10kW 3-phase 3-level T-type inverter reference design for solar string inverter

This proven reference design outlines how to implement a three-level, three-phase DC/AC T-inverter stage based on SiC. The higher switching frequency of 50KHz reduces the size of the magnetic components of the filter design and therefore increases the power density. By using SiC MOSFETs that reduce switching losses, higher DC bus voltages up to 1000V and lower switching losses are ensured, resulting in peak efficiencies of 99%. This design can be configured as a two- or three-level inverter. The system is controlled by a single C2000 microcontroller (MCU), TMS320F28379D, which generates PWM waveforms for all power electronic switching devices in all operating modes.

characteristic

• ● Rated nominal input voltage/maximum input voltage: 800V/1000VDC
• ● Maximum output power at 400VAC 50/60Hz T-type connection is 10kW/10KVA
• ● The power factor range during operation is 0.7 lagging to 0.7 leading.
• ● Full-bridge inverter based on high-voltage (1200V) SiCMosFET, with peak efficiency as high as 99%
• ●The output current THD at full load is less than 2%
• ● Use AMC1301 for isolated current sensing to implement load current monitoring
• ● Isolated driver ISO5852S with reinforced isolation for driving high-voltage SiC MOSFETs, and UCC5320S for driving intermediate Si IGBTs