Anti-countercurrent monitoring protection system suitable for photovoltaic power generation

Abstract

The utility model relates to the technical field of photovoltaic power generation, in particular to an anti-countercurrent monitoring protection system suitable for photovoltaic power generation, which comprises a voltage stabilization module, a distribution module, an inverter, a monitoring module and an energy storage module, and is characterized in that the monitoring module is respectively connected with the inverter and the energy storage module; the distribution module comprises a main control chip and two groups of conversion modules, and the main control chip is respectively connected with the monitoring module and the two groups of conversion modules; one group of conversion modules is respectively connected with the voltage stabilization module and the inverter, and the other group of conversion modules is respectively connected with the voltage stabilization module and the energy storage module; the main control chip adjusts the electric energy converted by one group of conversion modules according to a control signal sent by the monitoring module, transmits the electric energy to the inverter, and transmits the residual electric energy to the energy storage module through the other group of conversion modules; according to the utility model, the technical problem of preventing the countercurrent phenomenon under the conditions that the photovoltaic assembly is not damaged and the output power of the photovoltaic assembly is ensured is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to photovoltaic power generation technical field, specifically, relate to a kind of anti-backflow monitoring protection system suitable for photovoltaic power generation. BACKGROUND

[0002] Photovoltaic power generation refers to that solar cell panel generates direct current under sunlight, and converts into alternating current for user by inverter. Photovoltaic power generation system has long service life, and maintenance cost is low, and long-term can save a large amount of energy expenditure for enterprise and individual. However, photovoltaic power generation has a significant drawback, i.e. reverse current phenomenon. When photovoltaic power generation exceeds local load power consumption, excess power will flow back into power grid, and further destroy original power flow distribution of power grid, cause certain node voltage in power grid to rise, exceed voltage resistance range of power grid equipment, and cause equipment failure;Moreover, reverse current can introduce harmonic, and harmonic can interfere with normal operation of other sensitive equipment in power grid, and make power quality of power grid decline. In addition, if there is no effective anti-backflow measure between photovoltaic power generation system inside user and power grid, photovoltaic system can continue to send power to power grid side under the condition such as power grid outage, which can pose threat to life safety of maintenance personnel.

[0003] The Chinese invention patent with the patent name of "a photovoltaic anti-backflow device" and the publication number of CN119324437A has been disclosed, which comprises acquisition circuit, boost circuit, main control circuit and DSP circuit, each circuit cooperates with each other, can monitor load power of load in real time, and adjusts output power of photovoltaic module according to load power;The utility model patent can prevent reverse current phenomenon, but adjusting output power of photovoltaic module reduces efficiency of photovoltaic module, and waste part of electric energy, more seriously, frequent adjustment of output power of photovoltaic module is easy to cause internal structure stress damage due to rapid change of voltage and current, or long-term thermal stress accumulation leads to performance decline or even failure of module, and further increase risk of photovoltaic module suffering damage. UTILITY MODEL CONTENT

[0004] The purpose of the present application is to provide an anti-backflow monitoring protection system suitable for photovoltaic power generation, which solves the technical problem of preventing reverse current phenomenon without damaging photovoltaic module and ensuring output power of photovoltaic module.

[0005] In order to solve the above technical problems, the scheme adopted by the present application is as follows:

[0006] The utility model provides a kind of anti-return flow monitoring protection system suitable for photovoltaic power generation, it is characterized by: including voltage stabilizing module, distribution module, inverter, monitoring module, energy storage module, the distribution module is connected with voltage stabilizing module, energy storage module, inverter, monitoring module respectively, the monitoring module is connected with inverter, energy storage module respectively;

[0007] The voltage stabilizing module is used for converting unstable direct current transmitted by the photovoltaic module into stable direct current and transmitting it to the distribution module.

[0008] The distribution module is used for transmitting stable direct current to the inverter or the energy storage module. The distribution module adjusts the proportion of the electric energy transmitted to the inverter or the energy storage module according to the control signal sent by the monitoring module.

[0009] The distribution module includes a master control chip, two groups of conversion modules, the master control chip is connected with the monitoring module and the two groups of conversion modules respectively. One group of the conversion modules is connected with the voltage stabilizing module and the inverter respectively, and the other group of the conversion modules is connected with the voltage stabilizing module and the energy storage module respectively.

[0010] The master control chip adjusts the electric energy converted by one group of the conversion modules and transmits it to the inverter according to the control signal sent by the monitoring module, and simultaneously transmits the remaining electric energy to the energy storage module through the other group of the conversion modules.

[0011] The energy storage module is used for storing electric energy.

[0012] The monitoring module is used for judging whether the photovoltaic power generation amount transmitted by the inverter exceeds the local load power consumption, and sending a control signal to the master control chip according to the comparison result.

[0013] In some embodiments, the two groups of conversion modules each include a second type of DC-DC converter, the two groups of second type of DC-DC converters are connected with the master control chip respectively, the electric energy input ends of the two groups of second type of DC-DC converters are connected with the output ends of the voltage stabilizing module respectively; the electric energy output end of one group of the second type of DC-DC converters is connected with the output end of the inverter, and the electric energy output end of the other group of the second type of DC-DC converters is connected with the output end of the energy storage module.

[0014] In some embodiments, each group of the conversion modules includes a signal generator, and the master control chip controls the second type of DC-DC converter to start or adjust the converted electric energy through the signal generator.

[0015] In some embodiments, each group of the conversion modules further includes a filter circuit, and the conversion module outputs electric energy through the filter circuit.

[0016] In some embodiments, the filter circuit is an LC filter circuit.

[0017] In some embodiments, the distribution module further comprises a communication module, and the master control chip is connected with the monitoring module and transmits data through the communication module.

[0018] In some embodiments, the communication module comprises an RS485 communication chip, and the model of the RS485 communication chip is MAX485.

[0019] In some embodiments, the voltage stabilizing module comprises a DC-DC converter, and the model of the DC-DC converter is LT3652.

[0020] In some embodiments, the monitoring module comprises a smart meter, and the smart meter is a three-phase three-wire smart electric energy meter.

[0021] In some embodiments, the model of the master control chip is STM32F103C8T6.

[0022] The technical scheme of the present application has at least the following advantages and beneficial effects:

[0023] The utility model discloses a voltage stabilizing module, distribution module, inverter, energy storage module, monitoring module are provided with, and distribution module includes master control chip and two sets of conversion module, a set of conversion module connects inverter, and another set of conversion module connects energy storage module, when the system normal work, a set of conversion module will stable DC transmission to inverter, and the DC is changed into AC by inverter for load use, simultaneously, monitoring module real -time monitoring inverter transmission's power generation power and load's consumption power, and data transmission is judged in master control chip, another set of conversion module does not work at this time, if master control chip judges that load consumption power is less than photovoltaic module's power generation power, and master control chip changes a set of conversion module's output power, prevents the reverse flow phenomenon from happening, and simultaneously starts another set of conversion module, and the extra electric energy is transmitted to energy storage module through another set of conversion module, so that the electric energy of photovoltaic power generation can not reduce work efficiency because of the insufficient load consumption capacity, and the phenomenon that part electric energy is wasted is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is the overall signal flow chart of the utility model;

[0025] Figure 2 It is the circuit diagram of the voltage stabilizing module of the utility model;

[0026] Figure 3 It is the signal generator circuit diagram of a set of conversion module of the utility model;

[0027] Figure 4 A second type DC-DC converter circuit diagram of a group of conversion modules of the utility model;

[0028] Figure 5 A signal generator circuit diagram of another group of conversion modules of the utility model;

[0029] Figure 6 A second type DC-DC converter circuit diagram of another group of conversion modules of the utility model;

[0030] Figure 7 A circuit diagram of a communication module of the utility model. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0032] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. If the terms "center", "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed, which is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the application. It should also be noted that, unless otherwise explicitly specified and limited, if the terms "set", "install", "connect" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or detachably connected, or integrally connected, they can be mechanically connected, or electrically connected, they can be directly connected, or indirectly connected through an intermediate medium, or the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0033] Embodiment 1

[0034] Please refer to Figures 1-7 The utility model provides a kind of anti-flow monitoring protection system suitable for photovoltaic power generation, including voltage stabilizing module, distribution module, inverter, monitoring module, energy storage module, distribution module is connected with voltage stabilizing module, energy storage module, inverter, monitoring module respectively, monitoring module is connected with inverter, energy storage module respectively;

[0035] a voltage stabilizing module for converting unstable direct current transmitted by the photovoltaic module into stable direct current and transmitting the stable direct current into the distribution module;

[0036] a distribution module for transmitting the stable direct current into an inverter or an energy storage module; the distribution module adjusts the proportion of the electric energy transmitted into the inverter or the energy storage module according to the control signal transmitted by the monitoring module;

[0037] the distribution module comprises a master control chip and two groups of conversion modules, the master control chip is connected with the monitoring module and the two groups of conversion modules respectively; one group of conversion modules is connected with the voltage stabilizing module and the inverter respectively, and the other group of conversion modules is connected with the voltage stabilizing module and the energy storage module respectively;

[0038] the master control chip adjusts the electric energy converted by one group of conversion modules and transmitted into the inverter according to the control signal transmitted by the monitoring module, and transmits the remaining electric energy into the energy storage module through the other group of conversion modules;

[0039] an energy storage module for storing electric energy;

[0040] a monitoring module for judging whether the photovoltaic power generated by the inverter exceeds the local load power consumption, and transmitting a control signal into the master control chip according to the comparison result.

[0041] It should be explained that the DC-DC converter is a power converter for converting one direct current into another direct current.

[0042] It should be pointed out that the model of the master control chip is STM32F103C8T6.

[0043] In the embodiment, the energy storage module comprises a mobile power supply, and the battery type of the mobile power supply is a lithium iron phosphate battery.

[0044] In the embodiment, the monitoring module comprises a smart meter, and the smart meter is a DSZ71 type three-phase three-wire smart electric energy meter, which transmits data to the master control chip through an RS485 interface.

[0045] an inverter for converting the direct current transmitted by the distribution module into alternating current, the inverter transmits the alternating current to the load through the monitoring module to supply power to the load; in the embodiment, the model of the inverter is MID33-50KTL3-X2.

[0046] The utility model further comprises a power module, and the power module is used for providing working power for the voltage stabilizing module, the distribution module, the inverter, the monitoring module and the energy storage module.

[0047] The input end of the voltage stabilizing module is connected with the photovoltaic module, and the output end of the voltage stabilizing module is connected with the distribution module; for example,Figure 2 As shown, the voltage stabilizing module includes a DC-DC converter U1, a battery interface U2, Schottky diodes D1, D2, D4, a general diode D3, general capacitors C1, C2, C3, C4, an ESD diode D5, resistors R1, R2, R3, R4, R5, R6, and an inductor L1;

[0048] Specifically, as shown in the figure, Figure 2 The anode of the Schottky diode D1 is provided as an S_IN input terminal, the cathode of the Schottky diode D1, one end of the general capacitor C1, one end of the resistor R1, pin 1 of the DC-DC converter U1, pin 3 of the DC-DC converter U1, the cathode of the Schottky diode D4, one end of the general capacitor C4, and one end of the ESD diode D5 are connected, and an S_OUT output terminal is provided at this point; the other end of the resistor R1, pin 2 of the DC-DC converter U1, and one end of the resistor R2 are connected, the other end of the resistor R2, the other end of the general capacitor C1, and pin 6 of the DC-DC converter U1 are connected and grounded; pin 13 of the DC-DC converter U1 and the anode of the Schottky diode D2 are connected and grounded, the cathode of the Schottky diode D2, pin 12 of the DC-DC converter U1, one end of the general capacitor C2, and one end of the inductor L1 are connected, the other end of the general capacitor C2, the cathode of the general diode D3, and pin 11 of the DC-DC converter U1 are connected, the anode of the general diode D3, pin 9 of the DC-DC converter U1, one end of the resistor R4, one end of the general capacitor C3, one end of the resistor R3, the anode of the Schottky diode D4, and pin 1 of the battery interface U2 are connected, the other end of the resistor R3, pin 10 of the DC-DC converter U1, and the other end of the inductor L1 are connected; pin 8 of the DC-DC converter U1 and one end of the resistor R6 are connected, pin 7 of the DC-DC converter U1, one end of the resistor R5, and one end of the resistor R4 are connected, the other end of the resistor R5, the other end of the resistor R6, one end of the general capacitor C3, and pin 2 of the battery interface U2 are connected and grounded; the other end of the general capacitor C4 and the other end of the ESD diode D5 are connected and grounded;

[0049] It should be noted that the model of the DC-DC converter U1 is LT3652; the ESD diode U5 is used to protect the electronic device from electrostatic discharge damage;

[0050] It should be noted that the S_IN input terminal is connected to the output terminal of the photovoltaic module, the S_OUT output terminal is connected to the distribution module, and the unstable electrical energy received by the S_IN input terminal is converted into stable electrical energy by the DC-DC converter U1, and the stable electrical energy is output by the S_OUT output terminal.

[0051] The two groups of conversion modules each include a Class II DC-DC converter, the two groups of Class II DC-DC converters are connected with the master control chip respectively, and the power input ends of the two groups of Class II DC-DC converters are connected with the output ends of the voltage stabilizing modules respectively; the power output end of one group of Class II DC-DC converters is connected with the output end of the inverter, and the power output end of the other group of Class II DC-DC converters is connected with the output end of the energy storage module.

[0052] It should be noted that each group of conversion modules includes a signal generator and a filter circuit, the master control chip controls the Class II DC-DC converter to start or adjust the converted power through the signal generator; and the conversion module outputs power through the filter circuit.

[0053] It should be noted that the filter circuit is an LC filter circuit.

[0054] Further, one group of conversion modules includes a digital potentiometer U3, a timer U4, a Class II DC-DC conversion chip U5, a general diode D6, a polarized capacitor C5, general capacitors C6 and C7, an ESD diode D7, triodes Q1, Q2 and Q3, resistors R7, R8, R9, R10, R11, R12 and R13, and an inductor L2.

[0055] Among them, the signal generator of one group of conversion modules includes the digital potentiometer U3, the timer U4, the general diode D6, the polarized capacitor C5, the general capacitor C6, the triodes Q1 and Q2, and the resistors R7, R8, R9, R10 and R11; the Class II DC-DC converter of one group of conversion modules includes the Class II DC-DC conversion chip U5, the triode Q3, the ESD diode D7, the general capacitor C7, the inductor L2, and the resistors R12 and R13.

[0056] Among them, the LC filter circuit includes the general capacitor C7 and the inductor L2.

[0057] Specifically, as Figure 3As shown, in a signal generator of a set of conversion modules, pin 1 of digital potentiometer U3, one end of resistor R7, and one end of resistor R8 are connected to a power supply. The other end of resistor R7 is connected to pin 3 of digital potentiometer U3, where the SCL1 transmission terminal is set. The other end of resistor R8 is connected to pin 4 of digital potentiometer U3, where the SDA1 transmission terminal is set. Pin 5 of digital potentiometer U3, the anode of polarized capacitor C5, pin 2 of DC-DC converter chip U5, and pin 6 of timer U4 are connected. Pin 6 of digital potentiometer U3, the cathode of diode D6, and pin 7 of timer U4 are connected. The anode of diode D6 and pin 8 of timer U4 are connected. One end of resistor R9 and one end of resistor R10 are connected to the power supply. The other end of resistor R10 is connected to the collector of transistor Q2, which is set as the PWM_OUT1 output terminal. Pin 4 of timer U4, the other end of resistor R9, and the collector of transistor Q1 are connected. The emitter of transistor Q1 is grounded, and the base of transistor Q1 is set as the CON_IN1 input terminal. Pin 3 of timer U4, one end of resistor R11, and the base of transistor Q2 are connected. Pin 5 of timer U4 is connected to one end of ordinary capacitor C6. The other end of ordinary capacitor C6, the cathode of polarized capacitor C5, the other end of resistor R11, and the emitter of transistor Q2 are connected and grounded.

[0058] Specifically, such as Figure 4 As shown, in a set of conversion modules of a type II DC-DC converter, the base of transistor Q3 is set as the CON_IN2 input terminal, the collector of transistor Q3 is connected to one end of resistor R12, and the other end of resistor R12 is connected to the power supply; the emitter of transistor Q3, pin 5 of type II DC-DC converter chip U5, and one end of resistor R13 are connected; the other end of resistor R13, pin 3 of type II DC-DC converter chip U5, pin 6 of type II DC-DC converter chip U5, one end of ordinary capacitor C7, and one end of ESD diode D7 are connected and grounded; pin 4 of type II DC-DC converter chip U5 is set as the PWM_IN1 input terminal; pin 2 of type II DC-DC converter chip U5 is connected to one end of inductor L2; the other end of inductor L2 is connected to the other end of ordinary capacitor C7 and is set as the OUT1 output terminal here; pin 1 of type II DC-DC converter chip U5 is set as the IN1 input terminal;

[0059] It needs to be explained that the IN1 input end and the S_OUT output end of the voltage stabilizing module are connected, the OUT1 output end and the inverter input end are connected, the PWM_IN1 input end and the PWM_OUT1 output end are connected, the SCL1 transmission end and the pin PB6 of the master control chip are connected, the SDA1 transmission end and the pin PB7 of the master control chip are connected, the CON_IN1 input end, the CON_IN2 input end and the pin PA3 of the master control chip are connected;

[0060] It needs to be explained that the master control chip adjusts the digital potentiometer U3 resistance value to adjust the timer output PWM signal, and the second type DC-DC conversion chip U5 adjusts the power output power according to the PWM signal;

[0061] It needs to be explained that the VDD power supply in the figure represents the working voltage of the electronic device, which is converted from the VCC power supply; the power conversion is the prior art, which will not be described too much here.

[0062] Further, another group of conversion modules and a group of conversion modules are similar, as shown in Figure 5 and Figure 6 The difference lies in that the control modes of the reset end of the timer and the enable end of the second type DC-DC conversion chip are different;

[0063] Specifically, as shown in Figure 5 , in the signal generator of the other group of conversion modules, the pin 4 of the timer U7, the other end of the resistor R18 and the emitter of the triode Q4 are connected, the other end of the resistor R18 is grounded, and the collector of the triode Q4 is connected to the power supply through the resistor R16;

[0064] Specifically, as shown in Figure 6 , in the second type DC-DC converter of the other group of conversion modules, the pin 5 of the second type DC-DC conversion chip U8, one end of the resistor R20 and the collector of the triode Q6 are connected, the other end of the resistor R20 is connected to the power supply, the emitter of the triode Q6, the pin 3 of the second type DC-DC conversion chip U8, the pin 6 of the second type DC-DC conversion chip U8, one end of the general capacitor C10 and one end of the ESD diode D9 are connected and grounded;

[0065] For ease of understanding, the control modes of the reset end of the timer and the enable end of the second type DC-DC conversion chip in each group of conversion modules will be described:

[0066] For a group of conversion modules, after the system starts, the pin 4 (reset end) of the timer U4 receives a high level, the timer U4 starts to work, the pin 5 (enable end) of the two-class DC-DC conversion chip U5 receives a low level, the two-class DC-DC conversion chip U5 starts to work; if the control signal output by the master control chip is input into the CON_IN1 input end and the CON_IN2 input end, the pin 4 of the timer U4 receives a low level, the timer U4 stops to work, the pin 5 of the two-class DC-DC conversion chip U5 receives a high level, the two-class DC-DC conversion chip U5 stops to work.

[0067] For another group of conversion modules, after the system starts, the pin 4 (reset end) of the timer U7 receives a low level, the timer U7 does not work, the pin 5 (enable end) of the two-class DC-DC conversion chip U8 receives a high level, the two-class DC-DC conversion chip U8 does not work; if the control signal output by the master control chip is input into the CON_IN3 input end and the CON_IN4 input end, the pin 4 of the timer U7 receives a high level, the timer U7 starts to work, the pin 5 of the two-class DC-DC conversion chip U8 receives a low level, the two-class DC-DC conversion chip U8 starts to work.

[0068] The purpose of such design is that when the system starts, a group of conversion modules can directly start to stably transmit the received electric energy to the inverter; if the master control chip judges that the load consumption power is less than the power generation power of the photovoltaic module, the master control chip changes the output power of the group of conversion modules, and simultaneously starts another group of conversion modules, so as to ensure that the photovoltaic power generation can provide appropriate electric energy to the load, and prevent the reverse flow phenomenon from occurring; the excess electric energy is transmitted to the energy storage module through another group of conversion modules, so that the electric energy of the photovoltaic power generation will not reduce the working efficiency due to the insufficient load consumption capacity, and the phenomenon that part of the electric energy is wasted is avoided; the master control chip can also close the transmission channel of a group of conversion modules, and open the transmission channel of another group of conversion modules, so as to control the electric energy generated by the photovoltaic power generation to be directly transmitted to the energy storage module through another group of conversion modules, and realize charging of the energy storage module, which is suitable for some scenes in which the mobile power supply needs to be charged.

[0069] It should be noted that, as Figure 6As shown, another group of conversion modules is provided with a CON IN3 input end, a PWM OUT2 output end, an SCL2 transmission end, an SDA2 transmission end, a CON IN4 input end, a PWM IN2 input end, an OUT2 output end, an IN2 input end; the IN2 input end is connected with the S OUT output end of the voltage stabilizing module, the OUT2 output end is connected with the input end of the energy storage module, the PWM IN2 input end is connected with the PWM OUT2 output end, the SCL2 transmission end is connected with the pin PB8 of the master control chip, the SDA2 transmission end is connected with the pin PB9 of the master control chip, the CON IN3 input end, the CON IN4 input end and the pin PA4 of the master control chip are connected.

[0070] For the convenience of understanding, the working process of the system will be described as follows:

[0071] When the system starts, the voltage stabilizing module starts to work and converts the unstable direct current power generated by the photovoltaic module into stable direct current power; one group of conversion modules starts to work and transmits the stable direct current power to the inverter, the inverter converts the direct current power to generate alternating current power, the inverter transmits the alternating current to the load through the monitoring module, the monitoring module monitors the power generation power transmitted by the inverter and the consumption power of the load in real time, and transmits the data to the master control chip; another group of conversion modules does not work.

[0072] The master control chip judges whether the triggering standard of reverse current phenomenon is reached according to the power generation power and the consumption power; if not, the system maintains the present situation;

[0073] If yes, the master control chip outputs a signal to the digital potentiometer U3 of one group of conversion modules, the digital potentiometer U3 adjusts the resistance value, and then the timer U4 adjusts the output PWM signal, the PWM signal is transmitted to the second type DC-DC conversion chip U5, the second type DC-DC conversion chip U5 adjusts the output power and transmits it to the inverter; at the same time, the master control chip outputs control signals to the CON IN3 input end and the CON IN4 input end of another group of conversion modules, the timer U7 and the second type DC-DC conversion chip U8 start to work; the master control chip outputs a signal to the digital potentiometer U6 of another group of conversion modules to adjust the resistance value, and then the timer U7 adjusts the output PWM signal, the PWM signal is transmitted to the second type DC-DC conversion chip U8, and the output power of the second type DC-DC conversion chip U8 is transmitted to the energy storage module.

[0074] It should be noted that the distribution module further comprises a communication module, and the master control chip is connected with the monitoring module and transmits data through the communication module.

[0075] Further, the communication module comprises an RS485 communication chip U9, a general capacitor C11, resistors R21, R22, R23, R24, R25 and R26.

[0076] Specifically, pin 1 of the RS485 communication chip U9 is connected with one end of the resistor R21, and an RX transmission end is arranged at the position; pin 2 of the RS485 communication chip U9 is connected with pin 3 of the RS485 communication chip U9, and an EN transmission end is arranged at the position; pin 4 of the RS485 communication chip U9 is connected with one end of the resistor R22, and a TX transmission end is arranged at the position; the other end of the resistor R21 and one end of the resistor R23 are connected and connected with a power supply, the other end of the resistor R23, pin 8 of the RS485 communication chip U9 and one end of the general capacitor C11 are connected, the other end of the general capacitor C11, pin 5 of the RS485 communication chip U9 and one end of the resistor R24 are connected and grounded; pin 7 of the RS485 communication chip U9, the other end of the resistor R24 and one end of the resistor R25 are connected, and an RS485_B transmission end is arranged at the position; pin 6 of the RS485 communication chip U9, the other end of the resistor R25 and one end of the resistor R26 are connected, and an RS485_A transmission end is arranged at the position; the other end of the resistor R22 and the other end of the resistor R26 are connected and connected with the power supply.

[0077] It should be noted that the TX transmission end is connected with PA9 of the master control chip, the RX transmission end is connected with PA10 of the master control chip, the EN transmission end is connected with PA2 of the master control chip, the RS485_A transmission end and the RS485_B transmission end are connected with the monitoring module.

[0078] It should be noted that the RS485 communication chip is of the type MAX485.

[0079] It should be noted that the triodes in the embodiment are all NPN type.

[0080] It should be noted that the above electronic devices can be purchased in the domestic and foreign markets.

[0081] Up to now, the various embodiments of the utility model have been described in detail. In order to avoid shielding the concept of the utility model, some details known in the art are not described. According to the above description, those skilled in the art can fully understand how to implement the technical scheme of the utility model herein, and the scope of the utility model is defined by the appended claims.

Claims

1. A reverse current protection system for photovoltaic power generation, characterized by: The application relates to a photovoltaic power generation system, which comprises a voltage stabilizing module, a distribution module, an inverter, a monitoring module and an energy storage module. The voltage stabilizing module is used for converting unstable direct current transmitted by a photovoltaic module into stable direct current and transmitting the stable direct current into the distribution module. The distribution module is used for transmitting the stable direct current into the inverter or the energy storage module. The distribution module comprises a main control chip, two groups of conversion modules, the main control chip is connected with the monitoring module and the two groups of conversion modules, one group of the conversion modules is connected with the voltage stabilizing module and the inverter, and the other group of the conversion modules is connected with the voltage stabilizing module and the energy storage module. The main control chip adjusts the electric energy converted by one group of the conversion modules according to the control signal sent by the monitoring module and transmits the electric energy into the inverter, and simultaneously transmits the residual electric energy into the energy storage module through the other group of the conversion modules. The energy storage module is used for storing electric energy. The monitoring module is used for judging whether the photovoltaic power generation amount transmitted by the inverter exceeds the local load power consumption, and sending a control signal into the main control chip according to the comparison result.

2. The anti-backflow monitoring protection system for photovoltaic power generation according to claim 1, characterized in that, Each group of the conversion modules comprises two types of DC-DC converters, the two types of DC-DC converters are connected with the main control chip, the electric energy input ends of the two types of DC-DC converters are connected with the output ends of the voltage stabilizing module, the electric energy output end of one group of the two types of DC-DC converters is connected with the output end of the inverter, and the electric energy output end of the other group of the two types of DC-DC converters is connected with the output end of the energy storage module.

3. The anti-backflow monitoring protection system for photovoltaic power generation according to claim 2, characterized in that, Each group of the conversion modules comprises a signal generator, the main control chip controls the two types of DC-DC converters to start or adjust the converted electric energy through the signal generator.

4. The anti-backflow monitoring protection system for photovoltaic power generation according to claim 2, characterized in that, Each group of the conversion modules further comprises a filter circuit, and the conversion modules output electric energy through the filter circuit.

5. The anti-backflow monitoring protection system for photovoltaic power generation according to claim 4, characterized in that, The filter circuit is an LC filter circuit.

6. The anti-backflow monitoring protection system for photovoltaic power generation according to claim 1, characterized in that, The distribution module further comprises a communication module, the main control chip is connected with the monitoring module and transmits data through the communication module.

7. The anti-backflow monitoring protection system for photovoltaic power generation according to claim 6, characterized in that, The communication module comprises an RS485 communication chip, and the model of the RS485 communication chip is MAX485.

8. The anti-backflow monitoring protection system for photovoltaic power generation according to claim 1, characterized in that, The voltage stabilizing module comprises a type 1 DC-DC converter, and the model of the type 1 DC-DC converter is LT3652.

9. The anti-backflow monitoring protection system for photovoltaic power generation according to claim 1, characterized in that, The monitoring module comprises a smart electric meter, and the smart electric meter is a three-phase three-wire smart electric energy meter.

10. The anti-backflow monitoring protection system for photovoltaic power generation according to claim 1, characterized in that, The model of the main control chip is STM32F103C8T6.

Images