЙ МОДУЛЯЦИИ

The relevance of investigation of induction motor electric drives with frequency converters having voltage source inverter with space-vector modulation is shown. The brief survey of researches of such matter is carried out. The aim of this article is to develop mathematical and computer model of frequency converter with space-vector modulation algorithms by means of Matlab Simulink, this model has to be implemented into the Matlab models of AC electric drives with induction and synchronous motors. To achieve such an aim, it needs to introduce techniques of electric drive theory, numerical techniques, techniques of algebraic equations system solution, techniques of computer simulation. The still two-phase framework is applied to describe the converter model. The two-level voltage source inverter is chosen for the investigation of modulation algorithms. To verify the mathematical model of space-vector modulation, the model of 5.5 kW induction motor is used. Induction motor and power switches are modelled by means of Matlab SimPowerSystems units. The results of simulation show the adequacy of the developed model in both steady state and transient modes. One can conclude the dependence of total harmonic distortion of the induction motor stator current from load torque, switching frequency of voltage source inverter’s power switches and stator current frequency for the electric drive with scalar control system.

Methods and techniques of synchronous multi-zone modulation for the control of power electronic converters

This paper presents a short survey of the results of elaboration and investigation of novel methods, schemes, and algorithms of synchronous multi-zone space-vector modulation of signals in power electronic converters of electrical energy parameters, focused on improvement of operation efficiency of converter-based transport-oriented electric drives and of photovoltaic power conversion systems, which were published mainly in the two-year period 2019–2020. These methods and algorithms of synchronous pulse-width modulation (PWM) allow providing continuous synchronization and symmetries of waveforms of the converters output voltage, with minimization of undesirable sub-harmonics in spectra of voltage and current, and also with minimization of undesirable common-mode voltage in electric transport systems and in photovoltaic systems, which leads to corresponding loss reduction and efficiency increasing of these systems.

Discontinuous Space Vector Modulation for Three-Phase Five-Levels Packed-U-Cell Converter

This article proposes an optimal 3D space vector modulation algorithm for the three-phase five-levels packed U-cell converter. The algorithm consists of selecting a common-mode voltage that results in discontinuous modulation, as a result, the reference voltage vector is clamped to the external faces of the 3D space vector diagram and there is always a phase that does not switch for a certain period. Hence, the search for nearest vectors is reduced to a 2D plane and there are no redundancies in the abc coordinates. Moreover, the switching sequence is defined online in order to reduce the converter phase voltage transitions while ensuring half-wave symmetry. In addition, a cost function is proposed to optimize the number of commutations and maintain the capacitor voltages balanced. The proposed algorithm presents advantages when compared to other strategies, such as low computational effort, reduced switching losses, and smaller capacitors. Simulation results demonstrate the good performance and effectiveness of the proposed modulation compared to works previously published in the literature. Finally, experimental results from 2-kVA three-phase five-levels packed-U-cell converter are given to support the theoretical developments.

Analysis of Current Error Space Phasor for a Space Vector-Modulated Indirect Matrix Converter

AC motor drives fed from current-controlled power electronic converters are popular on account of their superior steady-state and transient performance. Hysteresis control is a popular current control technique, which needs modifications to compensate for its demerits. Appraisal of current error as a space phasor for implementing the hysteresis controller is one such modification. Current error space phasor (CESP)-based hysteresis controller for voltage source inverters-fed motor drives are capable of achieving superior dynamic performance. With the modified hysteresis current controller, the drive operates at a constant switching frequency and ensures an optimal switching vector selection. This article presents the analysis of CESP for a space vector-modulated indirect matrix converter (IMC). The modified algorithm for space vector modulation of IMC accommodates for the variations in dc-link voltage since CESP is input voltage dependent. The boundary for the hysteresis current controller is calculated from the computed values of CESP. The time-varying nature of the hysteresis boundary ensures a constant switching frequency operation for IMC. Thus, a CESP-based hysteresis controller is proposed for the vector control of the IMC-fed permanent magnet synchronous machine (PMSM) drive. Experimental results are presented for validating the performance of the proposed controller.

A novel fast SVPWM method based on two-stage transformation for three-level inverter

Compared with the two-level inverter, the three-level inverter has excellent performance in pressure voltage switching loss and harmonic applied to the fields of the speed regulation and new energy generation. However, the computational complexity of the space vector pulse width modulation (SVPWM) method for multilevel inverter restricts the implementation on low cost microprocessor. This paper proposes a novel fast SVPWM method for three-level inverter to convert the space voltage vector in the three-level space to the two-level by vector subtraction with the central vector. The conduction time of each switch can be computed quickly so that the runtime is reduced significantly. Finally, the experimental results verify the effectiveness and practicability of the new space vector modulation algorithm based on two-stage transformation.

A generalized switching function-based SVM algorithm of single-phase three-leg converter with active power decoupling

In this paper, a generalized switching function-based space vector modulation (SVM) algorithm is presented and evaluated to minimize the dc voltage utilization and the ac utility grid current total harmonic distortion. This paper explores the control and modulation techniques of a single-phase three-leg converter with an active power decoupling method, where a generalized SVM algorithm is proposed and evaluated for easy implementation in a digital control platform. The active power decoupling method with the proposed converter can be achieved via dependent control and modulation techniques. The control method is separated into the ac active power control part and the dc power ripple control part, which can maintain a unity power factor at the ac utility grid and reduced the double-frequency ripple power effect on the dc-side. Simulation results validate the performance of the modulation algorithm and its control and demonstrate the feasibility of the proposed power converter, as well as the two mentioned operation modes of the power converter.

Simplified hybrid space vector modulation for multilevel diode clamped converter

This study proposes a new simplified hybrid space vector modulation (HSVM) algorithm for multilevel diode clamped converter (DCC). The main idea consists in combining the advantages of both space vector modulation (SVM) algorithms synthesised in abc and αβ coordinates to establish a new hybrid, simplified and generalised SVM algorithm. The HSVM algorithm offers a simple method to compute the duration time, automatic generation of all redundant states of the adjacent switching vectors without triangles identification stage and switching sequence definition for any DCC level. Moreover, all the computational processes are performed in one unique sector thanks to the proposed new reference voltage vector defined in abc-coordinates. The proposed algorithm does not require any coordinates transformation or lookup tables. Also, it can be implemented with minimum computational burden using a low resources digital platform. The proposed HSVM is verified through MATLAB simulation and validated experimentally using three-level DCC laboratory prototype. For high-level DDC, the HSVM is tested in real time using hardware-in-the loop testing technology. Different case studies are performed to demonstrate the high performance of the proposed HSVM and its ability in lowering the computational resources requirement.

Space Vector Modulation in the 45° Coordinates α′β′ for Multilevel Converters

Space vector modulation (SVM) strategy is widely used in two-level and three-level converters because of its advantages. However, the sector triangles, switching states, and switching sequences increase dramatically as the number of levels increases, which makes it difficult to implement the SVM algorithm in industrial applications of high-voltage and high-power multilevel converters. To extend the SVM strategy to high-voltage and high-power converters, a new SVM algorithm is proposed in this article with the 45° coordinates α'β'. In the α'β' coordinates, based on the relationship between the phase voltage and the line voltage of a star-connected converter, the reference vectors calculated from phase-voltage reference signals are directly used as line-voltage reference vectors. Moreover, two line-voltage levels are used as two components of the space vector, with the sum of these two components being the third line-voltage level. These three components are directly used as the switching state signals of the control line voltages. The proposed method avoids the 2/3 conversion that must be completed in the conventional SVM algorithm and does not need to calculate redundant switching states. It greatly simplifies the SVM algorithm and ensures that the common-mode voltage of the converter is zero. Finally, the proposed algorithm is validated with extensive experimental results.

Direct Space Vector Modulation with Novel DC-Link Voltage Balancing Algorithm for Easy Software Implementation of Three-Phase Three-Level Converter

The present paper proposes a direct space vector modulation and novel balance algorithm for easy software application of three-level converters which operate in three-phase. In the case of the conventional space vector modulation, to get the on-state times of the switches, the dwell times of the three nearest stationary vectors, which are obtained after sector and region selection algorithms, should be rearranged. These processes, therefore, contain diverse conditional statements and complicated calculations such as inverse trigonometric functions and square roots. However, the burden of the software application of the proposed algorithm is greatly reduced by not using the sector selection algorithm, the region selection algorithm, and the on-state time allocation process as the proposed modulation can directly control the switch on-state time. In a three-level topology, it is required to balance top and bottom capacitor voltages because the DC-link voltage is composed of two capacitor voltages; the unbalanced voltage of each DC-link capacitor causes the overvoltage of the switching devices. Thus, the DC-link voltage balancing algorithm is proposed, and it is also very simple and effective without additional circuits because it controls the switch on-state time directly as well. The 5-kW prototype proved the validity of the proposed algorithm with its feasibility.

SMC based DTC-SVM control of five-phase permanent magnet synchronous motor drive

&lt;span&gt;This article presents an improved Direct Torque Control (DTC) technique with space vector modulation (SVM) for a five-phase permanent magnet synchronous motor (PMSM) using a sliding mode speed control (SMC).The proposed control scheme of the five-phase PMSM combines the advantages of SMC control and the SVM algorithm. The SMC method insensitive to uncertainties, in particular external disturbances and parameter variations. In this paper, the SMC controller is used to control the rotor speed of the five-phase PMSM based on DTC-SVM. The rotor speed response, torque and stator flux are determined and compared with traditional control method. The simulations results confirm the validity and effectiveness of the proposed control technique in terms of performance and robustness against machine parameter variations (inertia variation). The efficiency of the proposed method applied on the five-phase PMSM is verified by the MATLAB/Simulink.&lt;/span&gt;

New Simplified and Generalized Three-Dimensional Space Vector Modulation Algorithm for Multilevel Four-Leg Diode Clamped Converter

This article aims to propose a new simplified and generalized three-dimensional space vector modulation (3DSVM) for four-leg multilevel diode clamped converter (FL-DCC). The idea is to use the three-dimensional space vector diagram of the multilevel FL-DCC in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">αβγ</i> space, while all calculation stages of the 3DSVM algorithm will be carried out in a new frame called <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ρστ</i> . The proposed 3DSVM algorithm provides, for any inverter level, 1) simple way to calculate the duration time; 2) automatic generation of the adjacent switching states; 3) balancing the dc capacitor voltages, and 4) switching sequence definition without prism and tetrahedron identification stage. All 3DSVM steps are implemented in only one sector, thanks to the proposed new reference voltage vector. Such feature makes possible to build a generalized 3DSVM that can be implemented with minimum computational burden in simple embedded digital platforms. Simulation and experimental results are provided to demonstrate the proposed concept.

Induction motor harmonic reduction using space vector modulation algorithm

The vector control was proposed as an alternative to the scalar control for AC machines control. Vector control provide high operation performance in steady state and transient operation. However, the variable switching frequency of vector control causes high flux and torque ripples which lead to an acoustical noise and degrade the performance of the control scheme. The insertion of the space vector modulation was a very useful solution to reduce the high ripples level inspite of its complexity. Numerical simulation results obtained in MATLAB/Simulink show the good dynamic performance of the proposed vector control technique and the effectiveness of the proposed sensorless strategy in the presence of the sudden load torque basing on the integral backstepping approach capabilities on instant perturbation rejection.