CN212033993U

CN212033993U - BOOST circuit

Info

Publication number: CN212033993U
Application number: CN202020433699.1U
Authority: CN
Inventors: 刘金明; 鹿明星; 孙晓通
Original assignee: Sineng Electric Co ltd
Current assignee: Sineng Electric Co ltd
Priority date: 2020-03-30
Filing date: 2020-03-30
Publication date: 2020-11-27
Anticipated expiration: 2030-03-30

Abstract

The utility model discloses a BOOST circuit, input capacitance C1 one end and the anodal input A of circuit in this circuit, terminal E is connected on the input board, the input capacitance C1 other end and circuit negative pole input B, terminal F is connected on the input board, terminal E is connected with power inductance L1 one end on the input board, terminal F is connected with circuit negative pole output D on the input board, power inductance L1 other end and power board are connected terminal M, power board upper end terminal M and power tube Q1 collecting electrode, diode D1 anodal connection, diode D1 negative pole and output capacitance C2 are anodal, circuit positive pole output C is connected, power tube Q1 projecting pole is connected with the outside terminal N of power plate after being connected with output capacitance C2 negative pole, connect terminal N and terminal D through the cable in the power plate outside. The utility model discloses power board negative pole electric current has been reduced to can reduce PCB copper sheet area, reduce the specification requirement of binding post and cable, reduce cost.

Description

BOOST circuit

Technical Field

The utility model relates to a photovoltaic power generation field especially relates to a BOOST circuit.

Background

In the photovoltaic power generation industry, the BOOST circuit is widely applied to the MPPT functional module, and is also used in the distributed combiner box and the group-string inverter. A typical BOOST circuit configuration is shown in fig. 1, AB being the input port and CD being the output port. When the device works normally, the AB port inputs low voltage, and the CD port outputs high voltage. In a 1000V pv system, the typical input voltage is 600V, the output voltage is 800V, taking access to 4 pv strings as an example, the AB port input current is 50A at maximum, and the negative output current is input voltage input current/output voltage, regardless of BOOST conversion losses, i.e. 600V 50A/800V equals 37.5A.

Because photovoltaic equipment's unit power is bigger and bigger, single BOOST circuit power can reach more than 25KW, has 4 ways or more BOOST circuits in a machine simultaneously, consequently, hardly places whole BOOST circuit on same PCB veneer. Currently, the conventional board splitting method is as follows, as shown in fig. 2, in which 201 is an input board, 202 is a heat sink, 203 is a power board, an input capacitor C1 is placed on the input board, a power inductor L1 is mounted in a separate heat sink to lead out a cable, and a switching tube Q1, a diode D1 and an output capacitor C2 are placed on the power board. According to the board-splitting mode and the current calculation, 37.5A current needs to flow through the power board, in winter, the input voltage rises, and the output current is larger, so that in the design of a single board, the input maximum current needs to be referred to, namely, the copper sheet and the terminal between two points of the negative pole ND on the power board need to be selected according to 50A. Therefore, the output cathode current is large, a larger PCB copper sheet is required to be designed for heat dissipation, and terminals and cables with high current specifications are selected, so that the cost is high, and the area of the PCB is large; and the electromagnetic compatibility is worse and the stability is relatively worse.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the problem that the above background art part mentioned through a BOOST circuit.

To achieve the purpose, the utility model adopts the following technical proposal:

a BOOST circuit comprises an input capacitor C1, a power inductor L1, a switching tube Q1, a diode D1 and an output capacitor C2; the switch tube Q1, the diode D1 and the output capacitor C2 are placed on a power board, the cathodes of the switch tube Q1 and the output capacitor C2 are connected in parallel to output, and the power board only has one negative terminal.

In particular, the input capacitor C1 is placed on the input board, and the power inductor L1 is mounted in a separate heat sink to lead out the cable; one end of the input capacitor C1 is connected to a circuit positive input terminal a and a terminal E on the input board, the other end of the input capacitor C1 is connected to a circuit negative input terminal B and a terminal F on the input board, the terminal E on the input board is connected to one end of a power inductor L1, the terminal F on the input board is connected to a circuit negative output terminal D, the other end of the power inductor L1 is connected to a terminal M on the power board, the terminal M on the power board is connected to a collector of a power tube Q1 and a positive electrode of a diode D1, a negative electrode of a diode D1 is connected to a positive electrode of an output capacitor C2 and the circuit positive output terminal C, an emitter of the power tube Q1 is connected to a negative electrode of an output capacitor C2 and then to a terminal N outside the power board, and the terminal N and the terminal D are connected to the outside.

In particular, the power inductor L1 is arranged in a separate radiator to lead out a cable, and the input capacitor C1, the switching tube Q1, the diode D1 and the output capacitor C2 are placed on a power board; one end of the input capacitor C1 is connected to a circuit positive electrode input end a and a terminal E on the power board, the other end of the input capacitor C1 is connected to an emitter of the power tube Q1, a negative electrode of the output capacitor C2 and a terminal N outside the power board, the terminal E on the power board is connected to one end of the power inductor L1, the other end of the power inductor L1 is connected to the external terminal M, the external terminal M is connected to a collector of the power tube Q1 and a positive electrode of the diode D1, a negative electrode of the diode D1 is connected to a positive electrode of the output capacitor C2 and a circuit positive electrode output end C, an emitter of the power tube Q1 is connected to a negative electrode of the output capacitor C2 and then to the terminal N outside the power board, a circuit negative electrode input end B is connected to the circuit negative electrode output end D, and the terminal N and the terminal D are connected to the.

In particular, the negative pole of the power board is connected with a protection module in series.

In particular, the protection module employs a relay or a fuse.

The utility model provides a BOOST circuit connects switch tube and output capacitance negative pole in parallel and exports together, makes the power board have only one negative pole binding post, has reduced power board negative pole electric current, thus can reduce PCB copper sheet area, reduce the specification requirement of binding post and cable, reduce cost; the wiring process of the whole machine is simplified, the electromagnetic compatibility is higher, and the stability is higher.

Drawings

FIG. 1 is a schematic diagram of a typical BOOST circuit configuration;

FIG. 2 is a schematic diagram of a conventional BOOST circuit board;

FIG. 3 is a connection diagram of the BOOST circuit board according to the embodiment of the present invention

Fig. 4 is a connection diagram of the BOOST circuit board according to the second embodiment of the present invention.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. The preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The utility model provides a BOOST circuit includes input capacitance C1, power inductance L1, switch tube Q1, diode D1 and output capacitance C2. The switch tube Q1, the diode D1 and the output capacitor C2 are placed on the power board, the cathodes of the switch tube Q1 and the output capacitor C2 are connected in parallel to output, and the power board only has one cathode terminal; the wiring process of the whole machine is simplified, the electromagnetic compatibility is higher, and the stability is higher. In addition, in order to further ensure safety, in this embodiment, the negative electrode of the power board may be further connected in series with a protection module, where the protection module may employ a protection device such as a relay or a fuse. In the present application, an input board refers to a single board on which an input port circuit of a BOOST circuit is located, and mainly includes an input capacitor, an input voltage sampling circuit, an input current sampling circuit, and the like. The power board is a single board where a power conversion circuit of the BOOST circuit is located, and mainly comprises a switch tube, a diode, a bus capacitor, a driving circuit, a bus sampling circuit and the like.

The following description will be made in detail with reference to the first embodiment and the second embodiment:

example one

As shown in fig. 3, fig. 3 is a connection diagram of the BOOST circuit board according to an embodiment of the present invention. The BOOST circuit in this embodiment includes an input capacitor C1, a power inductor L1, a switch Q1, a diode D1, and an output capacitor C2. Wherein the input capacitor C1 is placed on the input board 301, the power inductor L1 is installed in a separate heat sink 302 to lead out the cable, and the switching tube Q1, the diode D1 and the output capacitor C2 are placed on the power board 303; wherein, one end of the input capacitor C1 is connected with the positive input end A of the circuit and the terminal E on the input plate 301, the other end of the input capacitor C1 is connected with the negative input end B of the circuit and the terminal F on the input plate 301, the terminal E on the input plate 301 is connected with one end of the power inductor L1, the terminal F on the input plate 301 is connected with the negative output end D of the circuit, the other end of the power inductor L1 is connected with the terminal M on the power plate 303, the terminal M on the power plate 303 is connected with the collector of the power tube Q1 and the positive electrode of the diode D1, the negative electrode of the diode D1 is connected with the positive electrode of the output capacitor C2 and the positive output end C of the circuit, the emitter of the power tube Q1 is connected with the negative electrode of the output capacitor C2 and, the terminal N and the terminal D are connected by a cable outside the power board 303, and the BOOST circuit function can be fully realized.

During operation, the negative current of the power board 303 only has the difference between the currents of the input AB terminal and the output CD terminal, taking 600V input voltage as an example, 50A input current, 800V output voltage of the CD terminal, and 37.5A output current, at this time, the current flowing through the N point is input current-output current, that is, 50-37.5A is 12.5A, compared with the scheme shown in fig. 2, the current can be reduced by about 75%, performance requirements on the PCB and the negative terminal are reduced to a great extent, and under the working condition that the input voltage is increased, the current of the N point is also smaller, so that the copper skin area of the PCB can be reduced, specification requirements on the connection terminal and the cable are reduced, and the cost is reduced; the wiring process of the whole machine is simplified, the electromagnetic compatibility is higher, and the stability is higher. In order to further ensure safety, in this embodiment, the negative electrode of the power board 303 may be further connected in series with a protection module, where the protection module may employ a protection device such as a relay or a fuse.

Example two

As shown in fig. 4, fig. 4 is a connection diagram of the BOOST circuit board according to the second embodiment of the present invention. The BOOST circuit in this embodiment includes an input capacitor C1, a power inductor L1, a switch Q1, a diode D1, and an output capacitor C2. The power inductor L1 is arranged in a separate heat sink 401 to lead out a cable, and the input capacitor C1, the switching tube Q1, the diode D1 and the output capacitor C2 are arranged on the power board 402; one end of the input capacitor C1 is connected to a circuit positive input terminal a and a terminal E on the power board 402, the other end of the input capacitor C1 is connected to an emitter of the power transistor Q1, a negative electrode of the output capacitor C2, and a terminal N outside the power board 402, the terminal E on the power board 402 is connected to one end of the power inductor L1, the other end of the power inductor L1 is connected to the external terminal M, the external terminal M is connected to a collector of the power transistor Q1 and a positive electrode of the diode D1, a negative electrode of the diode D1 is connected to a positive electrode of the output capacitor C2 and a circuit positive output terminal C, an emitter of the power transistor Q1 is connected to a negative electrode of the output capacitor C2 and then to the terminal N outside the power board 402, a circuit negative input terminal B is connected to a circuit negative output terminal D, and the terminal N and the terminal D are connected to the outside the power board. In this embodiment, the input capacitor C1 is also integrated into the negative output, which has the same effect as the first embodiment. In order to further ensure safety, in this embodiment, the negative electrode of the power board 402 may be further connected in series with a protection module, where the protection module may employ a protection device such as a relay or a fuse.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims

1. A BOOST circuit is characterized by comprising an input capacitor C1, a power inductor L1, a switching tube Q1, a diode D1 and an output capacitor C2; the switch tube Q1, the diode D1 and the output capacitor C2 are placed on a power board, the cathodes of the switch tube Q1 and the output capacitor C2 are connected in parallel to output, and the power board only has one negative terminal.

2. The BOOST circuit of claim 1, wherein the input capacitor C1 is placed on the input board, and the power inductor L1 is housed in a separate heat sink to draw the cable out; one end of the input capacitor C1 is connected to a circuit positive input terminal a and a terminal E on the input board, the other end of the input capacitor C1 is connected to a circuit negative input terminal B and a terminal F on the input board, the terminal E on the input board is connected to one end of a power inductor L1, the terminal F on the input board is connected to a circuit negative output terminal D, the other end of the power inductor L1 is connected to a terminal M on the power board, the terminal M on the power board is connected to a collector of a power tube Q1 and a positive electrode of a diode D1, a negative electrode of a diode D1 is connected to a positive electrode of an output capacitor C2 and the circuit positive output terminal C, an emitter of the power tube Q1 is connected to a negative electrode of an output capacitor C2 and then to a terminal N outside the power board, and the terminal N and the terminal D are connected to the outside.

3. The BOOST circuit of claim 1, wherein the power inductor L1 is housed in a separate heat sink to lead out the cable, and the input capacitor C1, the switching tube Q1, the diode D1 and the output capacitor C2 are placed on the power board; one end of the input capacitor C1 is connected to a circuit positive electrode input end a and a terminal E on the power board, the other end of the input capacitor C1 is connected to an emitter of the power tube Q1, a negative electrode of the output capacitor C2 and a terminal N outside the power board, the terminal E on the power board is connected to one end of the power inductor L1, the other end of the power inductor L1 is connected to the external terminal M, the external terminal M is connected to a collector of the power tube Q1 and a positive electrode of the diode D1, a negative electrode of the diode D1 is connected to a positive electrode of the output capacitor C2 and a circuit positive electrode output end C, an emitter of the power tube Q1 is connected to a negative electrode of the output capacitor C2 and then to the terminal N outside the power board, a circuit negative electrode input end B is connected to the circuit negative electrode output end D, and the terminal N and the terminal D are connected to the.

4. The BOOST circuit according to one of the claims 1 to 3, wherein the negative pole of the power board is connected in series with a protection module.

5. The BOOST circuit of claim 4, wherein the protection module employs a relay or a fuse.