CN201464592U - Leakage detection device for photovoltaic grid-connected inverter - Google Patents

Abstract

The utility model relates to a leakage detection device for a photovoltaic grid-connected inverter, which comprises a fuse wire F1 and a detection circuit, wherein the detection circuit comprises an operational amplifier U1, an isolating part U2 and a light emitting diode D1; the isolating part U2 is connected with the output end of the operational amplifier U1; the negative terminal of the light emitting diode D1 is connected with the isolating part U2; and the light emitting diode D1 is connected with an auxiliary power supply VCC1 through a resistor R9. The leakage detection device of the utility model has simple circuits and low cost.

Description

A kind of earth detector of photovoltaic combining inverter

Technical field

The utility model relates to the photovoltaic power generation technology field, is specifically related to a kind of earth detector of photovoltaic combining inverter.

Background technology

If the insulating property of electrical equipment energising part are not good enough, will crisis human body safety, so carry out detection of electrical leakage be must, reached and eliminated electric leakage, avoid being struck by lightning and the purpose of electrostatic induction.

The detection and protection apparatus for leakage of present solar photovoltaic interconnected inverter uses sensor, cost height, and circuit complexity.

The utility model content

It is simple that the purpose of this utility model provides a kind of circuit, and the earth detector of the photovoltaic combining inverter that cost is low is to overcome the deficiencies in the prior art.

For achieving the above object, the utility model adopts following technical scheme:

A kind of photovoltaic combining inverter earth detector, this device comprises fuse F ₁And testing circuit, described testing circuit comprises: operational amplifier U ₁, and with described operational amplifier U ₁The isolated part U that output terminal links to each other ₂, negative terminal and described isolated part U ₂The light emitting diode D that connects ₁, described light emitting diode D ₁Pass through resistance R ₉Connect accessory power supply VCC ₁

Wherein, described operational amplifier U ₁Inverting input passes through resistance R ₆With capacitor C ₁And capacitor C ₂An end of series circuit link to each other and tie point ground connection, described capacitor C ₁, C ₂Series circuit and thermistor V ₄, V ₅The series circuit parallel connection, parallel circuit earth terminal and thermistor V ₂, V ₃An end of series circuit link to each other the other end of described parallel circuit and thermistor V ₀, V ₁An end of series circuit link to each other described thermistor V ₂, V ₃The series circuit other end and described thermistor V ₀, V ₁The equal ground connection of the other end of series circuit, described parallel circuit and thermistor V ₀, V ₁The link of series circuit by fuse F ₂With input power positive end J ₁Link to each other the earth terminal of described parallel circuit and described input power supply negative terminal J ₂Link to each other, and with described fuse F ₁Link to each other described fuse F ₁Other end ground connection.

Wherein, described operational amplifier U ₁In-phase input end pass through resistance R ₁₁With described fuse F ₁Earth terminal link to each other described operational amplifier U ₁In-phase input end also pass through resistance R ₁₂Connect accessory power supply VCC ₂

Wherein, described operational amplifier U ₁Inverting input and positive power source terminal be connected with resistance R ₇, described positive power source terminal and accessory power supply VCC ₂Link to each other, and pass through resistance R ₈With described isolated part U ₂Link to each other.

Wherein, described isolated part U ₂With light emitting diode D ₂The output terminal that links to each other links to each other described isolated part U with the control circuit of inverter ₂Another output head grounding.

Wherein, described input power supply is a solar cell, and described accessory power supply is solar cell or civil power.

Wherein, described isolated part U ₂Be non-linear optocoupler.

The utility model isolated part is non-linear optocoupler, makes that like this circuit of this device is simple, and cost reduces; Accessory power supply can be solar cell or civil power, stops power supply thereby inverter when being in standby when solar cell like this, also can rely on mains-supplied, makes this device work on.

Description of drawings

The earth detector structural representation of Fig. 1 photovoltaic combining inverter of the present utility model.

Embodiment

The earth detector of a kind of photovoltaic combining inverter that the utility model proposes is described as follows in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, photovoltaic combining inverter earth detector of the present utility model, this device comprises fuse F ₁And testing circuit, shown in frame of broken lines among the figure, testing circuit comprises: operational amplifier U ₁, and with operational amplifier U ₁The isolated part U that output terminal links to each other ₂, be non-linear optocoupler, negative terminal and isolated part U ₂The light emitting diode D that connects ₁, light emitting diode D ₁Pass through resistance R ₉Connect accessory power supply VCC ₁,, make the utility model installation cost reduce, and circuit structure is simple owing to used non-linear optocoupler to isolate.

Operational amplifier U ₁Inverting input passes through resistance R ₆With capacitor C ₁And capacitor C ₂An end of series circuit link to each other and tie point ground connection; Capacitor C ₁, C ₂Series circuit and thermistor V ₄, V ₅The series circuit parallel connection, parallel circuit earth terminal and thermistor V ₂, V ₃An end of series circuit link to each other the other end of parallel circuit and thermistor V ₀, V ₁An end of series circuit link to each other thermistor V ₂, V ₃The series circuit other end and thermistor V ₀, V ₁The equal ground connection of the other end of series circuit, parallel circuit and thermistor V ₀, V ₁The link of series circuit by fuse F ₂With input power positive end J ₁Link to each other the earth terminal of parallel circuit and input power supply negative terminal J ₂Link to each other, and with fuse F ₁Link to each other fuse F ₁Other end ground connection.

Operational amplifier U ₁Inverting input and positive power source terminal be connected with resistance R ₇, described positive power source terminal and accessory power supply VCC ₂Link to each other, and pass through resistance R ₈With described isolated part U ₂Link to each other.

Operational amplifier U ₁In-phase input end pass through resistance R ₁₁With fuse F ₁Earth terminal link to each other, also pass through resistance R ₁₂Connect accessory power supply VCC ₂

Isolated part U ₂With light emitting diode D ₁The output terminal that links to each other links to each other isolated part U with the control circuit of inverter ₂Another output head grounding.

Input voltage is a solar cell, and accessory power supply is solar cell or civil power, stops power supply thereby inverter when being in standby when solar cell like this, and also the accessory power supply that can rely on civil power to provide provides power supply, makes this device work on.The chip of control circuit can be digital signal processor, single-chip microcomputer or other microprocessor.As fuse F ₁In the time of intact, amplifier U ₁In-phase input end voltage be (R ₁₁+ R ₁₂) VCC ₂, inverting input voltage is

$\frac{R_6}{R_6+R_7}\mathrm{VC}{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="H2009201082662E00011.png"\; state="\{\{state\}\}">C</figure-callout>}}_2$

In-phase input end voltage is lower than inverting input voltage, then amplifier U ₁Output voltage be low level, the symplectic control circuit of nonlinear optical does not have signal output; When having leaky, fuse F ₁After damaging disconnection, in-phase input end voltage is higher than inverting input voltage, then amplifier U ₁Output voltage be high level, the symplectic control circuit output signal of nonlinear optical, light emitting diode D ₁Shinny, by light emitting diode D ₁State then can detect fuse F effectively ₁Duty.Because amplifier U ₁Output terminal can not change along with the change of input voltage, make the easier realization of detection of electrical leakage.

Above embodiment only is used to illustrate the utility model; and be not to restriction of the present utility model; the those of ordinary skill in relevant technologies field; under the situation that does not break away from spirit and scope of the present utility model; can also make various variations and modification; therefore all technical schemes that are equal to also belong to category of the present utility model, and scope of patent protection of the present utility model should be defined by the claims.

Claims (7)

1. photovoltaic combining inverter earth detector, this device comprises fuse F ₁And testing circuit, it is characterized in that described testing circuit comprises: operational amplifier U ₁, and with described operational amplifier U ₁The isolated part U that output terminal links to each other ₂, negative terminal and described isolated part U ₂The light emitting diode D that connects ₁, described light emitting diode D ₁Pass through resistance R ₉Connect accessory power supply VCC ₁

2. photovoltaic combining inverter earth detector as claimed in claim 1 is characterized in that, described operational amplifier U ₁Inverting input passes through resistance R ₆With capacitor C ₁And capacitor C ₂An end of series circuit link to each other and tie point ground connection, described capacitor C ₁, C ₂Series circuit and thermistor V ₄, V ₅The series circuit parallel connection, parallel circuit earth terminal and thermistor V ₂, V ₃An end of series circuit link to each other the other end of described parallel circuit and thermistor V ₀, V ₁An end of series circuit link to each other described thermistor V ₂, V ₃The series circuit other end and described thermistor V ₀, V ₁The equal ground connection of the other end of series circuit, described parallel circuit and thermistor V ₀, V ₁The link of series circuit by fuse F ₂With input power positive end J ₁Link to each other the earth terminal of described parallel circuit and described input power supply negative terminal J ₂Link to each other, and with described fuse F ₁Link to each other described fuse F ₁Other end ground connection.

3. photovoltaic combining inverter earth detector as claimed in claim 1 is characterized in that, described operational amplifier U ₁In-phase input end pass through resistance R ₁₁With described fuse F ₁Earth terminal link to each other described operational amplifier U ₁In-phase input end also pass through resistance R ₁₂Connect accessory power supply VCC ₂

4. photovoltaic combining inverter earth detector as claimed in claim 1 is characterized in that, described operational amplifier U ₁Inverting input and positive power source terminal be connected with resistance R ₇, described positive power source terminal and accessory power supply VCC ₂Link to each other, and pass through resistance R ₈With described isolated part U ₂Link to each other.

5. photovoltaic combining inverter earth detector as claimed in claim 1 is characterized in that, described isolated part U ₂With light emitting diode D ₂The output terminal that links to each other links to each other described isolated part U with the control circuit of inverter ₂Another output head grounding.

6. photovoltaic combining inverter earth detector as claimed in claim 2 is characterized in that, described input power supply is a solar cell, and described accessory power supply is solar cell or civil power.

7. as each described photovoltaic combining inverter earth detector of claim 1-5, it is characterized in that described isolated part U ₂Be non-linear optocoupler.

Images