Power Electronics IP Search

Power Electronics — Engineering Energy Conversion IP

Power electronics is undergoing its most significant technological transition since the power MOSFET — the replacement of silicon-based power devices with wide bandgap semiconductors (SiC and GaN) enabling operation at higher voltages, temperatures, and switching frequencies with dramatically reduced energy losses. This transition is being driven by two megatrends: electric vehicle electrification requiring high-efficiency traction inverters and onboard chargers, and data centre power density increases requiring more efficient power conversion at rack and server level.

SiC MOSFET Technology — EV Traction Inverter Revolution

Silicon carbide's physical properties (3.3 eV bandgap, 2,200 V/μm breakdown, 3× higher thermal conductivity than silicon) enable traction inverters operating at 800V DC bus voltage (versus the 400V limit of silicon IGBTs) with dramatically lower switching losses at 10-20 kHz switching frequency. Tesla's Model 3 (2017) was the first mass-market EV with SiC MOSFETs in the main traction inverter — 24× STMicroelectronics SiC chips per phase leg. This triggered industry-wide adoption across BYD, Hyundai (Ioniq 5/6), GM (Ultium platform), Stellantis, Volkswagen, and virtually every new EV platform.

Key SiC traction inverter patent areas: gate driver design (SiC requires -5V to -15V gate-off voltage for robust short-circuit protection; high common-mode voltage dV/dt rejection of 100V/ns in isolated gate driver circuits), active gate control (variable gate resistance adaptation to balance switching loss against EMI), dead-time compensation algorithms (SiC body diode reverse recovery is minimal, enabling much shorter dead times than IGBT, but requires precision timing), motor current reconstruction during switching dead time, and predictive current control for permanent magnet synchronous motors (PMSM) and induction motors.

GaN Technology — High-Frequency Power Conversion

Gallium nitride HEMT (High Electron Mobility Transistor) devices use a two-dimensional electron gas (2DEG) at the AlGaN/GaN heterointerface — a channel with orders-of-magnitude higher mobility than silicon, enabling switching frequencies in the 1-10 MHz range. At these frequencies, passive component values shrink with frequency (inductor and capacitor values are inversely proportional to switching frequency), enabling dramatic converter miniaturisation. A 100W USB Power Delivery charger using GaN switches in a half-bridge LLC resonant topology can achieve what previously required a charger 3× its volume in silicon.

GaN patent areas: enhancement-mode (e-mode) GaN HEMT implementation (since depletion-mode is normally-on and unsafe for most power applications), p-GaN gate structures for e-mode operation, gate dielectric (GaN MIS-HEMT) approaches for reduced gate leakage, monolithic GaN integrated circuits combining level shifters and gate drivers on the same die as the power transistors (Navitas GaNFast technology, EPC GaN ICs), and cascode GaN configurations (pairing depletion-mode GaN with a low-voltage silicon MOSFET for normally-off behaviour).

Resonant Converters and Wireless Power

LLC resonant converters operate at or near the resonant frequency of an LCC tank circuit (inductor-inductor-capacitor), achieving zero voltage switching (ZVS) for the primary-side switches and zero current switching (ZCS) for secondary-side rectifiers — eliminating switching losses that dominate high-frequency operation in hard-switched converters. Patents cover LLC resonant tank design, frequency modulation (FM) vs pulse width modulation (PFM) control strategies, burst mode operation at light load, SR (synchronous rectifier) timing optimisation, and bidirectional LLC for vehicle-to-grid (V2G) charging.

Wireless Power Transfer using magnetic resonance coupling (Qi 2.0 standard, SAE J2954 for EVs) generates patents covering coil design and alignment tolerance, resonant frequency tuning, foreign object detection (FOD) using Q-factor measurement, dynamic WPT for moving EVs on electrified road segments, and multi-coil arrays for spatial freedom charging.