State variable decoupling and power flow control in PWMcurrent-source rectifiers
Espinoza, J.R.; Joos, G.
Industrial Electronics, IEEE Transactions on
Volume 45, Issue 1, Feb 1998 Page(s):78 - 87
Digital Object Identifier 10.1109/41.661308
Summary:Pulsewidth modulated (PWM) current-source rectifiers (CSR), among
other alternatives, offer marked improvements over thyristor
line-commutated rectifiers as a source of variable DC power. Advantages
include reduced line current harmonic distortion and complete
displacement power factor control, including unity displacement power
factor operation. However, due to nonlinearities of the PWM-CSR model,
their control has usually been carried out using direct line current
control in a three-phase stationary frame (abc). This paper proposes the
application of a nonlinear control technique that introduces more
flexibility in the control of the rectifier and results in a more
straightforward approach to controller design. The proposed technique is
based on a nonlinear state variable feedback approach in the rotating
frame (dq). The approach allows the independent control of the two
components of the line current (active and reactive) with the same
dynamic performance, regardless of the operating point. The control
strategy also eliminates the need for input damping resistors and
rejects the effect of supply voltage variations. Furthermore, a space
vector modulation (SVM) technique is used to maximize the supply voltage
utilization. This paper includes a complete formulation of the system
equations and a controller design procedure. Experimental results on a 2
kVA digital-signal-processor-controlled prototype confirm the validity
of theoretical considerations
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