Continental Says Brake System Boosts Hybrids’ Efficiency

Continental says its MK C1 brake-by-wire system for hybrid vehicles reduces carbon-dioxide emissions and improves fuel economy by maximizing electrical-energy recovery.

Results of tests supervised and certified by TÜV, an independent product-testing service, showed the MK C1 system, installed in a standard plug-in hybrid vehicle, “reduced CO2 emissions by around 8 g/mi (5 g/km) on average compared with a conventional – non-brake-by-wire – hybrid brake system,” Robert Beaver, chief engineer-electronic brake systems at Continental North America, says in a news release.

Current regulations call for light vehicles in the U.S. to emit no more than 213 g/mi (128 g/km) of greenhouse gas, primarily CO2, by 2020, down from 222 g/mi (133 g/km) this year.

The tests showed the MK C1 electrohydraulic system recovered on average 160 Wh of additional electrical energy in the deceleration phases of the individual cycle, or about 32% more than a conventional hydraulic hybrid brake system, Continental says.

The MK C1 makes this possible by consistently using the electric motor as a generator during braking, the supplier says. The intelligent hybrid control can use the additional generated electricity for fuel-efficient driving, reducing CO2 emissions and fuel consumption.

“For the efficiency of a hybrid vehicle, it is important to use up as little of the vehicle’s kinetic energy as possible on the wheel brakes, because this energy is lost,” Beaver says. “Our MK C1 brake-by-wire system enables full utilization of the recuperation potential. This allows the vehicle to recover more electricity and achieve measurable CO2 savings.”

For an MK C1-equipped EV with energy consumption of 29 kWh/100 miles, the increase in efficiency would equate to a 4% increase in range based on a 310-mile (497-km) route – more than 12 miles (19 km), Continental says.

The MK C1 system also has safety advantages. The electromechanically generated full brake pressure allows “advanced driver assistance systems or automated vehicles to be brought to a standstill more quickly from a higher speed without driver intervention than in the case of conventional brake systems,” Continental says.