Vector Control of Multimotor Drive

Three-phase induction machines are currently the industry standard for industrial electrical drives. These machines are replacing dc drive systems for a variety of reasons, including cost, dependability, robustness, and maintenance-free operation. Three phase induction motors are operated as separately stimulated dc motors for field-oriented control. The advancement of power electronics and signal processing systems has eliminated one of the most significant drawbacks of such ac systems: the issue of control. The task of variable speed control of induction devices is no longer a disadvantage with modern field oriented vector control systems.  The desire to improve system performance, particularly when power supply and semiconductor power ratings are limited, promotes the usage of phase numbers other than three. In this chapter a novel scheme of connecting two, three phase induction motors in parallel fed by two inverters; viz. VSI and CSI and their vector control is presented and instead of using two inverters for three phase motor, a single multiphase motor design is discussed.

This paper introduces multiphase induction motor drives system under sensorless conditions, which is simulated and analyzed by utilizing its multiple control freedoms in the mode of high frequency signal injection. In this method, because nine phase induction motor have four orthogonal d-q planes compared to traditional three phase induction motor, so high harmonic plane can be used for other applications, for example, extracting rotor position based on high frequency injection signal technique. In the multiphase induction motor, inductance value is smaller in the high harmonic plane contrast to fundamental plane, in other words, it can get larger current signal amplitude under the same voltage amplitude, reducing the difficulty of the position signal extraction. changing rotor slot numbers will affect the air-gap length distribution, and it can be concluded that there is a saliency in the d 7 -q 7 plane through modulation of rotor slots. The module is simulated in the environment of simulink and ansoft.

In recent years, AC induction motors have replaced DC motor. The most important reason for this is that DC motors have a mechanical brush and commutator system that is subject to wear and tear over time. While DC motor drivers need a lot of maintenance due to this system, induction motors do not require almost any maintenance since this system is not available. In recent years, technological advances in the field of multiphase induction motors have led to a significant evolution. A lot of research has been done around the world and a lot of new and interesting developments have been reported to the literature. This paper provides information about six-phase induction. In addition, what kind of advantages the concept of multiphase provides and how this structure is formed contains information about them. The six-phase induction motor will be simulated through the MATLAB/SIMULINK package program and compare with three phase induction motor. Both motors were run in simulation using the same parameters. At the end of the simulation, current, moment and speed graphs of the six-phase induction motor and three-phase induction motor will be drawn according to time. The study also included equations used during modeling and equivalent circuits belonging to a six-phase induction motor. It has been graphically shown that a six-phase induction motor is more advantageous than a three-phase motor. For example, in six-phase induction motors, the transition time to a continuous state is shorter. In addition, while the frequency of torque vibration increases, its amplitude decreases, the current value of each phase decreases, the stator copper losses are less than the three-phase induction motor. In motors, usually the power needed is divided by the number of phases. So the more phases there are, the greater the power carrying capacity. Today, multi-phase induction motor drives are used in special applications such as electric vehicles, space technology, aerospace applications, as moving power on ships, electric trains, which require high reliability and power.

Chapter deals with electrical drives with induction machines. After short introduction concerning basic construction variants and general problems of modeling induction motor drives, mathematical models are developed on a basis of previously introduced Lagrange’s method. Models transformed in a classical way are presented by use of orthogonal transformation along with the options governing free parameters of these transformations. Subsequently, other models are developed, in which only one side electrical variables are transformed – stator’s or rotor’s, while the other side remains untransformed, with natural variables. These models are applied in simulation and presenting various problems of drive systems with electronic power converters and for other external asymmetry cases. Some of them are classical drive problems like DC breaking, operation of Scherbius drive or soft-start systems. Other concern modern systems with electronic power converters, more precisely and successfully modeled and computed in this way. They are drives with two- and three-level voltage source inverters used in PWM control (SVM, DPWM) as well as current source inverters – CSI. These kinds of models are also applied to present vector control (VC) or field oriented control (FOC) and direct torque control (DTC) of induction motor drives. Abovementioned problems are widely illustrated by examples computed for various dynamic states, with and without automatic control, and for that purpose four induction motors of different rated power are presented. Finally a problem of structural linearization of induction motor drive is covered, beside a number of useful state observer systems that are discussed.

This study investigates the effect of phase transposition on the performance of the five-phase induction machine with different stator connections, namely, star, pentagon, and pentacle. The possibility of phase transposition for the five-phase machine can be calculated from the permutations of the number of phases, which yields 120 possible sequences that the five-phase machine can be connected. The sequences in the three-phase induction machine provides either a forward- or a backward-rated full speed. However, among these 120 connections for the five-phase induction machine, this study investigates which sequences will provide forward speed, reverse speed, balanced operation, and unbalanced operation. This study also discusses the effect of these sequences on machine performance.

Based on studying the transform theory of the multiphase system and the rotor field oriented control (RFOC) of multiphase induction motor (IM), the mathematical modulation of RFOC used in multiphase IM with closed-loops of harmonic currents is modeled. It can be used to solve the problems of harmonic currents in the conventional vector control of multiphase IM. The fundamental current and each of harmonic currents can be controlled independently for decoupling. The harmonic currents can be restrained effectively. In the paper, a nine-phase IM is proposed to verify the hypothesis. Experimental results confirm the theoretical analysis well. The paper further achieves the technology of electronic pole changing (EPC) under RFOC of multiphase IM. It is feasible for multiphase IMto realize pole-changing without cutting off the power and the EPC proposed could effectively extend the operational range of constant power in multiphase IM.

Application of adaptive fuzzy control to ac machines

In general, rotating electrical machines can be modeled by an equivalent two phase machine. This means that an unbalanced 3-phase induction motor can be modeled by using an unbalanced two phase induction motor model. This paper shows this concept by modeling a faulty 3-phase induction motor in which one of its feeding phases is opened. The paper also presents a new fault-tolerant vector control (which is modified from the conventional vector control) that can be used to control a faulty three-phase induction motor. Simulation results show the good performance of the proposed method.

In this paper efficiency improvement of a Six-phase Induction Machine (6PIM) with fuzzy Anfis method is presented. Six phase induction machine is supplied by SPWM (Sine Pulse Width Modulation). The motor efficiency in low speed or low load conditions (under nominal point) is low. The purpose of this paper is to reduce core losses of six phase induction motor in these conditions. Fuzzy flux search controller is a simple technique and robust against parameter changes that can be easily implemented. Loss minimum point of six phase induction motor is related to stator current, thus by decreasing of current the loss is decreased. Results are presented in the paper to verify the effectiveness of the proposed approach. DOI: http://dx.doi.org/10.5755/j01.eee.19.10.5895

This paper presents a generalized model of multi-phase induction motor drive using matlab/simulink. Multiphase induction motor (more than three phases) drives possess several advantages over conventional three-phase drives, such as lower torque pulsation, higher torque density, fault tolerance, stability, high efficiency and lower current ripple. When the number of phases increases, it is also possible to increase the power /torque per rms ampere for the same volume machine. In this paper, a generalized dq-axis model is developed in Matlab/Simulink for a multi-phase induction motor. The simulation results are presented for 5, 6, 7, 9 and 12 phase induction motor under varying load conditions. Transient response of the multi-phase induction motors are given for different number of phases.

Modeling of three phase induction motor has been extensively discussed in literature. Several models have been developed and applied by different authors to solve different problems. This paper presents a differentmodel of the symmetrical three phase induction motor in which there is an alignment of the direct axis component of the rotor flux vector to direct axis of the reference frame. The alignment reduces the quadrature axis flux component to zero, removes the dependencies associated with the d-q components of the stator current and simplifies the rotor dynamics. The model is not commonly used in literature to study motor behavior when vector control is not the objective. The model is analyzed in the synchronous reference frame and simulated. Simulation results for torque, speed and flux in the motor are presented. Also presented are the waveforms of stator voltages and currents in both the d – q and a-b-c reference frames and the rotor d-q axis currents. These results provide a correct description of the three phase induction motor behavior under load and no-load conditions.

Induction machines are undoubtedly a crucial part of the industry and so they need to function in a stable and secured manner. Negligence in maintenance or careless operation of the induction machines can induce faults in the machines resulting in failures and ultimately giving rise to loss of funds and resources. In this paper, three phase induction motor model has been designed in LabVIEW. It has been modeled in such a way that it can be simulated as an ideal or healthy motor as well as a faulty motor having faults such a stator winding fault, rotor fault and bearing or eccentricity fault. It can be simulated for various ratings of induction motors and the values of current, voltages and different waveforms associated with the faults can be obtained which can be used in any application where faults in induction motors need to be detected.

Learning Vector Quantization Neural Network Based External Fault Diagnosis Model for Three Phase Induction Motor Using Current Signature Analysis

Induction motor is the most motor applicable in the world. especially three phase induction motor. Furthermore 95% of induction motor are used as propulsion in industry. However, maintenance costs are large enough more than 50% of operating costs of the industry or the factory. To reduce these costs is to detect early faults in induction motors. One way to detect initial faults is to measure and analyze the temperature of the induction motor. In this research, the authors design temperature monitoring of a three-phase induction motor using the internet of things to make it easier for users to monitor the temperature of an existing three-phase induction motor and to schedule maintenance if temperature reach the operating limit. The field system elements consist of SoC ESP32 to collect data from 2D temperature, to drive lead screw and to send data to cloud. The SoC ESP 32 is connected to the AMG8833 temperature sensor array which collect the frame of temperature of a three-phase induction motor in the form of an 8x8 array. In addition, the SoC ESP32 is also connected to the motor driver L293D to regulate the movement of geared DC motor. Geared DC motor is used to drive the lead screw which already has a mount for placing the AMG8833. From the test on 18.5 kW, 360V induction motor installed in chemical industry, it is obtained the sensor can measure temperature accurately and it travel smoothly above frame. In the storage using MongoDB database, the data transmission fulfilled the QoS requirement.
 

A system has built to monitor conditions of a 3-phase Induction motor. The purpose of the system is to detect fault when the Induction motor is being operated. To build a fault detection system various methods have been used in this work. A prototype setup has built to test and evaluate the results of the developed system. The first method used to develop the system was through current monitoring where sensors used to monitor the current drawn by the 3-phase Induction Motor while operating on non-faulty and faulty conditions. Vibration sensor was used to monitor vibrations from rotating shaft on no-fault and fault conditions and Vibration Energy Harvester setup was made and equipped with the system. Vibration Energy Harvester (VEH) was acquiring vibration from the rotating shaft to generate signals to feed into the system. Results were obtained from the methods used to monitor the 3-phase Induction Motor during both no fault and fault conditions. Appropriate threshold values set to all methods used to monitor condition of the 3-hase induction motor. The results obtained shows that all three methods can be used to monitor condition of 3 -phase induction motor but the stability and reliability of the results obtained differs from one another.