Power Integrations Targets Bus and Truck EVs With New Module Drivers
The fresh IGBT/SiC gate-driver family, SCALE EV, is purposed to drive the high-powered automotive and traction inverters deployed in EVs, especially those of the larger variety.
Unveiled yesterday at PCIM Europe in Nuremberg, Germany, Power Integrations' (PI) new SCALE EV board-level gate drivers feature two gate-drive channels and include all necessary local power supplies, communication, and monitoring capabilities. The new boards are automotive-qualified and ASIL B certified, allowing for implementation of ASIL C traction inverter designs.
The 2SP0215F2Q0C (left) and Infineon's IGBT half-bridge module (right). Images [modified] used courtesy of Power Integrations/Infineon
As illustrated below, PI has engineered its driver to fit onto Infineon’s power module near perfectly, yet still provide the requisite spacing for reinforced isolation according to the IEC 60664 standard; the driver, tailor-made to satisfy requirements for 800-volt system voltages, provides 11.4 mm of creepage and clearance.
PI's board mounts effortlessly onto Infineon's module. Screenshot used courtesy of Power Integrations
To meet functional safety standards, communication lines to the system’s µC are routed through two independent on-board connectors. 5 V power supplies allow the driver to locally generate all necessary isolated voltages.
SCALE EV — Basic Considerations
The SCALE EV family is rated at 1200 V for 400 and 800-volt systems, and its members can integrate with power modules handling up to 1,000 A. Most importantly, their design supports both silicon carbide (SiC) MOSFETs and silicon (Si) IGBTs. The units carry a 5500-meter altitude rating, with conformal coating available as an option.
Family members feature overvoltage protections and diagnostic functions including gate monitoring, on-chip temperature monitoring and signal transmission monitoring. Short-circuit and over-current response times are specified at less than one microsecond for SiC MOSFETs and less than three microseconds for IGBTs.
A Single-board Solution
Designing a gate driver takes rather specialized engineering experience, and satisfying tough, rigid automotive standards is even more difficult. But per Peter Vaughan, PI’s director of automotive business development, SCALE EV makes the process far less painful.
“Gate-driver design is critical to both the performance and reliability of electric vehicles,” Vaughan said. “By offering a product where the development, testing and qualification plus ASIL certification have already been done, we are dramatically reducing development time and cost.”
What’s more, because the driver actually sits on top of the power module, no extra board space is required.
DC-link Active Discharge (AD) Function
The 2SP0215F2Q0C includes DC-link active discharge functionality to obviate the need for additional components. The purpose of the AD mode is to discharge the DC-link voltage through the power semiconductors of one or more half-bridges. The power module(s) is then operated for a short period of time in a “quasi half-bridge short-circuit” condition.
To manage the stress on the power semiconductors, the gate voltage is automatically reduced by the gate driver to limit the effective short-circuit current. This is made possible because the current is a direct function of the applied gate voltage.
The 2SP0215F2Q0C in relation to the half-bridge module that it serves to drive. Screenshot used courtesy of Power Integrations
In addition, the gate driver sports active short-circuit functionality, which will serve to decelerate the motor in the event of a fault.
PI describes SCALE EV members such as the 2SP0215F2Q0C as suited for any application with transportation decarbonization in mind.
EV applications include:
- Construction equipment.
- Agricultural equipment
Other uses include:
- Port shuttles
- Large loading cranes