Indirect Matrix Converter Research Articles

High-Gain-Integrated Switched Capacitor Indirect Matrix Converter

An ultrasparse matrix converter (USMC) is a derived form of an indirect matrix converter having a less number of switches. Even though it has unidirectional power flow capability, it is a quite appropriate candidate for specific applications, such as wind-energy systems, electrohydrostatic actuators, variable speed drives, and so on. However, the gain of the converter is still limited irrespective of various topological and control strategy modifications. Unlike the previous propositions, this paper is primarily focused on the integration of a switched capacitor boost network within the USMC to enhance gain, by preserving the advantages of the USMC. For controlling the proposed converter, a modified space vector modulation technique is also presented in this paper. In order to explore the potential of the proposed converter, analytical expressions are derived. The theoretical findings are further verified using simulation and experimental results.

A New Modulation Strategy to Reduce Common-Mode Current of Indirect Matrix Converter

This letter presents a new space vector modulation strategy adopting new zero vectors to achieve common-mode current (CMC) reduction for indirect matrix converter (IMC). By substituting conventional zero vectors by new zero vectors, the impedance of common-mode loop increases, which contributes to CMC reduction. Thus, the IMC system with the proposed method alleviates the adverse effects of CMC for ac drives. Moreover, additional hardware and complex commutation process are not required. Experiments are conducted to verify the effectiveness of the proposed method.

Carrier‐based PWM control strategy for three‐level indirect matrix converter

This article proposes a new carrier-based pulse width modulation (CBPWM) strategy for the control of TLIMC. The duty ratios of the rectifier stage and inverter stage are calculated by the SVPWM method. A carrier is constructed and combined with duty ratios to obtain modulation waves, which are regular and determined by the input voltage and output reference voltage. Then, the modulation waves are compared with the same carrier to obtain pulse signals. The pulse signals are used to produce driving signals of power switches through logic operation. The rectifier stage and inverter stage are controlled by the driving signals to obtain three-phase symmetrical sinusoidal input and output waveforms. The proposed method is identical in output to the original SVPWM method. Finally, simulation and experimental results are provided to verify the feasibility and validity of the proposed method.

Modeling and simulation of quasi-Z-source indirect matrix converter for permanent magnet synchronous motor drive

This paper aims to use a three-phase quasi-Z-source indirect matrix converter (QZSIMC) to expand the voltage gain for application in a Permanent Magnet Synchronous Motor (PMSM) drives. In this converter, a unique quasi-Z-source network (QZSN) connects the three-phase input voltage to conventional indirect matrix converter (IMC) in order to boost the supply voltage for PMSM because of limited voltage gain of IMC. Dual space vector modulation (SVM) is utilized to control the QZSIMC. The amplitude of output voltage for quasi-Z-source network is raised by the shoot-through of the rectifier stage, so the system voltage gain becomes greater. Through selecting the optimized value of shoot through duty ratio (<em>D</em>) and modulation index of the rectifier stage (), the drive system can automatically regulate the output voltage of QZSIMC during conditions of voltage sag , step change in load torque and reference speed change when the required voltage gain of QZSIMC is more than 0.866 depending on input voltage and required output voltage.The vector control technique based on closed loop speed control is proposed to control speed of the motor from zero to rated speed which is combined with the proposed converter to obtain the motor drive. The simulation results with MATLAB /Simulink 2015 are obtained to validate performance of PMSM drive.

Common-Mode Voltage Reduction With Improved Output Voltage for Three-to-Five-Phase Indirect Matrix Converters

In this paper, two common-mode voltage (CMV) reduction methods are proposed for the three-to-five-phase indirect matrix converter. The effectiveness of the proposed CMV reduction methods is due to the reconfiguration of the zero vectors from the inversion stage to the rectification stage in modulation schemes. In theory, the proposed methods not only reduce the peak value of the CMV by up to 27.9% but also improve the differential-mode performance of the output voltage, thus benefiting the electromagnetic interference design. Moreover, the voltage transfer ratio, the spectrum of the resultant CMV, and the total harmonic distortions of the current and voltage are analyzed in this paper, where, thus, the pros and cons of the proposed modulation schemes are presented. Simulations and experimental tests are provided to verify the effectiveness of the proposed methods.

SVPWM Method for Multilevel Indirect Matrix Converter with Eliminate Common Mode Voltage

The multilevel indirect matrix converter (IMC) is a merit of power converter for feeding a three-phase load from three-phase power supply because it has several attractive features such as: Sinusoidal input/output currents, bidirectional power flow, long lifetime due to the absence of bulky electrolytic capacitors. As compared to the conventional IMC, the multilevel IMC provides high output performance by increasing the level of output voltage. In this paper, the novel approach topology of multilevel IMC by using the combination of the cascaded rectifier and the three-level T-Type inverter is introduced. Furthermore, the new space vector pulse width modulation (SVPWM) method for the presented multilevel IMC that eliminate the common-mode voltage is proposed in this paper. The simulation study is carried out in PSIM software to verify the proposed modulation method. Then, an experimental system is built using a three-phase RL load, a multilevel IMC, a DSP controller board and other elements to verify the effectiveness of the proposed modulation method. Some simulation and experimental results are illustrated to confirm the theory analysis.

A novel low-cost microcontroller-based implementation of SVM algorithm for an indirect matrix converter

ABSTRACTModulation algorithms of indirect matrix converters (IMCs) are complicated and need powerful processors, such as DSP along with FPGA or CPLD for implementation. Using any extra hardware increases the cost and complexity and also reduces the reliability of the system. In this paper, a new realization for the space vector modulation (SVM) of the IMC is proposed so that it can be implemented by using a single low-cost 32-bit ARM-based microcontroller chip without any additional hardware. Therefore, due to the elimination of the extra hardware in the proposed method, the compact design in the control part of the system is provided so the reliability of the system is increased. Moreover, the cost of the system can be significantly reduced in low-power applications. This realization is based on using the timer-counter modules and the interrupt routine of the microcontroller. Therefore, the CPU burden is also minimized and the microcontroller can perform other tasks such as calculation of complex control algorithms. This feature can also be valuable in some applications. The experimental results of an IMC connected to the RL and a motor load demonstrate the validity of the proposed method.

A Novel SVM Technique With Enhanced Output Voltage Quality for Indirect Matrix Converters

In this paper, a space-vector-modulation method for indirect matrix converters is proposed to improve the output voltage quality in high modulation index ratios and to reduce the peak common-mode voltage (CMV). A novel approach in the rectifier stage modulation generates a variable dc-link voltage that is controlled to drive the inverter stage on the limit of the linear modulation during each switching period. This allows inherent formation of the output voltage using only two active vectors per sector, which reduces the peak CMV and enhances the output voltage quality. Analytical and experimental studies are carried out to validate the feasibility and the benefits of the proposed modulation technique.

A QPR-Based Low-Complexity Input Current Control Strategy for the Indirect Matrix Converters With Unity Grid Power Factor

Unity grid power factor (GPF) is essential for the indirect matrix converter (IMC) applications to satisfy the grid-friendly requirement. The existing unity GPF control strategies usually consist of high-complexity structures, resulting in difficult parameter adjustments and high-speed processor requirements. In this paper, a low-complexity input current control (LCICC) strategy is proposed for the IMC operating at the unity GPF. Unlike the conventional strategies designed in the $d$ -$q$ synchronous coordinate frame, the proposed LCICC strategy is set up in the $\alpha $ -$\beta $ stationary coordinate frame. Then, the quasi-proportional resonant (QPR) controllers are utilized for a novel input current control manner, which is implemented to regulate the input currents based on the reconstructed grid voltage and current vectors. By this design, the proposed strategy can help to reduce the control complexity, with the advantages of the conventional closed-loop control strategies reserved. The steady-state and dynamic-state performance of the proposed strategy is validated by the experiments on a downscaled prototype. Besides, comparative experimental research with respect to an existing typical strategy indicates that the computational burden can be reduced 14.9% by the proposed strategy.

An efficient control method for PMSM drive using an optimized indirect matrix converter

Abstract Recently in electrical industries, motor controls are very common due to its flexible features, for this control the variable frequency resources are the important factors. In this paper, we developed an effective control method using optimized indirect matrix converters for a PMSM system drive. In the general matrix converter, voltage transfer ratio is constrained, which is not appropriate for an application which has source voltage lower than the load voltages. In the proposed matrix converter topology, voltage can be stepped up in the conventional circuit without any additional components. Its control methodology is completely different from the conventional matrix converter. The control scheme of matrix converter proposed in this paper is controlled by means of the properly designed control loop. The result obtained will prove the effectiveness of the proposed scheme.

Modulation Strategies for Indirect Matrix Converter: Complexity, Quality and Performance

Modulation Strategies for Indirect Matrix Converter: Complexity, Quality and Performance

Modulation Strategies for Indirect Matrix Converter: Complexity, Quality and Performance

Modulation Strategies for Indirect Matrix Converter: Complexity, Quality and Performance

Optimum Boost Control of Quasi-Z Source Indirect Matrix Converter

Quasi-Z source indirect matrix converter (QZS-IMC) has been proved to have abilities of voltage boost, current filtering, variable voltage, and variable frequency. The voltage gain of QZS-IMC depends on QZS network shoot-through duty ratio D , rectifier modulation ratio $m_{i}$ , and inverter modulation ratio $m_{o}$ . Their multiple combinations are able to achieve the same voltage gain, but determining which is the optimal has not been addressed. In addition, the size of D is associated with the duration of shoot-through events of the QZS network, voltage and current stresses of power devices, and the system power losse. This paper proposes to find the optimal operation curve of D based on the constrained optimization theory. Simulation and experimental results validate theoretical analysis, the proposed optimal control, and the power loss reduction of the QZS-IMC.

Modelling and analysis of a NTVV-SVM based three-level twin-step matrix converter

Recently the tremendous advancement has been seen in the field of matrix converter topology. For high power drive applications, industries often need high power AC-AC converters like three level matrix converter because it is having the ability to generate a set of balanced sine waves for inputs as well as outputs. The three level matrix converters possess better output performance with reduced harmonic contents compared to all two-stage indirect matrix converters. In this matrix converter topology, the idea of neutral-point clamped-VSI is employed to the inversion step of the matrix converter circuitry. To control the power switches the gate signals are produced using NTVV based space vector modulation. To justify the theoretical study a complete model of a three-level twin-step matrix converter has been designed in Matlab/Simulink and its performances are analysed.

Predictive Control Strategies Operating at Fixed Switching Frequency for Input Filter Resonance Mitigation in an Indirect Matrix Converter

The classic model predictive control leads to a variable switching frequency which could produce resonances in the input filter of the matrix converter, affecting the performance of the system. This paper proposes two methods to mitigate the resonance of the input filter to solve this issue. The first method consists in a hybrid combination of model predictive current control with instantaneous reactive power minimization and an active damping method which consists in emulating a virtual resistor in parallel to the input filter’s capacitor. The second method imposes a sinusoidal source current instance to minimize the instantaneous reactive power at the input side. Both methods can be further enhanced with fixed switching frequency operations. Simulated results confirm the feasibility of the proposal demonstrating that the performance of the system is improved with source and load currents showing a significant reduction in the harmonic distortion produced by the filter resonance.

Comparison of SiC MOSFET‐based and GaN HEMT‐based high‐efficiency high‐power‐density 7.2 kW EV battery chargers

As two exemplary candidates of wide-bandgap devices, SiC MOSFETs and GaN HEMTs are regarded as successors of Si devices in medium-to-high-voltage (>1200 V) and low-voltage (<;650 V) domains, respectively, thanks to their excellent switching performance and thermal capability. With the introduction of 650 V SiC MOSFETs and GaN HEMTs, the two technologies are in direct competition in <;650 V domains, such as Level 2 battery chargers for electric vehicles (EVs). This study applies 650 V SiC and GaN to two 240 VAC/7.2 kW EV battery chargers, respectively, aiming to provide a head-to-head comparison of these two devices in terms of overall efficiency, power density, thermal performance, and cost. The charger essentially is an indirect matrix converter with a dual-active-bridge stage handling the power factor correction and power delivery simultaneously. These two chargers utilise the same control strategy, varying the phase-shift and switching frequency to cover the wide input range (80-260 VAC) and wide output range (200 V-450 VDC). Experimental results indicated that at the same efficiency level, the GaN charger is smaller, more efficient and cheaper, while the SiC charger has a better thermal performance.

Improvement in Power Quality of Matrix Converter Interfaced Wind Turbine Emulator

We have seen that the nominal power of single Wind Energy Converter Systems has been steadily growing up and reaching power ratings close to 10 MW. In the power conversion stage, we found that the medium-voltage power converters are replacing the conventional low-voltage back-to-back topology. Due to this reason the Matrix Converters interfaced have appeared as a promising solution for Multi-MW WECSs due to their characteristics such as modularity, reliability and the capability to reach high nominal voltages. In 2009-10, the country imported 159.26 million tons of crude oil which amounts to 80% of its domestic crude oil consumption and 31% of the country's total imports are oil imports. The growth of electricity generation in India has been hindered by domestic coal shortages and as a consequence, India's coal imports for electricity generation increased by 18% in 2010. So in this paper I try to develop fuzzy-logic based control strategy to capture maximum wind energy and reduce harmonics for proposed wind generation system and then develops fuzzy control for indirect matrix converter under steady-state and dynamic conditions. With these assumptions finally try to validate the proposed wind generation system in simulation environment to validate the developed control algorithms under various balanced /unbalanced conditions. Finally evaluate the performance of the developed wind generation system and its controls under various balanced/unbalanced wind conditions. During investigating details the robustness of the steady-state and dynamic performance of the developed system under various balanced/unbalanced conditions using simulation software I presents the experimental performance evaluation of the developed matrix converter prototype with wind emulator.

An Advanced Modulation Strategy for Three-to-Five-Phase Indirect Matrix Converters to Reduce Common-Mode Voltage With Enhanced Output Performance

This paper presents an advanced space vector modulation (SVM) strategy for a three-to-five-phase indirect matrix converter (IMC) to reduce common-mode voltage (CMV) with enhanced output performance. By replacing zero and medium voltage vectors with large voltage vectors to synthesize desired output voltage, the five-phase inverter stage modulation can reduce the CMV peak value by 47%, compared with the conventional SVM. In order to compensate the degraded output performance due to the absence of the zero voltage vectors, the rectifier stage modulation is modified by utilizing the two-vector and three-vector modulation techniques. Consequently, by combining the modulations of the rectifier and inverter stages, the proposed modulation strategy can suppress the CMV, as well as improve the output performance of the three-to-five-phase IMC. Simulation and experimental results are provided to verify the effectiveness of the proposed modulation strategy.

Evaluation of Synchronization and MPPT algorithms in a DFIG Wind Turbine Controlled by an Indirect Matrix Converter

&lt;span&gt;Most of generators utilized in wind turbines are the Doubly-Fed Induction Generator (DFIG). Indirect matrix converter (IMC) is a candidate for substituting the traditional back-to-back converter in the future due to advantages gained by elimination of electrolytic capacitor. Starting DFIG wind turbines and synchronizing to the grid is a challenge in practice because of large inrush currents that could damage switches. Synchronizing the DFIG wind turbine controlled by the IMC is presented in this paper. Also, maximum power point tracking algorithm performance of this configuration is examined. A laboratory scale prototype of the proposed configuration is built. Experimental results have confirmed effectiveness of this configuration.&lt;/span&gt;

Open-Circuit Fault Analysis and Diagnosis for Indirect Matrix Converter

Due to the absence of bulky dc-link capacitors, the matrix converter (MC) is a prospective candidate to replace the conventional two-stage ac–ac converter, especially in some applications which require high reliability. In order to enhance the reliability during system operation, this paper investigates an open-circuit fault detection technology for indirect MC. First, combining with the characteristics of the space vector modulation technique, this paper presents analysis work during the appearance of an open-circuit fault. Then, a novel fault diagnosis approach is proposed based on the circuit analysis. The proposed method establishes a unique corresponding relationship between switches and modulation sectors, and the faulty switch can be discriminated exactly by measuring the three-phase output voltages and the dc-link voltage. This method, which can locate the failure that occurs in rectifier stage or inverter stage correctly, offers favorable antidisturbance ability. The experiments are carried out to verify the feasibility and validity of the proposed fault detection method.