CN211296566U - A step-up DC-DC converter - Google Patents

Abstract

A boost DC-DC converter comprises an inductor L1, a diode D1, a capacitor C1, an inductor L2, a capacitor Co and 1 electronic switch, wherein the electronic switch is provided with a port a and a port b, one end of the inductor L1 is connected with the positive end of a direct-current power supply Vi, the other end of the inductor L1 is connected with the anode of a diode D1 and the port a of the electronic switch at the same time, the cathode of the diode D1 is connected with one end of the capacitor C1, one end of the capacitor Co and one end of a load Z at the same time, the port b of the electronic switch is connected with the other end of the capacitor C1 and one end of the inductor L2 at the same time, and the other end of the load Z is connected with the other end of the capacitor Co, the other end of the inductor L2. The utility model discloses has following operating characteristic: the input current and the output current are continuous, and the output voltage is greater than or equal to the direct-current power supply voltage and has the same polarity.

Description

A step-up DC-DC converter

technical field

The utility model relates to a direct current-direct current (DC-DC) converter, in particular to a boost type DC-DC converter with continuous input and output currents and the same polarity of input and output voltages, which can be used as a basic unit to form a multi-input And multi-output DC power system, such as: DC power module parallel system, LED array drive system, distributed photovoltaic power generation system, etc.

Background technique

Existing basic DC-DC converters with boost function include Boost converter, Buck-Boost converter, Cuk converter, Sepic converter and Zeta converter. As listed in Table 1, without considering the output capacitance, the above five basic DC-DC converters with boost function do not meet the requirements of "the input and output currents are continuous and the input and output voltages are of the same polarity". Require.

Table 1.

SUMMARY OF THE INVENTION

In order to overcome the deficiency that the existing basic DC-DC converters with a boosting function do not meet the requirement that the input and output currents are continuous and the input and output voltages have the same polarity, the utility model provides a boosted DC-DC. The converter can realize that the input and output currents are continuous and the input and output voltages have the same polarity, expanding the types of DC-DC converters.

The technical scheme adopted by the utility model to solve its technical problems is:

A step-up DC-DC converter includes an inductor L1, a diode D1, a capacitor C1, an inductor L2, a capacitor Co and an electronic switch, the electronic switch has a port a and a port b, and one end of the inductor L1 is connected to a DC power supply. The positive end of Vi is connected, the other end of the inductor L1 is connected to the anode of the diode D1 and the port a of the electronic switch at the same time, and the cathode of the diode D1 is connected to one end of the capacitor C1, one end of the capacitor Co and one end of the load Z at the same time. Port b is connected to the other end of the capacitor C1 and one end of the inductor L2 at the same time, and the other end of the load Z is connected to the other end of the capacitor Co, the other end of the inductor L2 and the negative end of the DC power supply Vi at the same time.

In this utility model, when the electronic switch is turned off, the diode D1 is turned on, the DC power supply Vi, the inductor L1, the diode D1, the capacitor C1 and the inductor L2 form a loop, the DC power supply Vi, the inductor L1, the diode D1, the capacitor Co and the load Z form another loop.

When the electronic switch is turned on, the diode D1 is turned off, the DC power source Vi, the inductor L1, the electronic switch and the inductor L2 form a loop, and the DC power source Vi, the inductor L1, the electronic switch, the capacitor C1, the capacitor Co and the load Z form another loop.

Further, the electronic switch adopts a one-way conduction electronic switch, that is, when the electronic switch is turned on, the current flows in from the port a and flows out from the port b. The preferred solution is to prevent current reverse flow.

Still further, the electronic switch includes a diode D2, an N-type MOS transistor M1 and a controller, the controller has a port vg, the anode of the diode D2 is connected to the port a of the electronic switch, and the cathode of the diode D2 is connected to N The drain of the N-type MOS transistor M1 is connected, the source of the N-type MOS transistor M1 is connected to the port b of the electronic switch, and the gate of the N-type MOS transistor M1 is connected to the port vg of the controller.

The controller determines the working state of the N-type MOS transistor M1, and the controller adopts a power supply control chip.

The technical idea of the present invention is as follows: reasonably configure the diode D1 and the electronic switch, so that the capacitor C1, the inductance L1 and the inductance L2 can store and release energy cooperatively in one working cycle, which not only realizes high-efficiency boost conversion, but also realizes The input current is continuous, the output current is continuous and the output voltage polarity is unchanged.

The beneficial effects of the utility model are mainly manifested in: the boosted DC-DC converter has a simple circuit structure, high efficiency, continuous input and output currents, consistent output and input voltage polarities, and output voltage Vo greater than or equal to DC Operating characteristics of the supply voltage Vi.

Description of drawings

Figure 1 is a circuit diagram of the present utility model.

FIG. 2 is a simulation working waveform diagram of an embodiment of the present invention.

Detailed ways

The present utility model will be further described below in conjunction with the accompanying drawings.

1 and 2, a step-up DC-DC converter includes an inductor L1, a diode D1, a capacitor C1, an inductor L2, a capacitor Co and an electronic switch, the electronic switch has a port a and a port b, One end of the inductor L1 is connected to the positive end of the DC power supply Vi, the other end of the inductor L1 is connected to the anode of the diode D1 and the port a of the electronic switch at the same time, and the cathode of the diode D1 is connected to one end of the capacitor C1, one end of the capacitor Co and the load Z at the same time. The other end of the load Z is connected to the other end of the capacitor Co, the other end of the inductor L2 and the negative end of the DC power supply Vi at the same time.

Further, in order to prevent reverse current flow, the electronic switch adopts a unidirectional conduction electronic switch, that is, when the electronic switch is turned on, the current flows in from port a and flows out from port b.

Still further, the electronic switch includes a diode D2, an N-type MOS transistor M1 and a controller, the controller has a port vg, the anode of the diode D2 is connected to the port a of the electronic switch, and the cathode of the diode D2 is connected to N The drain of the N-type MOS transistor M1 is connected to the drain, the source of the N-type MOS transistor M1 is connected to the port b of the electronic switch, and the gate of the N-type MOS transistor M1 is connected to the port vg of the controller.

The controller determines the working state of the N-type MOS transistor M1, and the controller adopts a conventional power control chip, such as UC3842 and the like.

When the embodiment is in continuous conduction mode (CCM), L2 can be approximated as a constant current source, and the entire steady-state operation process includes the following two stages.

Stage 1: N-type MOS tube M1 is turned off, diode D1 is turned on, DC power supply Vi, inductor L1, diode D1, capacitor C1 and inductor L2 form a loop, DC power supply Vi, inductor L1, diode D1, capacitor Co and load Z form another loop. At this time, C1 is charged and L1 is discharged. The input current ii and the output current io (referring to the current flowing into the capacitor Co and the load Z) all decrease linearly.

Stage 2: N-type MOS tube M1 is turned on, diode D1 is turned off, diode D2 is turned on, DC power supply Vi, inductor L1, diode D2, N-type MOS tube M1 and inductor L2 form a loop, DC power supply Vi, inductor L1, diode D2, N-type MOS transistor M1, capacitor C1, capacitor Co and load Z form another loop. At this time, C1 is discharged and L1 is magnetized. Both the input current ii and the output current io rise linearly.

FIG. 2 is a simulation working waveform diagram of the embodiment. It can be seen from FIG. 2 that the input current ii of the embodiment is continuous, the output current io is continuous, the ripple of the inductor current iL2 is small, the output voltage Vo is greater than the DC power supply voltage Vi, and Vo and Vi have the same polarity.

The content described in the embodiments of the present specification is only an enumeration of the realization forms of the concept of the utility model, and the protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments, and the protection scope of the present invention also covers Equivalent technical means that can be conceived by those skilled in the art according to the concept of the present invention.

Claims (4)

1. A step-up DC-DC converter, characterized in that: the boost DC-DC converter comprises an inductor L1, a diode D1, a capacitor C1, an inductor L2, a capacitor Co and 1 electronic switch, wherein the electronic switch is provided with a port a and a port b, one end of the inductor L1 is connected with the positive end of a DC power supply Vi, the other end of the inductor L1 is connected with the anode of a diode D1 and the port a of the electronic switch at the same time, the cathode of the diode D1 is connected with one end of the capacitor C1, one end of the capacitor Co and one end of a load Z at the same time, the port b of the electronic switch is connected with the other end of the capacitor C1 and one end of the inductor L2 at the same time, and the other end of the load Z is connected with the other end of the capacitor Co, the other end of the inductor L2.

2. A step-up DC-DC converter as claimed in claim 1, wherein: the electronic switch adopts a unidirectional conductive electronic switch, namely, when the electronic switch is conductive, the current flows in from the port a and flows out from the port b.

3. A step-up DC-DC converter as claimed in claim 2, wherein: the electronic switch comprises a diode D2, an N-type MOS tube M1 and 1 controller, wherein the controller is provided with a port vg, the anode of the diode D2 is connected with the port a of the electronic switch, the cathode of the diode D2 is connected with the drain of the N-type MOS tube M1, the source of the N-type MOS tube M1 is connected with the port b of the electronic switch, and the gate of the N-type MOS tube M1 is connected with the port vg of the controller.

4. A step-up DC-DC converter as claimed in claim 3, wherein: the controller adopts a power supply control chip.

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