Aircraft demand higher-voltage power. Developed by Airbus, Daher and Safran, the EcoPulse hybrid-electric demonstrator used an 800VDC system delivering up to 350kW to support six wing-mounted electric propellers (source: Airbus) Silicon carbide power electronics, insulation and fault protection must work together in high-voltage flights, writes Barry Mansfield. Cabin pressurisation, anti-icing, engine starting, pumps, brakes and actuators are increasingly going electric, while hybrid propulsion is set to push aircraft power demand higher still. But carrying more current requires heavier cabling, adding weight that aircraft designers can ill afford. In response, the sector is now moving towards higher-voltage power systems. A 1MW system draws 2,500A at 400V, 1,250A at 800V and 1,000A at 1kV. Raising the voltage allows the same power to flow at a lower current. This reduces heat generated in the cables, cutting energy losses and the need for cooling. Nasa is testing kilovolt-class power systems, while Airbus's €50m LEIA programme aims to demonstrate an integrated high-voltage electrical system on the ground by 2027. However, operating at 800V creates a particular vulnerability: as air pressure falls with altitude, the risk of partial discharge, corona and electrical arcing increases. Safran's Pierre-Julien Sonnette says 800V is "much higher than what we're used to", requiring engineers to "entirely redesign the electrical system". When air stops being an insulator. As aircraft climb, falling air pressure can make electrical breakdown between conductors more likely. The breakdown voltage depends on air pressure and conductor spacing, a relationship described by Paschen's law. Nasa cites a minimum DC breakdown voltage of about 327V in air under specific conditions, compared with around 230V RMS for 400Hz AC. At 800V careful insulation design and adequate electrical clearances are therefore vital to prevent arcing at altitude. Insulation can also deteriorate over time. Tiny air pockets, contamination and manufacturing defects can create areas of intense electrical stress. Vibration, repeated heating and cooling can worsen these weak points, lowering the voltage at which partial discharge begins. This threshold is called partial-discharge inception voltage (PDIV). The lower it falls, the more easily discharge can occur. In 2025 Nasa found that thermal cycling reduced PDIV in coated and resin-encased magnet wire after just a few cycles. SiC raises the stakes. Silicon Carbide (SiC) is helping aircraft designers push voltage and power density higher. Compared with conventional silicon devices, wide-bandgap switches can operate at higher temperatures and switch faster while cutting conversion losses. Ampaire's hybrid-electric Cessna 337, part of its flight-test fleet based at Camarillo Airport in California, was used to test an 800V, 250kW silicon carbide (SiC) inverter (source: Ampaire) This helps to shrink cooling hardware and some magnetic components, allowing more power to be packed into less space and weight. In June 2026 GE Aerospace and Wolfspeed agreed to develop standards for power modules using 10kV SiC switches, potentially making future converters smaller, lighter and more efficient. Wenzhi Zhou, who led Coventry University's study of partial discharge in electrified-aircraft machines, says wide-bandgap devices can switch around 10-times faster than silicon, with voltage slew rates, or rates of voltage change, of 30-50kV/μs. However, these rapid voltage changes stress motor windings and insulation, increasing the risk of partial discharge and making that discharge harder to distinguish from switching noise. Engineers are addressing this through active dv/dt filtering and improved discharge detection. The weight of integration. Researchers at the universities of Arkansas and Illinois developed an 800V, 250kW inverter for Ampaire using custom 1,200V SiC modules. It was successfully flight-tested in a Cessna 337 at Camarillo Airport, California. A Nasa engineer works on a dynamometer at the agency's Electric Aircraft Testbed in Sandusky, Ohio, where megawatt-scale electric propulsion systems are tested under simulated flight-altitude conditions (source: Nasa) This inverter achieved about 60kW/litre and 30kW/kg, using pin-fin baseplates to transfer heat directly into the coolant. The project shows why packaging, isolation, cooling, interconnects and electromagnetic interference must be considered together, while every added gram erodes the weight savings higher voltage is meant to deliver. The same pressure to save weight applies to insulation. Greater creepage and clearance distances, thicker insulation and shielding all compete for limited space and weight. Nasa has developed boron nitride insulation composites that can more than double thermal conductivity while maintaining dielectric strength. Better heat transfer could allow thinner, lighter insulation around cables and windings. An Airbus A380 contains around 300 miles of wiring. At that scale, even small reductions in insulation thickness and cable mass can save significant weight. Protection in microseconds. At megawatt power levels, protection systems must clear faults rapidly to limit damage from electrical arcing. To meet this need, Nasa's RTAPS programme developed a 1.2kV, 1kA solid-state DC circuit breaker for electrified aircraft that can cut off fault current in under 100μs in simulated 35,000ft conditions, while operating at more than 99.5% efficiency. Nasa's Electric Aircraft Testbed in Sandusky, Ohio, tests megawatt-scale electric aircraft powertrains under simulated flight-altitude conditions, allowing engineers to assess performance and reliability before flight (source: Nasa) On the detection side, Fraunhofer IISB and FAU Erlangen-Nürnberg are developing faster ways to identify insulation faults. Their hardware-based unit can recognise critical faults in less than 1.5ms, then command an electronic or pyrotechnic fuse to disconnect the faulty circuit. Safran's OSYRYS project, part of the EU's Clean Aviation programme, targets high-voltage and thermal-system validation by 2028, with further demonstrations and a certification-readiness roadmap to follow by 2030. Clean Aviation's goal is hybrid-electric regional aircraft entering service by 2035. Barry Mansfield is a business and technical writer

Wolfspeed silicon carbide deal backs BorgWarner inverter. Wolfspeed's full shift to US 200mm wafer production lets it offer BorgWarner the supply depth that scaling 800V EV platforms demand * October 29, 2026 Wolfspeed has agreed a multiyear deal to supply silicon carbide (SiC) devices for BorgWarner's new 800V SiC-based inverter platform for electric vehicles (EVs). The arrangement deepens a longstanding collaboration between the two suppliers and secures BorgWarner long-term access to the 1200V SiC technology it is using in the inverter. Continuity of supply sits at the centre of the deal. Wolfspeed says it will give BorgWarner consistent, uninterrupted access to its devices, backed by US production that has moved entirely to 200mm wafers. The company says its devices are built to withstand high heat and high voltage. Market growth provides the backdrop. EVs took 25% of global new car sales in 2025, while the International Energy Agency expects that share to approach half by 2035. Wolfspeed argues that SiC is becoming critical to the power density and performance automakers need as they scale up EV platforms. In a statement, Matthias Buchner, Senior Vice President of Global Sales and Chief Marketing Officer at Wolfspeed, said: "Our strategy is to combine our technology leadership with deep, long-term customer partnerships. Our supply agreement with BorgWarner demonstrates that strategy, bringing together advanced silicon carbide technology, proven quality and reliability, and scaled 200 mm manufacturing capabilities to deliver the performance and supply confidence BorgWarner needs for their next-generation EV platform."

Wolfspeed highlights AI data center growth, silicon carbide roadmap at annual meeting. Wolfspeed (NYSE:WOLF) said it is advancing its silicon carbide technology roadmap, expanding its presence in AI data centers and pursuing operating and capital-structure improvements, Chief Executive Officer Robert Feurle said at the company's 2026 annual shareholder meeting. The company also said shareholders approved all proposals presented at the virtual meeting, including the election of seven directors, the 2026 Employee Stock Purchase Plan, an advisory vote on executive compensation and the ratification of PricewaterhouseCoopers LLP as Wolfspeed's independent auditor for the current fiscal year. Technology and manufacturing roadmap. Feurle said Wolfspeed's strategy is centered on technology leadership, customer and revenue diversification, operational execution and financial discipline. He pointed to the company's June announcement that its fifth-generation silicon carbide MOSFET technology had reached commercial readiness. According to Feurle, the Gen 5 MOSFETs provide what he described as the industry's best specific on-resistance while maintaining switching behavior introduced with the company's Gen 4 products. Wolfspeed's 10 kV silicon carbide MOSFET was also recognized at PCIM, a European power-technology conference, as a top innovation at the event, Feurle said. The CEO said Wolfspeed believes its vertically integrated 200 mm manufacturing capabilities, along with developing 300 mm capabilities, position the company to support growing demand for silicon carbide technology. AI data center revenue growth. Feurle said Wolfspeed continues to make progress across its core end markets and improve relationships with longstanding customers. He also highlighted AI data centers as an emerging growth market for the company. Full-year fiscal 2026 revenue from the AI data center end market more than doubled from the prior year, according to Feurle. He said Wolfspeed has expanded its leadership presence with industry veterans in the San Francisco Bay Area and is seeing the benefits in both day-to-day customer interactions and revenue trends. "We are extremely well-positioned" to support AI data center adoption as it scales, Feurle said, citing the company's silicon carbide technology and manufacturing platform. Operations and financial discipline. Operational execution remains a central priority, Feurle said. Wolfspeed is focused on improving production yields and lowering unit production costs while maintaining speed, quality and cost discipline. These efforts are intended to support both legacy and new customers and create a stronger foundation for sustainable growth and profitability, he said. On financing, Feurle said Wolfspeed benefited from a refinancing completed in March that strengthened its capital structure and reduced its cost of capital. He also discussed the company's recently announced conditional 30-year, $1.5 billion loan commitment from the U.S. Department of War. The commitment is intended to help advance the domestic wide-bandgap semiconductor supply chain, according to Feurle. Feurle said the conditional commitment could provide long-term capital to support Wolfspeed's strategy and further strengthen its capital structure. He said the financing's pay-in-kind structure during its first five years could reduce intermediate-term cash interest payments, while lower capital costs could benefit customers, shareholders and national security. Shareholder votes approved. Melissa Garrett, Wolfspeed's general counsel and corporate secretary, said a quorum was present at the meeting based on shares represented virtually or by proxy. The company's inspector of elections reported that each proposal received the votes required for approval and that the advisory vote on executive compensation was favorable. Wolfspeed expects to report final voting results in a Form 8-K filing with the Securities and Exchange Commission within four business days of the meeting. About Wolfspeed (NYSE:WOLF). Wolfspeed, Inc is a semiconductor company focused on silicon carbide (SiC) technologies. Its products are designed to support the conversion and management of electrical power in applications that require high efficiency, high voltage, and operation at elevated temperatures. The company develops and manufactures SiC power devices, including metal-oxide-semiconductor field-effect transistors, diodes, power modules, and related components. It also produces SiC materials such as wafers and epitaxial substrates used by semiconductor manufacturers.