Why high voltage?

As the worldwide electrification trend continues to gain momentum, efficient energy transfer at higher power levels becomes an important consideration in today’s power electronic systems. Resistive loss (I²R) is the central factor limiting how much power a power supply can deliver. To improve system efficiency, increasing the voltages used to transmit and deliver power reduces the required current for the same power level and helps minimize losses through heat.

A few examples of high-voltage systems widely applied in today’s power networks include residential AC distribution power systems, telecommunication and server power systems, DC microgrids in renewable energy systems, energy storage systems, and electric vehicle (EV) onboard and offboard chargers. As an example, EV batteries are currently 400 V but increasingly trending toward 800 V in order to enable more instantaneous power transfer to the traction inverter for better acceleration performance.

Although operating under a higher voltage brings system efficiency benefits for power conversion, proper galvanic isolation and insulation are essential to allow a safe human interface. Moreover, a closed-loop system generally requires signal communication across the isolation boundaries. Add to this topology selection, magnetic circuit design, electromagnetic interference considerations, operating modes, thermal management, and layout and control optimizations, and you begin to understand some of the significant design challenges when working with high-voltage systems. Overall, innovations from three key areas – component innovations, topology innovations and system-level innovations – will increase high-voltage power-conversion system's efficiency and density, while simplifying designs.