Q&A: Vicor powers next-gen active suspension system
Electric vehicles evolve to support higher performance, reduced weight, and improved ride dynamics, power system design is being pushed to new limits
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Q&A: Vicor powers next-gen active suspension system
As electric vehicles (EVs) evolve to support higher performance, reduced weight, and improved ride dynamics, power system design is being pushed to new limits.
Q & A with Paige West, Electronic Specifier and Greg Green, Vicor
One area undergoing rapid innovation is active suspension – an increasingly critical function for ensuring passenger comfort and road-handling performance in modern EV platforms. Hongfa, a specialist in automotive systems, has developed what it describes as the smallest and lightest active suspension solution currently available, thanks in large part to a collaboration with Vicor.
Electronic Specifier discusses this further with Greg Green, Director of Automotive Marketing, Vicor.
Q: How was Vicor involved in the development of the new Hongfa active suspension system, and how did the collaboration begin?
A: Vicor and Hongfa began working in collaboration upon request of an automaker to address the need for a compact but powerful DC-DC converter to drive an active suspension power system. The Vicor technology provided the solution path that was needed to downsize the DC-DC converter and reduced the system design workload for Hongfa. The Vicor power module also provided the fastest transient speeds which were essential to optimizing the capacity for energy regeneration.
Hongfa has designed the smallest and lightest active suspension system on the market by combining 48V and Vicor power modules. Vicor Sine-Amplitude Converter modules can support active suspension power systems that require bidirectional current flow between the battery and suspension actuators.
Q: The BCM6135 is described as offering the industry’s fastest power conversion transient response. What technical innovations make that possible?
A: Vicor modules use the Sine Amplitude Conversion (SAC™) technology, a topology that supports zero-voltage/zero-current switching between the high and low voltages. Vicor drives this technology with proprietary controllers and components that enable creation of a total DC-DC converter in very small packages (0.01L). The transient is 8,000,000A/s, the fastest in the automotive industry.
A unique benefit of the BCM® technology is that the SAC topology operates at a very high frequency (over 1.4MHz) and has a slew rate of 8,000,000A/s, which presents customers with a capability that was previously impossible to achieve.
Q: What differentiates the BCM6135’s fixed-ratio, bidirectional design from conventional DC-DC converter topologies in automotive applications?
A: A unique benefit of the BCM technology is that the SAC topology operates at a very high frequency (over 1.4MHz) and has a slew rate of 8,000,000A/s, which presents customers with a capability that was previously impossible to achieve. The bidirectional nature of the products presents another benefit that competitors cannot match. Because of the SAC topology, the BCM6135 will process equal amounts of power whether boosting or bucking the current. These characteristics allow the BCM to perform like no other DC-DC technology for challenging application like active suspension.
The bidirectional nature of the BCM6135 presents another benefit that competitors cannot match. Because of the SAC topology BCM6135 can process equal amounts of power whether boosting or bucking the current.
Q: The final system is nearly half the size of its nearest competitor. How did Vicor packaging and thermal design innovations contribute to this compact footprint?
A: The Vicor BCM is a complete 2.5kW DC-DC converter in a package space of 0.01L (61 x 35 x 5.4mm), which eliminates many of the large discrete components typically used. The system assembler, such as Hongfa, only needs to package the connectors to the vehicles, some basic EMI filter packs and PMBus® interface. The BCM can be actively or passively cooled, requiring a cooling structure, and the system housing.
Q: What role did planar packaging and liquid cooling play in enabling high current delivery with minimal thermal overhead?
A: The planar packaging and overall BCM design allow the module to have a thermal coefficient of 1.4°C/W, which matches many standard packaged MOSFETs. Building the BCM into a design with liquid cooling will maximize the power output, as the SAC topology is thermally limited in peak power.
Q: Many prior active suspension designs were hindered by the limitations of 12V systems. How does the BCM6135 address these legacy issues?
A: The BCM6135 is a fixed-ratio converter that processes power very efficiently from HV to 48V. The active suspension power delivery network (PDN) requires a 48V bus and power modules to achieve the best performance.
Lower voltage supplies drive larger and less efficient actuators for the active suspension system. Some of the original systems introduced decades ago required hundreds of pounds of actuator motors and batteries to accept the large current and power fluctuations from the active suspension system. The 48V actuators are over 50% smaller and are more powerful than the older generation.
The BCM6135s are able to eliminate the batteries in the system due to their high slew rates and bidirectional power handling. An active suspension system using the BCM6135 at the core will save more than a hundred pounds of weight.
Q: What advantages does the Vicor 800V-48V solution offer for emerging 48V zonal architectures and EV powertrains?
A: The Vicor BCM6135 enables several improvements to the DC-DC converter and LV network in an electrified vehicle. Firstly, using the BCM6135 will reduce the size of the main DC-DC converter by up to 50%, and cut weight by 50%. Secondly, the power switching capability allows for the deletion of a 48V battery, as the BCM6135 will deliver power from the HV battery to the load faster than drawing the power out of a 48V battery. And finally, the DC-DC conversion system can be downsized enough to be fit inside the high-voltage battery housing, eliminating extra cooling lines and HV power cables.
Q: Do you see broader adoption of fixed-ratio, high-voltage DC-DC modules in mainstream vehicle electronics in the coming years?
A: Yes, we do see a broader application of our technology in the coming years. The increase in application will be driven by the ability of Vicor technology to address the toughest power problems that OEMs will face in building power-, space- and weight-efficient vehicles. Vicor DC-DC modular converters are the most power dense in the market and they can be used in parallel – making it very easy to scale power and adapt to the vary power demands of fleets of vehicles.
Q: How is Vicor positioning its power modules to meet the growing demand for compact, high-efficiency designs in the EV and advanced mobility sectors?
A: We are working with Tier 1 partners and OEM engineering teams to find the tough problems that can be addressed by the BCM6135. We work in partnership with these companies to show how our technology enables the most elegant and effective solution to converting the power and reducing size and weight. We focus on addressing the issues where our technology is the best solution and making the customer successful.
This article was originally published by Electronic Specifier.
Greg Green is the Director of Automotive Customer Programs at Vicor Corporation. He has over 33 years of experience in the automotive industry, spanning across manufacturing, design engineering and product line management with OEM’s, and Tier 1 suppliers. Greg’s auto industry experience includes manufacturing, product development, and business development. Greg holds a B.S. Degree in Aerospace Engineering from the University of Michigan, and an M.S. in Manufacturing Management from Kettering University.
Greg Green, Director of Automotive Marketing
