Conventional Matrix Converter Research Articles

A Sinusoidal Doubly Salient Electromagnetic Machine Drive Fed by Third-Harmonic Injection Two-Stage Matrix Converter With Integrated Injection Inductor

This manuscript studies a sinusoidal doubly salient electromagnetic machine (SDSEM) drive fed by third-harmonic injection two-stage matrix converter (3TSMC) with integrated injection inductor to improve the power density of the whole system. First, compared with the conventional matrix converter (MC), the 3TSMC suffers from larger volume due to the inductor in the harmonic current injection circuit. In the proposed system, the harmonic injection current is synthesized by the field current of SDSEM and the injection inductor is removed. Then, the control strategy is proposed to decouple the current injection control and field current control, which means that the harmonic current and the field current can be regulated flexibly. Finally, a prototype is built to evaluate the proposed system and control strategy. Furthermore, the proposed 3TSMC-fed drive with the corresponding control strategy is also suitable for the other DC-excited three-phase sinusoidal AC machines, such as wound rotor synchronous machines.

A VSC-Based Isolated Matrix-Type AC/DC Converter Without Bidirectional Power Switches

In this paper, a three-phase voltage-source converter (VSC) based isolated matrix-type AC/DC converter is proposed for wind energy conversion system (WECS). The line-frequency transformer (LFT) is replaced by the high-frequency transformer (HFT), and there is no need for the intermediate electrolytic capacitors used in conventional two-stage power conversion system. Moreover, the bidirectional switches used for conventional matrix converter (MC) are eliminated in the proposed topology. Consequently, the complicated four-step commutation scheme is avoided and the additional conduction loss caused by serial connection of power switches can be eliminated. The proposed isolated matrix-type AC/DC can be regarded as the dual VSC circuit, where two VSCs alternately work during each switching cycle. Hence, the voltage vectors based space vector modulation (SVM) can be employed and the control schemes for non-isolated VSCs can be used for the proposed converter. For safe operation, the commutation strategy is proposed for the leakage-inductor current of HFT. Both simulations and experiments are conducted to verify the performance of the proposed converter.

Control Scheme Based on Improved Odd-Harmonic Repetitive Control for Third-Harmonic Injection Two-Stage Matrix Converter

The third-harmonic injection two-stage matrix converter (3TSMC) not only inherits the advantages of the conventional two-stage matrix converter (TSMC), but also has simple modulation strategy and low switching losses. The injection current control is the key to achieving sinusoidal input currents of 3TSMC. The injection current reference consists of the third harmonic and its odd harmonics, making it difficult to obtain high control accuracy with a proportional integral (PI) controller. In this paper, a control scheme is proposed for the injection current of 3TSMC, which consists of an improved odd-harmonic repetitive controller (IORC), a PI controller and a feedforward controller. Compared with the conventional repetitive controller (CRC) and existing odd-harmonic repetitive controllers (ORC), the IORC has the highest gains and bandwidths at odd-harmonic frequencies, offering the proposed control scheme high control accuracy and fast transient response. The stability conditions of the system with the proposed control scheme are analyzed, and the design guidelines for the control parameters are provided on this basis. The experimental results demonstrate the effectiveness of the proposed control scheme.

Matrix Converter Based on Trapezoidal Current Injection

The matrix converter (MC) is a direct ac–ac power converter featuring high power density and high efficiency. However, the conventional MC (CMC) topologies require high control complexity and high transistor capacity, hindering the wide applications. An emerging MC topology (3CI-MC) based on the third-harmonic current injection (3CI) reduces the control complexity, but requires more transistors and a complex clamping circuit. This article proposes the trapezoidal current injection (TCI) technique to form a novel MC topology (TCI-MC), which consists of a line-commutated converter (LCC), a TCI circuit, and a voltage source converter (VSC). Compared with the 3CI-MC, the proposed TCI-MC not only maintains the advantages of simple modulation and independent voltage control but also achieves lower current stress on the LCC part of the circuit. The total transistor capacity (TTC) of the proposed TCI-MC is the lowest among all the considered MC topologies. The clamping circuit is also simplified and the bidirectional switches are eliminated, reducing the implementation cost. Simulation and experimental results have verified the validity of the proposed topology.

Design, implementation and performance evaluation of multi-function boost converter

This paper introduces a single-phase multi-function converter (MFC) circuit that can perform the power electronics functions of a DC–DC, a DC–AC, an AC–AC, and an AC–DC boost converter. The power circuit of the proposed converter contains only four bi-directional switches, which is sufficient side by side with a switched logic-based control system to execute converter functions. The proposed converter can implement the boosting converter function, which is a drawback of the conventional single-phase matrix converter, which is limited to performing the buck converter functions. The mathematical analysis of each converter function is presented. A state space averaging technique is employed to obtain the time-invariant state space model for a better understanding of the converter characteristics. The frequency response approach is used to demonstrate the effect of circuit parameters on converter stability using the time-invariant state-space model. Moreover, the performance analysis of the system is checked through the building of a simulation model of the proposed converter via MATLAB/Simulink and MATLAB/Simscape toolbox integration. Additionally, the actual performance of the proposed converter is verified through a laboratory prototype experimental study. The experimental results confirm those obtained by computer simulation, clearly demonstrating the successful operation of the proposed circuit as a multi-function converter with acceptable levels of total harmonic distortion (THD).

Review, Challenges and Potential of AC/AC Matrix Converters CMC, MMMC, and M3C

This article presents a review and a comparison of the conventional matrix converter (CMC), multimodular matrix converter (MMMC), and multilevel matrix modular converter (M3C) topologies, which are three of the main topologies of the matrix family. The study of the CMC supplies basic knowledge for these structures and then the concept of multilevel matrix converters used in MMMC and M3C topologies is approached. The study addresses modulation strategies and switching sequences for the topologies to provide implementation guidelines and harmonic content reduction. The design is also carried out and results of the three topologies are shown to exemplify their operation. Finally, the article presents a comparison between the topologies to highlight the advantages and challenges of each one. This study contributes information on the three topologies, which are not easily found in the literature, especially in terms of modulation and switching strategies. It also highlights applications and research points that have to improve.

An Extended Control of the Input Angle for Matrix Converters Connected With the Nonunity Power Factor Loads

This article proposes a novel pulsewidth modulation (PWM) modulation algorithm for multiphase conventional matrix converters, with three inputs and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$k$</tex-math></inline-formula> outputs, using the transfer function of the load angle. The proposed approach extends the range of power angle control at the input during the operation with a maximum voltage transfer ratio. The proposed concept is based on the direct analytic voltage PWM modulation with an elliptical trajectory of reference load voltages. The proposal has been verified using the circuit simulation in PSIM software, symbolic analysis using MATLAB, and finally through an experiment.

A Direct Modulation for Matrix Converters Based on the One-Cycle Atomic Operation Developed in Verilog HDL

This article presents a fast direct pulsewidth modulation (PWM) algorithm for the conventional matrix converters developed in Verilog hardware description language. All PWM duty cycle calculations are performed in one cycle by an atomic operation designed as a digital module using field-programmable gate array basic blocks. The algorithm can be extended to any number of output phases. The improved version of the discontinuous direct analytic voltage PWM (DAV-PWM) method is proposed, in which the use of trigonometry, angles, and program loops has been eliminated. The proposed DAV-PWM is equivalent to the space vector modulation; it can be applied during input asymmetry and also allows for the control of the displacement input angle. The proposal has been verified using the circuit simulation in PSIM, digital structure modeling in ModelSim, and finally through an experiment.

Space vector pulse width amplitude modulation strategy for three-level direct matrix converter

The total harmonic distortion and switching stress of a three-level direct matrix converter (TLDMC) is greatly reduced in comparison with those of a conventional matrix converter (MC). Meanwhile, the TLDMC leads to major advantages in comparison with existing multi-level AC–DC–AC converter topologies in terms of reduced switch counts and lowered switching power loss. In this paper, a space vector pulse width amplitude modulation (SVPWAM) strategy for the TLDMC is proposed, which can reduce the number of switching actions and improve the voltage utilization by eliminating the zero vector of each sector. An indirect modulation model of a TLDMC is discussed according to the topology of TLDMC in this paper. For the space vector modulation of the TLDMC, the space vector pulse width modulation (SVPWM) with a zero-vector of the fictitious rectifier stage is improved to form the SVPWAM. In addition, the virtual space vector pulse width modulation (VSVPWM) strategy is used for the fictitious inverter stage. Finally, simulation and experimental results verify the correctness of the proposed method.

The Conceptual Research over Low-Switching Modulation Strategy for Matrix Converters with the Coupled Reactors

In this paper, different Pulse Width Modulation (PWM) strategies for operating with a low-switching frequency, a topology that combines Conventional Matrix Converters (CMCs), and Coupled Reactors (CRs) are presented and discussed. The principles of the proposed strategies are first discussed by a conceptual analysis and later validated by simulation. The paper shows how the combination of CMCs and CRs could be of special interest for sharing the current among these converters’ modules, being possible to scale this solution to be a modular system. Therefore, the use of coupled reactors allows one to implement phase shifters that give the solution the ability to generate a stair-case load voltage with the desired power quality even the matrix converters are operated with a low-switching frequency close to the grid frequency. The papers also address how the volume and weight of the coupled reactors decrease with the growth of the fundamental output frequency, making this solution especially appropriate for high power applications that are supplied at high AC frequencies (for example, in airport terminals, where a supply of 400 Hz is required).

A New Approach to the PWM Modulation for the Multiphase Matrix Converters Supplying Loads with Open-End Winding

This article presents three variants of the Pulse Width Modulation (PWM) for the Double Square Multiphase type Conventional Matrix Converters (DSM-CMC) supplying loads with the open-end winding. The first variant of PWM offers the ability to obtain zero value of the common-mode voltage at the load’s terminals and applies only six switches within the modulation period. The second proposal archives for less Total Harmonic Distortion (THD) of the generated load voltage. The third variant of modulation concerns maximizing the voltage transfer ratio, minimizing the number of switching, and the common-mode voltage cancellation. The discussed modulations are based on the concept of sinusoidal voltage quadrature signals, which can be an effective alternative to the classic space-vector approach. In the proposed approach, the geometrical arrangement of basic vectors needed to synthesize output voltages is built from the less number of vectors, which is equal to the number of the matrix converter’s terminals. The PWM duty cycle computation is performed using only a second-order determinant of the voltages coordinate matrix without using trigonometric functions. A new approach to the PWM duty cycles computing and the load voltage synthesis by 5 × 5 and 12 × 12 topologies has been verified using the PSIM simulation software.

A Family of Asymmetrical SVPWM Schemes with Normal and Open-Circuit Fault-Tolerant Operation Capability for a Three-Phase Isolated AC-DC Matrix Converter

The three-phase isolated ac–dc matrix converter (3P-IMC) inherits all the merits of the conventional matrix converter. But it also suffers from a large number of bidirectional switches and cannot operate safely in an open-circuit fault condition. Hence, with a general space vector PWM (SVPWM) model presented in this article, three types of asymmetrical SVPWM (ASVPWM) schemes are first proposed for normal and open-circuit fault-tolerant operation. The ASVPWM schemes have more kinds of synthetic vectors with asymmetrical distribution, however, also feature a higher freedom and flexibility to further improve the system performance. Then by sectional combining the above ASVPWM schemes with the conventional one, the 3P-IMC could be continued to operate with a tight dc output voltage regulation under single-switch open-circuit fault condition, which has an inherent open-circuit fault-tolerant capability. Compared with the conventional two-phase fault-tolerant operation, the proposed strategy has a smaller output voltage ripple, lower current stress, lower current harmonic, higher maximum output power, etc. The safety and reliability of the converter are greatly improved. Finally, a 3P-IMC experimental prototype is built up to verify the performance of the proposed ASVPWM schemes.

An Efficient of Direct Torque Control of Indirect Three Level Matrix Converter Fed Dual Stator Induction Motor Based on Synergetic Controller

As know, Direct Torque Control (DTC) suffers from the high ripples of the torque and flux, caused by the variable switching frequency. Torque ripple in DTC drives can be reduced if an Indirect Three-Level Matrix Converter (ITLMC) is employed instead of a conventional Two-Level Indirect Matrix Converter. Nevertheless, this problem can be still large if low switching frequencies are used. In order to overcome this problem, a Constant Switching Frequency controller (CSFC) is proposed to replace the five-level hysteresis torque comparator for reducing the ripples and improving the flux regulation in low and zero speed operation. Furthermore, the control scheme performance is enhanced by inserting a robust Synergetic Controller (SC) in the outer loop for speed regulation. Simulation results with a comparative analysis have indicated the special merit of the proposed scheme, which makes it competitive with the existing control strategies.

Modeling and analysis of single phase quasi Z source matrix converter fed induction motor drives

Single-phase quasi z-source matrix converter which is used for AC drives and induction heating applications is designed here. The foremost gain of matrix converter is the elimination of dc link filter. By comparing with established matrix converter, the quasi Z source matrix converter provides high voltage gain, requires less number of switches and LC filter functions which is integrated in the proposed network so as to repudiate additional filter components. The proposed topology describes the direct quasi Z source matrix converter in order to increase voltage gain in load side. The sinusoidal PWM technique has been employed and proposed circuit is simulated in MATLAB/SIMULINK. The experimental set up has been implemented and the results shows that the Quasi Z source matrix converter provides high efficiency. Compared with the conventional matrix converter it dispense low input current and high power.

Performance Analysis of Dual Space Vector Modulation Technique-Based Quasi Z-Source Direct Matrix Converter

—This article proposes a dual space vector control strategy for quasi Z-source direct matrix converter (QZSDMC) which is made up of quasi Z-source network coupled to a matrix converter (MC). It ensures effective regulation of voltage regulation range and overpowers the voltage transfer ratio restrictions of conventional matrix converter. The QZSDMC can afford buck boost operation by observing the bidirectional operation capability and shoot through duty ratio. Also, it provides continuous input current and eliminates the need for input LC filter. First, the principle of operation of the proposed QZSDMC is presented in detail. Then, a dual space vector pulse width modulation technique for QZSDMC has been analyzed along with the distribution of shoot through time in the zero vector. The proposed topology with the control strategy has been simulated in MATLAB/SIMULINK and the simulation results are verified with the experimental results from the basic prototype machine controlled by FPGA.

Direct Modulation for Conventional Matrix Converters Using Analytical Signals and Barycentric Coordinates

This paper proposes the generalized direct modulation for Conventional Matrix Converters (CMC) using the concept of analytical signals and barycentric coordinates. The paper proposes a novel approach to the Pulse Width Modulation (PWM) duty cycle computing, which allows faster prototyping of direct control algorithms. The explanation of the new idea using analytical considerations demonstrating the principles of direct voltage synthesis has been presented in the article. The study concerns mainly the CMC $3\times 3$ but solutions for $3\times {n}$ , $5\times {5}$ , and $5\times {3}$ topologies have also been discussed. The transformation of instantaneous input voltages to analytic signals great permits for simple presenting of real input voltage conditions such as waveform type, asymmetry or other deformation like higher–order harmonics. The proposed interpolation methods allow for determining the values of PWM duty cycles using simple formulas based on the determinants of the 2nd–degree matrices. Therefore, the proposed method, which based on the barycentric coordinates, frees an algorithm from trigonometry and angles.

Application of Analytic Signal and Smooth Interpolation in Pulsewidth Modulation for Conventional Matrix Converters

This article proposes an alternative and novel approach to the pulsewidth modulation (PWM) duty cycles computation for conventional matrix converters (CMC) fed by balanced, unbalanced, or nonsinusoidal ac voltage sources. The presented solution simplifies the prototyping of direct modulation algorithms. PWM duty cycles are calculated faster by the smooth interpolation technique, using only vector coordinates, without trigonometric functions, and angles. Both input voltages and output reference voltages are expressed by analytic signals in the proposed direct modulation. Input voltages are represented by the rotating vector collection in the 2-D Cartesian coordinate system. All reference output voltages are located inside the triangular surface, named here as the voltage synthesis field, formed by these rotating vectors. A certain degree of reference signals placement freedom allows us to maximize the voltage transfer ratio to 0.866 with less switching compared to the optimum-Venturini direct method. The proposed solution was verified by simulations and experiments for CMC3 × k. The comparison with the optimum-Venturini modulation is included. The proposed PWM duty cycle computation approach can also be applied to multiphase CMC converters for any number of inputs as well as outputs.

Investigating the Performances of Direct Torque and Flux Control for Dual Stator Induction Motor with Direct and Indirect Matrix Converter

This work investigates the performances of Direct Torque Control (DTC) of Dual Stator Induction Motor (DSIM) powered by two types of Matrix Converter (MC), namely the direct and indirect MC. To this end, the design of DTC with conventional Direct Matrix Converter (DMC) is firstly presented. Then, in order to illustrate the main feature of Indirect Matrix Converter (IMC) in terms of the output voltages and input currents waveforms, the full steps of IMC are well explained. To discuss the performance of each scheme, both techniques are simulated in the Matlab / Simulink environment for a 4.5 kW DSIM at different operating conditions. The obtained results show that the IMC provides high performance in torque and flux at different conditions and while minimization the Total Harmonic Distortion (THD) in the input current compared by the conventional DMC.

Optimization of efficiency for power system using three phase AC to AC matrix converter with the algorithm of fuzzy controller

This paper suggested a new contribution of three phase AC to AC matrix converter MC via fuzzy logic controller FLC to enhance the whole system. However, the weakness of matrix converter is that the input- output voltage transfer is control to 87% for input and output waveform. Also, matrix converter is more sensitive to the trouble of input voltage which deteriorates the system performance. To overcome these problems, and to improve the efficiency of system, FLC with matrix converter is proposed to minimize the sensitivity to the load, and to increase voltage transfer. In this paper the currents a,b,c are converted to alpha and beta current via Clarke transformation . In this method two FLC are used. The error (between alpha current and reference current) (e) and the change of this error (de) will apply to first FLC. The output of FLC is actual alpha current. In the other hand, the error of beta current and the change of error are also passes through the second FLC to produce the actual beta current. The actual alpha and beta current is converted to direct and quadrature d-q current by park transformation. The d-q current is converted to (a, b, c) out currents by inverse park transformation, the results of this method express that the matrix converter with FLC is more capable, high accuracy with better efficiency as compared with conventional matrix converter system.

Optimization of efficiency for power system using three phase AC to AC matrix converter with the algorithm of fuzzy controller

This paper suggested a new contribution of three phase AC to AC matrix converter MC via fuzzy logic controller FLC to enhance the whole system. However, the weakness of matrix converter is that the input- output voltage transfer is control to 87% for input and output waveform. Also, matrix converter is more sensitive to the trouble of input voltage which deteriorates the system performance. To overcome these problems, and to improve the efficiency of system, FLC with matrix converter is proposed to minimize the sensitivity to the load, and to increase voltage transfer. In this paper the currents a,b,c are converted to alpha and beta current via Clarke transformation . In this method two FLC are used. The error (between alpha current and reference current) (e) and the change of this error (de) will apply to first FLC. The output of FLC is actual alpha current. In the other hand, the error of beta current and the change of error are also passes through the second FLC to produce the actual beta current. The actual alpha and beta current is converted to direct and quadrature d-q current by park transformation. The d-q current is converted to (a, b, c) out currents by inverse park transformation, the results of this method express that the matrix converter with FLC is more capable, high accuracy with better efficiency as compared with conventional matrix converter system.