The Need

Recently, interest in high-voltage (HV) Silicon Carbide (SiC) based semiconductor power devices and their applications has grown. Many HV SiC based semiconductor power devices have been developed to date. The gate drive circuit of HV SiC power devices is critical to ensure fast and reliable switching operation. The isolated power supply of a gate drive circuit must be able to sustain high isolation voltage and achieve high common-mode rejection, which is implemented with transformers that require a large magnetic core to separate the primary and the secondary windings and create sufficient creepage distance. This results in a large and heavy gate drive circuit. As an alternative solution for an isolated gate-drive power supply, wireless power transfer using separated coils has been studied. However, this solution is also sensitive to EMI, and it requires large space for isolation and shielding. Currently, there is a need for an isolated power supply of a gate drive circuit that can sustain high isolation voltage and achieve high common-mode rejection without the use of a large and heavy magnetic core.

The Technology

Researcher at The Ohio State University, led by Dr. Jin Wang, have developed an fiber optic based gate drive circuit that receives driving power and signals from optical receivers. The construction of this devices eliminates electrical connections between the laser transmitter and the gate drive circuits. The device has many benefits over traditional gate drive circuits for semiconductor devices.

Commercial Applications

• Semiconductor power devices
• Medium and high voltage motor drives
• Circuit breakers
• Medium and high voltage AC and DC micro grid systems
• Power converters for renewable energy integration
• STATCOM
• Active power filters
• FACTS devices
• Solid-state transformers

Benefits/Advantages

• High galvanic isolation voltage
• High noise immunity
• Significant size and weight reduction of the circuit
• High reliability
• High voltage or lightening protection
• Wireless transmission
• Spark protection
• Corrosion resistance