SU1352596A1 - D.c.voltage converter - Google Patents

Abstract

The invention relates to conversion technology and may be used in the development of high-voltage power sources. The purpose of the invention is to increase efficiency and provide stabilization of the output power of the converter. The converter contains a control node 1, a push-pull transistor power amplifier 2 with an output transformer 3, the high-voltage secondary winding of which is connected to an initial rectifier 4 with a capacitive filter 5, and the power input of the converter is connected to its input terminal through the choke 6. Performing an output transformer with a non-magnetic gap in the core ensures switching of the rectifier diodes at uleym. current. The conversion frequency is chosen close to the resonant frequency of the transformer. Conversion ± EPI is used when charging inductive superconducting and battery accumulators, when matching electrical power | with a load, when changing it over a wide range, 2 Il. a (lfie.1

Description

one

The invention relates to converter technology and can be used in the development of high-voltage power supplies for the conversion of a constant voltage.

The purpose of the invention is to increase the efficiency and provide a stabilization mode for the output power of the converter.

Fig, 1 shows a functional diagram of the converter; Fig. 2 g of a voltage chart, which explains its principle of operation.

The converter contains a control unit 1, a push-pull transistor amplifier 2 of power with an output transformer 3, the high-voltage secondary winding of which is connected to the output rectifier 4 with a capacitive filter 5, and the power input of the power amplifier is connected to the input terminal of the converter through a choke 6, and the output transformer The mat is made with a non-magnetic gap in the core.

The Converter operates as follows.

Due to the inclusion of a linear throttle at the input of the converter, the inductance of which is greater than the inductance of the primary winding of the transformer, the input current of the converter and the collector currents of open transistors are constant during the half-period and are equal in modulus 1. Assume that at time t. O (Fig. 2a) opened one of the transistors. In its collector circuit current flows 1ts 1 const. With an open diode, the rectifier voltage on the secondary winding is constant and equal to the voltage on the load. The voltage on the primary winding is also constant (Fig. 2c) and is different from zero, which leads to a change in the magnetizing current of the transformer (Fig. 2a). As soon as the magnetizing current at t TY reaches the value 1, its further growth stops (the rate of increase becomes zero). The voltage on the windings, proportional to the rate of change of the magnetizing current, will also become zero (Fig. 2c). When this happens, the current of the rectifier diode will be cut off (figure 2b). The nature of the voltage change on the choke is shown in Fig. 2 g. Thus, the switching of the rectifier diodes

525962

Solids occur at zero current through them, which leads to a decrease in power losses in transistors and diodes and an increase in the efficiency of the converter. From the voltage diagrams it follows that the specified mode of operation is possible if the condition that the duty cycle of the current q pulses arriving at the 10th input of the capacitive filter is greater than one

q 1/21 :, - /.

When q 1, the current cut-off will not occur, the current pulses of diode 15 will become trapezoidal, and the magnetizing current will be triangular.

At the same time, q --- x

20

X

nrf ;,

to.

where K - coefficient of transformation

Transformer; ffl is the conversion frequency; L, f - | transformer inductance, reduced to the primary winding. . The conversion frequency is chosen close to the resonant frequency of the transformer in order to reduce the charge current of the transformer's parasitic capacitance, and selecting the transformer inductance by introducing a gap creates the condition q 1. The output characteristic is described by a hyperbola

I.U. --5T: -bfr ---

Consequently, the converter is a load power stabilizer with internal pulse-width modulation.

The use of the invention allows to increase the efficiency of the converter and to provide a stabilization mode for the output power, which is used, for example, when charging energy storage devices.

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Claims (1)

Invention Formula A DC converter containing a control node, a push-pull transistor power amplifier with an output transformer, the secondary winding of which is connected via a rectifier with a capacitive filter to the output terminals of the converter, and a choke connected in series to the input power that, in order to increase efficiency and provide a mode of stabilization of the output (rig.g. Editor N.Slobod nickname Compiled by V. Moin Tehred M. Khodanych Order 5573 / 54Discount 659Subscription VNIIPI USSR State Committee on affairs of inventions and discoveries 113035, 4/5, Raushska nab. Production and printing company, Uzhgorod, Projecto st., 4 formatter is made with a non-magnetic gap. Proofreader I. Muska