SU1304152A1 - A.c.voltage-to-d.c.voltage converter - Google Patents

Abstract

This invention relates to electrical engineering and can be used in static converters. The aim of the invention is to increase the control accuracy. The variable component of the output voltage through the circuit 23, the amplifier 20 and the potential isolation unit 17 is fed to the input of the control unit 6. When the voltage on it is equal to the set threshold values, the keys are switched 7-10. Using a capacitor 22 and a resistor 21, the variable component of the output voltage is applied to the input of the amplifier 20 with virtually no attenuation, which ensures the maximum ratio of the useful signal to the level of interference. The amplifier 20 amplifies the signal and restores the form of this component by compensating for distortions that occur when the signal drops through circuit 23. At the output of amplifier 24, the voltage taken from the output of divider 25 and proportional to the output voltage of the transmitter is compared with the reference signal. In this case, a higher gain factor of the amplifier 24 ensures high precision of adjustment. 1 hp f-ly, 2 ill. (Л г: -гг1 7-: 6 sn i «- - fсо about 4

Description

11304152

FIELD: electrical engineering. I

technology, namely, converters of alternating voltage into a constant, providing high precision control.

The purpose of the invention is to improve the accuracy of regulation by reducing the level of pulsations and improving noise immunity.

FIG. 1 shows a device diagram of the input of block 6. As soon as a voltage is applied, FIG. 2 - diagrams, see - at the input of block 6 reaches the value.

operating principle of the converter.

The proposed converter contains a controlled rectifier 1 with a control unit of the rectifier 2. The output of rectifier 1 is connected to the input of a smoothing LC filter 3, to the output of which is connected through the choke 4

bridge converter output 5

The voltage is very low. Therefore, using a capacitor 22 and a resistor 21 in the circuit 23, the variable component of the output voltage is applied to the input of the amplifier 20 with almost no attenuation, which ensures that the maximum ratio of the useful signal to the noise level. Further

thirty

equal to the threshold value established in it, the keys 7–10 in the converter 5 switch 5, due to which the voltage at its output changes sign and acquires the form shown in fig. Thus, at the output of the LC filter 3, a sawtooth voltage is formed, the constant voltage with the width relative to it, the diagram of which is shown in figure 2a. pulsed regulation with block 6 With high demands on the quality of control of this converter, it provides a pulsation output voltage with an output device for switching keys 7–10 when the voltage at its input reaches the threshold values established on it. The output of the rectifier control unit 11, equipped with an adder 12 and a regulating amplifier 13, is connected to the input of the rectifier control unit 2, and the outputs are connected to its two inputs; on the amplifier 20 is usi-. reference point 14 and signal conditioning and shape recovery

This component compensates for the distortions that occur when the converter is constantly 35 times less than the last sixth through the circuit 23. Thus, with a control system, the voltage is connected to the input of the unit 6 via the control system the potential 17 block, the potential for de-energizing with a pulse-width pulse-guided galvanic isolation, is set by the pulse width of the circuits, and one of the inputs of the junction box 16 of the output voltage depends on the source output kak 18 signals from the variable transfer ratio of ° through the block 19 of the potential component of the output voltage; isolating, providing galvanic through amplifier 20 and block 17 and to the isolation of circuits. One of the inputs depends on 45 threshold voltages installed in block 6 of the control amplifier 20 in the system. At the input of the amplifier 16, a parallel switch .24 is connected to the voltage removed from the resistor 21, which together with the stroke of the divider 25 and proportional to the output voltage of the converter connected in series with it, is compared to the reference signal . The drag chain 23. The second output is amplified by the output voltage of the converter. At the same time, a large gain factor of the amplifier 24 ensures high precision of adjustment. Control system

13 of the current included in the output circuit of the converter 5. The output of the block 16 of the regulator 20 is connected to the output of the control amplifier 24, one of the inputs of which is connected to the voltage divider 23. The circuit 23 and the divider 25 are directly connected at the output of the LC-55 converter of the constant voltage filter 3. Thus, the blocks 11 and neither with the pulse-width regulation 16 constitute the regulation system 26 consisting of amplifiers 20 and 24 , nor the output voltage of the conversion circuit 23 and the divider 25, allows the operator 5.pechat the pulsation level as a finger.

2

The Converter operates as follows. I

FIG. 2 o. The voltage and output diagram of the LC filter is shown. Through the circuit 23, the amplifier 20 and the block 17, the variable component of the output voltage of the diagram of which is shown in FIG. 2S, transmitted to

The voltage is very low. Therefore, using a capacitor 22 and a resistor 21 in the circuit 23, the variable component of the output voltage is applied to the input of the amplifier 20 with almost no attenuation, which ensures that the maximum ratio of the useful signal to the noise level. Further

equal to the threshold value established in it, switches of keys 7–10 in converter 5 occur, due to which the voltage at its output changes sign and acquires the form shown in fig. Thus, a sawtooth voltage is formed at the output of the LC filter 3, the diagram of which is shown in FIG. 2.a When the requirement for the quality of the output voltage of the pulsation is high, the output of the amplifier 20 is amplified. signal conditioning and shape recovery

and high precision control of the output voltage. A prerequisite for achieving these goals is also the ability of the DC-DC converter 6 with pulse-width regulation to operate at a high frequency. In block M, the signal from the sensor 15, measuring the magnitude of the output current of the converter 5 ,. compared with the reference signal from source 14. As a result, the control angle 1 sets the control angle at which the output current of converter 5 corresponds to the reference signal. In this way, the output current of the converter 5 is set, and thereby the load is distributed between rectifier 1 and converter 5. The own voltage sensor, which provides galvanic isolation of circuits and built according to the modulator-demodulator principle, is the source interference. Therefore, the inclusion of this sensor between the regulator and the output of the filter for isolating the circuits due to the low level of ripple, i.e. and | - due to the low level of the signal transmitted through the sensor, does not ensure the normal operation of the converter. Since the level of the signals at the output of the amplifier 20 and the source 18 is significantly higher than the amount of noise, the inclusion of sensors for galvanic uncoupling of the circuits between the constant-voltage converter control system with pulse-width control, output of the driving voltage source and input converter-constant control systems characterized by the fact that, at a reasonable voltage, eliminates the above difficulty.

Claims (2)

1. AC to DC converter containing a source connected in series the reference signal, the first input of the primary isolation. the adder, the first control amplifier, the phase control unit, the control input of the controlled rectifier, the power inputs of which are intended to be connected to the supply mains, and the output of the LC filter to the load, characterized in that, in order to increase the control accuracy by reducing the level pulsations, it is equipped with a current sensor, a bridge converter, a choke, a two-threshold control unit, a voltage divider, a differentiating link, a second adder, a second and third regulating amplifiers, the first of which with two inputs, a reference signal source, and the output of the LC filter are connected to the inputs of a voltage divider and a differentiating circuit and through the choke output of a bridge converter whose power input is intended to be connected to a constant voltage source, the first inputs of a second adder and a second regulating amplifier connected to the outputs of the voltage divider and the differentiating circuit, respectively, the second input of the second adder is connected to the output of the reference signal source, and the output through the third regulating gain s to the second input of the second regulating amplifier whose output is coupled to the input of two-threshold control unit, whose output is connected to a control input of the bridge converter, the current sensor output is connected to the second input of the first adder. 2. The converter according to claim 1, which is designed to increase noise immunity, it is equipped with two potential isolation blocks, the output of the source signal being set to the second input of the second adder via the first potential isolation block, the output of the second control amplifier is connected to the input of the block two-threshold control through the second potential unit / / x x X / y / / / / Pu / 7. - / L-K-GY-- - - - / f cfjue.Z Editor E. Kopcha Compiled by S. Luzanov Tehred I.Popovich Proofreader L. Patay Order 1322/56 Circulation 661 VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab ,, d. 4/5 Production and printing company, Uzhgorod, st. Project, 4 Subscription