The topic of using elevators for vertical transportation in buildings has been discussed for many years. The continuous development of the industry, coupled with an increase in demand for housing, has led to a serious shortage of space in modern cities. As a result, tall buildings have become an integral part of everyday life. In this context, elevators are now recognized as one of the major energy consumers in the construction industry, and even a slight improvement in their performance can result in significant energy savings. Additionally, elevators are considered one of the most sensitive types of mechanical loads because they primarily transport people. Therefore, they must operate with the utmost quality and in the shortest possible time, while ensuring complete safety. Achieving these two goals together can meet the needs of this industry. The use of high-efficiency motors, such as high-pole permanent magnet synchronous motors, can be an effective step in reducing energy consumption. This is because, in addition to having higher efficiency, they eliminate mechanical elements such as gearboxes. Among various types of permanent magnet synchronous motors, the use of an interior permanent magnet synchronous motor with a maximum torque per current control strategy can provide the required torque for elevator applications efficiently due to its reluctance torque characteristics and low energy consumption. In this research, in order to reduce motor losses and achieve the maximum torque per current control strategy, the motor model is initially presented, considering iron losses. Then, by using the motor loss relationships and optimization methods such as the Pontryagin's method, a reference speed curve is introduced based on load, distance, and motor parameters. This curve is calculated exclusively for each elevator movement and minimizes motor losses while ensuring passenger comfort features such as maximum allowable speed, acceleration, and jerk (derivative of acceleration). It is observed that the methods mentioned, such as using the maximum torque per current control strategy and creating a reference speed curve proportional to load and distance, depend on motor parameters such as inductances. These parameters can change due to factors such as temperature and stator current. Therefore, in this research, a parameter estimation method based on high-frequency signal injection is proposed in such a way that it can accurately and dynamically estimate the motor inductances before movement and during the start-up, when the motor current is high. Thus, by applying this method, the dependency of the loss reduction improvement method on motor parameters can be reduced. Moreover, the capability to eliminate position sensors at low speeds can be utilized. Furthermore, with the estimation of the initial position from lower-cost encoders such as incremental encoders, it is possible to enhance the motor control system's performance. The performance of the proposed methods is initially eva‎luated in the Simulink-MATLAB simulation environment and compared with conventional methods. Additionally, to validate the simulations, the high-frequency signal injection method is implemented practically.

محمدصادق گلسرخي

غلامرضا عرب ماركده

محمد ابراهيمي , احمدرضا تابش