Converter switch apparatus and method

A switch apparatus comprising:

• a semiconductor power switch connected to a DC link;
• and
• a gate drive unit connected to a gate of the semiconductor power switch, wherein for at least some different DC link voltages of the DC link, the gate drive unit is configured to deliver different gate drive voltages to a gate of the semiconductor power switch, to drive the semiconductor power switch to deliver current from the DC link to a load.

A method comprising:

• receiving a control signal at a gate drive unit;
• and
• adjusting a gate drive voltage provided by the gate drive unit to a semiconductor power switch, based on the control signal, to maintain a switching current slew rate of the semiconductor power switch within a pre-defined slew rate envelope, without direct measurement of the switching current slew rate.