Dynamic output feedback linearizing control of saturated induction motors with torque per ampere ratio maximization

The paper presents a novel maximum torque per Ampere (MTA) controller for induction motor (IM) drives. The proposed controller exploits the concept of direct (observer based) field orientation and guarantees asymptotic torque tracking of smooth reference trajectories and maximizes the torque per Ampere ratio when the developed torque is constant or slowly varying. A dynamic output-feedback linearizing technique is employed for the torque subsystem design. In order to improve torque tracking accuracy a motor magnetizing curve is taken into account during MTA optimization and controller design. The achieved steady-state system efficiency have been compared experimentally for three types of controllers, namely: standard vector control with constant flux operation, controller based on classic maximization of torque per Ampere ratio for linear magnetic circuit and controller based on MTA strategy for saturated induction motor. It is shown experimentally that the controller designed for saturated induction motor provides not only higher torque per Ampere ratio but also increases power factor and reduces active power consumption hence improving the drive efficiency. Operation with slowly varying torque references has also been analysed. It is shown that the proposed controller is suitable for applications that do not demand an extremely fast dynamic response, for example for electric vehicle drives

Maximum torque-per-amp tracking control of saturated induction motors

An improved maximum torque per Ampere (MTPA) controller for induction motor (IM) drives is presented. The proposed MTPA field oriented controller guarantees asymptotic torque tracking of smooth reference trajectories and maximises the torque per Ampere ratio when the developed torque is constant or slow varying. Due to use closed loop flux observer and high-gain PI controllers for both stator current components the proposed solution provides improved robustness with respect to parameters variations and inverter non-idealities. Experimental tests prove the accuracy of the proposed control over a full torque range. In addition, a higher torque per Ampere ratio is achieved together with an improved efficiency of electromechanical energy conversion

Maximum torque-per-Amp control for traction IM drives: theory and experimental results

A novel maximum torque per Ampere (MTPA) controller for induction motor (IM) drives is presented. It is shown to be highly suited to applications that do not demand an extremely fast dynamic response, for example electric vehicle drives. The proposed MTPA field oriented controller guarantees asymptotic torque (speed) tracking of smooth reference trajectories and maximises the torque per Ampere ratio when the developed torque is constant or slow varying. An output-feedback linearizing concept is employed for the design of torque and flux subsystems to compensate for the torque-dependent flux variations required to satisfy the MTPA condition. As a first step, a linear approximation of the IM magnetic system is considered. Then, based on a standard saturated IM model, the nonlinear static MTPA relationships for the rotor flux are derived as a function of the desired torque, and a modified torque-flux controller for the saturated machine is developed. The flux reference calculation method to achieve simultaneously an asymptotic field orientation, torque-flux decoupling and MTPA optimization in steady state is proposed. The method guarantees singularity-free operation and can be used as means to improve stator current transients. Experimental tests prove the accuracy of the control over a full torque range and show successful compensation of the magnetizing inductance variations caused by saturation. The proposed MTPA control algorithm also demonstrates a decoupling of the torque (speed) and flux dynamics to ensure asymptotic torque tracking. In addition, a higher torque per Ampere ratio is achieved together with an improved efficiency of electromechanical energy conversion

Indirect field-oriented torque control of induction motors with maximum torque per ampere ratio

В даній статті представлено нові теоретичні та експериментальні результати в галузі векторного керування асинхронними двигунами. Розроблено новий алгоритм непрямого струмового векторного керування моментом асинхронного двигуна, який гарантує максимальне співвідношення момент-струм в усталених режимах роботи. Запро-понований алгоритм забезпечує достатньо високі динамічні показники регулювання моменту, що підтверджено результатами математичного моделювання та експериментальних досліджень.The paper reports new theoretical and experimental results in vector control of induction motors. A novel indirect field-oriented torque tracking controller is designed for current fed induction machine, which guarantees maximal torque per Ampere ratio during steady state. The proposed controller assures quite fast dynamics in the torque response. Results of simulation and experimental tests illustrate important features of the control proposed.В этой статье представлены новые теоретические и экспериментальные результаты в области векторного управления асинхронными двигателями. Разработан новый алгоритм непрямого токового векторного управления моментом асинхронного двигателя, который гарантирует максимум соотношения момент-ток в установившихся режимах работы. Предложенный алгоритм обеспечивает достаточно высокие показатели качества регулирования момента, что подтверждено результатами математического моделирования и экспериментальными исследованиями

Induction motors torque control with torque per ampere ratio maximization

The paper reports new theoretical and experimental results in vector control of induction motors. A novel direct field-oriented torque tracking controller is designed using output-feedback linearizing procedure which guarantees asymptotic torque tracking and maximal torque per Ampere ratio during steady state. The efficiency improvement is obtained by adjusting the flux level according to optimization procedure of maximal torque per Ampere (MTA) ratio that is very close to the optimization criterion of minimum losses. Main advantage of MTA control is simplicity of practical implementation. The proposed controller assures quite fast dynamics in the torque response and exponential stability. An intensive experimental investigations proof the effectiveness of the proposed control technique

Dynamic output feedback linearizing control of saturated induction motors with torque per ampere ratio maximization

The paper presents a novel maximum torque per Ampere (MTA) controller for induction motor (IM) drives. The proposed controller exploits the concept of direct (observer based) field orientation and guarantees asymptotic torque tracking of smooth reference trajectories and maximizes the torque per Ampere ratio when the developed torque is constant or slowly varying. A dynamic output-feedback linearizing technique is employed for the torque subsystem design. In order to improve torque tracking accuracy a motor magnetizing curve is taken into account during MTA optimization and controller design. The achieved steady-state system efficiency have been compared experimentally for three types of controllers, namely: standard vector control with constant flux operation, controller based on classic maximization of torque per Ampere ratio for linear magnetic circuit and controller based on MTA strategy for saturated induction motor. It is shown experimentally that the controller designed for saturated induction motor provides not only higher torque per Ampere ratio but also increases power factor and reduces active power consumption hence improving the drive efficiency. Operation with slowly varying torque references has also been analysed. It is shown that the proposed controller is suitable for applications that do not demand an extremely fast dynamic response, for example for electric vehicle drives