Independent Vector Control Research Articles

Decoupled Control of a Multi-Machines System Fed by a Single Multilevel Inverter Six-Phase

The use of multiphase motors offers an additional possibility of independent control of a set of series-connected motors that are supplied from a single inverter.This paper presents independent vector control of six-phase two-motor drive machine series-connected fed by a seven-level six-phase inverter. Via appropriate phase transposition during the series connection of the stator windings, the fully decoupled control of the two machines is possible. The control system multi-machines classic based on vector control with conventional inverters comprise various problems are related to low power quality, pressure on motor bearing, etc. However, decoupling control of a series six-phase two-motor drive machine by a seven-level six-phase inverter is developed. A simulations result clearly shows the possibility of independent vector control of the two machines, although a single seven-level six-phase inverter is used as the supply.

Research on dual‐winding permanent magnet generator system with integrated dual‐channel controller

AbstractThis article presents a dual‐winding permanent magnet generator (PMG) system with integrated dual‐channel controller to meet the requirements of high power density, high reliability, and high output performance of aircraft electric power system. The dual‐winding of the PMG are designed to have the same phase spatially, with which the same rotor position can be applied in independent vector control. In addition, a dual‐channel controller is applied to control the two sets of windings, which achieves high‐performance control under normal state and fault‐tolerant control under fault state. The integrated dual‐channel controller integrates two sets of main power circuits into one controller and uses a main control unit, which simplifies the PMG system leading to reduction in the overall volume and weight. Reliability analysis of dual‐winding PMG system is proposed to be compared with that of the single‐winding PMG system. A dual‐winding cooperative control strategy and a fault‐tolerant control strategy are proposed to achieve high‐performance control of DC‐link voltage under normal condition and redundant functions under fault condition. As a result, the reliability of the PMG system is improved. The experimental results validate the effectiveness of the proposed PMG system and the control strategy.

A novel fuel-cell-driven system for rail transit vehicles based on dual-source motors

Currently, to alleviate environmental problems and energy crises, fuel cells are gradually being used in rail transit vehicle drive systems. In existing fuel-cell-driven systems, direct current (DC)/DC converters are widely used, but there are serious shortcomings in terms of cost, efficiency and market application. To solve these problems, a novel dual-source-driven system is innovatively presented in this study. In the dual-source-driven system, the multi-mode operating state of the dual-source motor was taken into consideration, and based on the independent vector control method, the dual-source-driven system was modelled and simulated to achieve the motor-independent control between power output and power generation as well as the energy exchange between fuel cell and secondary power battery under any working conditions. To verify the effectiveness of the proposed dual-source-driven system, the electric-driven performance test was carried out by the dual-source system experimental verification platform. The result for this drive system topology is further improved compared with the same level of DC/DC-driven system configuration used for this purpose.

Independent Fuzzy Logic Control of Two Five-phase Linear Induction Motors Supplied from a Single Voltage Source Inverter

Background and Objectives: The principal aim of this paper is to show an independent vector control of two five-phase Linear Induction Motors (LIMs) that are supplied from a single VSI. Methods: The LIMs are running at the same speed but with different load conditions. This concept can be especially beneficial in long trains with distributed power. To achieve excellent control characteristics and to reduce the undesirable tension forces between the train mechanical couplers, Fuzzy Logic Controllers (FLCs) have been utilized.Results: As a result, the fault occurrence of the train control systems decreases, and the system reliability increases. The results prove the electrical independence in control of a five-phase two-LIM drive supplied with a single VSI. Furthermore, in the presence of the train mechanical couplers and connections, the application of FLC offers excellent control characteristics and reduces the undesirable tension forces. Furthermore, to obtain a more worthwhile validation of the theoretical results, an experimental set up has been constructed and results have also been presented.Conclusion: According to the results, the undesirable tension forces imposed on train couplers are reduced. Consequently, it leads to higher system efficiency, lower deterioration of the train couplers and connections, greater system reliability, and higher passenger safety and comfort.

Sliding mode control of a Five-Phase Series- Connected Two-Motor Drive

In this work, we study vector control and sliding mode control of series-connected five-phase two asynchronous machines supplied with a three levels inverter. After presentation of multiphase machines, we worked out the mathematical model of five phase asynchronous machine supplied with voltage inverter. Application of Park transformation reduces considerably the mathematical model of machine. After, we applied vector control and sliding mode control to the five-phase induction machine. After that, we study a multi-machine system which comport five-phase two asynchronous machines supplied with a single voltage inverter. In the last, we had the independent vector control and the sliding mode control of series-connected five-phase two asynchronous machines. We observe that an appropriate transposition of phase’s order permits an independent control of two machines.

A six-phase series-connected two-motor drive with decoupled dynamic control supplied by a three-level six-phase inverter

This paper presents independent vector control of six-phase two-motor drive machine series-connected fed by a three-level six-phase inverter. Via appropriate phase transposition during the series connection of the stator windings, the fully decoupled control of the two machines is possible. The control system multi machines classic based on vector control with conventional inverters comprise various problems are related to low power quality, pressure on motor bearing, etc. However, decoupling control of a series- six-phase two-motor drive machine by a three-level six-phase inverter is developed. A simulations results clearly shows the possibility of independent vector control of the two machines, although a single three-level six-phase inverter is used as the supply.

Wide Air-gap Control for Multi-module Permanent Magnet Linear Synchronous Motors without Magnetic Levitation Windings

This paper proposes a wide air-gap control method for the multi-module permanent magnet linear synchronous motor (MM-PMLSM) based on independent vector control. In particular, the MM-PMLSM consists of symmetrical multi-module and multi-phase structures, which are basically three-phase configurations without a neutral point, unlike conventional three-phase machines. In addition, there are no additional magnetic levitation windings to control the normal force of the air-gap between each stator and mover. Hence, in this paper, a dq-axis current control applying a d-q transformation and an independent vector control are proposed for the air-gap control between the two symmetric stators and mover of the MM-PMLSM. The characteristics and control performance of the MM-PMLSM are analyzed under the concept of vector control. As a result, the proposed method is easily implemented without additional windings to control the air-gap and the mover position. The effectiveness of the proposed independent vector control algorithm is verified through experimental results.

Independent Position Control of Two Permanent Magnet Synchronous Motor Drives Fed by a Five-Leg Inverter

This paper presents the experimental test results of the independent vector control characteristics of two three-phase permanent magnet synchronous motors (PMSMs) fed by a five-leg inverter (FLI). Recently, the use of PMSM is more and more spreading in industrial field. It has the features of saving-weight and high-efficiency compared with DC motor and induction motor (IM). The maximum feature of the PMSMs is the realization of high performance position control. The independent position control validates for the factory automation (FA) apparatus as machine tool. If the independent position control of two motors with the FLI may be realized, the belt conveyer used at the FA apparatus as machine tool will become possible not only one dimension but also two dimensions with single inverter. In this paper, experimental results are verified for the independent position control of two PMSMs fed by the FLI with the vector control.

Modeling, Control, and Experimental Investigation of a Five-Phase Series-Connected Two-Motor Drive With Single Inverter Supply

This paper analyzes a recently introduced two-motor five-phase drive system with series connection of stator windings. It has been shown, using physical reasoning, that the introduction of an appropriate phase transposition in the series connection of two machines leads to a complete decoupling of the flux/torque-producing currents of one machine from the flux/torque-producing currents of the second machine. Consequently, independent vector control of the two machines becomes possible while using a single current-controlled five-phase voltage source inverter as the supply. The drive system modeling and control are first elaborated in this paper by taking both machines as induction motors. It is shown, using rigorous mathematical derivations, that the independent control of the two machines results due to the placement of machines in two different subspaces of the five-dimensional space. This is enabled by phase transposition in series connection. The models of the complete drive in the stationary common reference frame and in the rotor-flux-oriented reference frames of the two machines are developed. An associated vector control scheme for the two-motor drive is presented next. The second part of this paper describes an experimental setup used further on to evaluate the dynamic behavior of the two-motor drive. Performance is investigated by extensive experimentation for various transients (acceleration, deceleration, reversing, and disturbance rejection). Excellent decoupling of control of the two machines is achieved. Both the concept of the drive and the approach to modeling and control are thus fully verified experimentally. Finally, the advantages and shortcomings of the series-connected five-phase two-motor drive are discussed, and potential application areas are highlighted

Induction Machine/Syn-Rel Two-Motor Five-Phase Series-Connected Drive

Multimotor drives, based on utilization of multiphase machines, have been proposed recently. Independent vector control of all the machines of the group can be achieved while using a single multiphase voltage source inverter supply, provided that the stator windings are connected in series in an appropriate manner. The concept is applicable to any system phase number greater than or equal to five. Detailed theoretical and simulation studies have been reported for multiphase multimotor drive configurations of this type and it has been suggested that the concept is valid regardless of the type of ac machines. This paper examines operation of such a drive system when a five-phase induction machine is connected in series with a five-phase synchronous reluctance machine and provides detailed experimental verification of the possibility of independent control of the two-motor drive comprising five-phase motors of different types. The operating principles of the drive system are at first reviewed and a brief description of the experimental system is then given. An extensive presentation of experimental results, collected from a laboratory setup, is further provided. It is shown that fully independent and decoupled vector control of the two machines results, although a single supply source is used.

A performance analysis of a four‐leg inverter in two AC motor drives with independent vector control

AbstractThis paper presents a performance analysis of a four‐leg inverter (FLI) in driving two motors with vector control.We show that an expanded two‐arm modulation (ETAM) known as a modulation method of a five‐leg inverter is applicable for the four‐leg inverter and we theoretically analyze a performance analysis of the four‐leg inverter in driving two motors with vector control. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

A Series-Connected Two-Motor Six-Phase Drive With Induction and Permanent Magnet Machines

A novel concept for multimotor drives, based on utilization of multiphase machines, has been proposed recently. Independent vector control of all the machines of the group can be achieved while using a single multiphase inverter supply, provided that the stator windings are connected in series in an appropriate manner. One specific case of such a drive system is a two-motor drive, comprising a symmetrical six-phase machine connected in series with a three-phase machine. The group is supplied from a six-phase current-controlled voltage source inverter (VSI). The available considerations related to this two-motor drive system, consisting of two induction motors, are currently of purely theoretical nature, with the proof-of-concept provided by simulation only. This paper analyzes series-connected two-motor six-phase drive, comprising a six-phase symmetrical induction machine and a three-phase permanent magnet synchronous machine (PMSM) and provides, for the first time, detailed experimental verification of the possibility of independent control of the two motors. The operating principles of the drive system are at first reviewed and a brief description of the experimental system is then given. The emphasis is placed on an extensive presentation of experimental results, collected from a laboratory setup. It is shown that a truly independent and decoupled vector control of the two machines results, although a single supply source is used. The two-motor drive system of the proposed structure is seen as a potentially viable industrial solution for applications requiring one high-power and one low-power machine.

A Six-Phase Series-Connected Two-Motor Drive With Decoupled Dynamic Control

This paper analyzes a six-phase two-motor drive, consisting of a six-phase voltage-source inverter (VSI), a six-phase induction machine, and a three-phase induction machine. Stator windings of the two machines are connected in series in an appropriate manner. This enables full decoupling of the dynamics of the two machines by means of vector control. Detailed mathematical modeling of the system is performed and the set of d-q equations, describing the two machines connected in series to a six-phase VSI, is developed. The resulting model clearly shows the possibility of independent vector control of the two machines, although a single VSI is used as the supply. An experimental rig is constructed and existence of the decoupled dynamic control of the two machines supplied from a single VSI is fully verified by extensive experimental testing.

Vector Control of a Five-Phase Series-Connected Two-Motor Drive Using Synchronous Current Controllers

A novel concept for multi-motor drive applications has been developed recently, which enables dynamically decoupled control of all the machines in the group, although a single voltage source inverter is used as the supply. The concept requires utilization of multi-phase machines, whose stator windings have to be connected in series with an appropriate phase transposition, and it has been developed under the assumption that the inverter currents are controlled in the stationary reference frame. This article addresses the possibility of using synchronous current controllers within such a multi-motor drive system in order to realize fully decoupled dynamic control of all machines. The considerations of the article, although restricted to the series-connected two-motor five-phase drive system, can be extended to any other number of phases. It is shown that, in contrast to the situation that arises when current control is performed in the stationary reference frame, current control in the rotating reference frame requires appropriate modifications of the basic vector control scheme. The need for these modifications is explained and a method of realizing completely independent vector control of the two machines is proposed. The method is developed using rigorous mathematical modeling for the complete two-motor drive system. It is shown that completely decoupled dynamic control of the two machines results only if the calculation of the decoupling voltages during creation of machines' stator d-q axis voltage references is modified. Verification of the novel control scheme is provided by simulation.

A Five-Phase Two-Machine Vector Controlled Induction Moto Drive Supplied from a Single Inverter

SummaryTwo-motor drive systems, which require independent control of the two machines, are nowadays traditionally realised by using two three-phase voltage source inverters supplying independently two machines, paralleled to the common DC-link (Fig. 1). However, application of power electronics in electric drives enables utilisation of AC-machines with a phase number higher than three. If the number of phases is increased to five, an entirely different solution for the realisation of a two-motor drive system becomes feasible. It is shown in the paper that an increase of the stator phase number to five enables completely independent vector control of two five-phase machines that are supplied from a single current-controlled voltage source inverter. In order to achieve such an independent control it is necessary to connect five-phase stator windings of the two machines in series and perform an appropriate phase sequence transposition (Fig. 2). The concept is equally applicable to any five-phase AC machine type and its major advantage, compared with an equivalent two-motor three-phase drive, is the saving of one inverter leg. Instead of six inverter legs, only five are required. Detailed verification of the novel five-phase two-motor drive configuration is provided by simulating the operation in the torque and speed mode, using indirect rotor flux oriented control principles. The concept can be extended to higher number of phases in a simple manner. Its main advantages and drawbacks are addressed as well.

A Novel Concept of a Multiphase, Multimotor Vector Controlled Drive System Supplied From a Single Voltage Source Inverter

Since variable speed electric drive systems are supplied from power electronic converters, it is possible to utilize ac machines with a phase number higher than three. It is shown in the paper, using general theory of electrical machines, that an increase of the stator phase number to at least five (or more) enables completely independent vector control of two (or more) multiphase machines that are supplied from a single current-controlled voltage source inverter. In order to achieve such an independent control it is necessary to connect multiphase stator windings of the machines in series and perform an appropriate phase sequence transposition. The concept is equally applicable to any multiphase ac machine type and its major advantage, compared to an equivalent multimotor three-phase drive system, is the saving of a certain number of inverter legs. The actual saving depends on the number of phases. The concept is introduced using an n-phase induction machine as the starting point and further analysis is restricted to an odd number of phases, for the reason explained in the paper. Classification of all the possible cases that may arise is given, followed by presentation of connection diagrams for selected phase numbers. Detailed verification of the proposed concept is provided by simulating the operation of a seven-phase three-motor drive system, controlled using indirect rotor flux oriented control principles. Some preliminary experimental results, which confirm the feasibility of a two-motor series-connected drive system, are included as well. The main advantages and drawbacks of the concept, when compared with an equivalent three-phase multimotor drive system, are finally addressed.