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Graphic of a small hydrogen-fueled fuel cell vehicle.

Check out the interactive graphic of the power electronic components of a hydrogen-fueled fuel cell vehicle.

If you drive a car, use a computer, cook with a microwave oven, talk on any type of telephone, listen to a stereo, or use a cordless drill, you use power electronics. Thanks to power electronics, the electricity that runs the things we use every day is processed, filtered, and delivered with maximum efficiency and minimum size and weight. Inside a vehicle's electronic power steering system, power electronics control motors and help move the steering rack. This translates into improved steering response and lower energy consumption.

In broad terms, power electronics control the flow of electric power via electronic power devices. In vehicles, some of these devices convert direct current (supplied by the battery) to alternating current (required by the motor). Some common applications are electronic ignitions, power semiconductor voltage regulators, audio systems, and electronic motor controllers. Hybrid electric and fuel cell vehicles rely heavily on advanced power electronics, such as electronic motor controllers, to distribute the proper amount and type of power into and out of the appropriate subsystem at the appropriate time. The power electronics determine the exact nature and timing of the current and voltage waveforms to the motor.

Advanced power electronics is a major growth area in the world—that's why NREL takes a lead in conducting research and development in this field. And key to making hybrid electric and fuel cell vehicles practical is the development of low-cost, high-power integrated power electronics devices. In these advanced vehicles the motor controller, DC to DC converters, and inverters condition the electrical signal between the power generation unit (a fuel cell or battery) and the electric motor to provide power to various components. For example, motor controllers that use insulated gate bipolar transistors (IGBTs) regulate the power to the motor. DC to DC converters typically convert high DC voltage to low DC voltage to power the vehicle's auxiliary loads, such as lighting, windshield wipers, and radios. Inverters convert DC power from a fuel cell or battery to AC power for the electric motor. (See diagram below.)

To help commercialize advanced vehicles, NREL, DOE, industry, and other national laboratories are working on the design, development, and demonstration of advanced power electronics components and systems. Specifically, NREL is looking at advanced methods to cool and control the IGBTs and capacitors that are used inside motor controllers. For more information about these projects, visit the Research & Development pages.

The diagram below shows the basic power electronic components of a hydrogen-fueled fuel cell vehicle. Roll your mouse over each component to learn more. Graphic of fuel cell vehicle model displays it's power electronic components including: electric traction motor, 5 kW fuel cell, hybrid NiMH battery, motor controller, and radiator and a picture of a radiator showing side tank with cooler.  The electric traction motor converts electrical energy, produced by the fuel cell or battery, to mechanical to power the wheels. The fuel cell provides DC voltage that is used to power the motor and possibly other electrical devices. A fuel cell uses hydrogen gas and air to produce electricity. The battery stores electricity, which helps power the motor and other electrical devices. The motor controller takes DC power from the fuel cell or battery and delivers it to the traction motor in the form of AC power.  The controller reads the setting of the accelerator pedal (from potentiometers) and rapidly switches the power to the motor on and off - regulation the power accordingly.  A radiator is a type of heat exchanger.  It is designed to transfer heat from the hot coolant that flows through it to the air blown though it by the fan.  A goal of power electronics research focuses optimizing the fluid temperature to effectively extract the most heat.