In addition to the functionality and efficiency of the power electronics, the space requirements and weight are important criteria for automotive manufacturers. Continental’s third generation of power electronics is six times more powerful than the first generation, and the weight has been reduced from around 12 kg originally to around 8 kg, said Axel Weber, Head of Power Electronics Development in the Hybrid Electric Vehicle Business Unit.

Continental’s power electronics are designed as a modular and scalable system, and is used in a wide range of vehicles from the mild hybrid right up to the electric car, from the small car up to the luxury sedan. The system is a key component in every electrified drive, as it supplies both the electric motor as well as the high-volt battery with electricity—when the electric motor works as a generator and feeds electricity into the battery (recuperation). For functional reasons, the power electronics is therefore positioned between the high-volt battery and electric motor, regardless of where the control unit is installed in the vehicle.

The battery supplies the electrical energy as direct current, but the electric motor needs a three-phase alternating current. The power electronics converts the electricity accordingly, and guides it towards the engine in the required amperage and frequency; the engine is controlled by means of these parameters. Without the power electronics, the reverse procedure would not be possible.

During recuperation, the power electronics converts the alternating current generated by the electric motor into direct current, and thus charges the battery. The power electronics is also responsible for supplying the 12 V on-board power supply of the hybrid and electric vehicles with power.

The energy exchange between the high-volt grid (up to 450 V depending on the system) and the 12 V grid is guaranteed by a DC/DC converter, which also makes the traditional dynamo redundant. Another function of the power electronics is that it enables reverse driving by reversing the polarity and thus changing the electric motor's direction of rotation. The two central components in the power electronics are the inverter and the DC converter.

An important factor in the success of the Continental system is the innovative inverter, which enables a high number of cycles and makes a significant contribution to the efficiency of this power electronics. The DC/DC converter is also highly efficient, as it converts the voltage almost loss-free. Another special feature of the Continental system is that both components are integrated into a housing, and this makes the power electronics extremely compact.

Regarding electrified drives, we will see a stronger focus on two market sectors in the future. One of these is plug-in hybrid vehicles, because they can be driven purely on electricity on a daily basis without placing restrictions on the range of car journeys. The second field is vehicles with hybrid systems based on 48 V. Because this new technology can be integrated very easily into the architecture of conventionally powered vehicles and leads to considerable fuel savings—and the costs remain acceptable.

—Dr. Bernd Mahr, Head of the Hybrid Electric Vehicle Business Unit

Continental is going to launch its “48 Volt Eco Drive” system on the market as early as 2016.

The Continental Hybrid Electric Vehicle Business Unit is in charge of all core elements of the electric drive: power electronics, electric motors, and battery management.