Title :
Decoupled control of a four-leg inverter via a new 4×4 transformation matrix
Author :
Ryan, Michael J. ; De Doncker, Rik W. ; Lorenz, Robert D.
Author_Institution :
Syst. & Power Electron. Group, Capstone Turbine Corp., Chatsworth, CA, USA
fDate :
9/1/2001 12:00:00 AM
Abstract :
Four-leg (3-phase 4-wire) inverters are developed to power unbalanced/nonlinear three-phase loads. A unique 4×4 decoupling transformation matrix is used that enables direct transformation between the four degree-of-freedom (DOF) leg-modulation space of the inverter and its corresponding 3-DOF output-voltage space. This is analogous to the well-known 3×3 “abc-qd” transformation developed for the three-leg inverter. Details of this new 4×4 “Quad” transform are provided, along with a depiction of the voltage-vectors produced. Advanced synchronous-frame control techniques are applied with this 4-to-3 “abcn-qdo” transform to create a UPS-style inverter with sinewave output. Experimental results for an 8.6 kVA prototype inverter are presented
Keywords :
electric current control; invertors; uninterruptible power supplies; 3-DOF output-voltage space; 3-phase 4-wire inverters; 4×4 Quad transform; 4×4 transformation matrix; 4-to-3 abcn-qdo transform; 8.6 kVA; UPS-style inverter; current control; decoupled control; four degree-of-freedom leg-modulation space; four-leg inverter; nonlinear three-phase loads powering; sinewave output; synchronous-frame control techniques; unbalanced three-phase loads powering; voltage-vectors; Circuit testing; Circuit topology; Control systems; Leg; Phase modulation; Power electronics; Prototypes; Pulse width modulation inverters; Uninterruptible power systems; Voltage control;
Journal_Title :
Power Electronics, IEEE Transactions on
