Abstract This paper presents a novel design of an energy optimization approach for Induction Motor (IM) drives. Differently from former optimal control studies, the proposed control strategy is based on a designed cost function given as a weighting sum of power and energy models. The problem to be considered is to achieve the loss minimization of IM drives for any possible constraints imposed by the machine power quantity, such as ramp inputs in accelerate and decelerate modes and during different torque levels. The suggested energy optimization strategy, using the concept of Rotor Field Oriented Control (RFOC), allows a low-order current-fed IM model by means of a high-gain current control loop, which considers the stator currents as new inputs to the model and the rotor flux as a main state variable. An optimal rotor flux trajectory is determined by an off-line algorithm based on an optimal closed-loop control problem resulting in the Hamilton Jacobi Bellman equation. The resolution leads to an analytical solution which is implemented to RFOC and performs loss energy minimization during transient speed. Aiming to check the validity of the proposed strategy, a comparison study is conducted between RFOC operating with the optimal rotor flux and RFOC using a rated flux norm. The simulation and experimental results obtained for a 1.5 KW laboratory IM demonstrate the effectiveness of the proposed strategy.

中文翻译：

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瞬态过程中感应电机的损耗最小化

摘要 本文提出了一种用于感应电机 (IM) 驱动器的能量优化方法的新颖设计。与以前的最优控制研究不同，所提出的控制策略基于设计的成本函数，作为功率和能量模型的加权和。要考虑的问题是在机器功率量施加的任何可能约束下实现 IM 驱动器的损耗最小化，例如加速和减速模式下以及不同扭矩水平期间的斜坡输入。建议的能量优化策略，使用转子磁场定向控制 (RFOC) 的概念，允许通过高增益电流控制回路的低阶电流馈电 IM 模型，将定子电流视为模型的新输入转子磁通作为主要状态变量。最佳转子磁通轨迹由基于产生 Hamilton Jacobi Bellman 方程的最佳闭环控制问题的离线算法确定。该分辨率导致了一个解析解决方案，该解决方案实施到 RFOC 并在瞬态速度期间执行能量损失最小化。为了检查所提出策略的有效性，在使用最佳转子磁通的 RFOC 和使用额定磁通范数的 RFOC 之间进行了比较研究。为 1.5 KW 实验室 IM 获得的模拟和实验结果证明了所提出策略的有效性。该分辨率导致了一个解析解决方案，该解决方案实施到 RFOC 并在瞬态速度期间执行能量损失最小化。为了检查所提出策略的有效性，在使用最佳转子磁通的 RFOC 和使用额定磁通范数的 RFOC 之间进行了比较研究。为 1.5 KW 实验室 IM 获得的模拟和实验结果证明了所提出策略的有效性。该分辨率导致了一个解析解决方案，该解决方案实施到 RFOC 并在瞬态速度期间执行能量损失最小化。为了检查所提出策略的有效性，在使用最佳转子磁通的 RFOC 和使用额定磁通范数的 RFOC 之间进行了比较研究。为 1.5 KW 实验室 IM 获得的模拟和实验结果证明了所提出策略的有效性。