Transformers and Inductors for Electric Vehicles and Charging

Posted by Bill Dull | March 13, 2024 0 Comments

Electric cars are increasingly becoming popular due to their efficiency and smart features. Improved safety capabilities, such as autonomous driving and advanced driver-assisted systems, are fueling the demand for higher quantities of increasingly complex onboard electronic control units (ECUs). To function optimally, these circuits require automotive inductors and transformers with unique characteristics.

Components of Electric Vehicles

Before discussing these characteristics in more depth, here’s a brief primer on the key components that make up an electric vehicle (EV). It operates via an electric motor and uses energy stored in rechargeable batteries. Since they do not rely on fossil fuels for power and produce zero emissions, they are a more sustainable transportation option.

The main components of electric vehicles are:

  • Electric traction motor: The electric motor converts electrical power to mechanical energy that rotates the vehicle's wheels. Its regenerative braking mechanism slows down the vehicle and converts the kinetic energy into electrical power for future use.
  • DC/DC converter: This converts and distributes DC power from the battery to different components at the required voltage level and recharges the auxiliary battery.
  • Auxiliary batteries: The auxiliary battery powers the electronic accessories within the EV.
  • Traction battery pack: The traction battery pack powers the electric motor and functions as an electrical storage system.
  • Charge port: The charge port connects the vehicle to an external power supply, charging the battery pack.
  • Thermal cooling system: The thermal system maintains proper operating temperatures so that the EV's main components can perform optimally.
  • Onboard charger: Onboard chargers convert the AC power from the external power supply to DC energy, charging the traction battery pack.
  • Power inverter: Power inverters convert DC power to AC power, which can then be used to power onboard electronics in the vehicle.
  • Controller: Controllers regulate electrical power from the electric motor and batteries as well as torque production.
  • Transmission: The transmission transfers mechanical energy from the electric motor to make the wheels rotate. EVs don’t require multi-speed transmissions, but the gearbox should have high efficiency to prevent power loss.

Transformers and the EV Trend

The demand for electric vehicles is predicted to skyrocket over the next several years, and to keep up with the growth, electric vehicle charging infrastructure must be developed rapidly. This involves creating a mass network of EV charging stations for drivers to drive long distances without range anxiety.

Transformers are among the crucial EV charging station components facilitating energy supply during the charging process. EV charging infrastructure manufacturers must consider factors such as size, utility, power source interface, environmental friendliness, and installation costs before integrating transformers and EV charging systems. Transformers should be capable of ensuring a seamless power supply for prolonged periods as they charge different vehicles.

Currently, manufacturers are supplying medium and low-voltage smart transformers and substation lineups to be installed at commercial parking lots. Because EV chargers are non-linear loads that can cause current and voltage distortion in the power grid, proper selection of transformers is key to smooth operation of the entire system.

Power transformers are passive electromagnetic components that use inductive coupling to transfer electrical energy from one circuit to another. During this transfer, transformers convert power-level voltages, decreasing or increasing the levels based on the application’s requirements. Triad Magnetics offers both standard and custom power transformers for EV charging applications.

Inductors and the EV Trend iStock-1251125012 (3)

As mentioned above, electronic control units (ECUs) are systems that control the sensors, engines, brakes, and motors in an electric car. The latest EVs need more ECUs, sometimes more than a hundred for one car, to manage their increasingly sophisticated features and functionalities.

ECUs have DC-DC converters that regulate the battery's voltage at ideal levels to distribute power to different electric car components. Within these converters are power inductors that let DC power pass while forming a resistance against AC. The inductors are combined with integrated circuits (ICs), which perform high-speed switching and allow DC-DC converters to convert voltages to the necessary levels.

As more ECUs are installed in cars, there is increased demand for electronic components like capacitors, inductors, and EMC products. In particular, the global market for automotive inductors is projected to double that of 2020 by 2030.

Technical Considerations for Electronics in the EV Market

Triad Magnetics’ factory is IATF 16949:2016 certified, guaranteeing the highest quality and performance standards for our automotive products. Established by the International Automotive Task Force (IATF), IATF 16949:2016 is a quality management system designed to improve and standardize quality standards for automotive products around the world. Based on the ISO 9001 standard, this regulation applies to all organizations that produce components, parts, and assemblies for automotive applications.

IATF 16949:2016 certified companies follow specific frameworks to achieve the following:

  • Reduce errors and defects in products and processes
  • Comply with all relevant legal and regulatory requirements
  • Improve customer safety and satisfaction

Working with IATF 16949:2016 certified organizations gives customers peace of mind that their products are being made efficiently and cost-effectively. These high-quality products are less likely to be defective, which would otherwise result in recalls.

Two areas where EV developers must consider regulatory and safety requirements are thermal management and electromagnetic compatibility.

Thermal Management

Due to the high-voltage, high-temperature operation of electric vehicles, designs for EV electronic components like inductors must take into consideration heat management issues. At the same time, cooling systems must be compact enough to fit designated areas of the vehicle. Other problems with current thermal management systems include the limited cooling effectiveness of the gate drive, capacitors, and controllers. To address these issues, EV developers must use highly conductive, electrically isolated thermal materials that are cost-effective and do not compromise vehicle efficiency.

In EV charging stations, quick charging rates can cause considerable voltage losses and harmonics, overloading the transformer especially during peak charging times. These issues lead not only to power quality issues but also transformer and capacitor overheating. For chargers installed in locations without climate control, transformers with low temperature rise specifications work best to protect the equipment from very low and very high ambient temperatures.

Electrical Radiation Standards

Electromagnetic interference (EMI) is a concern for all electronic components, including those found in electric vehicles. EV developers must consider the electromagnetic compatibility (EMC) of vehicle powertrain components, which can malfunction if not properly shielded from EMI noise.

In charging stations, the biggest sources of EMI are DC-DC and AC-DC converters. EMI noise can disrupt the circuits and signals necessary to charge the vehicle with the right amount of power. EMI-compliant chargers must prevent EMI emission and protect electronics from the EMI emitted from other devices. Regulations for EMC-compliant EV charging stations vary depending on the environment, with some common standards including:

  • FCC Part 15 Part B - Class A / Class B
  • IEC 61851-23
  • IEC 61851-21-2

Transformers and Inductors from Triad Magnetics

The rising demand for electric cars is reflected in the rising demand for electronic components that support their performance, such as transformers for EV charging stations and inductors for ECUs.

Triad Magnetics provides over 1,000 standard part numbers, maintaining a comprehensive inventory of high-quality transformers and inductors in its global distribution network. Triad’s standard products can also be adapted into custom solutions to fit unique electric vehicle applications.

To learn more about current trends in electric vehicles and charging technology, contact Triad today. Request a quote to start your project.