CN205317841U - A keep apart current detection circuit for photovoltaic power generation - Google Patents

A keep apart current detection circuit for photovoltaic power generation Download PDF

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Publication number
CN205317841U
CN205317841U CN201620079648.7U CN201620079648U CN205317841U CN 205317841 U CN205317841 U CN 205317841U CN 201620079648 U CN201620079648 U CN 201620079648U CN 205317841 U CN205317841 U CN 205317841U
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China
Prior art keywords
circuit
signal
diode
difference amplifier
chip
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Expired - Fee Related
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CN201620079648.7U
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Chinese (zh)
Inventor
国际平
张文瑞
刘振龙
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HARBIN GUOLI ELECTRIC CO Ltd
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HARBIN GUOLI ELECTRIC CO Ltd
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Abstract

The utility model provides a keep apart current detection circuit for photovoltaic power generation, including RC filter circuit, signal clamp circuit, differential amplification circuit, signal isolation circuit and power module, power module provides the power for this detection circuitry, RC filter circuit includes two sets of RC filtering units, signal clamp circuit includes two sets of diode circuit from top to bottom, differential amplification circuit includes the difference amplifier chip, the signal is connected with the positive going input end of difference amplifier chip after the first RC of group filtering unit is connected with first upper and lower diode circuit, the signal is connected with the reverse input end of difference amplifier chip after upper and lower diode circuit is connected with the second through the RC of second group filtering unit, the output and the signal isolation circuit connection of difference amplifier chip, carry out isolated transmission through the signal isolation circuit. This detection circuitry, the measuring current scope is wide, and it is high to detect the precision, and it is wide to measure frequency range, can test the direct current and also can test alternating current, and the interference killing feature is strong.

Description

A kind of isolation current detection circuit for photovoltaic generation
Technical field
This utility model relates to a kind of isolation current detection circuit for photovoltaic generation.
Background technology
Without the inverter that isolating transformer is grid-connected in solar energy photovoltic power system, owing to grid connection efficiency is high, the feature that cost is low is increasingly subject to people and payes attention to, and is widely used. But, without isolating transformer, then the DC component of solar photovoltaic inverter output electric current must be controlled. The value of DC component is most important to the safe operation of photovoltaic generating system. Excessive DC component injects electrical network, it is possible to make the magnetic core of transformer on electrical network saturated. Therefore direct-current component must be limited in milliampere level. The voltage of photovoltaic generation is generally all within several hectovolts to kilovolt, and so high voltage, so little electric current, for the purpose of personal safety, it is necessary to require isolation measurement. Hall current sensor is typically only capable to test big electric current or small area analysis, and same sensor can not all keep good certainty of measurement when big electric current and small area analysis. Current transformer is usually constructed with measurement frequency limitation.
Summary of the invention
The purpose of this utility model is in that to provide a kind of isolation current detection circuit for photovoltaic generation, solves the problem that in solar energy power generating, a Hall current sensor in the measurement of DC component can not be taken into account current range and precision; Also frequency limitation during current transformer measurement electric current is solved.
This utility model adopts the following technical scheme that a kind of isolation current detection circuit for photovoltaic generation, including RC filter circuit, signal clamping circuit, differential amplifier circuit, signal isolation circuit and power module, power module provides power supply for this testing circuit, RC filter circuit includes two groups of RC filter units, signal clamping circuit includes about two groups diode circuits, differential amplifier circuit includes difference amplifier chip, signal is connected with the positive input of difference amplifier chip after first group of RC filter unit and about the first diode circuit connect, signal is connected with the reverse input end of difference amplifier chip after second group of RC filter unit and about the second diode circuit connect, the outfan of difference amplifier chip is connected with signal isolation circuit, isolation transmission is carried out through signal isolation circuit.
This utility model also has following technical characteristic: two groups of described RC filter units include two resistance and two electric capacity, upper and lower diode circuit includes four diodes and two resistance, differential amplifier circuit includes difference amplifier chip, model IN114, signal isolation circuit includes linear isolation opto-coupler chip, model ISO124, the earth terminal GND1 of a termination data side after resistance R1 and electric capacity C1 parallel connection, other end connects signal, one end of resistance R3, the other end of resistance R3 connects 3 feet of difference amplifier chip, the positive pole of diode D1, the negative pole of diode D3, the negative pole of diode D1 connects the positive vdd terminal of power supply, the positive pole of diode D3 connects the negative VEE end of power supply, the earth terminal GND1 of a termination data side after resistance R2 and electric capacity C2 parallel connection, other end connects one end of signal, resistance R4, and the other end of resistance R4 connects the negative pole of 2 feet of difference amplifier chip, the positive pole of diode D2, diode D4, the negative pole of diode D2 connects the positive vdd terminal of power supply, and the positive pole of diode D4 connects the negative VEE end of power supply, 1 foot other end of the one termination difference amplifier chip of resistance R5 connects 8 feet of difference amplifier chip, 7 feet of difference amplifier chip connect the positive vdd terminal of power supply, 4 feet of difference amplifier chip connect the negative VEE end of power supply, 5 foot earth terminal GND2 of difference amplifier chip, the outfan of difference amplifier chip is connected with 15 feet of linear isolation opto-coupler chip by resistance R6, the positive vdd terminal of termination power of electric capacity C3, linear isolation opto-coupler chip 1 foot, the other end earth terminal GND1 of electric capacity C3, one termination power of electric capacity C4 bears 2 feet of VEE end, linear isolation opto-coupler chip, the other end earth terminal GND1 of electric capacity C4,16 foot ground end GND1 of linear isolation opto-coupler chip, the one positive VDD1 end of termination power of electric capacity C6, linear isolation opto-coupler chip 9 feet, the other end earth terminal AGND of electric capacity C6, one termination power of electric capacity C5 bears 10 feet of VEE1 end, linear isolation opto-coupler chip, the other end earth terminal AGND of electric capacity C5,8 foot earth terminal AGND of linear isolation opto-coupler chip, 7 feet of linear isolation opto-coupler chip are the output interfaces of signal.
The beneficial effects of the utility model and having the advantages of: this utility model is a kind of isolation current detection circuit for photovoltaic generation, not only can guarantee that precision simultaneously but also can guarantee that safe isolation current measurement, detection. Measuring current range width, accuracy of detection is high, measures wide frequency range, can test direct current and also can test alternating current, and capacity of resisting disturbance is strong, has very strong common mode disturbances rejection ability.
Accompanying drawing explanation
Fig. 1 is circuit diagram of the present utility model.
Fig. 2 is power module circuitry figure of the present utility model.
Detailed description of the invention
Below in conjunction with the drawings and specific embodiments, this utility model is further described:
Embodiment 1
As shown in Figure 1, a kind of isolation current detection circuit for photovoltaic generation, including RC filter circuit, signal clamping circuit, differential amplifier circuit, signal isolation circuit and power module, power module adopt single supply power isolation and amplifier positive-negative power power module be this testing circuit provide power supply, RC filter circuit includes two groups of RC filter units, for the filtering to clutter and interference signal, signal clamping circuit includes about two groups diode circuits, differential amplifier circuit includes difference amplifier chip, differential amplifier circuit adopts the instrument grade differential amplifier circuit of high cmrr, signal is connected with the positive input of difference amplifier chip after first group of RC filter unit and about the first diode circuit connect, signal is connected with the reverse input end of difference amplifier chip after second group of RC filter unit and about the second diode circuit connect, the outfan of difference amplifier chip is connected with signal isolation circuit, isolation transmission is carried out through signal isolation circuit, signal isolation circuit adopts high accuracy, the isolation optocoupler of high linearity.Two groups of described RC filter units include two resistance and two electric capacity, upper and lower diode circuit includes four diodes and two resistance, differential amplifier circuit includes difference amplifier chip, model IN114, signal isolation circuit includes linear isolation opto-coupler chip, model ISO124, the earth terminal GND1 of a termination data side after resistance R1 and electric capacity C1 parallel connection, other end connects one end of signal, resistance R3, and the other end of resistance R3 connects the negative pole of 3 feet of difference amplifier chip, the positive pole of diode D1, diode D3; The negative pole of diode D1 connects the positive vdd terminal of power supply; The positive pole of diode D3 connects the negative VEE end of power supply; The earth terminal GND1 of a termination data side after resistance R2 and electric capacity C2 parallel connection, other end connects one end of signal, resistance R4, and the other end of resistance R4 connects the negative pole of 2 feet of difference amplifier chip, the positive pole of diode D2, diode D4; The negative pole of diode D2 connects the positive vdd terminal of power supply, and the positive pole of diode D4 connects the negative VEE end of power supply; 1 foot other end of the one termination difference amplifier chip of resistance R5 connects 8 feet of difference amplifier chip, 7 feet of difference amplifier chip connect the positive vdd terminal of power supply, 4 feet of difference amplifier chip connect the negative VEE end of power supply, 5 foot earth terminal GND2 of difference amplifier chip, the outfan of difference amplifier chip is connected with 15 feet of linear isolation opto-coupler chip by resistance R6, the positive vdd terminal of termination power of electric capacity C3, linear isolation opto-coupler chip 1 foot; The other end earth terminal GND1 of electric capacity C3; One termination power of electric capacity C4 bears 2 feet of VEE end, linear isolation opto-coupler chip; The other end earth terminal GND1 of electric capacity C4,16 foot ground end GND1 of linear isolation opto-coupler chip, the one positive VDD1 end of termination power of electric capacity C6, linear isolation opto-coupler chip 9 feet, the other end earth terminal AGND of electric capacity C6, one termination power of electric capacity C5 bears 10 feet of VEE1 end, linear isolation opto-coupler chip, the other end earth terminal AGND of electric capacity C5,8 foot earth terminal AGND of linear isolation opto-coupler chip, 7 feet of linear isolation opto-coupler chip are the output interfaces of signal. When there being electric current to flow through from sampling resistor, produce pressure reduction at resistance two ends. After RC wave filter, deliver to the amplified feeding linear amplification isolation optocoupler of differential amplifier circuit carry out signal isolation. Signal after isolation can the circuit such as welding wave shaping, single-chip microcomputer, DSP. The input side that power module is differential amplifier circuit and optocoupler provides the positive-negative power of isolation.
This utility model is a kind of isolation current detection circuit for photovoltaic generation, not only can guarantee that precision simultaneously but also can guarantee that safe isolation current measurement, testing circuit. Measuring current range width, accuracy of detection is high, measures wide frequency range, can test direct current and also can test alternating current, and capacity of resisting disturbance is strong, has very strong common mode disturbances rejection ability.

Claims (2)

1. the isolation current detection circuit for photovoltaic generation, including RC filter circuit, signal clamping circuit, differential amplifier circuit, signal isolation circuit and power module, power module provides power supply for this testing circuit, it is characterized in that, RC filter circuit includes two groups of RC filter units, signal clamping circuit includes about two groups diode circuits, differential amplifier circuit includes difference amplifier chip, signal is connected with the positive input of difference amplifier chip after first group of RC filter unit and about the first diode circuit connect, signal is connected with the reverse input end of difference amplifier chip after second group of RC filter unit and about the second diode circuit connect, the outfan of difference amplifier chip is connected with signal isolation circuit, isolation transmission is carried out through signal isolation circuit.
2. a kind of isolation current detection circuit for photovoltaic generation according to claim 1, it is characterized in that: two groups of described RC filter units include two resistance and two electric capacity, upper and lower diode circuit includes four diodes and two resistance, differential amplifier circuit includes difference amplifier chip, model IN114, signal isolation circuit includes linear isolation opto-coupler chip, model ISO124, the earth terminal GND1 of a termination data side after resistance R1 and electric capacity C1 parallel connection, other end connects signal, one end of resistance R3, the other end of resistance R3 connects 3 feet of difference amplifier chip, the positive pole of diode D1, the negative pole of diode D3, the negative pole of diode D1 connects the positive vdd terminal of power supply, the positive pole of diode D3 connects the negative VEE end of power supply, the earth terminal GND1 of a termination data side after resistance R2 and electric capacity C2 parallel connection, other end connects one end of signal, resistance R4, and the other end of resistance R4 connects the negative pole of 2 feet of difference amplifier chip, the positive pole of diode D2, diode D4, the negative pole of diode D2 connects the positive vdd terminal of power supply, and the positive pole of diode D4 connects the negative VEE end of power supply, 1 foot other end of the one termination difference amplifier chip of resistance R5 connects 8 feet of difference amplifier chip, 7 feet of difference amplifier chip connect the positive vdd terminal of power supply, 4 feet of difference amplifier chip connect the negative VEE end of power supply, 5 foot earth terminal GND2 of difference amplifier chip, the outfan of difference amplifier chip is connected with 15 feet of linear isolation opto-coupler chip by resistance R6, the positive vdd terminal of termination power of electric capacity C3, linear isolation opto-coupler chip 1 foot, the other end earth terminal GND1 of electric capacity C3, one termination power of electric capacity C4 bears 2 feet of VEE end, linear isolation opto-coupler chip, the other end earth terminal GND1 of electric capacity C4,16 foot ground end GND1 of linear isolation opto-coupler chip, the one positive VDD1 end of termination power of electric capacity C6, linear isolation opto-coupler chip 9 feet, the other end earth terminal AGND of electric capacity C6, one termination power of electric capacity C5 bears 10 feet of VEE1 end, linear isolation opto-coupler chip, the other end earth terminal AGND of electric capacity C5,8 foot earth terminal AGND of linear isolation opto-coupler chip, 7 feet of linear isolation opto-coupler chip are the output interfaces of signal.
CN201620079648.7U 2016-01-27 2016-01-27 A keep apart current detection circuit for photovoltaic power generation Expired - Fee Related CN205317841U (en)

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Application Number Priority Date Filing Date Title
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107643464A (en) * 2017-08-31 2018-01-30 太仓市高泰机械有限公司 A kind of high-precision tiny signal current measurement module
CN110708014A (en) * 2019-08-05 2020-01-17 浙江腾圣储能技术有限公司 Detection system and method based on photovoltaic bus board

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107643464A (en) * 2017-08-31 2018-01-30 太仓市高泰机械有限公司 A kind of high-precision tiny signal current measurement module
CN110708014A (en) * 2019-08-05 2020-01-17 浙江腾圣储能技术有限公司 Detection system and method based on photovoltaic bus board
CN110708014B (en) * 2019-08-05 2021-07-06 浙江腾圣储能技术有限公司 Detection system and method based on photovoltaic bus board

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CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20160615

Termination date: 20170127

CF01 Termination of patent right due to non-payment of annual fee