A water-cooled power resistor for braking systems in hybrid and electric vehicles, the REOHM BWD 330, has been launched by REO. The unique design of the resistor allows excess energy generated during braking to be converted into heat and used in heating systems, increasing vehicle energy efficiency while reducing voltage transients. This makes it ideal for vehicles in agricultural, commercial, haulage and fleet applications.
The REOHM BWD 330 operates at 800V and provides continuous power between 15,000 and 60,000W depending on the model. It is resistant to temperatures from 40 to 120°C and is also capable of functioning properly under shock and vibration levels up to 100G. It is ingress protected to IP69K, meaning the device is resistant to high pressure spray-downs and shows no harmful effects on performance.
The product also reliably protects the braking system in the event of a voltage transient (spike). Voltage transients occur when vehicles brake suddenly and the power is not rapidly dissipated. As the REOHM BWD 330 converts the braking energy into heat, the water-cooling system quickly transfers this into other processes such as heating.
“Despite developments in energy recovery systems, emergency situations and high power braking will always generate excess energy,” explained Steve Hughes, Managing Director of REO. “In these situations, the heat energy generated must be immediately dissipated in order to avoid damaging the system. Traditionally, air-cooling systems are used to reduce the heat of the resistor."
“However, it is much more energy efficient to transfer this heat to other necessary processes such as heating systems. While there are a large number of directives in place to ensure vehicles are fuel efficient, there are other ways that automotive applications can be more energy efficient. Reusing braking energy in heating systems instead of simply eliminating it is one such way."
“The REOHM BWD 330 addresses this. Water is a good conductor of heat, so the product’s water-cooling system allows this energy to be efficiently reused and its design makes it easy to integrate into different systems. By using a water-cooled design, we've also reduced the footprint, which is up to 88% smaller than conventional resistors.”
The REOHM BWD 330 is certified to the latest automotive standards for mechanical and electrical components, including fire protection and electromagnetic compatibility.