Impact of PWM strategies on RMS current of the DC-link Voltage Capacitor of a dual-three phase drive

The major drawback of usual dual three-phase AC machines, when supplied by a Voltage Source Inverter (VSI), is the occurrence of extra harmonic currents which circulate in the stator windings causing additional losses and constraints on the power component. This paper compares dedicated Pulse Width Modulation (PWM) strategies used for controlling a dual three phase Permanent Magnet Synchronous machine supplied by a six-leg VSI. Since the application is intended for low-voltage (48V) mild-hybrid automotive traction, an additional major constraint arises: the compactness of the drive related to the size of the DC-bus capacitor. Thus, the PWM strategy must be chosen by taking into consideration its impact on both, the motor and the RMS value of DC-bus current

Разработка системы векторного управления полупроводникового преобразователя, обеспечивающей полигармонический режим работы многофазной электрической машины

A system for vector control of current in the circuit of a polyphase electric machine has been developed. For this, on the basis of the analysis of electromagnetic processes in a multiphase semiconductor converter of electrical energy, its discrete mathematical model was created, which takes into account the redistribution of electromagnetic energy by individual spatial harmonic components depending on the number of phases. Using this mathematical model and the scheme of injection of higher current harmonics, which provides a polyharmonic mode of operation of a semiconductor converter, a method for independent control of the spatial harmonic components of the input current of the converter has been developed. The formation in each of the phases of polyharmonic currents, conjugated in shape and phase with the voltage supplying the converter, is carried out by means of control actions in the form of voltage vectors of a semiconductor switch, the implementation of which is carried out by the method of multiphase space-vector modulation. To check the developed provisions, a simulation model of a nine-phase semiconductor converter of electrical energy with a vector control system was created. The results of the study of the model confirmed the adequacy of the developed technical solutions, the use of which will ensure the most complete realization of the own advantages of a multiphase electric machine in order to generally improve the weight, size and energy indicators of the autonomous power supply system.Разработана система векторного управления током в цепи многофазной электрической машины. Для этого на основе проведенного анализа электромагнитных процессов в многофазном полупроводниковом преобразователе электрической энергии создана его дискретная математическая модель, которая учитывает перераспределение электромагнитной энергии по отдельным пространственным гармоническим составляющим в зависимости от числа фаз. С использованием данной математической модели и схемы инжекции высших гармоник тока, которая обеспечивает полигармонический режим работы полупроводникового преобразователя, разработан способ независимого управления пространственными гармоническими составляющими входного тока преобразователя. Формирование в каждой из фаз полигармонических токов, сопряженных по форме и фазе с питающим преобразователь напряжением, осуществляется посредством управляющих воздействий в виде векторов напряжения полупроводникового коммутатора, реализация которых осуществляется методом многофазной пространственно-векторной модуляции. Для проверки разработанных положений создана имитационная модель девятифазного полупроводникового преобразователя электрической энергии с системой векторного управления. Результаты исследования модели подтвердили адекватность разработанных технических решений, применение которых позволит обеспечить наиболее полную реализацию собственных преимуществ многофазной электрической машины в целях общего улучшения массогабаритных и энергетических показателей автономной системы электроснабжения

Comparison between Three Phase and Five Phase Induction Motor by using Converter

Multiphase variable speed drives are becoming strong contenders for various applications. Industries have accepted the multilevel voltage source inverters (VSIs) and converters technologies in three-phase systems. Now a days attempts are being made for integrating multilevel VSIs and converters with the multiphase drive technology. Our paper provides a comparison between three phase and five phase induction motor by using converters. A general configuration of converter is considered and the differences with regard to the control of standard three-phase to three-phase converters are underlined. Our paper presents comparison between current, voltage and fault occurring in three phase and five phase induction motor. Our paper give parameters of five phase induction motor. ON the basis of fault occurring in three phase and five phase induction motor we had examine the working condition of the induction motor in three and five phase. DOI: 10.17762/ijritcc2321-8169.150713

Explicit model predictive control on the air path of turbocharged diesel engines

The turbocharged diesel engine is a typical multi-input multi-output (MIMO) system with strong couplings, actuator constraints, and fast dynamics. This paper addresses the air path regulation in turbocharged diesel engines using an explicit model predictive control (EMPC) approach, which allows tracking of the time-varying setpoint values generated by the supervisory level controller while satisfying the actuator constraints. The proposed EMPC framework consists of calibration, engine model identification, controller formulation, and state observer design. The proposed EMPC approach has a low computation requirement and is suitable for implementation in the engine control unit (ECU) on board. The experimental results on a turbocharged Cat ® C6.6 diesel engine illustrate that the EMPC controller significantly improves the tracking performance of the exhaust emission variables against the decentralized single-input single-output (SISO) control method

Mathematical model development of a polyphase semiconductor converter of electric power with a vector control system. Part 1

Возможность работы многофазной электрической машины в полигармоническом режиме является одним из преимуществ перед трехфазной электрической машиной. Обеспечение функционирования электрической машины в полигармоническом режиме работы позволит улучшить ее массогабаритные и энергетические показатели. При этом для получения максимальной активной мощности электрической машины необходимо решить задачу согласования во временной области полигармонической ЭДС и тока. Особенности совместного функционирования многофазной электрической машины и полупроводникового преобразователя электрической энергии обусловливают особый подход к синтезу системы управления. Для синтеза системы управления многофазным полупроводниковым преобразователем электрической энергии разработана его математическая модель, которая учитывает перераспределение электромагнитной энергии по отдельным пространственным гармоническим составляющим в зависимости от числа фаз источника электрической энергии. Разработанная математическая модель позволит реализовать способ независимого управления пространственными гармоническими составляющими входного тока полупроводникового преобразователя. Результаты математического моделирования показали, что разработанная математическая модель позволяет корректно исследовать электромагнитные процессы в многофазных полупроводниковых преобразователях электрической энергии и может являться основой для разработки системы векторного управления током в цепи электрической машины.The polyphase electric machine ability to operate in polyharmonic mode is one of its advantages over a threephase electric machine. Ensuring the electric machine operation in a polyharmonic mode will improve its weightsize and energy parameters. At the same time, in order to obtain the maximum active power of an electric machine, it is necessary to solve the matching problem of polyharmonic EMF and current in the time domain. The distinctive features of joint operation of a polyphase electric machine and a semiconductor converter of electric power determine a special approach to the control system synthesis. To synthesize the control system for a polyphase semiconductor converter of electric power, its mathematical model has been developed. It applies the electromagnetic energy redistribution over individual spatial harmonic components depending on the phase number of an electric power source. The developed mathematical model will make it possible to implement a method for independent control of the input current spatial harmonic components of a semiconductor converter. The mathematical modeling results have shown that the developed mathematical model allows proper electromagnetic process study in polyphase semiconductor converters of electric power and can be the basis for the current vector control system development in the electric machine circuit

Online estimation of rotor variables in predictive current controllers: A case study using five-phase induction machines

Predictive current control (PCC) has been recently proposed like an alternative to conventional PI-PWM current control techniques. Implemented solutions are based on inaccurate estimation of the rotor electrical variables to reduce the computational cost of the method. In this study, the utility and computational cost of PCC with different methods for the online estimation of the rotor variables are studied. Experimental results are provided to characterize the obtained benefits and drawbacks, using a five-phase induction machine as a case example.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

Modulated model predictive control for a 7-level cascaded h-bridge back-to-back converter

Multilevel Converters are known to have many advantages for electricity network applications. In particular Cascaded H-Bridge Converters are attractive because of their inherent modularity and scalability. Predictive control for power converters is advantageous as a result of its applicability to discrete system and fast response. In this paper a novel control technique, named Modulated Model Predictive Control, is introduced with the aim to increase the performance of Model Predictive Control. The proposed controller address a modulation scheme as part of the minimization process. The proposed control technique is described in detail, validated through simulation and experimental testing and compared with Dead-Beat and traditional Model Predictive Control. The results show the increased performance of the Modulated Model Predictive Control with respect to the classic Finite Control Set Model Predictive Control, in terms ofcurrent waveform THD. Moreover the proposed controller allows a multi-objective control, with respect to Dead-Beat Control that does not present this capability

FCS-MPC-Based Current Control of a Five-Phase Induction Motor and its Comparison with PI-PWM Control

This paper presents an investigation of the finite-control-set model predictive control (FCS-MPC) of a five-phase induction motor drive. Specifically, performance with regard to different selections of inverter switching states is investigated. The motor is operated under rotor flux orientation, and both flux/torque producing (d-q) and nonflux/torque producing (x-y) currents are included into the quadratic cost function. The performance is evaluated on the basis of the primary plane, secondary plane, and phase (average) current ripples, across the full inverter's linear operating region under constant flux-torque operation. A secondary plane current ripple weighting factor is added in the cost function, and its impact on all the studied schemes is evaluated. Guidelines for the best switching state set and weighting factor selections are thus established. All the considerations are accompanied with both simulation and experimental results, which are further compared with the steady-state and transient performance of a proportional-integral pulsewidth modulation (PI-PWM)-based current control scheme. While a better transient performance is obtained with FCS-MPC, steady-state performance is always superior with PI-PWM control. It is argued that this is inevitable in multiphase drives in general, due to the existence of nonflux/torque producing current components. © 1982-2012 IEEE