01. Conventional Vs. Electric Vehicles
Conventional vehicles are based on the internal combustion engine and are driven by fuel consumption. As a result, imported oil makes up a large part of a country's economy. In contrast, electric vehicles, which are powered by electricity, not only support the economy but also ensure the country's energy security. As electric vehicles become more popular, it is important to understand how they function, especially how the battery system works.
Electric vehicles rely on rechargeable batteries for their operation. While providing power to the electric motor, the battery heats up and needs to be dissipated through a thermal management system. An EV's battery cooling system
regulates the temperature of the battery and other electronic systems. So, how do electric vehicles work? What are the battery cooling methods?
02. How Electric Vehicles Work
Electric cars are the future of mobility. Compared to conventional cars, electric cars offer a better driving experience with excellent torque, power, speed, and acceleration. In addition to this, electric vehicles have other advantages such as zero fuel consumption, environmental friendliness, low maintenance requirements, high efficiency, and reliability.
These advantages are due to its principle of operation: the conversion of electrical energy to drive mechanical motion. This requires batteries, chargers, and electric motors to work in tandem with each other: rechargeable batteries supply the electric vehicle with electrical energy, which is then converted into drive power by the electric motor as required. When the batteries run out of power, the electric car will not be able to move an inch. To ensure that your electric car runs reliably, the battery is critical. So what are the common battery types?
03. Common Electric Vehicle Battery Types
Electric cars rely on various types of rechargeable batteries. Lithium-ion and lithium-polymer batteries are two of the most common in modern electric vehicles. Both have a high energy density compared to their weight. In addition to these, nickel-metal hydride batteries are also used in hybrid electric vehicles, and lead-acid batteries are used for auxiliary power supply in electric vehicles.
04. Adverse Effects Of Overheated Batteries
Overheating is one of the main culprits that accelerate the aging of batteries. Heat makes it difficult for the battery to work, and over time, battery performance will continue to decline. DC fast charging is detrimental to battery life because the fast charging current causes the battery temperature to rise.
High battery temperatures can cause the battery fluid to evaporate, damaging the internal structure of the battery and causing irreversible damage. At optimal temperatures, discharge power availability, regenerative braking charging, and battery health are at their best. As temperatures rise, battery life, EV drivability, and economy decrease. Therefore, the role of battery cooling systems in electric vehicles should not be underestimated.
05. Battery Liquid Cooling Systems in Electric Vehicles
The battery cooling system regulates the temperature of the battery pack because electric vehicles use cooling circuits containing liquid coolants such as glycol. In this, an electric pump circulates the coolant through the battery and a radiator releases the heat into the surroundings.
BCS for electric vehicles can be categorized into two types: passive liquid cooling systems and active liquid cooling systems.
Passive Liquid Cooling System
In passive liquid cooling systems, the cooling power depends on the temperature difference between the ambient temperature and the battery temperature. The cooling performance can be improved by connecting a fan behind the radiator.
Active Liquid Cooling System
The active liquid cooling system comes into play when the ambient temperature is higher than the battery temperature or when the temperature difference between the two is too small. The active liquid cooling system consists of two circuits. Its primary circuit is similar to the passive liquid cooling system. The secondary circuit, on the other hand, is located in the air conditioning circuit and consists of two heat exchangers that serve as an evaporator and condenser.
To ensure the reliability of the electric drive, fast response of the battery cooling system of the electric vehicle is essential. For this reason, accurate and reliable simulation analysis of the battery's thermal management system is required to identify problems early in the design process and reduce potential risks when the product is on the ground.
06. Simulation Analysis Solutions For Thermal Management Systems
As the industry development of electric vehicles enters the fast lane, the PCB usage of new energy vehicles can be up to several times that of traditional vehicles, and there is no doubt that their electronic costs account for a rising proportion of the entire vehicle. For higher performance and energy efficiency, a product's power stage must be able to manage larger currents while meeting stringent power dissipation and size requirements.
As a result, designers are faced with more complex battery thermal management challenges. However, at present, many thermal effect analysis methods are difficult to accurately, reliably, and comprehensively simulate their impact on the electronics, for example, problems such as over-concentration of currents are often overlooked, at which point electro-thermal co-simulation analysis is the best solution.
Over the past decades, TKT HVAC
has perfected our trolley cooling systems in order to efficiently cool batteries in electric vehicles. We have optimized the design of our battery thermal management systems, which are designed to effectively increase battery life. At the same time, the safety of electric vehicles and people is improved.