Motor Temperature Research Articles

Design and Analysis of Composite Rocket Motor Casing

Abstract: Rocket motors are widely employed to provide thrust, or impulsive force, which gives the flight vehicle a chosen velocity and facilitates delivery to the intended destination. Newton's second and third principles make up the majority of the rocket motor's operating principle. As a non-air inhalation propulsionclass, rocket motors do not require atmospheric oxygen for the combustion of the fuel that is stored inside of them. The motor hardware is going to be exposed to high temperatures and pressure loads during operation. In order to verify the rocket motor's temperatures and stress levels, structural and thermal design must be completed for the specified input parameters. This study has been approved for publication with structural

Temperature field analysis and cooling structure optimization of permanent magnet linear synchronous motor

A water-cooled permanent magnet linear synchronous motor was designed, and the investigation focused on the temperature distribution of motor and the optimization of the cooling structure to address its electromagnetic thermal effects. Firstly, the electromagnetic model of the motor was employed to calculate losses using finite element analysis. Subsequently, the motor's temperature distribution under various operating conditions was determined through electromagnetic-thermal coupling analysis, with prototype measurements validating the predicted outcomes. Secondly, the study placed emphasis on the impact of different water-cooled structure parameters on the motor's cooling performance, resulting in a 69 % reduction in the maximum temperature of the motor module after the cooling system was applied. Building on this, cooling structure parameters underwent optimization and design via the response surface optimization method, which achieved a reduction of 0.617 K in the motor's maximum temperature. The analysis findings revealed a substantial improvement in the motor's thrust performance by a factor of 3.08 when the water flow rate reached 1 m/s. This research can serve as a fundamental reference for the design of water cooling structures for permanent magnet linear synchronous motors.

Improvements on permanent magnet synchronous motor by integrating heat pipes into windings for solar unmanned aerial vehicle

The successful market uptake of all-electric propulsion systems is closely related to the performance metrics of the electrical motor used within. In light of this, various road-maps have been set for the next two decades by aerospace and automotive bodies targeting ambitious future targets of the motor's power densities and efficiencies. In achieving motors with such step-improvement performance metrics, often the thermal management is a key challenge. In this paper, a cooling structure for a propulsion motor of solar unmanned aircraft is proposed which combines the stator windings with heat pipes, and which is shown to simultaneously improve the heat dissipation as well as the efficiency. This paper firstly determines the heat transfer characteristic of the heat pipe experimentally which is then used in the development of a bespoke thermal network model of the motor. The effects of the cooling structure on the motor's temperature rise, copper losses, torque, and efficiency are studied in detail. Finally, a prototype is developed and a test platform is built. The experimental results are consistent with the analytical result, verifying the correctness of the thermal network model and the benefits of the proposed mechanism. Compared to the motor without heat pipes, the temperature rise of the motor is reduced by 35%, while its efficiency is improved by a significant 1.5%.

Model Reference Adaptive Control-Based Speed Control of Brushless DC Motors With Low-Resolution Hall-Effect Sensors

A control system with a novel speed estimation approach based on model reference adaptive control (MRAC) is presented for low cost brushless dc motor drives with low-resolution hall sensors. The back EMF is usually used to estimate speed. But the estimation result is not accurate enough at low speeds because of the divided voltage of stator resistors and too small back EMF. Moreover, the stator resistor is always varying with the motor's temperature. A speed estimation algorithm based on MRAC was proposed to correct the speed error estimated by using back EMF. The proposed algorithm's most innovative feature is its adaptability to the entire speed range including low speeds and high speeds and temperature and different motors do not affect the accuracy of the estimation result. The effectiveness of the algorithm was verified through simulations and experiments.

A Nonintrusive Winding Heating Method for Induction Motor Using Soft Starter for Preventing Moisture Condensation

Moisture condensation may cause degradation of key motor components when a motor is de-energized. To prevent moisture condensation, a motor's temperature must be maintained higher than the ambient temperature when de-energized. This paper proposes a nonintrusive motor heating technique using soft starters. By controlling the operation of the solid-state switches in soft starters, adjustable ac current can be injected into the three phases of the stator windings without inducing any output torque. The motor temperature can therefore be maintained at a desired temperature due to the heat dissipation during current injection. In addition, two motor temperature control approaches are proposed in this paper to minimize the required energy consumption for preventing moisture condensation. The proposed technique is experimentally validated on a 7.5-hp ODP (open drip proof) induction motor. The experimental results show that the average stator winding temperature can reach 9 ° above the ambient temperature with acceptable current magnitudes. In addition, it is shown that the motor temperature rise can be controlled by adjusting the operation of the solid-state switches in soft starters. The importance of the proposed technique lies in its noninvasive nature: the technique only uses the existing hardware of soft starters; the motor's condition is not interrupted since no output torque is induced during the current injection. The proposed winding heating technique can be easily extended to other types of ac machines or inverter-fed applications.

Real Time Prediction of Temperatures in an Induction Motor Using a Microprocessor

ABSTRACT The paper describes a microprocessor based thermal prediction device for induction motors, which has applications in ageing control and motor protection. A lumped parameter linear model is used to describe the dynamic thermal performance of an induction motor. The model is formulated out of purely dimensional information and constant thermal coefficients, to be applicable to any similar machine. The heat input is derived from measurements of the induction motor supply alone. The thermal model is solved in real time by a microprocessor, which estimates the motor's temperatures from the external inputs of motor phase current and ambient temperature. Results are presented for a 5.5 kW machine.