New Industry Products

Embedded AI Switch-Mode Controller Eliminates Switching Losses

June 01, 2018 by Paul Shepard

Pre-Switch, Inc. today introduced Pre-Flex™ Technology, an embedded AI (Artificial Intelligence) controller IC which effectively eliminates transistor switching losses in hard-switched architectures for virtually any power converter topology. Pre-Flex dramatically reduces cost, size and weight, while increasing efficiency and reliability of power converters in the server, solar, wind, EV, traction and motor drive markets.

Pre-Flex has switched 900V Wolfspeed SiC MOSFETs up to 1MHz, and 650V Infineon IGBTs at over 100kHz with unprecedented efficiencies. The technology presently scales from 1kW to above gigawatts.

Pre-Flex technology learns and adapts "in-system," on a cycle-by-cycle basis, to reliably force resonant soft-switch across changing loads, input voltages, temperatures and manufacturing tolerances. The technology has proven efficiencies greater than those of five-level topologies at a fraction of the cost and complexity.

Pre-Flex also significantly lowers EMI and dramatically decreases dV/dt for any switch type. Pre-Flex enables Silicon carbide-like performance for low-cost IGBTs, and allows SiC- and GaN-based topologies to switch up to 20x faster than they do today.

Built into the architecture are innovative cycle-by-cycle safety features and communications that were never possible before.

"We have removed the biggest barrier to advancing the power conversion industry," said Bruce Renouard, chief executive officer of Pre-Switch, Inc. "Our technology enables simple, reliable and cost-effective forced resonant soft-switching on any topology."

Pre-Switch is working with development partners interested in leading their respective industries by designing their next-generation power converters with Pre-Flex technology.

The Pre-Flex™ Family of ICs are organized by switch type and desired phase output. Pre-Flex ICs use embedded AI that learns in-system and optimizes an external forced-resonant circuit to ensure minimum switching loss reduction. Depending on the chip used, Pre-Flex is designed to work with either a half-bridge, full-bridge or three-phase configuration power converters.

Each IC includes a built-in serial communications port to communicate fault conditions and Pre-Switch Blink™ data, which ensure maximum safety features on a cycle-by-cycle basis. The Pre-Flex IGBT family is frequency-limited to 100kHz and typically eliminates 70-85% of system switching losses.

The Pre-Flex SiC/GaN family is frequency-limited to1MHz and typically eliminates 90-95% of switching losses and has a lossless dV/dt filter built into the architecture.

Pre-Flex™ Family ICs:

  • Pre-Flex 1-phase for IGBT
  • Pre-Flex 3-phase for IGBT
  • Pre-Flex 1-phase for SiC/GaN
  • Pre-Flex 3-phase for SiC/GaN

Pre-Drive™ EconoDUAL Evaluation Board - Controller + Gate Driver

The Pre-Drive PDEC1215A is the world's first EconoDUAL™ 1200V IGBT 200A half-bridge gate driver that incorporates built in ZVS circuitry. This module is a plug-and-play compatible driver with other leading hard-switched gate gate drivers.

This product is designed so that engineers can measure the system-level benefits of Pre-Switching in a three-phase industrial system prior to production development.

Pre-Drive turns any system into a soft-switch system and provides instant benefits, including:

  • Lower switching loss for Eon, Eoff and Err, typically 75-80% of total when compared to real-world hard-switching systems
  • Higher Fsw for a given current
  • Higher current for a given Fsw
  • Lower dv/dt: -1V/ns turn on, -2V/ns turn off when Vbus is 800V or below
  • Reverse recovery overshoot currents <20% of load current
  • Full Pre-Switch Blink™ advanced cycl- by-cycle safety features with LED visual readout
  • Full 150A working current at Fsw 1-5kHz

"By significantly reducing IGBT switching losses without increasing dV/dt, Pre-Switch is creating a possibility to redefine our VFD motor drives to be smaller and more efficient without being harmful to motor insulation and bearings," said Adalberto Jose Rossa, Drives R&D manager of WEG Drives & Controls.

"We are investigating this technology, and initial test results at double-pulse and at short-circuit conditions have inspired us to test a complete drive with Pre-Switch technology. We look forward to analyzing reliability data of the system under real motor load conditions," Jose Rossa added.

"The higher switching frequencies enabled by Pre-Switch are able to provide a lower motor current ripple," said Carlos Afonso Hümmelgen, Drives R&D coordinator from WEG Drives & Controls. "Lower motor current ripple yields reduced motor harmonic losses, and increased motor and system efficiency."

Pre-Switch will be at PCIM Europe 2018 in Nuremberg, Germany, at booth 6-147 in Hall 6.