Space Vector PWM Algorithm Research Articles

Five-phase space vector carrier-based PWM for third harmonic injection

Five-phase AC drives allow a third harmonic voltage to be fed into the stator winding – in addition to the fundamental voltage – to generate a third harmonic magnetic air gap field. This allows the generation of an additional small constant torque. Furthermore, the undesirable saturation harmonics that occur with saturated iron can be compensated. The desired third harmonic voltage is commonly generated via time-consuming space vector PWM algorithms, which are not well-suited for real-time application, or via look-up tables, which require an increased storage capacity. In our case, the desired third harmonic voltage is generated in the five-phase voltages by adding a non-sinusoidal zero-sequence voltage with five times the fundamental frequency to the fundamental voltage reference signals in carrier-based pulse width modulation (PWM) with a constant switching frequency. This is equivalent to a space vector PWM method (SVPWM) and avoids a significantly high calculation effort. The PWM algorithm programmed in MATLAB in real time allows the fast generation of a third harmonic voltage per phase with freely definable amplitude and phase shift without requiring a lot of storage capacity.

Hybrid passivity‐based control of a three single‐phase star‐connected unidirectional five‐level rectifier with a space vector pulse‐width modulation algorithm for voltage balance

SummaryThe unidirectional multilevel rectifier has been used in numerous industrial applications due to its reduced active power switches, higher power density, and lower cost compared to conventional bidirectional converters. Recently, the unidirectional five‐level rectifier has been proposed for its lower device stress and the potential for extension to higher levels. However, it adopts a conventional linear proportional integral (PI) control strategy and sinusoidal pulse‐width modulation (SPWM) method, resulting in a complex control structure, particularly for the balance control of the midpoint voltage, and suboptimal dynamic performance. To address this issue and enhance system's large‐scale stability, a hybrid passivity‐based control (PBC) strategy, along with a simplified mathematical model, has been proposed. The hybrid PBC control strategy includes an outer loop active disturbance rejection (ADR)‐PI controller and inner loop PBC controller, providing a simple overall control structure and strong anti‐interference ability. Additionally, a space vector pulse‐width modulation (SVPWM) algorithm has been briefly introduced and applied to further improve the recovery and balance speed of the DC‐side capacitor voltages. Simulation and experiment results have validated the feasibility and effectiveness of the proposed hybrid PBC strategy and the SVPWM algorithm.

A unified duty-cycle modulation algorithm for a three-level NPC inverter

In this paper, it is a kind of challenge to simplify the conventional pulse width modulation (PWM) algorithms for a three-level neutral-point-clamped inverter. Thus, the unified duty-cycle modulation (UDM) algorithm is presented. It is more attractive than the carrier-based PWM (CBPWM), space-vector PWM (SVPWM), and unified PWM algorithms with a simpler calculation by utilizing the usefulness of the SVPWM algorithm to synthesize the duty cycles in time-domain and the CBPWM algorithm to synthesize the duty cycles in frequency-domain with the lesser conditions and the blankness of the lookup tables, switching sequence design, and zero-sequence component finding. Besides, it is outstanding with three outcomes: (1) comprehensive mathematical models of the dwell times, (2) permanent mathematical models of the duty cycles in time-domain, and (3) simplified PWM algorithm, which has a better workflow with the reduction of the computation burden. As it is very easy to implement as the sinusoidal PWM technique while its performance is equivalent to the SVPWM algorithm, this makes the proposed UDM algorithm a good candidate to optimize between the performance and the cost. Both the simulation and experimental results can confirm the feasible practicability and performance. The comparison with the conventional algorithms can evidently emphasize the superiority.

Segment Reduction-Based Space Vector Pulse Width Modulation for a Three-Phase F-Type Multilevel Inverter with Reduced Harmonics and Switching States

An improved segment reduction-based space vector pulse width modulation (SVPWM) for an F-type three-level inverter (FT2LI) is presented in this article. The proposed SVPWM algorithm decreases the additional switching state transition of each triangle with the application of an improved nine- and three-segment reduction switching strategy. The main feature of the segment reduction technique is that it eliminates second-order harmonics in the inverter output side with good total harmonic distortion (THD), low switching losses, and minimum filter requirements when compared with carrier-based PWM (CBPWM) techniques such as multi-carrier sine PWM (MC-SPWM), sixty-degree PWM (60° PWM), and switching frequency optimal PWM (SFO PWM). The proposed modulation algorithm for FT2LI is implemented on the MATLAB/Simulink platform. The performance of the proposed segment reduction-based SVPWM algorithm is tested experimentally on an FT2LI at various amplitude and frequency modulation indices, and the experimental results are verified with the simulation results. Additionally, a comparative analysis carried out to study the relationship between the segment reduction-based SVPWM and CBPWM techniques inferred that the suggested segment reduction-based SVPWM algorithms can optimize high-order harmonic distributions and have a minimum computational burden.

EVOLUTION AND DISSEMINATION OF SPECIALIZED STRATEGIES, METHODS, AND TECHNIQUES OF SYNCHRONOUS PULSEWUDTH MODULATION FOR CONTROL OF VOLT-AGE SOURCE INVERTERS AND INVERTER-BASED SYSTEMS

This publication provides a brief historical overview of the development of methods and techniques of pulsewidth modulation (PWM) for voltage source inverters, published mainly in Ukrainian publishing houses and in Ukrainian periodicals. Accent has been done to review of results of investigation of alternative methods and techniques of synchronous space-vector-based multi-zone PWM for inverters with low switching frequency. In particular, in the mentioned publications, the basic strategies, schemes, and algorithms of synchronous multi-zone modulation have been further developed, modernized, modified, and disseminated in relation to new promising topologies of power conversion systems, including: two-inverter-based electric drives with open-end winding of electrical motor; dual three-phase electric drives of symmetrical and asymmetric types; 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 PWM, applied for control of inverter-based systems, provide continuous synchronization and symmetry of basic voltage waveforms of systems during the whole control range including zone of overmodulation of inverters. It provides minimization of even harmonics and undesirable subharmonics (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 characteristics of the phase and line voltages of 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. References 30, tables 2, figures 25.

An SVPWM Algorithm for a Novel Multilevel Rectifier with DC-Side Capacitor Voltage Balance

The recently proposed novel unidirectional multilevel rectifier, a three single-phase star-connected multilevel rectifier, has the characteristic of having a large number of DC-side capacitors and a complex capacitor voltage balancing control structure under conventional carrier-based phase-shift sine wave pulse-width modulation (SPWM). Hence, a space vector pulse-width modulation (SVPWM) algorithm for the novel multilevel rectifier is proposed in this paper, which can quickly balance the capacitor voltage without an additional voltage balancing control structure. Firstly, it divides the space vectors of the rectifier, then it determines the two basis voltage vectors that synthesize the output reference voltage. After that, based on the analysis of the relationship between switching states and the charge–discharge of capacitors, the final action sequences of redundant vectors are determined according to the principle of keeping the capacitor charge–discharge time consistent. Thus, the capacitor voltages can be automatically balanced without an additional voltage balancing control structure. Finally, simulation and experimental results validated the feasibility and effectiveness of the proposed SVPWM algorithm. The results also show improvements in current quality, capacitor voltage balance and the fluctuation of the neutral point voltage on the DC-link, allowing for further reduction in the overall volume and cost of the rectifier.

Open-Circuit Fault-Tolerant Vector Control for Five-Phase SPMSM Based on Five-Phase Six-Leg Inverter

Five-phase permanent-magnet synchronous motor (PMSM) has the ability of fault-tolerant operation, which is beneficial for high reliability occasions. A fault-tolerant current vector control strategy based on five-phase six-leg inverter is proposed for open-circuit fault in this article. It deals with single-, double-, and triple-phase fault conditions. First, the overall control scheme is established based on the mathematical model of five-phase surface-mounted PMSM. To release more control degrees of freedom, the constraint for the sum of fault-tolerant phase currents is removed, and the control variates method is used to calculate the optimal fault-tolerant currents. Furthermore, to achieve the current tracking, the corresponding reduced-order current transformation matrices are derived, and the corresponding main power topology, the five-phase six-leg voltage source inverter (VSI), is established. The unbalanced operation of the topology is investigated, the equivalence to the full-bridge VSI is proved, and the voltage utilization and voltage unbalance of five phase half-bridge, full-bridge, and six-leg inverter are compared. Then, the corresponding carrier-based PWM control strategy based on zero-sequence injection has been proposed, which is equivalent with the three-dimensional space vector PWM algorithm and is computationally efficient. The experimental results confirm the effectiveness of the proposed fault-tolerant control strategy.

SVPWM Strategy Based on the 45$^\circ$ Coordinates to Suppress Common-Mode Voltage for Multilevel Converters

This article proposes an optimized space vector pulsewidth modulation (SVPWM) strategy with minimum common-mode voltage (CMV). Compared with earlier SVPWM methods, the proposed optimized strategy is implemented in the 45 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> coordinates. Locating the sector triangle, calculating the duty cycles, and determining the switching sequences require only basic arithmetic operations, which greatly reduces the computational complexity. The switching state with minimum CMV corresponding to the space vector can be calculated directly. The proposed optimized modulation strategy effectively solves the problem that the traditional SVPWM is difficult to be implemented as the number of levels increases. It can be easily extended to any level converters without additional computational burden. Based on the proposed optimized SVPWM strategy with minimum CMV, the SVPWM strategy for eliminating CMV is proposed. The proposed SVPWM strategy for eliminating CMV improves the utilization of the redundant cells and reduces the total harmonic distortion of phase voltages without increasing the difficulty of implementing the SVPWM algorithm. Finally, the proposed two SVPWM strategies are verified with extensive simulations and experiments.

A predictive control method for switching sequence selection based on SVPWM for five‐level converter

AbstractAiming at the problems of complex realization, single control target and difficulty in selecting the optimal zero sequence voltage when the traditional space vector PWM (SVPWM) algorithm is adopted in five‐level active neutral‐point‐clamp (5L‐ANPC) converter, a predictive control optimal switching sequence selection (PC‐OSSS) method is proposed. The method adopts the SVPWM control strategy base on the line voltage coordinate and then realizes the selection of optimal switching sequence through the multi‐objective predictive control method. Firstly, the principle of SVPWM based on line voltage coordinate is introduced, and all switching sequences that can be output are obtained. Secondly, the mathematical models of the floating capacitor (FC) voltage, the neutral point (NP) voltage and the common mode (CM) voltage corresponding to each switch sequence are established. Finally, the optimal switch sequence is selected by using the predictive control method based on priority ranking. Compared with traditional SVPWM, the outstanding advantage of this method is that the traditional qualitative comparison method is replaced by quantitative calculation. The multi‐objective control performance of the converter is improved while retaining the advantages of the traditional SVPWM fixed frequency. Finally, the practicability and effectiveness of the proposed control strategy are verified by simulation and experiment.

GRID-CONNECTED PV SYSTEM EMPLOYING THREE INVERTERS REGULATED BY SYNCHRONOUS SCHEME OF PWM

The paper presents comparative analysis of three versions of the modified scheme of space-vector-based synchronous pulsewidth modulation (PWM), applied for control of three two-level inverters of transformer-based photovoltaic (PV) system, and focused on providing of the symmetry of winding voltage of power transformer during the whole adjustment range. Power supply of inverters is providing by the corresponding three solar strings consisting of a set of PV panels, and the outputs of three inverters are connected specifically with inverter-side windings of multi-winding grid-tired transformer. Results of MATLAB-simulation prove the fact of advanced spectral composition of the winding voltage of triple-inverter-based PV installation regulated by algorithms of synchronous space-vector PWM, assuring potential reduction of losses in these systems. References 10, table 1, figures 9.

Type-1 and type-2 fuzzy logic-based space vector modulation for two-level inverter fed induction motor

Two-level inverter control with type-1 and type-2 fuzzy logic-based space vector pulse-width modulation (PWM) method for induction motor drive (IMD) is presented in this paper. A new sampling time independent strategy with type-1 and type-2 fuzzy based methods are used in generating three phase duty ratios which are directly obtained without mathematical equations. The conventional method of space vector modulation (SVM) produces the duty ratios for the inverter which are sampling time dependent. However, in type-1 and type-2 fuzzy based space vector PWM algorithms, the three phases duty ratios generated are sampling time independent and with a new integrated dead-time insertion in SVM itself, can be implemented practically for any switching frequency. As the rule-base for Mamdani non-singleton interval type-1 and type-2 fuzzy inference systems are designed manually, with the expert knowledge of conventional space vector PWM, the duty ratios of the inverter are generated such that the performance of the IMD is improved. The simulation studies for aforementioned cases is performed in matrix laboratory (MATLAB) and experimental validation for the proposed space vector PWM algorithms is validated using real-time sacraetheologiae magister (STM) hardware with STM32F429I Cortex M4 processor for a 1 hp IMD.

Common-Mode Voltage Reduction and Neutral Point Voltage Balance Modulation Technology of Quasi-Z-Source T-Type Three-Level Inverter

The quasi-Z-source T-type inverter is a new type of three-level inverter. Compared with other three-level inverters, the quasi-z-source T-type inverter is characterized by its fault tolerance capability and boost capability. In the inverter, the modulation strategy greatly affects the performance. Aiming at the problems in three-level inverters such as excessive common-mode voltage and unbalanced neutral point potential, a space vector pulse width modulation (SVPWM) for a quasi-z-source T-type three-level inverter based via line voltage coordinate is proposed in this paper. The main research work and achievements of this paper include: (1) based on the existing research results, an SVPWM modulation strategy for the quasi-Z-source T-type inverter is proposed. The modulation method proposed by this paper can effectively reduce the common-mode voltage and balance the neutral point voltage. (2) This paper analyzes the principle of the line voltage coordinate system and makes some modifications to the line voltage coordinate system so that the proposed modulation scheme can be applied to the line voltage coordinate system. Compared with the traditional αβ coordinate system, the SVPWM algorithm in the line voltage coordinate system has the characteristic of simple calculation. The simulation and experiment results show that the control method has good performance under the conditions of dynamic response and imbalance.

Implementation of the spatial voltage vector modulation algorithm using an artificial neural network

An algorithm for space vector pulse width modulation (SVPWM) based on an artificial neural network is proposed.In calculating the action time of the voltage vectors according to the traditional SVPWM algorithm, the values of the relative phase angle on the sectors are used as variables, which causes difficulties in their calculation.To overcome these shortcomings, mathematical models have been compiled that determine the opening time of the power element by the absolute phase angle on the inverter converter. Since mathematical models have different types of calculation formulas for sectors and it is impossible to express them in an unambiguous formula, to eliminate these difficulties, a function was built using an artificial neural network, with which you can generally determine the opening time of a power element in phases A, B and C.Regardless of the sectors, the SVPWM algorithm sets the opening time of the power element according to the phase angle θ on the inverter converter.The generalized ability of the artificial neural network and its accuracy, as well as the simulation operation time in the MATLAB environment, were tested.The proposed method makes it possible to achieve high speed control accuracy and significantly reduce the operation time.When controlling the traction drive of an electric rolling stock with an asynchronous traction motor, it is possible to reduce the regulation period, as a result, the traction capacity of electric locomotives and metro electric trains with vector control or with direct torque control increases by about 1.1–1.2 times.

A Simplified Space Vector Pulse Width Modulation Algorithm of a High-Speed Permanent Magnet Synchronous Machine Drive for a Flywheel Energy Storage System

A space vector pulse width modulation (SVPWM) algorithm is an important part of the permanent magnet synchronous machine (PMSM) drive to achieve direct current (DC) to alternating current (AC) conversion. The execution of the conventional SVPWM algorithm is a complex process which will limit the sampling frequency of the high-speed PMSM drive. Low sampling frequency will cause high current total harmonic distortion (THD) and eddy current loss. To increase the sampling frequency, this paper proposes a novel simplified SVPWM algorithm. The proposed SVPWM algorithm turns the vector composition problem of the conventional SVPWM algorithm into an optimization problem of the dwell time of the basic vector. The proposed SVPWM algorithm has an optimal vector dwell time (OVDT). The dwell time of the basic vector can be directly calculated by solving the optimization problem. The proposed SVPWM algorithm does not need sector identification compared to the conventional algorithm. The experiments of the proposed SVPWM algorithm are performed in a high-speed PMSM drive of a flywheel energy storage system (FESS). Compared to the conventional SVPWM algorithm, the execution time of the proposed SVPWM algorithm is reduced by 38%. By using the proposed SVPWM algorithm, the sampling frequency can be increased from 33 kHz to 40 kHz. With the higher sampling frequency, the current THD is reduced by 25.6%. The effectiveness of the proposed simplified SVPWM algorithm is verified experimentally.

Amplitude Sampled Reference-Based Space Vector Pulse Width Modulation for Control of Voltage Source Converters

Memory, speed, reliability, and efficiency are the main characteristics of concern in new contemporary control techniques of electric power converters. Space vector pulse width modulation (SVPWM) is a widespread digital compute-intensive control technique used in the control of power converters. This study aims to overcome the large number of calculations needed by the SVPWM algorithm, which limits its implementation in many advanced industrial applications. This paper presents a low-cost software implemented simplified SVPWM technique. The proposed strategy generates the inverter switching times in a straightforward manner with no need for complicated and time-consuming sector identification and look-up switching tables. A simulation study has been done using MATLAB/SIMULINK environment for the three-phase voltage source converter (VSC). The results in terms of total harmonic distortion (THD) in the converter line voltage are compared for the proposed technique, conventional SVPWM, and space pulse width modulation (SPWM). The execution time is reduced considerably with a slight increase in the value of THD and about 14.4 percent DC-link voltage utilization over the SPWM.

Research on an Improved Three-Level SVPWM Modulation Algorithm Based on ID-NPC Topology

The conventional three-level SVPWM (Space Vector Pulse Width Modulation) algorithm is a basic modulation algorithm, which can be performed easily due to clear modulation ideas. Considering different criteria for sectors, however, the basic vector action time is calculated repeatedly, the selection of vector action sequence is cumbersome, and the algorithm execution time is extended as a result of processing by the digital processing chip. In order to better adapt to the PMSM (Permanent Magnet Synchronous Motor) control requirements of the ID-NPC (Improved Diodes Neutral Point Clamped) topology for converter control objects, the sector judgment part, time effect part and vector synthesis part are optimized according to the principles of saving hardware resources and shortening the execution cycle. The vector synthesis optimization algorithm of 2 × amplitude substitution and the vector synthesis algorithm of 1/2 × amplitude substitution are both proposed. Finally, the ID-NPC topology is used to verify the proposed modulation algorithm.

Research on MTPA Control Strategy of Permanent Magnet Synchronous Motor Based on Fast SVPWM Algorithm

In recent years, the poor endurance of electric vehicles has been one of the main problems that have limited the development of new energy vehicles. Improving system efficiency and reducing system losses are currently one of the main methods to improve endurance. A fast SVPWM (Space Vector Pulse Width Modulation Technology) algorithm is used to improve the traditional SVPWM judgment, simplifying the complicated coordinate transformation and trigonometric function calculation of the traditional SVPWM technology judgment. Then it is applied to MTPA (Maximum Torque Per Ampere) control for Simulink model simulation to verify the effect. The experiment proves that the MTPA control under the improved SVPWM algorithm has higher response speed and stability than the traditional id = 0 control. The size of the stator current is about 1-2A smaller than id = 0 control, which achieves better MTPA control.

Experimental and numerical analysis on SVPWM based grid connected photovoltaic system

Space Vector Pulse Width Modulation (SVPWM) for 3-phase nested neutral point clamped multilevel inverter (NNPC-MLI) which is suitable for grid connected (PV) system is implemented. The use of nested NPC topology helps in increasing the level in output voltage of the inverter. The main task of the system is to balance the flying capacitor voltage using SVPWM, since we have two capacitors in each leg. In this proposed system inverter generates four level in the output voltage, with minimized voltage stress in each switch. Balancing of neutral point voltage is done by redundant inverter switching states. The implementation of modulation technique for voltage balance control is elaborated in detail. Total harmonic distortion (THD) factor in the output is decreased by SVPWM algorithm in this NNPC topology as compared to other inverter topologies. The input for the inverter is taken from PV source and the output is given to grid connected system. Reduction of switching losses is the other added benefit for the nested configuration. The proposed structure is verified using MATLAB/SIMULINK and the simulation results were obtained.

Modeling of Conduction and Switching Losses for IGBT and FWD Based on SVPWM in Automobile Electric Drives

The modeling of conduction and switching losses for insulated gate bipolar transistors (IGBTs) and free-wheeling diodes (FWDs) in automobile applications is becoming increasingly important, especially for the improvement of the system efficiency and the reliability prediction. The traditional modeling of conduction and switching losses based on the space vector pulse width modulation (SVPWM) is not applicable in practice due to the complex curve-fitting and the computation demands. In this paper, a simple and practical losses model for IGBTs and FWDs is proposed based on the SVPWM algorithm. Firstly, the traditional power losses model is introduced briefly. Then, the piecewise linear switching losses model and the conduction losses model based on the equivalent three-order harmonic model of the duty cycle are proposed. The comparison of experimental results between the traditional model and the proposed model is presented in the experiment validation. Furthermore, the power analyzer is adopted to measure the inverter losses, and the chips losses are further validated when other extra losses are considered. The proposed model shows good modeling accuracy with the large benefit of smaller measurement and lower computation requirements.

Four-Degree-of-Freedom Overmodulation Strategy for Five-Phase Space Vector Pulsewidth Modulation

This article proposes a four-degree-of-freedom overmodulation strategy for five-phase space vector pulsewidth modulation (SVPWM) in order to reduce the low-order harmonics of the output voltage during overmodulation. Based on the nearest-four-vector SVPWM algorithm, this overmodulation strategy calculates the corresponding third harmonic injection rate according to the modulation ratio in the overmodulation region. What is more, this strategy optimizes and controls the third harmonic so that basic voltage vectors of the fundamental wave subspace and the third harmonic subspace can be controlled simultaneously, thus effectively decreasing the low-order harmonic contents without reducing control degrees of freedom. The whole overmodulation region is divided into three subregions with linearized approximation to reduce the complexity of computation. Simulation and experimental results demonstrate that under the same modulation ratio during overmodulation, the proposed overmodulation strategy can improve the dc bus voltage utilization of a five-phase inverter, make the third harmonic controllable with four control degrees of freedom, and also reduce the low-order harmonic contents of the output voltage.