Thermal Analysis of Water Cooled ISG Based on a Thermal Equivalent Circuit Network

Abstract

-Recently, the interior permanent synchronous motor (IPMSM) has been applied to an integrated starter and generator (ISG) for hybrid electric vehicles. In the design of such a motor, thermal analysis is necessary to maximize the power density because the loss is proportional to the power of a motor. Therefore, a cooling device as a heat sink is required internally. Generally, a cooling system designed with a water jacket structure is widely used for electric motors because it has advantages of simple structure and cooling effectiveness. An effective approach to analyze an electric machine with a water jacket is a thermal equivalent network. This network is composed of thermal resistance, a heat source, and thermal capacitance that consider the conduction, convection, and radiation. In particular, modeling of the cooling channel in a network is challenging owing to the flow of the coolant. In this paper, temperature prediction using a thermal equivalent network is performed in an ISG that has a water cooled system. Then, an experiment is conducted to verify the thermal equivalent network.

Taguchi's robust design optimisation of water‐cooled ISG motors considering manufacturing tolerances

“…This is modelled by where ρ m is the density, V m is the volume, and c is the specific heat. Although the equations are simply presented in this section, the detailed expressions are shown in [2, 3].…”

“…If the current or PM loss increases, the coil or PM temperature rises. Hence, the dielectric breakdown in the coil and irreversible demagnetisation in the PMs may occur [2][3][4]. Therefore, the temperature of the coils and PMs should be analysed to prevent the damage of the motor product.…”

Taguchi robust optimum design for reducing the cogging torque of EPS motors considering magnetic unbalance caused by manufacturing tolerances of PM

“…Electric motors have been employed as a driving source for various applications and motor applications were expanded to vehicle and mechanical systems, recently. In particular, on account of high efficiency and torque density, a permanent magnet (PM) motor is mainly applied to electric power steering (EPS) systems [1][2][3][4][5]. EPS systems have increasingly been favoured as alternatives to hydraulic power steering (HPS) owing to the advances in electrical machines, sensors, and control electronics [6].…”

Characteristics of IPMSM According to Rotor Design Considering Nonlinearity of Permanent Magnet

“…ERMANENT MAGNET (PM) motors have been widely used and studied for a long time because of their high output power per unit volume by using high performance PM, high power factors [1]- [3] and easy modification of motor design into various shapes and structures [4], [5]. Particularly, there has been extensive research on electric motors using sintered NdFeB PM, where the objective was to acquire high efficiency and high output power and to minimize the motor size [6].…”