Hongfa’s compact active suspension power design uses Vicor modules and 48V to transform driving

Xiamen Hongfa Electroacoustic Co., Ltd (Hongfa) has designed the industry’s highest performance and smallest active suspension power system ever designed, using Vicor’s BCM6135, with a goal to drive this long-time luxury feature into the mid-range vehicle fleets.

Figure 1  Hongfa has designed the smallest and lightest active suspension system on the market by combining a 48V architecture and high-density power modules. Four Vicor fixed-ratio BCM6135, 800V-to-48V DC-DC bus converters are used to convert high voltage to 48V and route power to each wheel.  The BCM6135 is bidirectional and provides the fastest transient response of any DC-DC converter. This symmetrical switching speed enables optimal energy regeneration when directly linked to the DC-DC converter.

Overcoming decades of false starts by prominent automotive technology providers, Hongfa struck a balance between the need to manage active suspension system size, weight and transient performance against the requirement for higher efficiency, improved EMI and symmetrical regenerative power capacity.

Hongfa, whose relays are enabling new 48V zonal architectures, partnered with Vicor to integrate a fixed ratio 800V-48V, DC-DC converter power module that sits alongside a network of sensors, electromechanical actuators and sophisticated software to adjust vehicle suspension in real time. The collaboration yielded the smallest active suspension system – almost half the size of the nearest competitor – with the industry’s fastest power conversion transient response.

Early industry efforts in the 1970s included a complex electromagnetic solution which strained the capabilities of 12V battery power systems and required four 200-pound motors.  Historically, 12VDC has proven to be inadequate for powering active suspension motors without adding size, weight and cost.  Additionally, some conventional DC-DC converters can deliver power without the need for an intermediate battery, but the trade-off is that they are bulky and lack the fast transient response time required to meet the regenerative demands to recoup and store power.

Figure 2 The Hongfa active suspension system (Power System SpecsHF3661 800V-48V DC/DC System) is liquid cooled and is the most compact on the market, weighing 2.6kg and measuring 197mm x 201mm x 71mm.

Vicor’s fixed-ratio 800V to 48V DC-DC bus converter modules (BCM’s) are inherently bidirectional and provide the fastest transient response (8 million amps/second) of any DC-DC converter topology. BCMs also offer symmetrical bidirectional performance with the ability to buck or boost with the same power level.  Their planar advanced packaging simplifies thermal management system design, further reducing overall footprint and weight.

Hongfa’s solution leverages Vicor’s high density power modules to create a compact (197mm x 201mm x 71mm) 5kw power supply for each actuator. The system can rapidly process up to 6kW of peak power in either direction. The design of the converter is greatly simplified by using a pair of Vicor BCM6135 modules operating in parallel, instead of several hundred discrete components.

The converter has an operating range between 420V to 920V.  With liquid cooling it can deliver up to 100A of current with 97.3% efficiency. The system housing volume is under 1.8l and weighs in at 2.6 kg, providing a major weight reduction over other systems.

“Vicor’s BCM6135 power modules not only delivered the performance we need, they also significantly shortened our development time and have made designing this system much easier for us,” said Mr. Peter Li, Director of Research and Development at Hongfa.

The combination of 48V and high-density power modules are enabling new levels of innovation in automotive electrification – reducing space, weight and offering superior performance. Together, Hongfa and Vicor are leveraging their joint automotive expertise to develop advanced technology and support the evolution of high-performing electric vehicles.