RU1771051C - Stabilizing electric power supply source - Google Patents

Abstract

Usage: conversion technology in secondary power systems of electronic equipment. SUMMARY OF THE INVENTION: the device comprises an adjustable converter (1), a driver (2) of a control voltage, two threshold devices (3, 9), an RCD chain (11) and a mismatch amplifier (5) Adder

Description

YU

The invention relates to a conversion technique.

A known power supply 1, comprising an adjustable converter, the transformers of which, through a control voltage generator, a first threshold device, an RCD circuit, a single vibrator and a second threshold device are connected to a timing capacitor and an adjustable current source, the latter being shunted by a core, and the control input of the current source is connected to the output of the mismatch amplifier.

The device has the following disadvantages:

- on the plot of the parametric limitation of the load current (figure 2), described by the dependence

 2UH

 at

I -5, where y

1-M2

and

other

0)

with rational values of the parameter M UHHOM / kE 0.7 ... 0.8, the short-circuit current of the load IHO in accordance with the dependence (1) for U 0

IHO IHHOM -. 0 2 ... 3 (2)

1-M2

several times higher than the rated load current IHHOM, it leads to an increase in the mass of heat sink radiators and a decrease in reliability due to an increase in the load factor of converter elements;

-the device has a low stabilization coefficient;

- there is no possibility of parallel operation of several IVEPs, since in the current limiting section the device is a converter of the input voltage to the load current, i.e. input voltage ripples are not practiced.

The aim of the proposed invention is to increase reliability, improve overall dimensions, as well as increase the stabilization coefficient with the expansion of functionality due to the parallel operation of several IVEC, which allows unlimited increase in power by unified modules.

The goal is achieved. that an adder and a forming circuit are introduced into the stabilizing power supply (1), where the adder output is connected to the input of the current source, the first adder input is connected to the output of the matching amplifier, and the second input is connected through the forming circuit to the converter output. In addition, a second forming chain has been introduced connecting tre0)

th input of the adder and the input ignition of the converter.

Figure 1 presents a diagram of the proposed device; figure 2 and 3 are options

5 designs of forming chains with corresponding load characteristics.

The power source contains an adjustable converter 1, the transistors of which are connected via a control voltage generator 2 and a first threshold device 3 to a reference voltage source 4, the output of which is connected to the first input and the output of converter 1 to the second

15 by the input of the mismatch amplifier 5, an adjustable current source 6, a timing capacitor 7, and a key 8 connected to the second threshold device 9, the one-shot 10, and the RCD chain 11, and an adder 12 is connected between the 20 mismatch amplifiers 5, the inputs of which are connected to the first 13 and second 14 forming chains. The device operates as follows.

25 On an unregulated portion of the load characteristic of the prototype device (1), the conversion frequency is unchanged, while in accordance with dependence (2), the short-circuit current But significantly exceeds the rated load current IHHOM. Obviously, in order for the current in this section to be constant, it is necessary to appropriately change the frequency or. which is the same, condense charge time: atora 7

35 by source current 6 Ozar) until the threshold voltage 9 (Unop) is triggered. Since on this interval

With unop

t

40

1zar

the current in the inductor will also increase linearly, the amplitude of the current will be determined as

1 YOUL1 CUn ° i

L

(3)

LL13ar

From the condition of the amplitude / current constant of the 45 throttle current (and hence the load current), the law of variation of the current 13 ar to determine the vertical section of the load current limitation

E-UH Eu-Tsn UH

fifty

1zar

- const or

charge

R

R

The last dependence, shown graphically in Fig. 2a, for the Unnom plot is realized by the circuit (Fig. 2h), where the input of the current mirror is used as the adder (currents).

For this circuit, we have

I - UH - .ЕУ + Eu-Tsn 0 R R2Ri

 EU about. EU: L1 +

R2

where 1o E

Ri

(4)

R2 + Ri

at RiR2

Thus, to ensure a constant current, it is necessary that the first two terms in dependence (4) are proportional to the supply voltage (E), and the third (U / Ri) is proportional to the load voltage UHHOM, which is unambiguously realized by the choice of .resistance RI and R2.

If necessary, to have a greater or lesser slope of the characteristic (dotted line in figa), respectively, reduce or increase the resistance RI while maintaining I const. Therefore, to obtain a quadrangular shape of the load characteristic (rectangular or trapezoidal), the forming circuit 13 consists of two resistors (Fig. 2, a), the currents of which are summed and charge the capacitor 7.

To obtain a more complex form of the load characteristic (Fig. 26), additional circuits with a non-linear element (diode or zener diode) are connected in parallel with the resistance RI. If it is necessary to use the natural portion of the load characteristic (points A and B in Fig. 2b), a zener diode with its threshold voltage is turned on in each of the parallel branches.

Thus, the proposed technical solution allows, due to the introduction of an adder and a forming chain, to obtain the desired shape of the load characteristic of the SECP, which reduces the load of the converter elements on the falling section of the load characteristic, and therefore, increase the reliability and improve the overall dimensions of the SECS. In addition, the device can be used as a charge converter for charging a capacitive energy storage device, where the form of the load characteristic is selected from the conditions of optimization of the power system.

A prerequisite for unlimited parallel expansion of the IVEC in order to increase the output power is to exclude the influence of changes in the supply voltage (E) when the OOS circuit is open on the load voltage UH or other (point A in Fig. 26). To fulfill this condition, the charge current of 3 ar must thus depend on E so that the amplitude of the collector current in dependence (3) remains unchanged. For this, the current 0 in dependence (4) should be proportional

0

supply voltage E. The corresponding implementation of the circuit is shown in Fig. 3, where the auxiliary voltage converter through the linear stabilizer LSN forms the supply voltage control circuit Eu, and the voltage kE acts on the input of the LSN, proportional to the input voltage for EMEP EMF. In this case, the current the charge of the capacitor 7 will be formed according to the dependence

1.zar t

k E-UH

 or

1ct E - UH

R

- const

R1zar Lk E - UH

which corresponds to complete compensation of 15 changes (ripple) of the supply voltage E over the entire range of variation of UHHOM, i.e. the load current does not depend on changes in E at UH UH / R, where k is the transformation coefficient of the converter transformer. The current mirror (Fig. 3a) performs the functions of both an adder 12 (for input currents) and a controlled current source 6 (for an output current of 3 ar), while the functions of the two forming chains 13, 14 are performed by a single resistor R.

On Fig, the summation of the currents is carried out directly in the capacitor 7, and the current of the circuit 14 is exponential, which allows you to compensate for the increase

30 pulses in the t + tpac converter due to the time of absorption of the charge of the power transistors.

Claims (2)

1. Stabilizing power supply according to ed. No. 1725355, characterized in that, in order to increase reliability and improve mass-dimensional 45 indicators, an adder and a circuit for generating a load characteristic are introduced into it, with the adder output connected to the control input of an adjustable current source, the first adder input connected to the output of the mismatch amplifier, and the second input through the indicated circuit with output terminals. 2. The power supply according to claim 1. This is due to the fact that, with the aim of expanding the functionality, the third adder input is connected to the output terminals via the introduced chain of forming the invariance to the supply voltage. ai and. Hham IKHVH but UNNO HZIlH j 1 I3 & f tf and