Electric power conversion systems – Current conversion – Including d.c.-a.c.-d.c. converter
Patent
1995-04-17
1996-10-22
Wong, Peter S.
Electric power conversion systems
Current conversion
Including d.c.-a.c.-d.c. converter
363 97, 363124, H02M 3335, H02M 324, H02M 700
Patent
active
055683690
DESCRIPTION:
BRIEF SUMMARY
The invention proceeds from a method for operating a voltage converter, in particular during a starting operation.
A method for current limitation of the input current of a voltage converter, in particular of a push-pull DC/DC converter, is disclosed in U.S. Pat. No. 5,095,416 and in the corresponding EP 0 407 691 A1. The input current is measured and integrated per operating cycle in the two push-pull branches. A control signal for a pulse-frequency modulator which determines the switching-on times of the push-pull switches of the voltage converter is derived from the integrated signal. The switching-on times of the push-pull switches are thus adjusted as a function of the measured input current, specifically in such a way that the arithmetic mean value of the push-pull converter remains constant.
WO 92/01355 discloses a switched-mode power supply in which the switching transistor is driven in such a way that during the switching-on phase its switching-on time is successively lengthened, whereas the stopping time remains constant. The switching-on phase is subdivided there into a plurality of time intervals. During the various time intervals, regulation is performed in such a way that the inrush current does not assume impermissible values.
In a similar solution in accordance with WO 85/04060, regulation is performed as a function of an error signal which leads to a change in the pulse duty factor of a pulse-modulated control signal.
Finally, JP 1283086 demonstrates a current-limiting device for a power supply unit, a definite number of time intervals being called up during the switching-on phase, using stored data. There, as well, regulation is performed as a function of an evaluated magnitude of error.
The object of the present invention is to specify a method for operating a voltage converter for switching mode, which permits energy-consuming current limitation without evaluating and regulating circuits. In addition, the aim is to demonstrate a voltage converter for carrying out this method, and applications thereof. This object is achieved by means of claim 10 with respect to the method, by means of claim 12 with respect to the voltage converter and by means of claims 15 or 16 with respect to the application. The further claims relate to embodiments of the method and of the voltage converter.
By contrast with the realization in accordance with U.S. Pat. No. 5,095,416, in the case of the invention there is no need for means for measuring the energy-consuming current or for evaluation. In the invention, the inherent inductance of the voltage converter and/or an inductor connected to the voltage converter are used for the purpose of current rise limitation. If, in particular during a starting operation of the DC/DC converter, the capacitive loads are loaded with a constant current, the output voltage will rise like a ramp. If this ramp-like rise is decomposed into a plurality of subphases, the rise in the output voltage can be approximated by means of a staircase function with a number of steps corresponding to the number of the subphases. The individual switching-on times within the corresponding subphases can now be dimensioned in such a way that the arithmetic mean value of the DC/DC converter current remains virtually constant and the inrush current does not become higher than a prescribed nominal current. In the method in accordance with U.S. Pat. No. 5,095,416, by contrast, the inrush current must be distinctly above the nominal current so that a certain control reserve is guaranteed for the limiter current, for example in the case of ageing, temperature effects, component tolerances. The method in accordance with the invention is insensitive to control fluctuations, control delays, etc. The method is suited, in particular, for satellite power supplies, for example for travelling wave amplifiers, in which no currents can be tolerated which are distinctly above a prescribed nominal current. By storing prescribed characteristic data for the switching-on times, the latter can be reproduced reliably an
REFERENCES:
patent: 4797803 (1989-01-01), Carroll
patent: 4823249 (1989-04-01), Garcia, II
patent: 5053937 (1991-10-01), Bloekl
patent: 5095416 (1992-03-01), Ohms
patent: 5113334 (1992-05-01), Tuson et al.
patent: 5438500 (1995-08-01), Ohms
Geiler Martin
Ohms Franz
ANT Nachrichtentechnik GmbH
Striker Michaeel J.
Vu Bao Q.
Wong Peter S.
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