SU1767669A1 - Delta-phase constant voltage regulator control device - Google Patents

Abstract

The essence of the invention: a device for controlling an rrt-phase pulsed constant-voltage regulator contains a master oscillator 1, m pulse-width modulators 2,3,4, m-phase pulse distributor, m control signal formers 9, 10.11. 5 il.

Description

FIG. I

The invention relates to the field of electrical engineering, in particular, to converter technology, and can be used to create power supply units for radio equipment and variable frequency drives of direct current.

A multiphase pulse stabilizer is known, which contains a power node made in the form of m parallel-connected semiconductor modules and a control unit that includes a master oscillator, a pulse-width modulator and a driver of control signals. To generate control signals for power switches of semiconductor modules, the control unit contains two clock pulse shapers, a strobe pulse shaper, a reference voltage source, a flip-flop, m I-NOT elements, a universal T-bit register, a second T-bit register, comparison circuit and auxiliary voltage unit. The disadvantage of such a device is its relative complexity.

The main disadvantage of all known multiphase pulse converter circuits, which largely limits their use, is the appearance of low-frequency output current (voltage) ripples due to asymmetry in the control of power modules and the non-identity of their parameters.

The closest in essence to the technical solution is a multiphase pulsed transistor, a constant voltage regulator (stabilizer) containing m power modules connected in parallel, made according to the single-cycle direct converter circuit. The device for controlling the converter contains a master oscillator and m channel pulse distributor, the outputs of which are connected to the inputs m of the pulse width modulators, the outputs Si, S2 ..., Sm connected to the control inputs of the power transistors of the converter module. The pulse distributor provides the formation of control signals with a phase shift of 2 l / t, providing alternately the open state of the keys of the converter modules. The pulse width modulator provides, in accordance with the control signal, a change in the relative duration of the open state of the key from 0 to 1. The advantages of multiphase transducers, as mentioned, can be fully realized only under symmetry conditions in the control of power modules and parameters of the used components of the scheme. However, operational amplifiers, commonly used in sawtooth voltage generator circuits of pulse width modulators, have a significant variation in gain factors, input resistance values, etc. As a result, the duration of the output control signal SiS2 ... Sm in each of the channels is different. This leads to a deterioration in the quality of the output voltage of the converter due to the appearance of low-frequency ripples in the output voltage (with a period of 2 n) and, as a consequence, the need to increase the mass-dimensional parameters of the output filter.

The aim of the invention is to improve the quality of the output voltage by balancing the control signals of the power modules and improving the mass-dimensional parameters of the converter by reducing these output filter characteristics.

To achieve this goal, the proposed device for controlling the m-phase pulse regulator of a constant voltage, as well as the known one, contains a master oscillator, an output connected to the m-phase pulse distributor, and m pulse-width modulators with S-| S2 outputs. .Sm having a common control input. In contrast to the known, the proposed device is equipped with m shapers of control signals, outputs 1p-, t / Ј, ... ft. Which are used as output pins and are intended for connection to the control inputs of the power switches of the regulator. One group of inputs of control signal formers is connected to the corresponding aphasic outputs 0.1.0.1.0.2.0-2 ... Qm.Qm of the m-phase pulse distributor made according to the shift register circuit, another group of inputs to the SiS2 outputs .Sm pulse width modulators. The synchronizing inputs of the modulators are connected to the output of the master oscillator. The connections between the inputs and outputs of the aforementioned control signal drivers are defined by a logical expression.

j QjSmQj + lSlQj + 2S2 ... Qj + m-lSm-1 + + QjSmQj + lSlQj + 2 S2 ... Qj + Ti-lSm - l, where j 1, 2 ... m, and if the index is j when Q is greater than m, its value decreases by m while simultaneously inverting O.

Fig. 1 shows a schematic of the proposed device for controlling a multiphase DC voltage regulator; Fig. 2 shows timing diagrams for explaining the principle of generating control signals by converter keys; FIG. 3 is a schematic diagram of the power section of a multiphase DC voltage regulator; FIG. 4 is a variant of the unit pulse width modulators of the device; Fig. 5 shows timing diagrams illustrating the operation of a pulse width modulator unit at various values of the control signal.

A device for controlling a multiphase pulse constant voltage regulator (see figure 1) contains a master oscillator 1, an output connected to the clock inputs of pulse width modulators (in the diagram of figure 1 m 3) 2-4 and m-channel shift register 5, which can be performed, for example, on 1-K triggers 6-8 with cross-linking. Para-phase outputs Qi, Qi ... Qm, Qm of flip-flops 6-8 and outputs Si, S2 ... Sm of pulse width modulators 2-4 are connected to the corresponding inputs of control signal drivers, 1/2, 7 / Q 9 -11, the outputs of which are used as output pins of the device. With m 3, the connection between the outputs From, From, Oz.Oz of the flip-flops 6-8 Si.S2.S3 pulse width modulators 2-4 and the outputs VJ1 of control signal drivers 9-11 is determined by the following

logical expressions

P Q1 SpQaSi + 01 SaQgS10382 V-2 028303810182 + 028303810182 No. Q3S3QiSiQ2S2 + Q3S3QiSiQ2S2 These expressions fully and unambiguously define the internal structure of driver formers 9-11. The specific embodiment shown in Fig. 1 contains four elements 2I-NO 12-15, and element 4I-2, OR 16. The connections between their inputs and outputs are determined by the corresponding expression above.

In general, for any number of m channels of a multiphase pulse controller, the structure of the driver control signals 9-11 varies. The relationship between its inputs and outputs ip is determined by the following, valid for any values, logical expression: QjSmQ j + 1 SlQj + 2S2 ... Qj + m-1Sm + 1 + + QjSmQH-1S lQj + 2S2 ... Qj + m-lsm-1

moreover, if the index j with Q is greater, m, then its value should be

reduced by m with simultaneous inversion of the signal O.

The power part of the multiphase pulse converter (see fig.Z) is similar to the structure of the known converter. It contains m parallel-connected power modules, made according to the single-ended direct converter circuit, in the form of m chokes 17-19 and reverse diodes 20-22,

included in the chain of its regulatory transistor 23-25.

One common conclusion (the connection point of the collectors of transistors 23-25) of the mentioned modules is connected to the first

The power supply terminal 26 and the other (with the connection point of the chokes 17-19) form the output terminal of the controller. To the output pins connected to the capacitor 27 of the filter. The second terminal 28 of the power source (which is also the second output terminal of the controller) is connected to the common point m of reverse diodes 20-22, the second electrodes connected to common points of the above transistors 23-25 and

throttles 17-19 in each of the power modules of the controller.

Pulse width modulators 2–4 can be made, for example, according to a well-known scheme, including a generator

a sawtooth voltage 29-31, the output connected to one of the inputs of the comparator 32-34, the second input of which is connected to the source of the control signal U. Figure 4 shows one of the possible variants of the modulator unit of the pulse width 2-4. Saw-tooth voltage generators 29-31 are made on operational amplifiers 35-37 covered by 100% negative feedback and connected by an input through a resistor 38-40 to an integrating chain from resistor 41-43 and capacitor 44-46, shunted by transistor 47-49 connected by a common input to the output of the master oscillator 1.

The outputs of operational amplifiers 35-37 are outputs of sawtooth voltage generators 29-31. Note that the comparator is connected to the source of the control signal (50. 51) by the like

inputs, and the last, m comparator 52 - antiphase input. The principle of forming the control signals 1 / -1 fa Y $ (Ug.lho.Un) is illustrated by the timing diagrams shown in Fig.2. Thus, the signal Ui from the output of the master oscillator 1 synchronizes the operation of the regulator and determines its internal (operating) frequency. When a signal Ui is applied to the counting input of the trigger 6-8 of the pulse distributor 5, on

the front outputs will generate paraphase signals (Qi, Qi .- .. QmQm) phase-shifted by the angle l / t, which are fed to the corresponding inputs of control signal drivers 9-11.

The main feature of the device operation is the order of formation of output signals U2, U3, U4 (SiS2 ... Sm} of pulse width modulators 2-4, which largely determines the external characteristic of the converter and the quality of its output voltage.

Obviously, because of the possible variation in the characteristics of the elements, the parameters of the output signals U2 – U4 of the modulators of the pulse width 2–4 are generally not the same, i.e. Si 5 82 5 Зз. When controlling a multiphase pulse converter using a known device, this led to the appearance of low-frequency ripples of the output voltage. The proposed device makes it possible to completely eliminate this drawback even with a known asymmetry of the parameters of the pulse width modulators 2-4. According to the shot said. Synchronized by a common LH signal from the output of the master oscillator 1, sawtooth voltage generators 29–31, which are part of the specified pulse width modulators 2–4, form common-mode voltage at the outputs; zheki appropriate form (see figure 5). Resistors 38-34, which provide a constant component of the output signal and its amplitude, set the maximum value of the output signal of the first sawtooth generator 29 equal to the minimum value of the output voltage of the second generator 30. In turn, the maximum value of the output voltage of the second sawtooth generator voltage 30 is set equal to the minimum value of the output voltage of the third generator 31, etc. These signals are fed to the corresponding inputs of the comparators 32-34, and a control signal is sent to their second inputs.

At any value of the control signal Uy, at the output of only one of the comparators 32-34, a variable duty cycle signal will be present, and at the outputs of all others, the signal will be either zero or one. This eliminates the main cause of the unbalance of the output control signals of the device, since at any given time every signal

7/1 / L. . . ft. FORMED NE BASIS

only one signal is Si, and its phase distribution (phase shift) is carried out using control signal generation nodes 9-11.

The generated pulse sequences QiQi, .. QmQm and Si, S2Sm arrive at the inputs of the corresponding elements of nodes 9-11, at the outputs of which, after carrying out the corresponding logical operations, new sequences of pulses will be obtained, t / ЈV n, followed by the above logical expressions. The number of each element 12-16 in node 9 corresponds to the index of the resulting pulse sequence, some of which are shown in Fig.2.

Depending on the magnitude of the control signal U, the shape of the output signals is CH. ife. Your device is changing. This is determined by the form of the U2-U4 signals of the pulse width modulators (see FIG. 5). If a

the control signal is less than the amplitude of the sawtooth voltage of the first generator 29, then the output signal Si has the form of a modulated signal (see U2 in Fig. 2a), the signal $ 2 has a zero signal, and the signal Z3 (in

Generally, Sm) is a positive potential (see FIG. Ba). The sequences of the control signals ip grz have in this case also the form of the modulated signal (see Ug in Fig. 2a) shifted between themselves

on the phase angle tg / gp. If the control signal becomes greater than the amplitude of the sawtooth voltage of the first generator 20, but less than the amplitude of the signal of the second generator 30, then the signal Si acquires

the positive potential, the signal 32 becomes modulated, and the signal Z3 remains having a positive potential (see Fig. 56).

The resulting output signals

 , tp2, trz devices take the form of a modulated signal, the relative duration of which varies from 2 / m to 1 / m (see signal Ug in Fig. 26). Finally, if the signal of the controllers C, / exceeds the amplitude of the output signal of the second generator of the sawtooth voltage 30, then the signals Si and Za become positive and the signal Z3 is modulated, the relative duration of which varies from 1 to 0.

The relative duration of the output signals t / i, 7/2, t / z of the device varies from 1 / m to 0 (see Ug in Fig. 2c). It is obvious that at each moment in time the duration of each of the control signals "/ h, / Ј, t / Q is determined only by the control signal, and does not depend on the parameters of the pulse width modulator circuit 2-4.

The generated control signal sequences ty, tfc, trz after the necessary amplification and galvanic isolation, are fed to the control inputs of transistors 23-25, and ensure the formation of a given output voltage of the converter.

As already mentioned, multiphase pulse transducers have a number of advantages, in particular, the filter elements of multiphase circuits are significantly less in total mass and volume as compared to filters in conversion circuits constructed according to traditional structures, with the same requirements for the parameters (quality) of the output voltage conditions of electromagnetic compatibility and reliability of operation. These advantages can be fully realized only under the condition of symmetry in the management of power cells and the identity of the parameters of the used components of the circuits. The proposed device for controlling the m-phase pulse regulator (or stabilizer) of a constant voltage, even with different parameters of modulated control signals, ensures the fundamental absence of low-frequency pulsations in the output voltage due to the aforementioned reasons.

Claims (1)

Apparatus of the Invention A device for controlling a t-phase pulse voltage regulator containing a master oscillator, an output connected to a t-phase pulse distributor, and m pulse width modulators with outputs Si, S2Sm and with common control input, characterized in that, in order to improve the quality of the output voltage, it is equipped with m forcing control signals, outputs Vi. # 21 which are used as the output pins of the device, and the inputs are connected to the corresponding paraphase Outputs Ch, Qi, Q2, Q2Qm, Qm of m-phase the pulse distributor made according to the scheme of the shift register, and to the outputs of the pulse-width modulators, the synchronizing inputs of which are connected to the output of the master oscillator, the relationship between the inputs and outputs of the said control signal drivers % QJSipQj lSiQj + 2S21..Ql + m.lSm-1 + + QjSmQJ + lSlQJ + 2S2 ... Qj + m-lSm-1, where j 1 2m, and if the index j with Q more t, then its value is reduced by m with simultaneous inversion of the signal Q. about ) )" (, v , i U 57 five   - G -fvto- V rS4-, Shch nP1 I / ) Have V  t,) ™ r bit tsy g and) IJ.fSa) U, (S) --one. Ut Uz (s.,) D) U, (s,) | bit U, sof-ojrijri ni n. I v FIG. B