Control Of Matrix Converter Research Articles

Математический анализ и моделирование преобразователя частоты матричного типа с непосредственным управлением по методу пространственно-векторной модуляции

Математический анализ и моделирование преобразователя частоты матричного типа с непосредственным управлением по методу пространственно-векторной модуляции

負荷周波数が電源周波数に同期したときのモジュラーマトリックスコンバータ制御

負荷周波数が電源周波数に同期したときのモジュラーマトリックスコンバータ制御

매트릭스 컨버터로 구동되는 유도전동기의 직접토크제어를 위한 모델예측제어 기반의 SVM 기법

This paper proposes a MPC (Model Predictive Control) method for the torque and flux controls of induction motor. The proposed MPC method selects the optimized voltage vector for the matrix converter control using the predictive modeling equation of the induction motor and cost function. Hence, the reference voltage vector that minimizes the cost function of the torque and flux error within the control period is selected and applied to the actual system. As a result, it is possible to perform the torque and flux control of induction motor using only the MPC controller without a PI (Proportional-Integral) or hysteresis controller. Even though the proposed control algorithm is more complicated and has lots of computations compared with the conventional MPC, it can perform torque ripple reduction by synthesizing voltage vectors of various magnitude. This feature provides the reduction of amount of calculations and the improvement of the control performance through the adjustment of the number of the unit vectors n. The proposed control method is validated through the PSIM simulation.

Research on Matrix Converter Based on Space Vector Modulation

In this study, we study the control strategy for matrix converter. Through absorbing ideas about virtual rectification put forward by P.D.Ziogas, the common control idea of AC-DC-AC convertor is introduced into control of matrix converter; SPWM modulation strategy and space vector modulation strategy for matrix converter are studied respectively. In terms of SPWM modulation strategy, it has some advantages: for example, main circuit structure is simple; control program is simple; control switch function does not need complex mathematical derivation and calculation. In terms of space vector modulation strategy, it has advantages as follows: the physical conception is clear; input power factor can be adjusted; output voltage and current sine degree are high. In this chapter, an in-depth analysis will be conducted for this control method.

High Performance Current Controller for Sparse Matrix Converter Based on Model Predictive Control

A novel predictive current control strategy for a sparse matrix converter is presented. The sparse matrix converter is functionally-equivalent to the direct matrix converter but has a reduced number of switches. The predictive current control uses a model of the system to predict the future value of the load current and generates the reference voltage vector that minimizes a given cost function so that space vector modulation is achieved. The results show that the proposed controller for sparse matrix converters controls the load current very effectively and performs very well through simulation and experimental results.

Generalized Direct Modulation Control Methods for Matrix Converters under Balanced and Unbalanced Operations

In this paper, the modulation strategy is developed for N-phase to m-phase matrix converters. Three switching strategies based on pulse width modulation (PWM) technique for control of matrix converters are proposed here. These are named positive, negative and combined switching strategies. By these switching strategies, the balanced and unbalanced output voltages are generated by any set of balanced and unbalanced input voltages. In the combined switching strategy, the output voltages can be established from the α part of the positive switching strategy and β part of the negative switching strategy. The factors α and β have a strong influence on the control of the different characteristics such as control of the input power factor regardless of the load power factor, elimination of the input current harmonics, reduction of total harmonics distortion (THD), etc. The proposed control methods can be easily developed for different types of the matrix converters regardless of the number of phases and the type of waveforms in input and output sides. The experimental and simulation results verify the capabilities of the proposed control methods in generating the desired output voltages.

A Simple Carrier-Based Modulation for the SVM of the Matrix Converter

Today, industry has not fully embraced the matrix converter solution. One important reason is its high control complexity. It is therefore relevant to propose a simpler but efficient modulation scheme, similar as three phase voltage source inverter modulators with the well-known symmetrical carrier-based ones. The modulation presented in this paper is equivalent to a particular space vector modulation (SVM) and takes into account harmonics and unbalanced input voltages, with the same maximum voltage transfer ratio (86%). The aim of this work is to propose a simple and general pulse-width-modulation method using carrier-based modulator for an easier matrix converter control. Furthermore, a simple duty cycle calculation method is used, based on a virtual matrix converter. Finally, simulations and experimentations are presented to validate this simple, original and efficient modulation concept equivalent to matrix converter SVM.

Implementation of EKF based sensorless drive system using vector controlled PMSM fed by a matrix converter

A PMSM sensorless drive fed by a matrix converter has been designed to show that a drive system with high performance and efficiency can be constructed by combining the advantages of matrix converters, permanent magnet synchronous motors and sensorless control. Sensorless control of the motor is performed by using Extended Kalman Filter. The characteristics of matrix converter and performance of PMSM which are implemented by using a digital signal controller has been analyzed. Differences between the sensored and sensorless PMSM drive systems are also presented by considering the waveforms of the drive system. Promising results illustrated that EKF based sensorless control of matrix converter fed PMSM drive system with a good performance is achievable at medium and high speed operations.

Control of indirect matrix converter with bidirectional output stage for micro-turbine

In this study, a new AC-DC-AC matrix converter is developed. This matrix converter is designed to connect a micro-turbine to the grid, to replace the traditional system used in micro-turbines, which is based on an inverter-rectifier system (VSR/VSI) with energy storage elements. A specific power circuit is introduced. The circuit consists of two stages, where the second stage is bidirectional. Also, a new switching technique is presented for the circuit mentioned above, which works with two voltage space vectors. The first vector corresponds to the input voltages (variable frequency) and second one to the output voltages (fixed frequency). This technique switching allowing to replace the VSR/VSI regarding operational concerns, with less loss, at lower cost and lower weight. For verifying the control algorithm, a laboratory prototype has been developed, using among other elements a Spectrum Digital eZdspTM TMS320F2812 card. In addition, the model predictive control (MPC) is used to control the electrical power of the micro-turbine generator by manipulating the fuel flow. The suggested method provided the optimal functioning not only for the small step changes but also for large random step changes.

Low-frequency dynamic modelling and control of matrix converter for power system applications

High-power density of a matrix converter (MC) necessarily introduces tight dynamic input–output coupling, which complicates controller design for high bandwidth applications. Strong contemporary interest in MC-based solutions for synchronous, power system applications demands high dynamic performance out of the MC, operated as a closed-loop system. The requisite system models reported either treat the MC – with its input and output filters – as a ‘black-box’ characterised by a set of eigenvalues, derived from linearised analysis around an equilibrium point. Alternatively, large-signal system analysis was reported for a feed-forward control approach with prescription of a throughput power boundary for stable operation. This study provides a designer's insight into MC modelling, based on linearised analysis, clearly establishing the influence of individual physical sub-systems on the overall dynamic performance. Onset of a cluster of right-half zeros, decided solely by the input filter, power factor, source voltage and power throughput, is shown to be the only factor threatening closed-loop stability. Subsequently, a controller with output feedback is designed to ensure stable operation well beyond the throughput power limit prescribed earlier. Comprehensive simulation and experimental results are provided to validate the analytical model and controller design.

Matrix Converter Based on Asymmetric Regular Sampling Method SPWM Control Strategy

In this paper, the Matrix converter can be viewed as AC-DC-AC converter, the asymmetric regular sampling method SPWM control technique is applied in the control of matrix converter, the asymmetric regular sampling method SPWM control strategy of matrix converter, 48 allowed switch combinations and Four-Step Current Commutation method is presented. Based on Matlab/simulink the simulation of the matrix converter with such strategy is carried out. Inductive load simulation is carried out on the matrix converter prototype. The simulation results verify the workability of the asymmetric regular sampling method SPWM strategy for matrix converter.

Design and Dimensioning of Essential Passive Components for the Matrix Converter Prototype

The continuous popularity of the research in the area of the matrix converter control theory has been supported by steady technological improvements. It is still common to use discrete semiconductor switches in an anti-serial connection, even though some integrated solutions have been presented by various vendors already. Furthermore, recently experimental all-in-one matrix converter power modules based on reverse blocking transistors were introduced. However, this development has not eliminated the need of the protection circuit and other passive components in the converter's power part. This article strives to describe design procedure for one kind of the matrix converter protection circuits and the design of the input filter for the 3 × 3 matrix converter prototype.

Matrix Converter Fed Field-Oriented Control of Permanent Magnet Synchronous Motor

Field-oriented control of permanent magnet synchronous motor fed by matrix converter is designed. By introducing space vector modulation for inverter, AC-AC matrix converter is equivalent to AC-DC-AC substitution. Then, perfect PWM technology is adopted for virtual rectifier and virtual inverter of substitution whose modulating schedule and model are analyzed and deduced. of field-oriented control for matrix converter fed permanent magnet synchronous motor is built up. Finally, simulations are carried out, and simulating results show that the proposed system is feasible and valid, which provides theoretical foundations for experimentation.

Simulation Model of Space Vector Modulated Control Matrix Converter-fed Induction Motor

Matrix converters as induction motor drivers have received considerable attention in recent years because of its good alternative to Voltage Source Inverter Pulse Width Modulation (VSI-PWM) converters. This study focus on developing a mathematical model for a Space Vector Modulated (SVM) direct controlled matrix converter. The mathematical expressions relating the input and output of the three phase matrix converter are implemented by using MATLAB/SIMULINK. The duty cycles of the switches are modeled using space vector modulation for 0.5 and 0.866 voltage transfer ratios. Simulations of the matrix converter loaded by passive RL load and active induction motor are performed. A unique feature of the proposed model is that it requires very less computation time and less memory compared to the power circuit realized by using actual switches. In addition, it offers better spectral performances, full control of the input power factor, fully utilization of input voltages, improve modulation performance and output voltage close to sinusoidal.

Fuzzy Controller for Matrix Converter System to Improve Its Quality of Output

In this paper, Fuzzy Logic controller is developed for ac/ac Matrix Converter. Furthermore, Total Harmonic Distortion is reduced significantly. Space Vector Algorithm is a method to improve power quality of the converter output. But its quality is limited to 86.7%.We are introduced a Cross coupled DQ axis controller to improve power quality. The Matrix Converter is an attractive topology for High voltage transformation ratio. A Matlab / Simulink simulation analysis of the Matrix Converter system is provided. The design and implementation of fuzzy controlled Matrix Converter is described. This AC-AC system is proposed as an effective replacement for the conventional AC-DC-AC system which employs a two-step power conversion.

Synchronous control of indirect matrix converter for three-phase power conditioner

This paper describes an average model of indirect matrix converter (IMC) with an output LC filter in stationary and rotating reference frames. The developed model is non-linear and should be linearized in order to design linear controllers. Transient performance of the IMC is compared with that of conventional inverter in classic AC/DC/AC system. In order to make the IMC applicable for power conditioner applications a synchronous controller is designed. A power conditioner acts in one or more ways to deliver a voltage of the proper level and characteristics to enable load equipment to function properly. In order to afford the power conditioner requirements the controller has two segments. One segment controls the IMC with balanced input supply voltage and the other controls the system with unbalanced input supply voltage. The system can provide balanced output voltages with slight distortion of line side currents. Theory analyses, the model validation and simulation results are presented to verify the effectiveness of this control method.

Simple Power Control for Sensorless Induction Motor Drives Fed by a Matrix Converter

This paper presents a new and simple method for sensorless control of matrix converter drives using a power flowing to the motor. The proposed control algorithm is based on controlling the instantaneous real and imaginary powers into the induction motor. To improve low-speed sensorless performance, the nonlinearities of a matrix converter drive such as commutation delays, turn-ON and turn-OFF times of switching devices, and on-state switching device voltage drop are modeled using a PQ power transformation and compensated using a reference power control scheme. The proposed sensorless control method is applied for the induction motor drive using a 3 kW matrix converter system. Experimental results are shown to illustrate the feasibility of the proposed strategy.

Enhanced stability of matrix converter cage drive using digital filter

In this article, the stability of the closed-loop, controlled matrix converter (MC)-fed induction motor drive system is evaluated by analyzing the migration of eigenvalues of the system state matrix, linearized around the operating point for closed-loop controlled MC-fed induction motor drive. A digital low-pass filter has been applied to the input voltages, and using these filtered voltages for calculating the duty-cycles of the MC, the system stability can be improved.

Analysis, Control and Comparison of Hybrid Two-Stage Matrix Converters for Increased Voltage Transfer Ratio and Unity Power Factor

Matrix converters have no boost capabilities. Their output voltage amplitude is therefore reduced compared to back-to-back inverter topologies. Moreover, they are sensitive to grid voltage fluctuations and disturbances and the voltage transfer ratio is further reduced under such grid perturbations. The present paper analyses the behaviour and limits of the two-stage matrix converters. It proposes and investigates three alternative topologies that modify the DC-link voltage of the two-stage matrix converter, by the means of additional circuitry, in order to increase the voltage transfer ratio above unity and to obtain immunity to grid disturbances. A high-performance control of the grid current is required to obtain a power factor close to unity. An effective control method is proposed for each converter. Feed-forward model based controllers allow obtaining good performances. Finally, the performances of the topologies are analysed and compared.

Optimal control of matrix converter based WECS for performance and stability enhancement at low wind speeds

In this paper, optimal control of new wind energy conversion scheme where four-leg improved matrix converter (MC) is used for performance and stability enhancement, particularly for sites where most of the time low wind speeds prevails, has been explained. The power factor at the interface with the grid is controlled by the MC to ensure purely active power injection into the grid for optimal utilisation of the installed wind turbine capacity. The generation system has fuzzy logic control with vector control in the inner loops. Fuzzy controller tracks the angular frequency with the wind velocity to extract the maximum power and programs the machine flux for performance, stability and efficiency enhancement during light load and low speeds. The complete control system has been developed and analysed using MATLAB/Simulink.