Power converter comprising an inverter module using normally on field effect transistors

摘要

The converter has an inverter module comprising switching arms connected between positive- and negative power supply lines (10, 11) of a direct-current (DC) power supply bus. Each arm has center connection points (M1-M3) located between upper transistors (T2, T4, T6) and lower transistors (T1, T3, T5). Grid control devices (CT1-CT6) are connected to the negative power supply line. A start-up source (Sd) is connected in parallel with a limiting resistor (RL) and to the control devices for the lower transistors. The start-up source is charged with negative voltage when the converter starts-up.