Optimal Modulation Algorithm for Hybrid Clamped Three-Level Inverter
Abstract: The principle of a
three phase hybrid clamped three-level inverter was presented. Taking sixty-four
switch states into consideration, the operational states of hybrid clamped
three-level inverter and different current circuits in different switch states
were detailed derived. Optimal modulation algorithm was proposed based on the
neutral small vectors by different combination, which can realize the automatic
balancing of the neutral-point voltage with few switching cycles and did not
need to measure the voltage of the clamped capacitors. The proposed modulation
algorithm was also capable of restraining the turn-off over-voltage of the
power switching devices effectively. Simulation results were given to verify
the feasibility and correctness. Experimental results obtained by DSP-based
implementation of the controller on 1 MW prototype show good performance in
terms of DC-bus voltages regulation (small neutral point potential function and
low DC ripple coefficient) and good sinusoidal current.
Author: Yi Liu, Guojun Tan,
Xiaoqun He
Journal Code: jptkomputergg160152
