RU2822564C1 - Dc step-up regulator - Google Patents

Abstract

FIELD: converter equipment.

SUBSTANCE: invention relates to converter equipment and can be used in designing energy-efficient controlled DC converters. Device contains input, output and common terminals for connection of direct current source and load, respectively, one circuit consisting of series-connected charging diode, capacitor, throttle and charging switch, connected between input and common terminal, discharge switch connected between connection point of throttle and charging switch of chain and input terminal, discharge diode is connected between the connection point of the charging diode and the capacitor of the chain and the output terminal. An additional switch is introduced, connected between the connection point of the charging diode, the discharge diode, the chain capacitor and the connection point of the charge switch, discharge switch and throttle of the chain, smooth decrease (increase) of output voltage is carried out by changing the relative duration of the open state of the additional switch and the discharge switch during their serial switching, obtaining an output voltage greater than the doubled input voltage with only one resonant circuit and smooth adjustment of the output voltage.

EFFECT: increase in the voltage conversion coefficient is more than 2 with a smaller number of elements and the presence of one resonant circuit with the possibility of smooth adjustment of the output voltage in a wide range.

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Description

The present invention relates to the field of converter technology and can be used to create energy-efficient adjustable DC converters. An adjustable boost DC voltage converter is known (Patent No. 2734101, Russian Federation, MPK N02M 3/18 (2006.01), application 2020117224 dated 05.26.2020, published 10.13.2020 Bulletin No. 29), containing an input, output and common terminal for connection source and load, n parallel-connected chains, each of which contains a charging diode, a capacitor, a choke and a discharge switch, two discharge diodes, the terminals of which are connected between the charging diodes of the first and second chains and two capacitors, forming two voltage levels. A two-level regulator containing a switch, a diode, a choke and a smoothing capacitor is connected to the capacitors.

Discrete regulation of the output voltage in the converter is carried out by changing the corresponding number of circuits that are discharged to the load using bit switches. Smooth regulation of the output voltage within a discrete range is carried out by switching the key of a two-level regulator.

The disadvantages of this adjustable boost converter include a large number of elements, as well as the presence of a bulky inductor as part of a two-level regulator with large dimensions.

A step-up voltage regulator for working with a three-phase load is known (Patent No. 2806896, Russian Federation, MPK N02M 7/537 (2006.01), application 2023113602 dated 05/25/2023, published 11/08/2023 Bulletin No. 31), containing input, common terminals for connection of the source, n chains, each of which consists of a charging diode, capacitor, choke, (n-1) bit switches connected between the connection point of the charging key and choke of the previous chain and the connection point of the charging diode and capacitor of the subsequent chain, bit switch included between the connection point of the charging key and the inductor of the last chain and the input terminal, two two-level pulse-width regulators, consisting of a diode and a capacitor that form the second voltage level and two diodes and capacitors that form the first voltage level, two regulating switches, chokes and smoothing capacitors, a three-phase load connected to a second pulse-width controller and a two-rack inverter. Smooth regulation of the load voltage is carried out by changing the relative duration of the open state of the keys of two-level pulse-width regulators, as well as using the inverter keys. Due to the low voltage drop across the control switch, dynamic power losses during regulation are reduced. The control range can be expanded by connecting the inputs of pulse-width regulators between the connection points of the charging diode and the capacitor of the three resonant circuits.

The disadvantages of this boost regulator include its large dimensions due to the presence of two pulse-width regulators, each of which uses a bulky inductor, as well as a large number of resonant circuits to obtain the required voltage conversion coefficient.

In addition, there is a known method for regulating the output voltage of a step-up DC-DC converter (Patent No. 2746272, Russian Federation, IPC N02M 3/18 (2006.01), application 2020135310 dated 10.28.2020, published 04.12.2021 Bulletin No. 11), containing an input, output and common terminals for connecting the input source and load, n parallel-connected chains, each of which consists of a series-connected charging diode, capacitor, inductor, charging key, (n-1) bit switches, each of which is connected between the inductor connection point and charging key of the previous chain and the connection point of the charging diode and capacitor of the subsequent chain, a discharge switch connected between the connection point of the inductor and the charging key of the last chain and the input terminal of the source, a discharge diode connected between the connection point of the capacitor and the charging key of the first chain and the output terminal for connection load, which is the prototype of the proposed invention, which consists in discrete regulation of the output voltage by changing the number of resonant chains discharging to the load, smooth regulation of the output voltage within a discrete range is carried out by changing the duration of the open state of the bit key of the last chain participating in the conversion process.

Due to the presence of chains that are sequential oscillatory circuits, switching of charging and discharging keys is carried out at a resonant frequency while maintaining soft switching of the keys. The hard switching mode is typical for a bit key, which is a regulating element. It should be noted that no additional cascades or devices are used to regulate the output voltage.

The disadvantage of the prototype is the large number of resonant circuits and switching switches to obtain the required voltage conversion coefficient: for requires (n-1) resonant circuits.

The task (technical result) is to increase the voltage conversion coefficient to more than 2 with a smaller number of elements and the presence of one resonant circuit with the ability to smoothly regulate the output voltage over a wide range.

The solution to the problem is achieved by the fact that in a DC boost regulator containing input, output and common terminals for connecting a DC source and load, respectively, one chain consisting of a series-connected charging diode, capacitor, inductor and charging switch, connected between the input and common terminal, a discharge switch connected between the connection point of the inductor and the charging key of the chain and the input terminal, a discharge diode connected between the connection point of the charging diode and the capacitor of the chain and the output terminal, an additional key is inserted connected between the connection point of the charging diode, discharge diode, capacitor chain and the connection point of the charging key, the bit key and the choke of the chain, a smooth decrease (increase) of the output voltage is carried out by changing the relative duration of the open state of the additional key and the bit key when they are switched in series, obtaining an output voltage greater than the value of twice the input voltage in the presence of only one resonant chains and smooth regulation of the output voltage.

In FIG. 1 shows the electrical circuit of a DC boost regulator,

In FIG. Figure 2 shows oscillograms of currents and voltages of the elements, explaining the principle of operation of the regulator; Fig. Figure 3 shows the adjustment characteristic.

The proposed device (Fig. 1) consists of a charging diode 1, a capacitor 2, a choke 3, a charging key 4, an additional key 5, a bit key 6, a bit diode 7, an input pin 8, a common pin 9 for connecting a source, an output pin 10, common terminal 11 for connecting the load, load 12, output capacitor 13, input DC source 14.

The proposed device (Fig. 1) contains a chain consisting of a series-connected charging diode 1, a capacitor 2, an inductor 3, a charging key 4. The chain is connected between the input pin 8 and the common pin 9. An input DC source 14 is connected to pins 8, 9 Between the connection point of the charging key 4, inductor 3 and the input pin 8, a bit switch 6 is connected. An additional switch 5 is connected between the connection point of the charging diode 1, capacitor 2, bit diode 7 and the connection point of the charging key 4, bit key 6 and inductor 3. The discharge diode 7 is connected between the connection point of the charging diode 1, capacitor 2, additional switch 5 and the output pin 10. A load 12, which represents an active resistance, and a smoothing capacitor 13 are connected in parallel to the output pin 10 and the common pin 11.

The proposed controller works as follows. At the initial moment of time, when control pulses are applied, the charging switch 4 opens and, through the opened charging diode 1, a resonant charge of the capacitor 2 is carried out from the input source 14 to voltage E1, the current through the diode 1 and the charging switch 4 has a piecewise sinusoidal shape. The parameters of capacitor 2 and inductor 3 are selected in such a way that the frequency of control pulses arriving at the keys is equal to the resonant frequency of the oscillatory circuit formed by capacitor 2 and inductor 3. After closing the charging key 4 at the moment θ = 180 degrees, the bit key 6 opens and the charged capacitor 2, through inductor 3, bit switch 6, is connected in series with input source 14. Through the opened bit diode 7, a voltage is applied to the load equal to the sum of voltage E1 and the voltage on the plates of capacitor 2. Thus, voltage 2·E1 is applied to the load. Due to the fact that the charging key 4 and the bit key 6 are switched at times when the current through them is zero, there are no dynamic power losses in them. The control pulses arriving at keys 4 and 6 are shifted relative to each other by 180 degrees, their switching is carried out in antiphase. An angle of 180 degrees corresponds to a moment in time equal to half the period of the control pulse , the angle of 360 degrees corresponds to the period of control pulses , Where - cyclic frequency.

To obtain a voltage on the load exceeding the value of 2·E1, as well as to regulate it, an additional switch 5 comes into operation. In this case, the keys operate as follows, as illustrated in Fig. 2. At the initial moment, key 4 opens and a resonant charge of capacitor 2 is carried out. By the end of the control pulse at θ = 180°, the current in the charge circuit decreases to zero, the control pulse is removed from key 4, and it closes. At the moment θ=180°, the additional key 5 is turned on. Part of the energy of the charged capacitor 2 is transferred to the inductor 3. The key 5 is in the open state in the range from 180 to (180+γ) degrees, where ( is the control angle of the additional key 5 (the relative duration of the open state of the additional key 5). At the moment θ=(180°+γ), the additional key 5 is turned off and the bit switch 6 is turned on. Due to the fact that the inductor circuit 3 opens, a self-induction voltage appears at its terminals: a positive potential at the upper terminal. and a negative potential at the bottom. Depending on the angle γ, the value of the self-induction voltage on the inductor 3 changes. The voltage of the input source 14 through the open switch 6 is added to the self-induction voltage on the inductor 3, as well as with the voltage of the charged capacitor 2, and the total voltage is supplied through the opened diode 7. to pin 10 and is applied to the load. Thus, a voltage exceeding 2·E1 is applied to the load. The energy efficiency of such a converter is ensured by the soft switching mode of the charging switch 4, namely by switching it at times when the current through it is zero. Switch 6 is turned on at the moment θ=(180°+γ), when the voltage on it is zero. The control pulse from key 6 is removed at θ=360 degrees. The voltage on switches 4 and 6 does not exceed the voltage of the input source E1. For key 5, the soft switching mode is retained when turned on.

In FIG. Figure 3 shows the adjustment characteristic of the converter, which represents the dependence of the conversion coefficient from the control angle γ additionally of switch 5, obtained by simulation in the PSIM software package at input voltage E1=24 V and load resistance 5 Ohms.

Thus, the proposed boost converter provides a voltage conversion coefficient greater than 2 with a smaller number of elements and the presence of one resonant circuit with the ability to smoothly regulate the output voltage over a wide range.

Claims (1)

A DC boost regulator containing input, output and common terminals for connecting a DC source and load, respectively, one chain consisting of a charging diode, capacitor, inductor and charging switch connected in series, connected between the input and common terminal, a discharge switch connected between the connection point between the inductor and the charging key of the chain and the input terminal, a discharge diode connected between the connection point of the charging diode and the capacitor of the chain and the output terminal, characterized in that an additional key is inserted into it, connected between the connection point of the charging diode, the discharge diode, the chain capacitor and connection point between the charging key, the bit key and the inductor of the chain, a smooth change in the value of the output voltage is carried out by changing the relative duration of the open state of the additional key and the bit key when they are switched in series, which ensures that an output voltage value greater than twice the input voltage is obtained in the presence of only one resonant chains, and smooth regulation of the output voltage.