CN111245059B

CN111245059B - Intelligent off-grid solar power generation protection circuit

Info

Publication number: CN111245059B
Application number: CN202010161779.0A
Authority: CN
Inventors: 周天沛
Original assignee: Xuzhou College of Industrial Technology
Current assignee: Xuzhou College of Industrial Technology
Priority date: 2020-03-10
Filing date: 2020-03-10
Publication date: 2020-09-15
Anticipated expiration: 2040-03-10
Also published as: CN111245059A

Abstract

An intelligent off-grid solar power generation protection circuit comprises a battery plate group, a storage battery E and a peripheral protection circuit, wherein the peripheral protection circuit comprises resistors R1-R15, a potentiometer RP1, an electrolytic capacitor C1, diodes D1-D11, voltage stabilizing diodes DW 1-DW 2, light emitting diodes LED 1-LED 6, a triode BG1, field effect tubes T1-T4, a switch S1, a relay J1, a normally open contact J1-1 of a relay J1, a photoelectric coupler IC1 and dual operational amplifiers IC 2-IC 4; the invention can monitor the working states of the storage battery and the battery panel in the solar power generation process in real time, and adjust the overcharge and the overdischarge of the storage battery in real time according to the monitoring result so as to prolong the service life of the storage battery; the damage to the cell panel and the phenomenon of poor contact are reminded in real time, and the solar power generation efficiency is improved.

Description

Intelligent off-grid solar power generation protection circuit

Technical Field

The invention relates to a power generation protection circuit, in particular to an intelligent off-grid solar power generation protection circuit, and belongs to the technical field of solar power generation.

Background

Solar power generation is known as the most ideal new energy source. The method mainly has the following advantages: no exhaustion risk; the method is safe, reliable, noiseless, pollution-free and absolutely clean (pollution-free); the method is not limited by resource distribution regions, and can utilize the advantages of building roofs; the power can be generated and supplied on site without consuming fuel and erecting a power transmission line; the energy quality is high; the users are easy to accept from the emotion; the construction period is short, and the time for acquiring energy is short, so that solar power generation is increasingly regarded as one of important forms of renewable energy utilization.

At present, when solar energy is used for power generation, the following problems exist: the service life of the storage battery can be prolonged only if the storage battery cannot be overcharged or overdischarged, but in the normal use process, except for regular check, a worker cannot know whether the storage battery is overcharged or overdischarged, which affects the normal use of solar power generation; in addition, the solar panel is damaged or has poor contact in the use process, and the solar power generation is also influenced, so that the conclusion about the use state of the storage battery and the solar panel in the solar power generation process can be given out by means which are lacked at present, and the solar power generation circuit cannot be protected.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides an intelligent off-grid solar power generation protection circuit which can monitor the working states of a storage battery and a battery panel in the solar power generation process in real time and adjust the overcharge and the overdischarge of the storage battery in real time according to the monitoring result so as to prolong the service life of the storage battery; the damage to the cell panel and the phenomenon of poor contact are reminded in real time, and the solar power generation efficiency is improved.

In order to achieve the purpose, the invention provides an intelligent off-grid solar power generation protection circuit which comprises a battery plate group, a storage battery E and a peripheral protection circuit, wherein the peripheral protection circuit comprises resistors R1-R15, a potentiometer RP1, an electrolytic capacitor C1, diodes D1-D11, voltage stabilizing diodes DW 1-DW 2, light emitting diodes LED 1-LED 6, a triode BG1, field effect tubes T1-T4, a switch S1, a relay J1, a normally open contact J1-1 of a relay J1, a photoelectric coupler IC1 and dual operational amplifiers IC 2-IC 4;

the battery panel PV1 and the battery panel PV2 form a battery panel group in a two-to-two parallel connection mode and are used for charging a battery E, the anode of the battery E is respectively connected with a pin 1 of a photoelectric coupler IC1, the cathode of a diode D1, a first fixed end and a sliding end of a potentiometer RP1, one end of a resistor R6, one end of a resistor R7, an 8 pin of a dual operational amplifier IC3, the cathode of the diode D5, the 8 pin of a dual operational amplifier IC4, the 8 pin of the dual operational amplifier IC2, the anode of a light emitting diode LED2, one end of a normally open contact J1-1 of a relay J1 and one end of a switch S1, the diode D2 is connected at two ends of the battery E in parallel, and the cathode of the diode D2 is connected with the anode of the battery E; a pin 2 of the photocoupler IC1 is respectively connected with a pin 1 of the dual operational amplifier IC2, one end of a resistor R12, the cathode of the light emitting diode LED3 and the anode of the light emitting diode LED1, a pin 7 of the photocoupler IC1 is respectively connected with the anode of the diode D1, the anode output port of the panel PV1 and the anode output port of the panel PV2, a pin 8 of the photocoupler IC1 is respectively connected with one end of the resistor R2, the gate of the field effect tube T1 and the gate of the field effect tube T2 after being serially connected with the resistor R1, the drain of the field effect tube T1 is respectively connected with one end of the resistor R3 and one end of the resistor R3, the other end of the resistor R3 is respectively connected with one end of the resistor R3, one end of the dual operational amplifier IC3 and the 5 pin of the resistor R3, the other end of the resistor R3 is respectively connected with the drain of the field effect tube T3, the drain of the resistor R3 and the cathode output port of the panel PV 3, the source electrode of the field effect transistor T2 is connected with the negative electrode output port of the panel PV1, the diode D3 is connected with the field effect transistor T1 in parallel, the negative electrode of the diode D3 is connected with the drain electrode of the field effect transistor T1, and the positive electrode of the diode D3 is connected with the source electrode of the field effect transistor T1; the diode D4 is connected in parallel with the field effect transistor T2, the cathode of the diode D4 is connected with the drain of the field effect transistor T2, and the anode of the diode D4 is connected with the source of the field effect transistor T2; a pin 2 of the dual operational amplifier IC2 is connected to the other end of the resistor R6 and the negative electrode of the zener diode DW1, a pin 3 of the dual operational amplifier IC2 is connected to the second fixed end of the potentiometer RP1, one end of the resistor R15 and a pin 5 of the dual operational amplifier IC2, a pin 6 of the dual operational amplifier IC2 is connected to the other end of the resistor R7 and the negative electrode of the zener diode DW2, a pin 7 of the dual operational amplifier IC2 is connected to the positive electrode of the light emitting diode LED3, the negative electrode of the light emitting diode LED2, the gate of the field effect transistor T3, one end of the resistor R13 and the gate of the field effect transistor T4, the other end of the resistor R12 is connected to the base of the transistor BG1, the collector of the transistor BG1 is connected to the positive electrode of the diode D5, the relay J1 is connected in parallel to the two ends of the diode D5, the drain of the field effect transistor T5 is connected to the drain of the field effect transistor T, the diode D10 is connected in parallel with the field effect transistor T3, the cathode of the diode D10 is connected with the drain of the field effect transistor T3, and the anode of the diode D10 is connected with the source of the field effect transistor T3; the diode D11 is connected in parallel with the field effect transistor T4, the cathode of the diode D11 is connected with the drain of the field effect transistor T4, and the anode of the diode D11 is connected with the source of the field effect transistor T4; the other end of the resistor R14 is connected with the cathode of the light-emitting diode LED4, and the anode of the light-emitting diode LED4 is respectively connected with the other end of a normally open contact J1-1 of the relay J1, the other end of the switch S1, the anode of the electrolytic capacitor C1 and the other end of the load; the other end of the resistor R10, the other end of the resistor R7, the other end of the voltage stabilizing diode DW 7 and the anode of the voltage stabilizing diode DW 7 are respectively connected with a pin 1 of the dual operational amplifier IC3, a pin 2 of the dual operational amplifier IC3 is connected with the other end of the resistor R4684, a pin 3 of the dual operational amplifier IC3 is connected with the other end of the resistor R8, a pin 7 of the dual operational amplifier IC3 is connected with the anode of the light emitting diode LED5 after being connected with a pin 7 of the dual operational amplifier IC3 in series, a pin 1 of the dual operational amplifier IC4 is connected with the anode of the diode D8, a pin 7 of the dual operational amplifier IC4 is connected with the anode of the diode D9, the cathode of the diode D8 and the cathode of the diode D9 are connected with the anode of the light emitting diode LED6, a pin 2 of the dual operational amplifier IC4 is connected with the anode of the diode D6, a pin 5 of the diode D7 is connected with the cathode of the diode D7, The pin 4 of the dual operational amplifier IC2, the cathode of the light emitting diode LED1, the other end of the resistor R13, the source of the field effect transistor T3, the source of the field effect transistor T4, the cathode of the light emitting diode LED6, the emitter of the transistor BG1, the pin 4 of the dual operational amplifier IC3, the pin 6 of the dual operational amplifier IC3, the cathode of the light emitting diode LED5, the cathode of the diode D6, the anode of the diode D7, and the pin 4 of the dual operational amplifier IC4 are all grounded.

As a further improvement of the invention, the battery plate has the size of 1290mm multiplied by 3300mm, the weight of 5.6Kg, the maximum output power of 50W, the maximum output voltage of 17.4V and the maximum output current of 2.87A.

As a further improvement of the invention, the storage battery E is a maintenance-free lead-acid storage battery with the rated voltage of 12V and the rated capacity of 150 Ah.

As a further improvement of the invention, the battery panel PV1 and the battery panel PV2 charge the storage battery E in two ways, and are respectively controlled by using the field effect transistor T1 and the field effect transistor T2, mainly for shunting the charging current to reduce the influence of the on-resistance of the field effect transistor.

As a further improvement of the invention, the model number of the photoelectric coupler IC1 is TLP 521-2; the model numbers of the double operational amplifiers IC 2-IC 4 are LM 358.

As a further improvement of the invention, the triode BG1 is an NPN tube type with the model number of S8050.

As a further improvement of the invention, the diodes D1-D11 are IN 4148.

As a further improvement of the invention, the regulated voltage value of the voltage stabilizing diode DW1 is 14.5V, and the regulated voltage value of the voltage stabilizing diode DW2 is 10.5V.

As a further improvement of the invention, the field effect transistors T1-T4 are N-channel field effect transistors with the model number of IRFZ 34.

As a further improvement of the invention, the relay J1 is JRX-20F.

Compared with the prior art, the battery panel adopts a mode of connecting the battery panel in parallel two by two, when the battery panel normally charges the storage battery E, the light emitting diode in the photoelectric coupler IC1 is conducted, so that the light receiving side of the photoelectric coupler IC1 is conducted, the field effect tube T1 and the field effect tube T2 are conducted to form a charging circuit, the light emitting diode LED5 is lightened, if the storage battery E is between 10.5V and 14.5V, the light emitting diode LED3 is lightened, when the voltage of the storage battery E reaches or exceeds 14.5V, the light emitting diode in the photoelectric coupler IC1 is cut off, so that the light receiving side of the photoelectric coupler IC1 is cut off, the field effect tube T1 and the field effect tube T2 are cut off, and the battery panel cannot charge the storage battery E, so that overcharging is avoided; at the same time, the LED3 goes off and the LED1 lights up, indicating that it is now in an overcharged state. When the switch S1 or the normally open contact J1-1 of the relay J1 is pressed down, the storage battery E discharges to the load, and the light-emitting diode LED4 is lightened; when the voltage of the storage battery is lower than 10.5V, the field effect transistor T3 and the field effect transistor T4 are cut off, the storage battery E cannot charge the load, overdischarge is avoided, meanwhile, the light emitting diode LED3 is turned off, and the light emitting diode LED2 is turned on to remind that the storage battery is in an overdischarge state; if a certain battery panel is damaged or has poor contact, abnormal charging can be caused, the voltage drops on a sampling resistor R3 and a resistor R4 are unequal, the difference value of the two is amplified by an amplifier B1 of a double operational amplifier IC3 and then sent to a window comparator consisting of a double operational amplifier IC4 and a peripheral circuit, if the difference value of the two is smaller than-0.6V or larger than 0.6V, a pin 1 or a pin 7 of a double operational amplifier IC4 outputs high level, a light-emitting diode LED6 is lightened, and the situation that one battery panel has one path of abnormality is indicated; the invention can monitor the working states of the storage battery E and the battery panel in the solar power generation process in real time, and adjust the overcharge and the overdischarge of the storage battery E in real time according to the monitoring result so as to prolong the service life of the storage battery E; the damage to the cell panel and the phenomenon of poor contact are reminded in real time, and the solar power generation efficiency is improved.

Drawings

Fig. 1 is a circuit schematic of the present invention.

Detailed Description

The invention will be further explained with reference to the drawings.

As shown in fig. 1, the intelligent off-grid solar power generation protection circuit comprises a battery plate group, a storage battery E and a peripheral protection circuit, wherein the peripheral protection circuit comprises resistors R1-R15, a potentiometer RP1, an electrolytic capacitor C1, diodes D1-D11, zener diodes DW 1-DW 2, light emitting diodes LED 1-LED 6, a triode BG1, field effect transistors T1-T4, a switch S1, a relay J1, a normally open contact J1-1 of a relay J1, a photocoupler IC1 and a dual operational amplifier IC 2-IC 4; the size of the battery plate is 1290mm multiplied by 3300mm, the weight is 5.6Kg, the maximum output power is 50W, the maximum output voltage is 17.4V, and the maximum output current is 2.87A; the storage battery E adopts a maintenance-free lead-acid storage battery, the rated voltage of the storage battery E is 12V, and the rated capacity of the storage battery E is 150 Ah; the battery panel charges the storage battery E by adopting two paths of charging, and the charging is controlled by using the field effect transistor T1 and the field effect transistor T2 respectively, mainly for shunting the charging current so as to reduce the influence of the on-resistance of the field effect transistor; the model of the photoelectric coupler IC1 is TLP 521-2; the models of the double operational amplifiers IC 2-IC 4 are LM 358; the triode BG1 is an NPN tube type with the model number of S8050; the type of the diodes D1-D11 is IN 4148; the voltage regulation value of the voltage regulation diode DW1 is 14.5V, and the voltage regulation value of the voltage regulation diode DW2 is 10.5V; the field effect transistors T1-T4 are N-channel field effect transistors with the model of IRFZ 34; the model of the relay J1 is JRX-20F;

The resistance values of these elements in fig. 1 are well known and can be adjusted as required by those skilled in the art.

The working principle is as follows: when the battery panel PV1 and the battery panel PV2 normally charge the battery E, the voltage of the pin 3 of the dual operational amplifier IC2 is smaller than the voltage of the pin 2, the pin 1 of the dual operational amplifier IC2 outputs a low level, the light emitting diode in the photoelectric coupler IC1 is conducted, so that the light receiving side of the photoelectric coupler IC1 is conducted, the field effect tube T1 and the field effect tube T2 are conducted to form a charging circuit, and the two field effect tubes are mainly used for shunting the charging current to reduce the influence of the conduction resistance of the field effect tube. A voltage drop occurs across the resistor R5, and after amplification by the amplifier B2 of the dual operational amplifier IC3, pin 7 of the dual operational amplifier IC3 outputs a high level, and the LED5 is turned on, indicating that it is now in a charged state. When the switch S1 or the normally open contact J1-1 of the relay J1 is pressed down, the storage battery E discharges to the load, and the light-emitting diode LED4 is lightened to show that the storage battery E is in a discharging state;

to prevent overcharge or overdischarge, charging should be stopped when the battery voltage reaches or exceeds 14.5V, and discharging should be stopped by disconnecting the load when the battery voltage is lower than 10.5V. When the voltage of the storage battery reaches or exceeds 14.5V, the voltage of a pin 3 of the double operational amplifier IC2 is larger than the voltage of a pin 2 (the reference voltage of the pin 2 is 14.5V), a pin 1 of the double operational amplifier IC2 outputs high level, a light emitting diode in the photoelectric coupler IC1 is cut off, so that the light receiving side of the photoelectric coupler IC1 is cut off, the field effect transistors T1 and T2 are cut off, the solar panel cannot charge the storage battery, and overcharging is avoided. Meanwhile, the light emitting diode LED1 is lightened to remind that the battery is in an overcharging state at present, the triode BG1 is also conducted, the relay J1 is electrified and attracted, the normally open contact J1-1 is closed, and the storage battery starts to discharge to the load. When the voltage of the storage battery is lower than 10.5V, the voltage of the pin 5 of the dual operational amplifier IC2 is lower than the voltage of the pin 6 (the reference voltage of the pin 6 is 10.5V), the pin 7 of the dual operational amplifier IC2 outputs low level, the field effect transistors T3 and T4 are cut off, and the storage battery E cannot charge the load, so that overdischarge is avoided. At the same time the LED2 lights up, alerting that it is now over-discharged. If the storage battery is between 10.5V and 14.5V, the voltage of the pin 3 of the dual operational amplifier IC2 is less than the voltage of the pin 2, the pin 1 of the dual operational amplifier IC2 outputs low level, the voltage of the pin 5 of the dual operational amplifier IC2 is greater than the voltage of the pin 6, the pin 7 of the dual operational amplifier IC2 outputs high level, the light-emitting diode LED3 is lightened to indicate that the storage battery is in a normal charging and discharging state, and when the light-emitting diode LED3 is lightened to indicate that the storage battery is in an abnormal charging and discharging state, namely the light-emitting diode LED3 is lightened, the light-emitting diode LED1 is lightened to indicate overcharge; the light-emitting diode LED3 turns off, and the light-emitting diode LED2 turns on, indicating overdischarge.

The solar cell panels of the power generation circuit are connected in parallel, and if a certain solar cell panel is damaged or is in poor contact, abnormal charging can be caused. Generally speaking, if two solar panels are working normally, the charging currents of two paths should be the same, that is, the voltage drops on the resistors R3 and R4 are equal, and when the charging circuit is abnormal, the voltage drops on the resistors R3 and R4 are unequal, and this difference is amplified by the B1 amplifier of the dual operational amplifier IC3 and sent to the dual operational amplifier IC4, the dual operational amplifier IC4 and the peripheral circuit constitute a window comparator, if the voltage drops on the resistors R3 and R4 are substantially equal, the difference between the two is amplified by the B1 amplifier of the dual operational amplifier IC3, its value should be (-0.6V, 0.6V), the low level is output by the

pins

1 and 7 of the dual operational amplifier IC4, the diodes D8 and D9 are cut off, and the light emitting diode LED6 is not lit. If the voltage drops on the resistors R3 and R4 are not equal, the difference value of the two is amplified by a B1 amplifier of a double operational amplifier IC3, the numerical value is smaller than-0.6V or larger than 0.6V, if the difference value is smaller than-0.6V, a pin 7 of the double operational amplifier IC4 outputs high level, a diode D9 is conducted, and a light-emitting diode LED6 is lightened; if the voltage is more than 0.6V, the pin 1 of the dual operational amplifier IC4 outputs high level, the diode D8 is conducted, the light-emitting diode LED6 is lightened, in short, the light-emitting diode LED6 is lightened, and the fact that one path of the solar cell panel is abnormal is shown.

Claims

1. An intelligent off-grid solar power generation protection circuit comprises a battery plate group, a storage battery E and a peripheral protection circuit, and is characterized in that the peripheral protection circuit comprises resistors R1-R15, a potentiometer RP1, an electrolytic capacitor C1, diodes D1-D11, voltage stabilizing diodes DW 1-DW 2, light emitting diodes LED 1-LED 6, a triode BG1, field effect tubes T1-T4, a switch S1, a relay J1, a normally open contact J1-1 of a relay J1, a photoelectric coupler IC1 and a double operational amplifier IC 2-IC 4;

2. The intelligent off-grid solar power generation protection circuit as claimed in claim 1, wherein the size of the battery plate is 1290mm x 3300mm, the weight is 5.6Kg, the maximum output power is 50W, the maximum output voltage is 17.4V, and the maximum output current is 2.87A.

3. The intelligent off-grid solar power generation protection circuit as claimed in claim 1 or 2, wherein the battery E is a maintenance-free lead-acid battery with a rated voltage of 12V and a rated capacity of 150 Ah.

4. The intelligent off-grid solar power generation protection circuit as claimed in claim 1 or 2, wherein the battery panel PV1 and the battery panel PV2 charge the battery E in two ways and are controlled by the FET T1 and the FET T2 respectively.

5. The intelligent off-grid solar power generation protection circuit of claim 3, wherein the type of the photocoupler IC1 is TLP 521-2; the model numbers of the double operational amplifiers IC 2-IC 4 are LM 358.

6. The intelligent off-grid type solar power generation protection circuit of claim 3, wherein the transistor BG1 is an NPN tube type with a model number of S8050.

7. The intelligent off-grid solar power generation protection circuit as claimed IN claim 3, wherein the type of the diodes D1-D11 is IN 4148.

8. The intelligent off-grid solar power generation protection circuit of claim 3, wherein the voltage regulation value of the voltage regulation diode DW1 is 14.5V, and the voltage regulation value of the voltage regulation diode DW2 is 10.5V.

9. The intelligent off-grid solar power generation protection circuit of claim 3, wherein the FETs T1-T4 are N-channel FETs of IRFZ 34.

10. The intelligent off-grid solar power generation protection circuit as claimed in claim 3, wherein the relay J1 is model JRX-20F.