Control system for voltage-source pulse width modulation step-up rectifier
First Claim
1. A control system for a voltage-source pulse width modulation step-up converter (hereinafter abbreviated as a PWM converter) comprising:
- a reactor connected in series between an a.c. power supply and an a.c. terminal of said PWM converter,a smoothing capacitor connected between d.c. terminals of said PWM converter,means for detecting an input voltage applied to said reactor,means for detecting a d.c. voltage V across said smoothing capacitor,means for detecting a load current flowing in said PWM converter,means for setting a voltage reference V* with respect to said PWM converter,means for outputting a current amplitude reference |I*| on the basis of a deviation between said voltage reference V* and said d.c. voltage V,means for outputting a current reference IU * synchronous with said input voltage to said reactor and having an amplitude corresponding to said current amplitude reference |I*|,means for outputting a voltage command VA for allowing said load current I to be in correspondence with said current reference IU *,means for outputting a voltage compensation command VLC leading said input voltage to said reactor by a phase angle of 90 degrees and having an amplitude corresponding to said current amplitude reference |I*|,means for calculating a vector sum of said voltage command VA and said voltage compensation command VLC to output said vector sum as a PWM control command VB, andmeans for effecting a PWM control of said PWM converter on the basis of said PWM control command VB.
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Accused Products
Abstract
In a voltage-source PWM step-up converter connected to an a.c. power supply through a reactor, even in the case where a reactor voltage drop VL changes in dependence upon a load current, it is required to compensate such a change to control a d.c. voltage so that it is equal to a predetermined value. Since this reactor voltage drop VL has a phase shift of substantially 90 degrees with respect to an a.c. power supply voltage, a control signal for compensating such a phase shift, resulting in the possibility that is exceeds above a linear control range of the control circuit to reach the saturation range. In view of this, in accordance with this invention, control signal means for compensating a reactor voltage drop VL is provided in the control circuit, thereby making it possible to perform a stable control to provide a stable d.c. output.
9 Citations
4 Claims
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1. A control system for a voltage-source pulse width modulation step-up converter (hereinafter abbreviated as a PWM converter) comprising:
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a reactor connected in series between an a.c. power supply and an a.c. terminal of said PWM converter, a smoothing capacitor connected between d.c. terminals of said PWM converter, means for detecting an input voltage applied to said reactor, means for detecting a d.c. voltage V across said smoothing capacitor, means for detecting a load current flowing in said PWM converter, means for setting a voltage reference V* with respect to said PWM converter, means for outputting a current amplitude reference |I*| on the basis of a deviation between said voltage reference V* and said d.c. voltage V, means for outputting a current reference IU * synchronous with said input voltage to said reactor and having an amplitude corresponding to said current amplitude reference |I*|, means for outputting a voltage command VA for allowing said load current I to be in correspondence with said current reference IU *, means for outputting a voltage compensation command VLC leading said input voltage to said reactor by a phase angle of 90 degrees and having an amplitude corresponding to said current amplitude reference |I*|, means for calculating a vector sum of said voltage command VA and said voltage compensation command VLC to output said vector sum as a PWM control command VB, and means for effecting a PWM control of said PWM converter on the basis of said PWM control command VB. - View Dependent Claims (2, 3, 4)
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Specification