Analyzing the thermostabilization systems of lithi-um-ion traction batteries of electric vehicles

Problem. Possible implementations of thermal stabilization systems for traction batteries of electric vehicles are considered. The analysis of possibilities to increase the efficiency of using lithium-ion rechargeable batteries at the expense of their temperature stabilization is carried out. The influence of the temperature factor on the useful capacity of traction batteries is shown. The microcontroller system of temperature stabilization of double action with function of the timer allowing to establish prematurely a mode of both cooling, and heating of storage batteries is offered. Methodology. The methods of theoretical basic electrical engineering have been developed in the production and calculation of circuits as well as the classical methods of statistics of signals from ADC. Results. The technique of processing information from the current, voltage and temperature sensors using a mathematical apparatus without using harmonic analysis is presented. The hardware implementation of the proposed method allows the use of simplified computing tools. Originality. Complex analysis of the data obtained from the current, voltage and temperature sensors is carried out. During the analysis, the range of velocities with stable operation of the measurement system was determined. Based on the data obtained, it is concluded that the use of a horn antenna as a concentrator substantially eliminates lateral interference and extends the range of possible velocity measurements. It is shown that the level of sampling significantly affects the upper limit of the measurement temperature. Practical value. The following results were obtained: - minimizing the harmful effects of negative temperatures on the battery capacity is possible through the use of preheating; - the system of temperature stabilization should be performed with the possibility of reversing the mode of circulation of thermal energy; - simplification of the process of determining the temperature is possible due to indirect measurements of the internal resistance of the heater; - in the case of pulse-width control, the service life of the heaters increases, and the heating time is reduced at constant power consumption; - application of the microprocessor system allows to increase functionality and flexibility of adjustment of the heating unit under various traction batteries.

The effect of operating parameters on the heat transfer in the heat pipe

Heat pipes are a good solution for temperature stabilization, for example, of microelectronics, because these kinds of systems are without any moving parts. Experimental research of the effect of operating parameters on the heat transfer in a cylindrical heat pipe has been conducted. The effect of the working fluid properties and the porous layer thickness on the heat flux and temperature difference in the heat pipe has been investigated. The temperature field of the heat pipe has been investigated using the IR-camera and K-type thermocouples. The data obtained by IR-camera and K-type thermocouples have been compared. It is demonstrated the power transferred from the evaporator to the condenser is a linear function of the temperature difference between them.

Investigation of the Effect of Temperature Stabilization in Radiation–Heat Converters Based on a Strong Absorbing Coating

Light–heat converters are promising for further development of contact laser surgery. The simplest converter consists of an optical fiber with a strong absorbing layer at the tip. We studied the time dependence of the tip temperature at different CW laser powers and revealed that, in several seconds, the temperature evolution becomes almost power-independent. Mathematical modeling showed that laser ablation of the tip coating is the main reason for this phenomenon.

A Realization of Stabilizing the Output Light Power from a Laser Diode: A Practical Approach

Semiconductor Laser Diodes (LDs) are known for their sensitivity to variation in ambient temperature. With the rise in case temperature the threshold current of the LD increases, causing the output light power to deteriorate drastically. Therefore, it is necessary to stabilize the temperature of the diode. Various approaches could be adopted in this regard. In this paper, an active cooling approach using the temperature compensation technique has been followed and presented in the form of a full design of the circuit according to the various datasheet parameters of the LD and other components. As a result of temperature stabilization, a significant improvement in the output light power stabilization was observed and the results are presented.