A real-time temperature rise prediction method for PM motor varying working conditions based on the reduced thermal model

Real-time and accurate temperature rise calculation can play a preventive role in preventing overheating motor damage. This article proposes a temperature rise calculation method for varying working conditions PM motors based on a reduced order model. The calculation model of this method consists of a thermal conductance matrix and a heat source matrix. The thermal conductance matrix is obtained by reducing the order of the detailed lumped parameter thermal network (DLPTN) conductance matrix, which significantly reduces the model order while retaining computational accuracy. A loss prediction function is introduced in acquiring the heat source matrix, which is constructed based on the relationship between motor loss and speed and power. It can predict the stator iron loss and PM loss with different speeds and powers in real-time, ensuring the accuracy of heat source loading. The experimental results show that this method can predict the temperature rise of critical nodes of the PM motor in real-time under varying working conditions. Its calculation results have high accuracy, providing an effective method for overheating PM motor protection.