1,721,094 research outputs found
Multiphase machine drives
No full textVariable-speed AC drives are nowadays based on three-phase electrical machines fed by power electronic converters acting as power interface between the electrical machine and AC or DC power sources. Nevertheless, in the last two decades the multiphase electrical drives have become an interesting alternative for particular applications. However, the application of multiphase drives is still limited, mainly due to their complexity and control that somehow make them more difficult to handle with respect to the conventional three-phase counterparts. Therefore, this work intends to be a useful tool to disseminate the fundamental concepts of multiphase drives to students and application engineers
A Comprehensive Voltage-Behind-Reactance Model of Twelve-Phase Synchronous Motors
No full textThe increased interest gained by the multiphase (MP) machines in recent years is justified by their potential advantages. With respect to three-phase machines, the multiphase ones have lower phase currents for a given power thus requiring reduced semiconductor switch ratings. Additionally, they show fault-tolerant behaviour thanks to the intrinsic redundant structure. Therefore, the drive reliability can be greatly enhanced since the machine can continue to operate even if one or several phases are lost. The definition of circuital-based machine models enables the simulation of single phase or multiphase faults. This feature is essential for the development of control strategies exploiting MP fault-tolerant capabilities through the additional degrees of freedom. This paper proposes a machine model based on the voltage-behind-reactance (VBR) modelling approach that properly accounts for the multiple mutual couplings between the machine phases. Simulation results are provided for a quadruple three-phase synchronous motor
Identification of Linear Permanent Magnet Synchronous Motor Parameters and Inverter Non-Linearity Effects
No full text\ua9 2018 IEEE. The paper presents an automatic parameter identification procedure for linear permanent magnet synchronous motors. The electrical parameters of a test machine are estimated by identification tests performed through the inverter. The method employs the available feedback signals that are needed by the control. The stator resistance and machine inductances are estimated through signal injection at standstill. The permanent magnets\u27 flux-linkage identification instead requires carriage movement. Subsequently, the inverter nonlinearity characteristics are identified, again at standstill, through a flux-observer. The proposed self-commissioning process requires only the nameplate data of the machine and no datasheet information of the power electronic devices is needed. The developed techniques can be used both with and without a position sensor. The complete process is automatic and safe to run on its own and requires least intervention from the operator
Stator-Flux-Oriented Control of Synchronous Motors: Design and Implementation
No full textThis paper deals with a stator-flux-oriented control method for permanent-magnet (PM) synchronous motors and synchronous reluctance motors (SyRMs). The stator-flux magnitude and the torque-producing current component are the controlled variables. This choice simplifies the references calculation (as compared to the current control in rotor coordinates), but the dynamics seen by the inner control loops become nonlinear and coupled, potentially compromising the control performance. We propose an exact input-output feedback linearization structure and a systematic design procedure for the stator-flux-oriented control method. Simulation and experimental results are presented to verify the dynamic performance of the designed controller using a 6.7-kW SyRM drive
Model Predictive Direct Flux Vector Control of Multi-three-Phase Induction Motor Drives
Full text link\ua9 1972-2012 IEEE. A model predictive control scheme for multiphase induction machines, configured as multi-three-phase structures, is proposed in this paper. The predictive algorithm uses a direct flux vector control scheme based on a multi-three-phase approach, where each three-phase winding set is independently controlled. In this way, the fault-tolerant behavior of the drive system is improved. The proposed solution has been tested with a multimodular power converter feeding a six-phase asymmetrical induction machine (10 kW, 6000 r/min). Complete details about the predictive control scheme and adopted flux observer are included. The experimental validation in both generation and motoring modes is reported, including open-winding postfault operations. The experimental results demonstrate full drive controllability, including deep flux-weakening operation
Finite Control Set and Modulated Model Predictive Flux and Current Control for Induction Motor Drives
No full textThe paper presents a new implementation of direct flux and current vector control of an induction motor drive using the techniques of model predictive control. The advantages offered by predictive control are used to enhance the dynamics of direct flux vector control. To minimize the problems of variable switching frequency inherent to finite control set predictive control, an alternative approach using pulse width modulation is studied for command execution as occurs in the so-called modulated model predictive control. A comparison between finite control set and modulated model predictive control is presented and the results are also compared with the control implementation through traditional proportional-integral regulators to highlight the advantages and drawbacks of predictive control based strategies. Apart from a greater harmonic content in stator currents, the predictive control can offers control dynamics comparable with proportional-integral control while maintaining immunity against machine parameter variations and excluding the need for controller tuning
Decoupled Torque Control of Multiple Three-Phase Induction Motor Drives
No full textIn recent years, the development of multiple three-phase drives for both energy production and transportation electrification has gained a growing attention. An important feature of the multiple three-phase drives is their modularity since they can be configured as three-phase units operating in parallel and using a modular control scheme. The multi-stator modelling approach represents a suitable solution for the implementation of modular control strategies able to deal with several three-phase units. Nevertheless, the use of the multi-stator approach leads to relevant coupling terms in the resulting set of equations. To solve this problem, a new decoupling transformation able to deal with a decoupled torque control of multiple three-phase induction motor drives is proposed. The experimental validation has been carried out with a modular power converter feeding a twelve-phase induction machine prototype (10 kW, 6000 rpm) using a quadruple three-phase stator winding configuration
Modulated Model Predictive Direct Power Control of DFIM Considering Magnetic Saturation Effects
No full textIn this paper, an optimal voltage vector based model predictive control strategy is investigated for the direct power control of a doubly fed induction machine. The model predictive control computes optimal voltage vector that minimizes the error in active and reactive power. The computed voltage vector, if within the linear regulation range, is passed onto a modulator to be applied in the next sampling instant. In the over-modulation range the voltage vector is linearly scaled down, before modulation, to maintain optimality. The paper also focuses on the saturation of main flux inside an induction machine and its impact on reactive power control when stator current sensors are not installed. The machine's saturation characteristic is fully utilized to realize full-state stator flux observer that is used to estimate stator currents which give accurate prediction of reactive power. Consequently, stator current sensors can be excluded. Simulations and experimental analyses are conducted on a test machine to verify fast dynamics of predictive control and the estimation accuracy of stator current. © 2018 IEEE
Decoupled and Modular Torque Control of Multi-Three-Phase Induction Motor Drives
Full text linkIn recent years, the development of multi-three-phase drives for both energy production and transportation electrification has gained growing attention. An essential feature of the multi-three-phase drives is their modularity since they can be configured as three-phase units operating in parallel and with a modular control scheme. The so-called multi-stator modeling approach represents a suitable solution for the implementation of modular control strategies able to deal with several three-phase units. Nevertheless, the use of the multi-stator approach leads to relevant coupling terms in the resulting set of equations. To solve this issue, a new decoupling transformation for the decoupled torque control of multi-three-phase induction motor drives is proposed. The experimental validation has been carried out with a modular power converter feeding a 12-phase induction machine prototype (10 kW, 6000 r/min) using a quadruple three-phase stator winding configuration
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