Motor drive converter and method with neutral point drift compensation
AssigneeGeneral Electric Company
InventorsPaul Michael Szczesny, Nikola Celanovic, James Patrick Lyons, Vlatko Vlatkovic
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Abstract
A high power motor drive converter comprises: a three level neutral point clamped (NPC) output power conversion stage including switches for supplying power to an AC drive motor; a split series connected DC capacitor bank coupled in parallel with the NPC output power conversion stage; and a controller for selecting switch positions for controlling the NPC output power conversion stage and compensating for a neutral point voltage imbalance of the DC capacitor bank by adjusting amplitudes of carrier voltages according to an amount of voltage imbalance in the split series connected DC capacitor bank.
Claims22
A high power motor drive converter comprising:
- a three level neutral point clamped (NPC) output power conversion stage including switches for supplying power to an AC drive motor;
- a split series connected DC capacitor bank coupled in parallel with the NPC output power conversion stage;
- and
- a controller for selecting switch positions for controlling the NPC output power conversion stage and compensating for a neutral point voltage imbalance of the DC capacitor bank by adjusting amplitudes of carrier voltages according to an amount of voltage imbalance in the split series connected DC capacitor bank.
A high power motor drive converter comprising:
- a three level neutral point clamped (NPC) output power conversion stage including switches for supplying power to an AC drive motor;
- a split series connected DC capacitor bank coupled in parallel with the NPC output power conversion stage;
- and
- a controller for selecting switch positions for controlling the NPC output power conversion stage and compensating for a neutral point voltage imbalance of the DC capacitor bank by using space vector analysis to calculate switch position duty cycles based on actual locations of voltage vectors to adjust amplitudes of carrier voltages according to an amount of voltage imbalance in the split series connected DC capacitor bank.
A method of controlling a high power motor drive converter including a three level neutral point clamped (NPC) output power conversion stage including switches for supplying power to an AC drive motor and a split series connected DC capacitor bank coupled in parallel with the NPC output power conversion stage, the method comprising:
- selecting switch positions for controlling the NPC output power conversion stage and compensating for a neutral point voltage imbalance of the DC capacitor bank by adjusting amplitudes of carrier voltages according to an amount of voltage imbalance in the split series connected DC capacitor bank.
Dependencies are inferred from the claim text.