A Novel Carrier Based PWM Control to Balance DC Neutral Point Voltage of Three Phase Four Leg Three – Level NPC Inverter.
1 year ago
Authors:
Nguyễn Đức Hiệu
Publication date:
24 / 06 / 2017
Name of Publishers:
The 11th SEATUC Symposium
Abstract:
Abstract:
In this paper, a novel offset Pulse with Modulation of three phase four leg 3-level neutral point clamped inverter is proposed. The NPC multilevel inverter has a simple topology, however, the neutral point voltage balancing is a serious problem. DC voltage imbalance can be compensated by regulating the DC neutral point (NP) current. The paper proposes a NP current control by selecting appropriate DC offset. An analysis of neutral point current for given working voltages in relation with the offset function will be provided. For a DC voltage unbalanced condition, PWM algorithm to select the offset for maximum ompensating current will be realized. Finally, the simulation and experiments will be implemented to verify the theory proposal.