CN205647259U - Be applied to photovoltaic inverter's big gain DCDC converter - Google Patents

Abstract

The utility model provides a be applied to photovoltaic inverter's big gain DCDC converter, inductance step up the method that unit and traditional converter combined together and can effectually avoid because of using isolation transformer and the produced EMI noise of coupling inductance liter to effectual raising circuitry's step up ratio. Because only switch tube, therefore required control circuit and essential boost converter control circuit do not have the difference. Because the right and wrong buffer circuit who adopts does not need magnetic element such as transformer, therefore the circuit has light in weight, power density height, small characteristics. Through the innovative approach, can also step up the unit to the inductance and extend, increase the figure of inductance for the gain of circuit becomes bigger. If the figure of former device is infinitely great, can reach infinitely great voltage gain in theory.

Description

A kind of large gain DC/DC changer being applied to photovoltaic DC-to-AC converter

Technical field

This utility model relates to photovoltaic DC-to-AC converter DC/DC changer technical field, more particularly, to one It is applied to the large gain DC/DC changer of photovoltaic DC-to-AC converter.

Background technology

Photovoltaic generation has become as a part important in generation of electricity by new energy technology.Photovoltaic generation pollutes little, zero-emission Put, have simultaneously and facilitate family separately installed, the advantage easily realizing distributed power generation.Photovoltaic generation can be made Means are effectively replaced for thermal power generation.Solar energy resources is the abundantest, and after using photovoltaic generation, people need not Worry the problem that Fossil fuel is exhausted again.

But voltage produced by normal domestic use photovoltaic panel is about 20-24V, but household voltage standard is 220V.Therefore, between photovoltaic panel and electrical network, need to access the DC/DC changer of a large gain, such as figure Shown in 1.

Existing large gain DC/DC converter technique mainly has DC/DC changer based on coupling inductance, based on The DC/DC changer etc. of isolating transformer.Coupling inductance and isolating transformer can give changer and control circuit Bring electromagnetic interference (EMI) noise of many, the stability of circuit will be had influence on, and can be to the environment band of surrounding Carry out electromagnetic pollution.

Utility model content

This utility model is to overcome at least one defect described in above-mentioned prior art, it is provided that one is applied to photovoltaic The large gain DC/DC changer of inverter.Inductance boost unit and conventional transducers (Buck, Buck-Boost, Cuk) method combined, improves converter circuit in the case of not using isolating transformer and coupling inductance Step-up ratio, thus reduce electromagnetic interference (EMI) noise.

For solving above-mentioned technical problem, the technical solution of the utility model is as follows:

A kind of large gain DC/DC changer being applied to photovoltaic DC-to-AC converter, for the input producing photovoltaic panel Voltage V_inCarry out boosting and be converted to output voltage V_out, including inductance boost unit, inductance boost unit bag Include 1 input and 1 outfan, input voltage V_inPositive pole connect the input of inductance boost unit, defeated Enter voltage V_inNegative pole meet switching tube S, electric capacity C respectively₀, resistance R_LOne end, inductance boost unit Outfan meets the other end and the diode D of switching tube S respectively₀Positive pole, diode D₀Negative pole connect respectively Electric capacity C₀With resistance R_LThe other end, resistance R_LTwo ends be respectively output voltage V_outPositive pole and negative pole.

In the preferred scheme of one, the physical circuit of described inductance boost unit is: inductance boost unit defeated Enter end and be connected with inductance L in turn between outfan₁, diode D₁, diode D₄, inductance boost unit Input has diode D between outfan the most secondary connection₃, diode D₆, inductance L₃, diode D₁'s Positive pole and diode D₃Negative pole between be in series with diode D₂, diode D₃Negative pole and diode D₄'s Inductance L it is in series with between positive pole₂, diode D₄Positive pole and diode D₆Negative pole between be in series with two poles Pipe D₅。

In the preferred scheme of one, the model of described switching tube S is IRF540N or IRF640N.

In the preferred scheme of one, described DC/DC changer also includes control circuit, and control circuit uses Digital control chip or simulation control chip.

In the preferred scheme of one, the model that simulation control chip uses is TI UC3842；Digital control core Sheet uses AVR single chip or STM32 ARM chip.

Compared with prior art, technical solutions of the utility model provide the benefit that: this utility model provides one Being applied to the large gain DC/DC changer of photovoltaic DC-to-AC converter, inductance boost unit combines with conventional transducers Method can effectively avoid because using isolating transformer and coupling inductance to rise produced EMI noise, and And effectively promote the step-up ratio of circuit.Because only that a switching tube, therefore required control circuit and base This Boost control circuit no difference.Owing to using non-isolated circuit, it is not necessary to transformator Deng magnetics, therefore circuit has lightweight, and power density is high, the feature that volume is little.

Accompanying drawing explanation

Fig. 1 is that photovoltaic panel is connected grid connected structure schematic diagram with DC/DC booster converter.

Fig. 2 is the circuit diagram of this utility model large gain DC/DC changer.

Fig. 3 is the circuit diagram of inductance boost unit.

Fig. 4 is switching tube circuit state schematic diagram when opening.

Fig. 5 is circuit state schematic diagram during switching tube closedown.

Fig. 6 is the inductance boost element circuit figure after extension.

Detailed description of the invention

Accompanying drawing being merely cited for property explanation, it is impossible to be interpreted as the restriction to this patent；

In order to the present embodiment is more preferably described, some parts of accompanying drawing have omission, zoom in or out, and do not represent reality The size of border product；

To those skilled in the art, in accompanying drawing, some known features and explanation thereof may be omitted is to manage Solve.

With embodiment, the technical solution of the utility model is described further below in conjunction with the accompanying drawings.

Embodiment 1

As Figure 2-3, a kind of large gain DC/DC changer being applied to photovoltaic DC-to-AC converter, for light The input voltage V that volt plate produces_inCarry out boosting and be converted to output voltage V_out, including inductance boost unit, Inductance boost unit includes 1 input and 1 outfan, input voltage V_inPositive pole connect inductance boost list The input of unit, input voltage V_inNegative pole meet switching tube S, electric capacity C respectively₀, resistance R_LOne end, The outfan of inductance boost unit meets the other end and the diode D of switching tube S respectively₀Positive pole, diode D₀Negative pole meet electric capacity C respectively₀With resistance R_LThe other end, resistance R_LTwo ends be respectively output voltage V_out Positive pole and negative pole.

In specific implementation process, the physical circuit of described inductance boost unit is: the input of inductance boost unit End is connected with inductance L in turn between outfan₁, diode D₁, diode D₄, inductance boost unit defeated Enter end and the most secondary connection have diode D between outfan₃, diode D₆, inductance L₃, diode D₁Just Pole and diode D₃Negative pole between be in series with diode D₂, diode D₃Negative pole and diode D₄Just Inductance L it is in series with between pole₂, diode D₄Positive pole and diode D₆Negative pole between be in series with diode D₅。

The type selecting of the present embodiment device should combine with the input and output of circuit, it is to avoid it is (disconnected that circuit enters DCM Discontinuous Conduction mode).Circuit is Low Side (source ground), and therefore switching tube gate leve driving chip is easier to and switch Pipe is connected, and switching tube selects conventional IRF540N or IRF640N.

The present embodiment DC/DC changer also includes control circuit, and control circuit can use digital control or mould Intend control mode.Simulation control can be with we selected typical control chip such as TI UC3842.Digital control can be selected for AVR single chip or STM32 ARM chip.

As illustrated in figures 4-5, inductance boost circuit is under switching tube on and off for principle of the present utility model Time, the voltage V at inductance two ends_LIt is respectively as follows:

$\begin{array}{cc}{V}_L=V_{in}& V_L=\frac{V_{in}-V_{out}}{3}\end{array}---\left(1\right)$

So according to voltage-second balance equation:

3V_inD+(V_in-V_out) (1-D)=0 (2)

Then the DC voltage gain of circuit is:

$\frac{V_{out}}{V_{in}}=\frac{1+2D}{1-D}---\left(3\right)$

Therefore, the circuit of the present embodiment, in the case of not using isolating transformer, still can obtain and be more than The voltage gain of Boost circuit.

As shown in Figure 6, on the basis of the present embodiment, the inductance boost unit proposed can be carried out further Expand, increase the number of inductance so that the gain of circuit becomes much larger.If the number of prototype part is infinitely great, Infinitely-great voltage gain can be reached in theory.

This utility model provides a kind of large gain DC/DC changer being applied to photovoltaic DC-to-AC converter, inductance boost The method that unit combines with conventional transducers can effectively be avoided because using isolating transformer and coupling inductance Rise produced EMI noise, and effectively promote the step-up ratio of circuit.Because only that a switching tube, Therefore required control circuit and basic Boost control circuit no difference.Owing to using Non-isolated circuit, it is not necessary to the magneticss such as transformator, therefore circuit has lightweight, and power density is high, body Long-pending little feature.

The corresponding same or analogous parts of same or analogous label；

Term the being merely cited for property explanation of position relationship described in accompanying drawing, it is impossible to be interpreted as the limit to this patent System；

Obviously, above-described embodiment of the present utility model is only by clearly demonstrating the act that this utility model is made Example, and it is not the restriction to embodiment of the present utility model.Those of ordinary skill in the field are come Say, can also make other changes in different forms on the basis of the above description.Here without also without All of embodiment is given exhaustive by method.All made within spirit of the present utility model and principle any repair Change, equivalent and improvement etc., within should be included in this utility model scope of the claims.

Claims (5)

1. it is applied to a large gain DC/DC changer for photovoltaic DC-to-AC converter, for what photovoltaic panel was produced Input voltage V_inCarry out boosting and be converted to output voltage V_out, it is characterised in that include inductance boost unit, Inductance boost unit includes 1 input and 1 outfan, input voltage V_inPositive pole connect inductance boost list The input of unit, input voltage V_inNegative pole meet switching tube S, electric capacity C respectively₀, resistance R_LOne end, The outfan of inductance boost unit meets the other end and the diode D of switching tube S respectively₀Positive pole, diode D₀Negative pole meet electric capacity C respectively₀With resistance R_LThe other end, resistance R_LTwo ends be respectively output voltage V_out Positive pole and negative pole.

The large gain DC/DC changer being applied to photovoltaic DC-to-AC converter the most according to claim 1, its Being characterised by, the physical circuit of described inductance boost unit is: the input of inductance boost unit to outfan it Between be connected with inductance L in turn₁, diode D₁, diode D₄, the input of inductance boost unit is to outfan Between also time connect and have diode D₃, diode D₆, inductance L₃, diode D₁Positive pole and diode D₃ Negative pole between be in series with diode D₂, diode D₃Negative pole and diode D₄Positive pole between be in series with Inductance L₂, diode D₄Positive pole and diode D₆Negative pole between be in series with diode D₅。

The large gain DC/DC changer being applied to photovoltaic DC-to-AC converter the most according to claim 1, its Being characterised by, the model of described switching tube S is IRF540N or IRF640N.

The large gain DC/DC changer being applied to photovoltaic DC-to-AC converter the most according to claim 1, its Being characterised by, described DC/DC changer also includes control circuit, control circuit use digital control chip or Simulation control chip.

The large gain DC/DC changer being applied to photovoltaic DC-to-AC converter the most according to claim 4, its Being characterised by, simulation control chip uses TI UC3842；Digital control chip use AVR single chip or STM32ARM chip.