Indirect Matrix Converter Research Articles

Novel common-mode voltage suppression method for indirect matrix converters based on open-active vectors

Novel common-mode voltage suppression method for indirect matrix converters based on open-active vectors

Control and Performance Analysis of an Indirect Matrix Converter Fed Triple Star Induction Motor

Efficient operation is a recommended factor in most of industrial applications. In this paper, an indirect matrix converter (IMC) topology is developed and proposed to substitute the classical (AC/DC/AC) three phase converter topologies; where the control strategy is frequently performed with a voltage source inverter (VSI). Large electrolytic capacitors are viewed as hazardous due to their short lifetime compared to ordinary capacitors and power switches, as well as their contribution to the total bulk and weight of the converter. Matrix converters may be the answer to getting rid of the capacitor, shrinking the converter, and improving its efficiency (MC). These advantages are offset by the fact that the (MC) calls for a tricky switching technique based on pulse width modulation, which is prone to commutation failure. The direct frequency conversion using the indirect matrix converter (IMC) with many advantages has appeared as an alternative to these conventional voltage inverters. This study investigates a field-oriented control (FOC) scheme for indirect matrix converter fed triple star induction motor (TSIM). After building the proposed IMC converter topology, an adequate field-oriented control strategy-based space vector modulation (SVM) is proposed and adapted for the control of the triple star induction motor. The FOC technique guarantees flux and torque decoupling while ensuring good operation performance as required in many industrial applications. The obtained numerical simulation results show and confirm the effectiveness of this control scheme.

A Spread-Spectrum Modulation Scheme for a 3 × 6 Indirect Matrix Converter Based on a Current Ripple Model

Focused on addressing harmonic suppression in multiphase indirect matrix converters (IMCs), this study explores spread-spectrum modulation technology through ripple analysis calculations. We introduce a current ripple spread-spectrum modulation (CR-SSM) method tailored for multiphase IMC systems. In this approach, a 3 × 6-phase IMC is modeled as a two-port network, and a small-signal model of the output side is established. The transfer function is utilized to analyze the two-port network in the complex frequency domain (s-plane). The time-domain expression of the output current ripple is derived in vector form. Subsequently, the distribution of the output ripple and locus are determined based on specified constraints. The carrier frequency is dynamically adjusted online according to the specified ripple locus. Compared to classical periodic PWM methods, this approach offers a broader range of frequency variations and achieves a more uniform output spectrum. Furthermore, CR-SSM optimizes system efficiency and enhances spread-spectrum modulation. Experimental results demonstrate that this method effectively enhances the quality of input and output waveforms in multiphase IMC systems.

Comparative evaluation of Z source / quasi Z-source direct and indirect matrix converters for PMG based WECS

The present era sees the dominance of wind energy conversion systems as a leading technology in renewable energy. Various technologies have been devised to harness wind energy, with variable speed systems emerging as particularly advantageous. Consequently, these systems are designed to operate at specified speeds using power electronic interfaces, maximizing power extraction from the wind. The integration of Permanent Magnet Generators (PMGs), directly linked to the wind turbine lacking a gearbox, allows operation at minimum speeds. To stabilize the continuously fluctuating output voltage of the PMG, power electronic converters are extensively utilized in Wind Energy Conversion Systems (WECS), ensuring a consistent voltage and frequency output. The voltage gain of Traditional matrix converters (MCs) is limited to less than 0.866. In turn, the Z-source (ZS) and discontinuous QZSDMC, as well as ZS IMCs, topologies have achieved voltage gains exceeding 0.866. However, the former provides complicated commutation issues from DMC, while the latter incorporates a Z source network in the DC link, resulting in a non-all-silicon solution. A novel continuous QZSDMC and QZSIMC are suggested, wherein a qZS network incorporates the grid-side filtering function. This design eliminates the need for an additional input filter in the proposed system. Three newly introduced topologies of ZSDMC, QZSDMC and QZSIMC are thoroughly compared across various parameters including voltage gain, current and voltage ripples, inductor current and capacitor voltage stresses, filtering capabilities, input current, and output voltage Total Harmonic Distortion (THD), finally efficiency. The paper presents their control and modulation methods to achieve the desired performance levels. Experimental comparisons validate the theoretical analysis and demonstrate the potential of the proposed QZSDMC as a promising topology.

DSVPWM-Based SSO-PIDR Control Scheme for Indirect Matrix Converter with Unity Power Factor Under Unbalanced Grid Voltage Condition

DSVPWM-Based SSO-PIDR Control Scheme for Indirect Matrix Converter with Unity Power Factor Under Unbalanced Grid Voltage Condition

Model predictive control of LC filter integrated quasi‐Z‐source indirect matrix converter

SummaryThe LC filter integrated quasi‐Z source indirect matrix converter (QZS‐IMC) filters the input voltages and currents while highly expanding voltage boost ratio through the combined QZS network, avoiding the additional input filter while maintaining full‐silicon solution. The traditional proportional‐integral (PI) control method of IMC is realized through the PI regulators with pulse width modulation (PWM), which is complicated due to elaborated vectors computation and duty cycle composition of IMC and extra control loops design is mandatory. This paper proposes a model predictive control (MPC) for the LC filter integrated QZS‐IMC. Based on the established discrete models of circuit voltages and currents, the proposed control method measures the present circuit variables and predicts the variables in the next sampling period. Then, a predefined cost function is evaluated with the predictions and references at each active switching states of the IMC. An optimal switching state that ensures the smallest value of the cost function is applied to the power devices at the beginning of next sampling time. Simulation and experiment are carried out to demonstrate effectiveness of the proposed MPC for the LC filter integrated QZS‐IMC.

A Reduced Current Ripple Overmodulation Strategy for Indirect Matrix Converter

A Reduced Current Ripple Overmodulation Strategy for Indirect Matrix Converter

Indirect Matrix Converter Hardware-in-the-Loop Semi-Physical Simulation Based on Latency-Free Decoupling

In the process of hardware-in-the-loop simulations (HILs) of indirect matrix converters (IMCs), solving the mathematical models of complex multiswitching converter topologies has become a major problem. The conventional approach is to split the complex mathematical model into multiple serial subsystems; however, this inevitably produces delays in the simulation steps between different subsystems, leading to numerical oscillations. In this paper, the method of latency-free decoupling is adopted, which has no time-step delay between different subsystems, making each subsystem a parallel operation. This can improve the numerical stability of the simulations and can effectively reduce the step size of the real-time simulation and alleviate the problem of real-time simulation resource consumption. In this paper, we discuss in detail the modeling process of IMC hardware-in-the-loop simulations with Finite Control Set Model Predictive Control (FCS-MPC), and experimentally validate our method using the Speedgoat test platform, resulting in a simulation step size of less than 200 ns. The simulation results are compared with the results of Matlab’s Simpower power system, which allows us to evaluate the accuracy of our model.

Electricity Theft Mitigation at Low Voltage Distribution End Using Indirect Matrix Converter

This paper presents the design and implementation of an indirect matrix converter for electricity theft mitigation at low voltage distribution network. The power distribution network saddle with the responsivity of delivering electricity to consumers are been face with electricity theft through meter bypassing and hook up connections, causing significant financial inflow problem to the utility company, particularly in a developing country. A step-down indirect matrix converter was designed and simulated with a frequency range of (10 – 20Hz) at the converter’s output. The analysis of the results favours the choose of 10Hz being the wort-case scenario to mitigate electricity with a total harmonic distortion (THD) of 204.99%. With different resistive and inductive loads, the effectiveness of the real-world system was investigated and the effects of lowering the frequency from 50Hz to 10Hz were observed and in particular make the electricity unusable. The proposed system is intended to be connected at the output of the distribution transformer to convert the power frequency to 10Hz and the other unit incorporated to the meter at the consumer end to convert their power frequency to 50Hz to make it usable. This system prevents unregistered clients from using the electricity, substantially lowering electricity theft and boosting the utility company's bottom line. In comparison to previous studies, the key advantage of matrix converters is that they don't require a DC-Link capacitor, making them more reliable and suitable for installation at the customer's premises.

ANFIS based sliding mode control of a DFIG wind turbine excited by an indirect matrix converter

<span lang="EN-US">Doubly fed induction generator (DFIG) is very popular in commercial turbines installed worldwide. Indirect matrix converter (IMC) is a fully silicon-based converter without capacitor that could be used in wind turbines. In this paper a robust ANFIS based second order sliding mode controller is proposed to control the DFIG wind turbine excited by IMC converter. ANFIS is a combination of fuzzy logic control and artificial neural networks. This hybrid combination could decrease the complexity of the wind turbine system. This scheme does not need the exact mathematical model of the system as needed in classical control methods. The effectiveness of the proposed controller is verified by simulation results compared to the classical PI controller.</span>

ANN Identification technique and fuzzy PI Control of a Hybrid Indirect Matrix Converter with a Flying Capacitor three level Inverter in Power Active Filtering Application

The current paper is concerned with fuzzy controllers employing neural networks to implement control over power electronics systems committed to power quality improvement in a distribution grid. An optimization method technique for tuning fuzzy PI controller gains is introduced to improve a Hybrid Indirect Matrix Converter's control with a flying capacitor three-level inverter (HIMC), and it is connected via an RL filter to the power grid (PG). The harmonics are identified by an Artificial Neural Network (ANN). The effectiveness of this method is shown in the simulation results by MATLAB/Simulink ( Simscap, simpower blocks).

Modeling and analysis of the LC filter-integrated quasi Z-source indirect matrix converter for the wind energy conversion system

A Quasi Z-Source Indirect Matrix Converter (QZSIMC) is proposed in this paper for Permanent Magnet Generator (PMG) based Direct Drive Wind Energy Conversion Systems (DDWECS) to enhance the voltage transfer ratio and also to control the output voltage under various loading conditions. The QZSIMC comprises three Quasi Z-Source (QZS) networks connected between PMG and load through a three-phase Indirect Matrix Converter (IMC). Two different PWM control techniques such as Carrier Based Pulse Width Modulation Technique and Modified Space Vector Pulse Width Modulation Technique are proposed to analyze the performance of QZSIMC. By changing the shoot through time period, the duty ratio of quasi Z-Source network can be increased which in turn increases the boost factor of both QZSIMC without affecting the efficiency of the converter. A closed-loop control system has also been designed to sustain constant parameters at the output. The proposed QZSIMC for PMG based DDWECS along with two different PWM Control Schemes are to be modeled using MATLAB/SIMULINK environment. To validate the simulation results, a 1 kW, 415 V, 50 Hz experimental setup with an FPGA SPARTAN-6 processor has been developed in the laboratory for QZSIMC and the results are investigated based on the parameters such as output voltage, output current, Switching Stress, Boost Factor, inductor current, capacitor voltage, Total Harmonic Distortion.

A New Four-Step Commutation Method for Indirect Matrix Converter With Active-Voltage Vectors Being Applied

The existing two commutation methods of the rectifier stage for indirect matrix converter (IMC) are zero-current commutation and four-step commutation. The premise of zero-current commutation is that the inverter stage of IMC uses a zero-voltage vector, but when the inverter stage cannot use zero-voltage vectors (such as space overmodulation, common mode suppression modulation, etc.), the four-step commutation is adopted. The conventional four-step commutation method has a complex switching sequence and requires additional sensors. Based on the natural freewheeling characteristic of IMC and the switching sequence of zero-current commutation, a new four-step commutation method is proposed when active-voltage vectors are applied in the inverter stage, first turn off the two switches at 1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sup> and 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> steps, and then turn on the two switches at 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> and 4 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> steps. The switching sequence of the new four-step commutation is not affected by the polarity of input voltage or output current direction, thus solving the complexity switching sequence problem of the conventional four-step commutation, and does not require additional voltage or current sensors, making the IMC commutation process safer and more reliable. Finally, this paper verifies the effectiveness of the new four-step commutation method of IMC through experiments.

Predictive Current Control for Three-Level Four-Leg Indirect Matrix Converter Under Unbalanced Input Voltage

In this paper, a robustness evaluation of model predictive current control with instantaneous reactive power minimization for a three-level four-leg indirect matrix converter is presented. Unbalanced voltages can be extremely dangerous, especially for motors and other inductive equipment. Unbalanced voltages can have a detrimental effect on equipment and the power system, which is exacerbated by the fact that a small phase voltage imbalance can result in a disproportionately large phase current imbalance. The robustness test is carried out by considering balance and unbalanced input voltages. The proposed control predicts the behavior of the load current and the instantaneous reactive power for every possible 96 switching states. Subsequently, it selects the optimum switching state which fulfils the objectives of the control without the need of modulators. The cost function has been adequately modified to consider the asymmetrical aspect of the input voltage. Experimental validation using a laboratory prototype was conducted by using FPGA under a wide range of input voltage unbalance. The experimental results show high fidelity load current reference tracking while maintaining relatively low instantaneous reactive power during the transient and steady-state condition. The percentage of reactive power after setting the optimal weighting factor, the average reactive power was found to reduce to approximately 10-20%.

Multiple load operation of indirect matrix converter for different frequencies using symmetrical space vector modulation

AbstractThis study describes an indirect matrix converter (IMC) that uses symmetrical space vector pulse width modulation (SSVPWM) to feed two loads from a single DC link at a variable frequency. Output stage‐I is connected to the static load, while output stage‐II is connected to the PMSM for speed control. It is appropriate for drive systems with variable frequency, such as those seen in wind power generation and aviation. In recent years, significant studies on AC‐AC converters have been conducted due to the rising interest in electric cars and renewable energy. The performance of permanent magnet motors is better than that of other types of AC motors due to their superior performance and residual flux permanent magnets. Contrary to normal back‐to‐back power conversion systems, IMC does not necessitate the use of capacitors in the DC‐link, decoupled control between the two‐stages, a simple clamping circuit or zero current switching in the rectifier stage, allowing the system's volume to be reduced. It is investigated how well the two output stages of the proposed IMC perform. To illustrate the benefits of the suggested IMC design, an improved SSVPWM is employed, and MATLAB/SIMULINK‐based simulations were performed to validate the efficacy of the modulation mechanism. In addition, the real‐time implementation of the work was validated using a real‐time simulator, OPAL‐RT (OP4510).

Topology and Modulation for a New Indirect Matrix Converter to Reduce the Common-Mode Voltage

In this paper, a new indirect matrix converter (IMC) topology with two insulated gate bipolar transistors (IGBT) set in the upper and lower dc-link is proposed to suppress the common-mode voltage (CMV). Meanwhile, two new space vector modulation (SVM) strategies are redesigned to control this topology. The first strategy utilizes the equivalent zero voltage vectors to replace the zero voltage vectors for reducing the CMV, while the second strategy selects and utilizes specific active voltage vectors and equivalent zero voltage vectors to suppress the CMV based on the input current sector. Comparative simulation and experimental research for the two strategies are carried out for the new IMC topology, which validates that the CMV can be reduced to 57.7% or 37.1% of the one in the conventional IMC system. Besides, the proposed new IMC system is experimentally verified that it can keep a satisfied CMV suppression performance when feeding an induction motor. Moreover, the efficiency analysis also indicates that the new topology will not bring in obvious additional power loss under the proposed SVM strategies even though two IGBTs are added in the dc-link.

Power Quality Analysis of Six Phase Indirect Matrix Converter Based on Multi Phase Generator

Nowadays, multiphase machine drives are considered in many applications, especially for medium and highpower applications. This paper focuses on the topology of the six to three phase (hexaphase) indirect matrix converter (IMC). The matrix converter (MC) is designed based on twelve bidirectional switches for the rectifier stage and six single switches for the inverter stage. It is interfaced to a high-performance, fault-tolerant multiphase permanent magnet synchronous generator (PMSG) on one side and to the grid on the other side. In the literature, the most common MCs are of the three-phase type and papers on multiple input converters (N&gt;3) are not common. This paper deals with all possible configurations of SVM that can be deduced in a hexaphase MC to determine the modulation indexes and then to assess the VTR (Voltage Transfer Ratio). Simulations are performed on a pure inductive load and THD analysis are performed on the input currents of the MC to show the impact of the studied configurations on the system.

Multi–Port High–Frequency AC–Link and Indirect Matrix Converters: A Generalized Structure

Multi–Port High–Frequency AC–Link and Indirect Matrix Converters: A Generalized Structure

A stochastic configuration networks-based nonsingular fast terminal sliding mode control approach for indirect matrix converter-driven permanent magnet linear synchronous motors

To further improve the fast and stability of the control system of an indirect matrix converter (IMC) driven permanent magnet linear synchronous motor (PMLSM), a nonsingular fast terminal sliding mode control (NFTSMC) algorithm based on the disturbance observer of stochastic configuration networks (SCNs) is proposed. The NFTSMC algorithm is used to design the outer loop controller, which can reduce the influence of the IMC by the power supply voltage and high-frequency harmonics generated by switching. To further reduce the disturbance of IMC-PMLSM during operation, in this paper, a nonlinear disturbance observer based on SCNs is constructed, which solves the drawback that the traditional disturbance observer needs to adjust the parameters frequently under different working conditions. Finally, a simulation model is established on the MATLAB/Simulink platform to verify the effectiveness and advantages of the proposed control method.

Dual, Three-Level, Quasi-Z-Source, Indirect Matrix Converter for Motors With Open-Ended Windings

In this paper, a novel variable-voltage, variable-frequency, dual, three-level, quasi-Z-source, indirect matrix converter topology is proposed, including a detailed description of a modulation method and a control strategy for three-phase motors with open-ended windings. The proposed power drive system (PDS) supports bidirectional power flow and has a combined control of DC-link voltage and output AC voltage frequency. Experimentally validation was performed on a 4-kW PDS. For a given supply voltage amplitude and the same power switch voltage rating in the DC/AC converter, the proposed PDS can double the voltage output gain, thus being an interesting solution for high-power applications with motors designed for higher voltages. The proposed PDS topology, modulation method and motor control strategy can reduce the common-mode component, low-order harmonic content, peak values and d <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">v</i> /d <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</i> of the motor phase voltage, ultimately leading to lower winding insulation voltage stress at low-speed, low-voltage operation, lower harmonic losses in the motor, and ride-through capability over voltage sags in the mains, which are important advantages.