System and method for protection of a multilevel converter
AssigneeGeneral Electric Company
InventorsRobert Roesner, Stefan Schroeder
Life of this patent
Estimating the term…
Abstract
A three level neutral point clamped (NPC) converter includes a plurality of phase legs each having at least two inner switching devices, at least two outer switching devices, at least two clamping diodes, and a protection circuit. An inner component failure sensing circuit is employed in the protection circuit to detect a failure condition in any of the inner switching devices or clamping diodes. The protection circuit further includes a gating signal generation circuit configured to generate a turn ON signal for a respective outer switching device that is adjacent to the failed inner switching device or the clamping diode.
Claims14
A three level neutral point clamped (NPC) converter comprising:
- a plurality of phase legs each having at least two inner switching devices, at least two outer switching devices and at least two clamping diodes;
- and
- a protection circuit comprising
- an inner component failure sensing circuit to detect a failure condition in any of the inner switching devices or clamping diodes,
- a gating signal generation circuit to generate a turn ON signal for a respective outer switching device that is adjacent to the failed inner switching device or the failed clamping diode when the failure condition is detected.
A method of protecting a three level power converter comprising DC link capacitors and phase legs including switching devices and connected to a power network, the method comprising:
- blocking charging of at least one DC link capacitor by short circuiting the power network through network impedances and turning off at least some of the switching devices.
A protection circuit for a three level neutral point clamped (NPC) converter comprising a plurality of phase legs each having at least two inner switching devices, at least two outer switching devices and at least two clamping diodes, the protection circuit comprising:
- an inner component failure sensing circuit to detect a failure condition in any of the inner switching devices or clamping diodes;
- a gating signal generation circuit to generate a turn ON signal for a respective outer switching device that is adjacent to the failed inner switching device or the failed clamping diode when the failure condition is detected and to generate turn OFF signals for remaining switching devices in the three level NPC converter.
Dependencies are inferred from the claim text.