CN115764817B - Quick turn-off device supporting two paths of photovoltaic module input and having monitoring function - Google Patents

Abstract

The invention relates to the technical field of photovoltaic power generation and communication, in particular to a rapid shutoff device with a monitoring function for supporting two paths of photovoltaic module input. It comprises the following steps: the four input ports and the two output ports are respectively connected with the positive electrode output and the negative electrode output of the first photovoltaic module and the second photovoltaic module; the 2 groups of MOS switches are respectively arranged on the negative electrode lines of the first photovoltaic module and the second photovoltaic module, wherein the negative electrode of the first photovoltaic module is connected with the positive electrode of the second photovoltaic module through the MOS switches; a logic control unit for controlling on and off of the switching unit; and the power supply unit converts the high-voltage input into the low-voltage output and supplies power for the logic control unit. The function of 2 related products in the traditional way can be realized by adopting 1 quick shutoff device supporting two paths of input, and only one processing chip, peripheral electronic materials, a PCB (printed Circuit Board) and the like are needed, so that the cost of raw materials is greatly reduced.

Description

Quick turn-off device supporting two paths of photovoltaic module input and having monitoring function

Technical Field

The invention relates to the technical field of photovoltaic power generation and communication, in particular to a rapid shutoff device with a monitoring function for supporting two paths of photovoltaic module input.

Background

Because of the reproducibility and cleanliness of solar energy, photovoltaic grid-connected power generation technology is rapidly developed. At present, a plurality of photovoltaic modules are connected in series to form a photovoltaic group string, and the photovoltaic group string is converted into alternating current through an inverter and then transmitted to a power grid. The direct-current voltage formed by the series photovoltaic module arrays is very high, and has great potential safety hazards, so that the photovoltaic modules are required to be rapidly turned off when in an abnormal state in order to improve the safety of the photovoltaic system, and the working stability of the whole series is prevented from being influenced. In the prior art, a shutoff device is connected to the rear of each photovoltaic module, and the power output of each photovoltaic module is controlled through the shutoff device, so that the voltage on the direct current cable can meet the safety regulation requirement.

Chinese patent CN201910711960 discloses a photovoltaic module shutoff device, in which a plurality of switching tubes connected in series receive a communication signal sent by a controller in the shutoff device, perform related on and off operations, and reduce failure rate of the shutoff device by using serial-parallel connection of the switching tubes, thereby improving stability and reliability. Furthermore, prior art component interrupters typically only support one input, such as those shown in fig. 1, including processors, switching units, switches, bypass diodes, and the like. After the voltage of the photovoltaic module is input, a command is sent to the switch unit through logic control so as to open the switch MOS, and the voltage is output to the later-stage module; the bypass diode D is used to conduct when the component breaker fails, bypass the single component breaker, and generate current from the bypass diode D for the subsequent stage so as not to affect the normal operation of other components in the whole string.

However, the component turnoff device only supports the input of one path of component, and at least one turnoff device is required to be arranged for each component in a system adopting the turnoff device, so that the installation cost of the whole system of the photovoltaic component is greatly increased. Secondly, when the quantity of the turnoff devices installed in the photovoltaic module system is large, the power line is used for carrier coupling, clutter signals on the power line are more interfered, the signal strength can be weakened when the transmission distance is long, the carrier communication is affected, the communication quality is reduced, and the normal turnoff of the module is affected.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides a rapid shutoff device supporting two paths of photovoltaic module input and having a monitoring function, which comprises:

the four input ports and the two output ports are respectively connected with the positive electrode output and the negative electrode output of the first photovoltaic module and the second photovoltaic module;

the switching unit at least comprises 2 groups of MOS switches which are respectively arranged on the negative electrode lines of the first photovoltaic module and the second photovoltaic module, wherein the negative electrode of the first photovoltaic module is connected with the positive electrode of the second photovoltaic module through 1 group of MOS switches;

The logic control unit is used for controlling the on and off of the switch unit;

and the power supply unit converts the high-voltage input into the low-voltage output and supplies power for the logic control unit.

As a preferable technical scheme of the invention, the rapid shutoff device supporting the input of the two paths of photovoltaic modules and having the monitoring function also comprises voltage sampling units respectively arranged between the positive output end and the negative output end of the photovoltaic modules; the voltage sampling unit is in communication connection with the logic control unit.

As a preferable technical scheme of the invention, the voltage sampling unit samples the output voltage of the photovoltaic module after receiving the sampling instruction of the logic control unit.

As a preferable technical scheme of the invention, an inductor is arranged on a negative electrode line of the second photovoltaic module, and one end of the inductor is connected with a negative electrode output of the second photovoltaic module through a group of MOS switches.

As a preferable technical scheme of the invention, the logic control unit is in communication connection with the inductance carrier; further, the logic control unit receives a carrier signal between the positive electrode and the negative electrode of the inductance differential circuit.

As a preferable technical scheme of the invention, a current sampling unit is arranged on a negative output line of the second photovoltaic module, and the current sampling unit is in communication connection with the logic control unit; further, the current sampling unit samples the current flowing through the second photovoltaic module after receiving the sampling instruction of the logic control unit.

As a preferable technical scheme of the invention, a bypass diode and a capacitor are respectively arranged between the positive output and the negative output of the first photovoltaic module and the second photovoltaic module; the anode of the bypass diode is connected with the first photovoltaic module or the second photovoltaic module through a group of MOS switches, and the cathode of the bypass diode is connected with the anode output of the first photovoltaic module or the second photovoltaic module.

As a preferable technical scheme of the invention, the logic control unit controls the on and off of the switch unit through the fast switch unit; preferably, the fast switch unit at least comprises 1 MOS switch, the G pole of the MOS switch is connected with the GPIO interface of the logic control unit, the S pole is grounded, and the D pole is connected with the G of the other MOS switch through a voltage dividing resistor.

As a preferred technical solution of the present invention, the power supply unit converts a high voltage input into a low voltage output and supplies power to the fast switching unit.

The second aspect of the invention provides a photovoltaic power generation system, which comprises the rapid shutoff device supporting two paths of photovoltaic component inputs and having a monitoring function, and further comprises a plurality of photovoltaic components; four input ports of the quick shutoff device are respectively connected with the positive electrode output and the negative electrode output of the two photovoltaic modules; at least one of the output ports of the quick turnoff device is connected in series with the output ports of other quick turnoff devices to form a photovoltaic group string; a plurality of photovoltaic groups are connected in series-parallel to form a photovoltaic array; and the photovoltaic array and the rear-stage photovoltaic module are connected to form the photovoltaic power generation system.

Compared with the prior related scheme, the technical scheme provided by the invention has the following beneficial effects:

firstly, the quick shutoff device provided by the invention supports two paths of input, and compared with products or technologies which only support one path of component input in the prior art, the operation cost of a photovoltaic power generation system is greatly reduced by adopting two paths of input through one shutoff device product. In addition, the quick turn-off function which can be realized only by 2 single-way components originally can be realized by adopting 1 quick turn-off device supporting two-way input, and the cost of raw materials such as peripheral electronic materials, PCB (printed circuit board), shell and the like is greatly reduced by only using one logic processing chip, so that the installation and operation cost of the whole photovoltaic system is further obviously reduced. Meanwhile, in the conventional photovoltaic system, each photovoltaic module is required to be provided with at least one shutoff device, and when the number of the shutoff devices in the system is large, the carrier communication transmission error between the shutoff devices is improved, and the communication quality is reduced, so that the control performance of each shutoff device is reduced, and the stable operation of the photovoltaic system is influenced. By adopting the quick shutoff device, the dosage of the quick shutoff device in the photovoltaic system is effectively reduced, the problem of communication quality reduction is effectively avoided, and the operation stability of the photovoltaic system is obviously improved.

And secondly, the quick shutoff device provided by the invention is characterized in that two paths of photovoltaic components are directly connected with the quick shutoff device, the input voltage is singly input through the quick shutoff device and then is serially output through internal processing, and instead of serially connecting the two paths of components, the superposition voltage is input into the quick shutoff device. Through single input of two paths of component voltages, the voltage of one path of component is transmitted to a power supply to perform voltage conversion before voltage superposition, different-size voltages are provided for a logic control unit, a fast switching unit and the like in the shutoff device, the input voltage of the power supply is ensured to be in a specific range, and the fluctuation amplitude is kept small, so that the conditions that the power supply unit is broken by high voltage or unstable in power supply and the like are avoided, and the performance of the shutoff device is influenced.

In addition, the control of the MOS switch arranged on the power output line of the photovoltaic module is carried out through the quick switch unit, the smart design of the circuit of the quick switch unit, the design of the voltage dividing resistor circuit and the optimization of the resistance value are carried out, the high and low levels provided by the logic control unit are subjected to multiple smart inversions while the smaller current loss is ensured, the stable conduction and interception of the MOS switch are ensured, and when the GPIO interface of the logic control unit outputs the high level, the MOS switch arranged on the negative line of the photovoltaic module is conducted, so that the power of the module is output to the later-stage module; when the GPIO interface of the logic control unit outputs low level, the MOS switch arranged on the negative line of the photovoltaic module is cut off to block power output.

In addition, the specific voltage detection and current detection circuits are arranged in the quick shutoff device, so that the current running state of the photovoltaic module can be effectively controlled, and the running parameters of the voltage and the current can be effectively monitored, the risk of the system can be reduced, and the safety guarantee can be provided. And the detection circuit is further optimized, so that the voltage at the two ends of the output of the assembly and the current flowing through the two assemblies can be obtained by monitoring in the verification process, the progress can be further regulated, and the monitoring accuracy is improved. In addition, the output end of the quick shutoff device is added with the coupling capacitance, so that the signal loss is less through capacitive signal coupling in the carrier signal transmission process, the condition that the shutoff device is too far from the system and the signal intensity is too low is avoided, and the quality of carrier communication is ensured.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of a shutdown device and a photovoltaic system including the same in the prior art.

Fig. 2 is a schematic diagram of a circuit frame of a quick turn-off device with a monitoring function for supporting two-path photovoltaic module input.

Fig. 3 is a schematic diagram of a circuit frame for implementing a voltage monitoring unit in a fast turn-off device according to the present invention.

Fig. 4 is a schematic diagram of a circuit frame for implementing a current monitoring unit in a fast turn-off device according to the present invention.

Fig. 5 is a schematic diagram of a circuit frame of a quick turn-off device with a monitoring function for supporting two-path photovoltaic module input.

Fig. 6 is a schematic diagram of a circuit frame of a quick turn-off device with a monitoring function for supporting two-path photovoltaic module input.

Fig. 7 is a schematic control flow diagram of a fast turn-off device with monitoring function supporting two-path photovoltaic module input.

Fig. 8 is a schematic diagram of a photovoltaic system including a fast turn-off device with monitoring function for supporting two-path photovoltaic module input.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

In the following description, the terms "first," "second," and "first," are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The following description provides examples and does not limit the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of elements described without departing from the scope of the application. Various examples may omit, replace, or add various procedures or components as appropriate. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined into other examples.

In the photovoltaic system in the prior art, in order to ensure that the voltage of the photovoltaic module (including but not limited to a photovoltaic panel, a photovoltaic cell and the like) with problems is reduced below a safety voltage in the operation process, so as to avoid safety risks, a shutoff device is often required to be provided for each photovoltaic module to conduct on-off operation. For example, referring to fig. 1, an output end of each photovoltaic module is connected to a shutoff device, and generally the shutoff device includes a logic control unit and a switch (for example, a MOS switch), and the logic control unit controls on and off of the switch disposed on an output line of the photovoltaic module, so as to achieve the effects of outputting and blocking power of the photovoltaic module. However, the common turnoff device only supports the input of one path of photovoltaic component (namely the positive and negative electrode input of one photovoltaic component), when the photovoltaic components in the photovoltaic system are more, the corresponding turnoff devices are more, because carrier communication is generally carried out between turnoff devices and logic control to carry out interaction of related data, when the number of turnoff devices is more, the layout distance between the turnoff devices is necessarily caused to be far, the carrier communication between the turnoff devices is caused to be interfered, corresponding communication signals cannot be completely transmitted to a target object, and the system operation is unstable. Moreover, when each photovoltaic module is equipped with a single shutoff device, a large amount of raw materials such as peripheral electronic materials, circuit boards and structural materials are necessarily required, the raw material cost is increased, and each quick shutoff device is required to be manufactured, so that the production and installation costs of the whole photovoltaic system are greatly increased. Therefore, the traditional turnoff product needs to be optimized in the aspects of intelligence and integration, so that various performances are improved, more comprehensive functions are realized, and the cost of installation, operation, maintenance and the like of the system is further reduced.

Next, a quick shutdown device supporting two-path input of the photovoltaic module and having a monitoring function, and a photovoltaic power generation system including the shutdown device will be described in detail.

Referring to fig. 2 and 8, the present invention provides a quick shutoff device supporting two-path photovoltaic module input with a monitoring function, comprising:

the four input ports and the two output ports are respectively connected with the positive electrode output and the negative electrode output of the first photovoltaic module and the second photovoltaic module. The positive and negative output of the photovoltaic module in the invention is the positive and negative input of the quick shutoff device, so that the input of the photovoltaic module in the application document can refer to the input of the quick shutoff device, and related information can be clearly obtained by a person skilled in the art in combination with specific specification and drawings. The quick shutoff device supports the input of two photovoltaic modules, namely, the quick shutoff device is provided with interfaces for connecting the positive output and the negative output of 2 photovoltaic modules. The photovoltaic modules are directly connected to the quick turnoff device, and then are connected in series through the quick turnoff device, namely the input voltage of the quick turnoff device is the output voltage of the single photovoltaic module, and the output voltage of the quick turnoff device is the superposition of the voltages of the two photovoltaic modules after being connected in series.

The switching unit at least comprises 2 groups of MOS switches which are respectively arranged on the negative electrode lines of the first photovoltaic module and the second photovoltaic module, wherein the negative electrode of the first photovoltaic module is connected with the positive electrode of the second photovoltaic module through 1 group of MOS switches. The switch unit is used for outputting the power of the photovoltaic module to the rear-stage module or turning off the power of the photovoltaic module to prevent the power output, thereby playing a role in safely controlling the photovoltaic module. According to the conduction condition (Vg-Vs > 2V) of the MOS switch, if the MOS switch is to be kept on, the G pole voltage is required to be always higher than the S pole, therefore, when the MOS switch is arranged on the positive input line, the S pole of the NMOS switch is connected with the photovoltaic component, and in order to make the G pole voltage higher than the S pole voltage, a voltage conversion circuit is required to be additionally added, so that the G pole voltage of the MOS switch is higher than the S pole. In the running process of the photovoltaic system, the general MOS switch is in a conducting state, the power of the photovoltaic module is transmitted to the rear-stage module, the photovoltaic module is cut off only when the photovoltaic module runs abnormally, namely the S pole and the G pole of the MOS switch are continuously in a high-voltage state, serious loss is brought to the MOS switch, the service life is greatly reduced, and the stability of the photovoltaic system is also greatly reduced. In the invention, the MOS switch is arranged on the negative electrode circuit of the photovoltaic module, and at the moment, because the S electrode of the MOS switch is connected with the negative electrode output of the photovoltaic module, namely in a grounded low-voltage state, the connection of the MOS switch can be ensured as long as the voltage higher than 2V is input to the G electrode of the MOS switch, so that the MOS switch is in a relatively low voltage state in the operation process of the photovoltaic system, the loss of the MOS switch is effectively reduced, and the operation stability of the photovoltaic system is correspondingly improved.

The logic control unit is used for controlling the on and off of the switch unit; the logic control unit is also called as a processor, wherein a built-in control chip is mainly used for receiving external instructions and information, sending sampling instructions to a monitoring unit on a shutoff device based on the external instructions and programs on the built-in chip, receiving data acquired by the monitoring unit, and sending the data to external (remote) control units such as an upper computer and the like. In addition, the logic control unit is provided with a threshold value, and when the data acquired by the monitoring unit exceeds the threshold value range, the MOS switch unit on the component line can be directly controlled to turn off the component.

And the power supply unit converts the high-voltage input into the low-voltage output and supplies power for the logic control unit. The logic control unit arranged in the quick shutoff device can be powered by the photovoltaic module connected with the logic control unit, and can also be powered by an external power supply. When the external power supply is used for supplying power, the power supply unit can be a power supply such as a battery for continuously supplying voltage and current. When the photovoltaic module is used for supplying power, the power supply unit can be a converter or a conversion circuit which converts high voltage of the photovoltaic module into power capable of driving the logic control unit to work.

In some preferred embodiments of the present invention, the fast shutoff device supporting two paths of photovoltaic module input and having a monitoring function further includes voltage sampling units (i.e. voltage monitoring units) respectively disposed between the positive output end and the negative output end of the photovoltaic module; the voltage sampling unit is in communication connection with the logic control unit; further, the voltage sampling unit samples the output voltage of the photovoltaic module after receiving the sampling instruction of the logic control unit.

Because the photovoltaic system converts the irradiated light energy into electric energy through the photovoltaic module for transmission, the voltage of the photovoltaic module is related to environmental factors such as illumination intensity, when the illumination intensity changes, or when the surface area of the module changes due to ash, shadow and the like, the output voltage of the photovoltaic module changes, and the output voltage directly influences the power generation efficiency of the system, so that the voltage change condition of each module needs to be known in real time.

In the invention, the sampling circuit in the voltage sampling unit is not particularly limited, and only the voltage difference between the positive output and the negative output of the photovoltaic module can be measured. In some embodiments, the voltage sampling unit includes a pull-up resistor and a pull-down resistor, and the positive output high level of the photovoltaic module is connected to the logic control unit after passing through the pull-up resistor and the pull-down resistor, and then the voltage is divided by the resistor (where a metering chip is provided, or alternatively, one metering chip may be separately provided, and then the data of the metering chip after metering is transmitted to the logic control unit). One end of the pull-up resistor is connected with the output of the component, and the other end of the pull-up resistor is connected with an ADC1 functional pin of the metering chip; one end of the pull-down resistor is connected with an ADC1 functional pin of the metering chip, and the other end of the pull-down resistor is grounded.

In some preferred embodiments of the present invention, referring to fig. 3, the voltage sampling unit includes an anode voltage dividing resistor circuit and a cathode voltage dividing resistor circuit, the anode output and the cathode output of the photovoltaic module are respectively connected to the anode ADC1 function pins of the metering chip after passing through the resistor circuits, and are transmitted to the logic control unit for processing after being metered by the metering chip. Further, the positive voltage dividing resistor circuit comprises a pull-up resistor R11 and a pull-down resistor R4, one end of the pull-up resistor R11 is connected with the positive output of the photovoltaic module, and the other end of the pull-up resistor R11 is connected with a positive ADC1 functional pin of the metering chip; one end of the pull-down resistor R4 is connected with one end of the pull-up resistor R11 and then connected with the positive pole ADC1 functional pin of the metering chip, and the other end of the pull-down resistor R4 is grounded. Further, the negative voltage dividing resistor circuit comprises a resistor R5, one end of the resistor R5 is grounded, and the other end of the resistor R is connected to a negative ADC1 functional pin of the metering chip.

In some preferred embodiments, the filter capacitors C31 and C32 are disposed on the positive voltage dividing resistor circuit and the negative voltage dividing resistor circuit, so that voltage fluctuation of the positive output of the photovoltaic module and voltage fluctuation generated when the negative electrode is grounded are reduced, and accuracy of voltage measurement is further improved. In the invention, the resistance values of the pull-up resistor R11 and the pull-down resistor R4 can be set according to the output voltage range of the photovoltaic module and the requirement of the voltage dividing resistor network.

In some embodiments, the resistance values of the pull-up resistor R11 and the pull-down resistor R4 are 300K and 2-3K, respectively. In order to further reduce the voltage sampling bias, high precision pull-up resistors and pull-down resistors are preferably used in the present invention. Further preferably, the pull-up resistor R11 is composed of several resistors connected in series (for example, see fig. 3, the pull-up resistor R11 is composed of three resistors R1, R2 and R3 connected in series, each of which has a resistance value of 100K), and further, the pull-up resistor R11 may be formed by connecting resistors with the same resistance value in series, where the sum of the resistance values of the several resistors connected in series is the same as the total resistance value of the pull-up resistor R11. The pull-up resistor formed by serially connecting resistors with small resistance can help to improve the sampling precision and reduce the sampling error.

In some preferred embodiments of the present invention, the fast turn-off device supporting two-path input of the photovoltaic module with the monitoring function further includes a current sampling unit (i.e. a current monitoring unit) disposed on a negative output line of the second photovoltaic module. According to the invention, as the two paths of photovoltaic modules are connected into the quick shutoff device and then are connected in series through the internal circuit and then output, when the currents output by the first photovoltaic module and the second photovoltaic module are different according to the current rule of the series circuit, the currents after being connected in series are automatically averaged, so that the currents flowing through the system after being connected in series are only detected. Similarly, because the output power of the photovoltaic module can change due to the change of external factors, the current monitoring unit in the application is mainly used for judging whether the current in the system fluctuates or exceeds the module bearing range, and the stability of the later-stage power supply is ensured.

In some embodiments, the current sampling unit includes a positive sampling resistor and a negative sampling resistor, and the current flowing through the positive sampling resistor and the negative sampling resistor is collected and transmitted to the metering chip for metering, so that the current value flowing in the system is obtained for omnibearing monitoring of the system.

Referring to fig. 4, in some embodiments, one ends of the positive sampling resistor R41 and the negative sampling resistor R42 are respectively connected to one ends of the filter capacitors C41 and C42, and then are respectively connected to the positive and negative ADC2 function pins of the metering chip, and the other ends of the filter capacitors C41 and C42 are respectively grounded. Further, the positive sampling resistor R41 and the negative sampling resistor R42 have the same resistance.

The current sampling unit is controlled by the logic control unit, wherein the current sampling unit is in communication connection with the logic control unit; further, the current sampling unit samples the current flowing through the second photovoltaic module after receiving the sampling instruction of the logic control unit. In the invention, the communication modes of the current sampling unit and the logic control unit are not particularly limited, and wired communication (such as carrier communication) and wireless communication (such as WiFi) can be adopted

The logic control unit (namely a processor) is a core component of the quick shutoff device, a processing chip is arranged in the quick shutoff device, and a corresponding processing program is arranged in the quick shutoff device. The logic control unit is mainly used for sending instructions to the voltage sampling unit and the current sampling unit to collect parameters such as voltage and current of the photovoltaic module, receiving the collected data and transmitting the collected data to a post-processing platform such as an upper computer in a wired or wireless mode.

In some embodiments, the logic control unit may receive an external instruction, and conduct on/off of a switch unit disposed on a negative electrode circuit of the photovoltaic module according to an instruction requirement, so that when an unsafe accident such as a fire disaster or an arc occurs, or when an operation such as maintenance is performed on the photovoltaic system, the logic control unit may block the power output of the photovoltaic module, so that the voltage of the system drops below a safe voltage. In some embodiments, the logic control unit sets a threshold value for parameters such as current and component voltage of the system, and specific parameters may be stored in a built-in chip in the logic control unit, where when the parameters such as component current and component voltage exceed a threshold range, the logic control unit may also turn off the switch unit by itself.

In some embodiments, the output voltage threshold of the photovoltaic module is 8-80 v; when the output voltage of the single photovoltaic module is higher than the threshold range or lower than the threshold range, the logic control unit turns off the corresponding photovoltaic module, and only when the output voltage of the module is within the threshold range of 8-80V, the power of the module is kept to be output normally. Further, the output current threshold value of the photovoltaic module is 0-20A; when the output current of the photovoltaic module is higher than the threshold range or lower than the threshold range, the logic control unit turns off the corresponding photovoltaic module, and only when the output current of the module is within the threshold range of 0-20A, the power of the module is kept to be output normally.

Referring to fig. 7, the logic control unit (i.e. the processor) periodically sends instructions (which may be sent simultaneously or sequentially) for data acquisition to the voltage sampling unit and the current sampling unit, and the voltage sampling unit and the current sampling unit sample the voltages and the currents of the components respectively and transmit the sampled data to the logic control unit, where the data transmission mode is not particularly limited, and the data transmission mode may be wireless, or may be wired, for example, the data transmission mode may be carrier communication. The logic control unit receives the collected voltage data and the current data, compares the collected voltage data and the current data with a built-in voltage/current threshold value respectively, judges whether the collected voltage data and the collected current data exceed a threshold value range, keeps the power of the component to be normally output when the voltage data and the current data both exceed the threshold value range, and switches off the switch unit (for example, a MOS switch) corresponding to the component to block the power output of the corresponding photovoltaic component whenever any one of the voltage data and the current data exceeds the threshold value range. When the carrier communication mode is adopted for data transmission, a modulation and demodulation related program is built in the logic control unit, the specific demodulation mode and related algorithm are not particularly limited, and various modes known by those skilled in the art can be adopted for receiving communication data and performing demodulation and reading.

In some preferred embodiments of the present invention, a bypass diode D1 and a bypass diode D2 are respectively disposed between the positive output and the negative output of the first photovoltaic module and the second photovoltaic module; the anode of a diode D1 arranged between the anode and the cathode of the first photovoltaic module is connected with the first photovoltaic module through a group of MOS switches, and the cathode of the diode D1 is connected with the output of the anode of the first photovoltaic module; the negative electrode of the bypass diode D2 arranged between the positive electrode and the negative electrode of the second photovoltaic module is connected with the positive electrode output of the second photovoltaic module, and the negative electrode is connected to the negative electrode output of the quick shutoff device through an inductor.

The bypass diode D1 and the bypass diode D2 are used for being conducted when the input of the photovoltaic module fails, a single module is bypassed, follow-up output follow current is supplied through the bypass diode D1 and the bypass diode D2, and the whole system is not influenced by the failure of the single shutoff device to supply power wholly. Referring to fig. 2, in this circuit, when the first photovoltaic module is abnormal, the MOS switch (N1) is turned off by the logic control unit, and at this time, the power of the second photovoltaic module flows to the output out+ through the bypass diode D1, the output voltage of the whole module is equal to the input voltage of the second photovoltaic module, and similarly, when the input of the second photovoltaic module is abnormal, the MOS switch (N2) is turned off by the logic control unit, and at this time, the power of the first photovoltaic module flows to the output OUT-through the bypass diode D2, and the output voltage of the whole module is equal to the input voltage of the first photovoltaic module.

In some preferred embodiments of the present invention, the switching units are disposed on the negative lines (VIN-and VOUT-) of the first/second photovoltaic modules. Because the switch unit generally adopts MOS switches, when the two MOS switches are conducted, a voltage difference needs to exist between the G pole and the S pole, and when Vg-Vs is generally larger than 2V, the two MOS switches are conducted, otherwise, the two MOS switches are cut off. Because the positive electrode of the photovoltaic module is generally in a high-voltage state, if the MOS switch is arranged at the positive electrode input and positive electrode output positions of the photovoltaic module, the G electrode of the photovoltaic module needs to be additionally boosted, so that the Vg-Vs voltage difference is not less than 2V, and the MOS switch is always in a higher voltage and current state, and the failure probability of the MOS switch is remarkably improved. The negative electrode circuit of the photovoltaic module is generally in a low-voltage state, so that the failure probability of the MOS switch is effectively reduced by arranging the switch unit on the negative electrode circuit (VIN-and VOUT-) of the first photovoltaic module/the second photovoltaic module, and the service life of the product is prolonged.

In some preferred embodiments of the present invention, decoupling capacitors C1 and C3 are respectively disposed between the positive output (i.e., the positive input of the quick-acting shutdown device) and the negative output (i.e., the negative input of the quick-acting shutdown device) of the first photovoltaic module and the second photovoltaic module, and by using the decoupling capacitors, current fluctuations formed in the power supply circuit during instantaneous changes of the input current can be prevented from affecting the normal operation of the circuit, and meanwhile, interference caused by power supply noise can be solved.

In some preferred embodiments, the first photovoltaic module and the second photovoltaic module are connected in series inside the fast shut-down device, and then carrier signal coupling capacitors C2 and C4 are arranged between the positive pole and the negative pole of the output end. Through setting up carrier signal coupling electric capacity C2 and C4 at the output, though carrier signal is through power line transmission, but self clutter and interference exist on the power line itself, lead to the signal can weaken in transmission process, this moment through the coupling electric capacity of output, carrier signal that the preceding one-level transmitted can pass this capacitive coupling, the carrier signal is transmitted to the quick turn-off of next one-level after the reinforcing signal, through this kind of coupling of continuous one-level, transmit carrier signal to last quick turn-off for every quick turn-off in the group cluster can all receive stronger carrier signal, thereby can the normal operating of effectual control turn-off.

In some preferred embodiments of the present invention, an inductor is disposed on a negative electrode line of the second photovoltaic module, and one end of the inductor is connected to a negative electrode output of the second photovoltaic module through a set of MOS switches. The voltage and current threshold values of the quick shutoff device have a wider range, and the output voltage and current of the photovoltaic module are determined based on the current and voltage requirements of the later-stage modules in the photovoltaic power generation system. When the current demand of the rear-stage component is increased instantaneously, the photovoltaic component is unstable in power supply caused by current mutation provided by the rapid shutoff device, the characteristics of the inductor determine that the current flowing through the inductor cannot be suddenly changed, and therefore the stability of the power supply of the whole system is well protected.

In some preferred embodiments, the logic control unit is communicatively coupled to the inductive carrier; further, the logic control unit receives a carrier signal between the positive electrode and the negative electrode of the inductance differential circuit. The anode of the photovoltaic module is generally in a high voltage state, the cathode voltage is in a low voltage state, and when the voltage at the two ends of the inductor is in a high voltage state, the carrier signals at the two ends of the inductor are collected and are easy to be interfered, so that the inductor is arranged at the cathode output end of the photovoltaic module, and the problems can be effectively avoided.

Referring to fig. 2, in some preferred embodiments of the present invention, the logic control unit controls on and off of the switching unit through a fast switching unit. In the invention, when the quick switch-off device normally operates, the logic control unit opens the MOS switch N1 and the MOS switch N2 through the quick switch unit (S1) and the quick switch unit S2, at the moment, a power supply forms a conducting path from VIN+ to VIN-, and forms a power supply output path from VOUT+ to VOUT-, and when the power supply output needs to be cut off, the quick switch unit S1 and the quick switch unit S2 respectively close the MOS switch N1 and the MOS switch N2, at the moment, the VIN+ to VIN-path is disconnected, so that the VOUT+ to VOUT-output path is disconnected, and the power supply output cannot be output to a later stage.

Preferably, the fast switch unit at least comprises 1 MOS switch, the G pole of the MOS switch is connected with the GPIO interface of the logic control unit, the S pole is grounded, and the D pole is connected with the G of the other MOS switch through a voltage dividing resistor.

Referring to fig. 5, in some preferred embodiments, the fast switching unit includes a MOS switch Q1-1 and a MOS switch Q1-2, the S pole of the MOS switch Q1-1 is grounded and connected to the gpio_0 interface of the logic control unit through the G pole, while one end of the pull-down resistor R1-1 is connected between the G pole of the MOS switch Q1-1 and the gpio_0 interface, and the other end thereof is grounded through the S pole of the MOS switch Q1-1; the D pole of the MOS switch Q1-1 is connected to an external input power supply through a pull-up resistor R1-4, the external input maintains stable voltage input, meanwhile, the D pole of the MOS switch Q1-1 is connected to the G pole of the MOS switch Q1-2 through a resistor R1-2, a pull-down resistor R1-3 is connected to a connecting line of the resistor R1-2 and the G pole of the MOS switch Q1-2, and the other end of the pull-down resistor is grounded through the S pole of the MOS switch Q1-2; the D pole of the MOS switch Q1-2 is connected to the G pole of the MOS switch (N1), a resistor R1-5 is arranged between the G pole of the MOS switch (N1) and the external input power supply, one end of a pull-up resistor R1-6 is connected on a G pole connecting line of the resistor R1-5 and the MOS switch (N1), and the other end of the pull-up resistor is connected to the negative pole input of the first photovoltaic module (namely the S pole of the MOS switch (N1)).

In the invention, the resistance values of the resistors on the constituent circuits in the fast switching units are correspondingly optimized, wherein the fast switching units S1 and S2 are identical units, and the circuit constituent modes can be identical. Taking the fast switch unit S1 as an example, since the resistors R1-4, R1-2, R1-3 are connected in series and then grounded, when the resistance of the resistors is low, a certain current will be lost in the electric energy input by the external power source, and the lower the resistance is, the more the corresponding loss is, so the resistance of the resistors cannot be too low. However, these resistors together with other resistors in the unit act as voltage dividers to regulate the voltages on different lines, so that it is necessary to ensure the corresponding ratio, and to ensure that the Vg-Vs voltage difference, current, etc. of each MOS switch are in a proper range, thereby realizing the function of rapidly turning off and on the corresponding MOS switch N.

In some preferred embodiments, the external input power source in the fast switching unit may be a photovoltaic module in the same system, and further, the power supply unit converts a high voltage input of the photovoltaic module into a low voltage output and supplies power to the fast switching unit.

In the invention, the electric energy output by the photovoltaic module can be converted into voltages with different magnitudes after being subjected to multistage DC/DC conversion by the power supply unit, and the voltages are respectively supplied to the logic control unit, the external input power supply and other elements. The unit for DC/DC converting the electric energy (mainly, voltage) is not particularly limited, and a DC/DC converter known to those skilled in the art may be selected and used, wherein the DC/DC converter includes a voltage converting circuit, and the DC/DC converter can convert by adjusting its conversion ratio so as to output a corresponding determined voltage as long as the output voltage is determined.

The DC/DC converter in the quick turn-off device mainly supplies power for the logic control unit and the MOS switch, wherein the driving voltage of the logic control unit is 3.3V, and the minimum voltage of the MOS switch is 8V in order to ensure the conduction of the MOS switch. At the same time, the excessively high voltage damages the voltage conversion circuit in the DC/DC converter, and the highest voltage thereof is ensured to be not higher than 80V in the present invention. Therefore, the input voltage range of the DC/DC converter (namely the power supply unit) is 8-80V, and the input voltage of the DC/DC converter is the output voltage of the photovoltaic module, so that the output voltage threshold range of the photovoltaic module is preferably 8-80V.

Embodiment 1, see fig. 3, 4, 6, a quick shutdown device and system supporting two-way photovoltaic module input with monitoring function, comprising: the four input ports and the two output ports are respectively connected with the positive electrode output and the negative electrode output of the first photovoltaic module and the second photovoltaic module; a decoupling capacitor C1 is arranged between positive and negative output ends of the first photovoltaic module, a bypass diode D1 and a carrier signal coupling capacitor C2 are arranged in parallel between the positive output of the quick shutoff device and the positive output of the second photovoltaic module, the positive electrode of the bypass diode D1 is connected with the negative output of the first photovoltaic module through a MOS switch (N1), the negative electrode is connected with the positive output of the first photovoltaic module, the positive output of the first photovoltaic module is connected to the positive output OUT+ of the quick shutoff device after passing through the decoupling capacitor C1, the negative electrode of the bypass diode D1 and one end of the carrier signal coupling capacitor C2, wherein the S electrode of the MOS switch (N1) is connected with the negative output of the first photovoltaic module, and the D electrode is connected with the positive electrode of the bypass diode D1; the G pole of the MOS switch (N1) is connected with the D pole of the MOS switch Q1-2, the G pole of the MOS switch (N1) is connected with a first external power supply (10V) through a resistor R1-5 (10K), one end of a resistor R1-6 (1M) is connected between the resistor R1-5 (10K) and the G pole of the MOS switch (N1), and the other end of the resistor R1-6 is connected between the negative output of the first photovoltaic module and the S pole of the MOS switch (N1); the S electrode of the MOS switch Q1-2 is grounded, the G electrode of the MOS switch Q1-2 is connected with the D electrode of the MOS switch Q1-1 through a resistor R1-2 (100K), one end of a resistor R1-3 (1M) is connected between the resistor R1-2 (100K) and the G electrode of the MOS switch Q1-2, and the other end of the resistor R1-3 is grounded through the S electrode of the MOS switch Q1-2; the D pole of the MOS switch Q1-1 is connected with the first external power supply (10V) through a resistor R1-4 (100K), the S pole is grounded, the G pole is connected with the GPIO_0 interface of the logic control unit, one end of the resistor R1-1 (10K) is connected between the GPIO_0 interface of the logic control unit and the G pole of the MOS switch Q1-1, and the other end of the resistor R1-1 is grounded through the S pole of the MOS switch Q1-1.

A decoupling capacitor C3 is arranged between the positive output end and the negative output end of the second photovoltaic module, a bypass diode D2 and a carrier signal coupling capacitor C4 are arranged in parallel between the negative output end of the quick shutoff device and the negative output end of the first photovoltaic module, the positive electrode of the bypass diode D2 is connected with the negative output end of the second photovoltaic module through a MOS switch (N2), the negative electrode of the bypass diode D2 is connected with the positive output end of the second photovoltaic module, and the positive output end of the second photovoltaic module is connected to an inductor L after passing through the decoupling capacitor C3, the negative electrode of the bypass diode D2 and one end of the carrier signal coupling capacitor C4 and is connected to the negative output OUT-of the quick shutoff device through the inductor L; the MOS switch (N2) is connected with the negative electrode output of the second photovoltaic module, the D electrode is connected with the positive electrode of the bypass diode D2, the G electrode is connected with the D electrode of the MOS switch Q2-2, the G electrode of the MOS switch (N2) is connected with a second external power supply through a resistor R2-5 (10K), one end of a resistor R2-6 (1M) is connected between the resistor R2-5 (10K) and the G electrode of the MOS switch (N2), and the other end of the resistor R2-6 is connected between the S electrode of the MOS switch (N2) and the negative electrode output of the second photovoltaic module; the S electrode of the MOS switch Q2-2 is grounded, the G electrode of the MOS switch Q2-2 is connected to the D electrode of the MOS switch Q2-1 through a resistor R2-2 (100K), one end of a resistor R2-3 (1M) is connected between the resistor R2-2 (100K) and the G electrode of the MOS switch Q2-2, and the other end of the resistor R2-3 is grounded through the S electrode of the MOS switch Q2-2; the D pole of the MOS switch Q2-1 is connected to a second external power supply through a pull-up resistor R2-4 (100K), the S pole of the MOS switch Q2-1 is grounded, and the G pole of the MOS switch Q2-1 is connected with a GPIO_1 interface of the logic control unit; one end of a resistor R2-1 (10K) is connected between the GPIO_1 interface of the logic control unit and the G pole of the MOS switch Q2-1, and the other end of the resistor R2-1 is grounded through the S pole of the MOS switch Q2-1.

Connecting the anode and the cathode of the first photovoltaic module or the second photovoltaic module to the input of a power supply unit, inputting the high voltage of the photovoltaic module into the power supply unit, wherein the power supply unit comprises a two-stage voltage conversion circuit, and after primary conversion by the power supply unit, reducing the voltage to 10V and outputting the voltage to the first external power supply and the second external power supply; and simultaneously, the voltage of the first photovoltaic module and the voltage of the second photovoltaic module are subjected to secondary conversion, then the voltage is reduced to 3.3V, and the voltage is output to a VCC_IN interface of the logic control unit to supply power to the VCC_IN interface. And differential input ends RX_N and RX_P of the logic control unit are respectively connected between the negative electrode and the positive electrode of the inductor L and are used for collecting carrier communication signals at two ends of the inductor L.

In addition, a voltage sampling unit is arranged between the anode and the cathode of the first photovoltaic module and the anode and the cathode of the second photovoltaic module, and the voltage sampling unit is in communication connection with the logic control unit; the positive electrode output of the photovoltaic module is connected with a resistor R1 (100K), the resistor R1 is connected with a resistor R2 (100K) and a resistor R3 (100K) in series, the other end of the resistor R3 (100K) is connected with a resistor R4 (2.49K), meanwhile, the other end of the resistor R3 (100K) is also connected to an ADC1 positive electrode input interface of the metering chip, one end of a filter capacitor C31 (33 nF) is connected between the other end of the resistor R3 (100K) and the ADC1 positive electrode input interface of the metering chip, and the other end of the filter capacitor C31 is grounded; the ADC1 negative electrode input interface of the metering chip is grounded through a resistor R5 (2.49K), one end of a capacitor 32 (33 nF) is connected between the resistor R5 (2.49K) and the ADC1 negative electrode input interface of the metering chip, and the other end of the capacitor is grounded. A current sampling unit is connected between the negative electrode output of the second photovoltaic module and the MOS switch (N2), and the current sampling unit is in communication connection with the logic control unit and controls the current sampling of the logic control unit; the negative electrode output of the photovoltaic module is connected with a resistor R41 (1.2K) and is connected to an ADC2 negative electrode input interface of the metering chip through the resistor R41 (1.2K), one end of a capacitor C41 (33 nF) is connected between the resistor R41 (1.2K) and the ADC2 negative electrode input interface of the metering chip, and the other end of the capacitor C41 is grounded; the positive input interface of the metering chip ADC2 is connected with a resistor R42 and is grounded through the R42, one end of a capacitor 42 (33 nF) is connected between the resistor R42 (1.2K) and the positive input interface of the metering chip ADC2, and the other end of the capacitor is grounded.

Working principle: the external environment is irradiated by strong enough light, and after the light can be converted into electric energy to a certain extent, the power supply unit converts the electric energy into working voltage (3.3V) capable of driving the logic control unit to work; the logic control unit independently controls MOS switches (N1 and N2) on the negative output lines of the photovoltaic module 1 and the photovoltaic module 2 through two GPIO signals.

The control method for the first photovoltaic module comprises the following steps:

when the power-on initial state is reached, the GPIO of the processor (logic control unit) is in a high-resistance state, at the moment, the MOS switch Q1-1 is in a cut-off state because the G electrode is provided with a pull-down resistor R1-1 and the S electrode is grounded, so that the G electrode and the S electrode are both in a low level and cannot reach the conduction condition (Vg-Vs is more than 2V) of the MOS switch; the D pole of the MOS switch Q1-1 is connected to 10V external voltage through a pull-up resistor R1-4, the D pole level of the MOS switch Q1-1 is 10V, the D pole is connected to the G pole of the MOS switch Q1-2 through a resistor R1-2, the G pole of the MOS switch Q1-2 is 10V with high level, the S pole is directly connected, at the moment, vg-Vs & gt2V is satisfied, the MOS switch Q1-2 is conducted, the D pole level is consistent with the S pole level and is low level (ground); the G pole of the MOS switch (N1) is connected to the D pole of the MOS switch Q1-2, and at this time, the G pole of the MOS switch N1 is also at a low level (ground), while the S pole thereof is the negative pole (also ground) of the link assembly 1, so that Vg and Vs have no level difference, and the MOS switch N1 is in an off state (off state).

When the logic control unit has enough driving voltage to output high level to the GPIO_0, the G pole level of the MOS switch Q1-1 becomes high, the voltage difference is generated between Vg and Vs, and at the moment, the MOS switch Q1-1 is conducted, and the D pole level is consistent with the S pole level (is ground); the G pole of the MOS switch Q1-2 is connected with the D pole of the MOS switch Q1-1, so the G pole of the MOS switch Q1-2 is also in a low level (ground), and the MOS switch Q1-2 is in an off state; when the MOS switch Q1-2 is turned off, the D pole is connected to 10V external voltage through the pull-up resistor R1-5 (10K), so that the D pole of the MOS switch Q1-2 is extremely high-level (10V), the G pole of the MOS switch N1 is also high-level, the Vg and Vs of the MOS switch N1 generate pressure difference, the MOS switch N1 is turned on, and the first photovoltaic module outputs power to supply power for the rear-end system components.

The control method of the second photovoltaic module is similar to the control method of the first photovoltaic module, and is controlled by the high level or the low level output by the GPIO interface of the logic control unit. The two paths of photovoltaic modules can be connected simultaneously or singly. When two paths of components are connected at the same time and the MOS switches N1/N2 are all on, the output voltage of the components through the quick shutoff device is the superposition of the input voltages of the two paths of photovoltaic components; when one of the photovoltaic modules needs to be turned off, for example, the MOS switch N2 is turned off, at this time, the electric energy of the first photovoltaic module can still be transmitted through the MOS switch N1, the second photovoltaic module can not transmit the electric energy due to the turn-off of the MOS switch N2, but because the bypass diode D2 and the capacitor C4 are arranged at the rear end of the MOS switch N2, the electric energy of the first photovoltaic module can be coupled to the output OUT-through the D2 and the C4, so that the electric energy of the first photovoltaic module can still be output; similarly, when the MOS switch N1 is turned off, the electric energy of the second photovoltaic module is coupled to out+ through the bypass diode D1 and the capacitor C2 at the rear end of the MOS switch N1, so that the electric energy of the second photovoltaic module can be output to the rear end. When the broadcast and television conversion capability of the first photovoltaic module and the broadcast and television conversion capability of the second photovoltaic module are different, the voltage superposition output of the first photovoltaic module and the second photovoltaic module is not affected when the output voltages are inconsistent; if the input currents are inconsistent and the difference is large, the back-end grid-connected inverter can carry out power adjustment on the whole string, so that the string currents tend to be consistent.

In summary, by outputting the high level or the low level through the GPIO interface of the logic control unit, the independent control of the first photovoltaic module and the second photovoltaic module can be realized, and the electric energy of the first photovoltaic module and the electric energy of the second photovoltaic module are output to the later-stage module in the photovoltaic system in an independent or overlapped mode. The GPIO interface of the logic control unit outputs a high level or a low level which is determined based on the overall operation condition of the photovoltaic system, when the photovoltaic system detects that the operation of a certain photovoltaic module is abnormal, the remote control unit such as an upper computer sends an instruction for turning off the abnormal photovoltaic module to the logic control unit, and the logic control unit outputs the low level to the corresponding GPIO interface according to the specific instruction, so that the corresponding MOS switch for controlling the power output of the photovoltaic module is turned off through the twice inversion of the fast switch unit. When the quick shutoff device is required to be started, the power of the photovoltaic module is output to the rear-stage module, and the corresponding GPIO interface of the logic control unit is output to a high level.

In addition, the voltage threshold set in the chip built in the logic control unit can be 8-80V, and the current threshold is 0-20A. And the logic control unit periodically transmits heartbeat signals to the voltage monitoring unit and the current monitoring unit, and performs data interaction with the monitoring units. When the voltage detected by the voltage monitoring unit in the quick shutoff device is lower than 8V or higher than 80V, the logic control unit can judge according to logic of the logic control unit, a shutoff instruction is not required to be issued through the platform, a system can be quickly turned off, and power is not supplied to the rear end; similarly, when the current detected by the current monitoring unit in the quick shutoff device is higher than 20A, the processor judges according to logic of the processor, and the processor does not issue a shutoff instruction through the platform, but can quickly shut down the system by itself, and does not supply power to the rear end.

Referring to fig. 8, another embodiment of the present invention provides a photovoltaic power generation system including the above-mentioned fast shutoff device with monitoring function supporting two-way input of photovoltaic modules, where the photovoltaic system is a distributed photovoltaic system, and includes n photovoltaic modules and n/2 fast shutoff devices (i.e. MRSD), and four input ports of the fast shutoff devices are respectively connected with the positive output and the negative output of the two photovoltaic modules; at least one of the output ports of the quick turnoff device is connected in series with the output ports of other quick turnoff devices to form a photovoltaic group string; n photovoltaic groups are connected in series-parallel to form a photovoltaic array; and the photovoltaic array and the rear-stage photovoltaic module are connected to form the photovoltaic power generation system. The embodiment further includes an inverter, an upper computer, a communication system and other components well known to those skilled in the art, which are included in a general distributed photovoltaic system, and the related known components and related connection modes are not particularly limited in the present invention, and may be adopted in a conventional manner.

The foregoing is merely exemplary embodiments of the present disclosure and is not intended to limit the scope of the present disclosure. That is, equivalent changes and modifications are contemplated by the teachings of this disclosure, which fall within the scope of the present disclosure. Embodiments of the present disclosure will be readily apparent to those skilled in the art from consideration of the specification and practice of the disclosure herein. This application is intended to cover any adaptations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a scope and spirit of the disclosure being indicated by the claims.

Claims (7)

1. A quick shutoff device supporting two-way photovoltaic module input with a monitoring function, which is characterized by comprising:

the four input ports and the two output ports are respectively connected with the positive electrode output and the negative electrode output of the first photovoltaic module and the second photovoltaic module; the switching unit at least comprises 2 groups of MOS switches which are respectively arranged on the negative electrode lines of the first photovoltaic module and the second photovoltaic module, wherein the negative electrode of the first photovoltaic module is connected with the positive electrode of the second photovoltaic module through 1 group of MOS switches; the logic control unit is used for controlling the on and off of the switch unit; the power supply unit converts high-voltage input of a single photovoltaic module into low-voltage output and supplies power to the logic control unit and the fast switch unit respectively; bypass diodes and capacitors are respectively arranged between the positive output and the negative output of the first photovoltaic module and the second photovoltaic module;

the logic control unit controls the on and off of the switching unit through the quick switching unit; the fast switching unit comprises a MOS switch Q1-1 and a MOS switch Q1-2, wherein the S electrode of the MOS switch Q1-1 is grounded and is connected with the GPIO_0 interface of the logic control unit through the G electrode, meanwhile, one end of a pull-down resistor R1-1 is connected between the G electrode of the MOS switch Q1-1 and the GPIO_0 interface, and the other end of the pull-down resistor R1-1 is grounded through the S electrode of the MOS switch Q1-1; the D pole of the MOS switch Q1-1 is connected to an external input power supply through a pull-up resistor R1-4, meanwhile, the D pole of the MOS switch Q1-1 is connected to the G pole of the MOS switch Q1-2 through a resistor R1-2, a pull-down resistor R1-3 is connected to a connecting line of the resistor R1-2 and the G pole of the MOS switch Q1-2, and the other end of the pull-down resistor is grounded through the S pole of the MOS switch Q1-2; the D pole of the MOS switch Q1-2 is connected to the G pole of the MOS switch (N1), a resistor R1-5 is arranged between the G pole of the MOS switch (N1) and the external input power supply, one end of a pull-up resistor R1-6 is connected on a G pole connecting line of the resistor R1-5 and the MOS switch (N1), and the other end of the pull-up resistor R1-6 is connected to the negative input of the first photovoltaic module;

The photovoltaic module further comprises voltage sampling units respectively arranged between the positive output end and the negative output end of the photovoltaic module; the voltage sampling unit is in communication connection with the logic control unit; the voltage sampling unit comprises an anode voltage dividing resistor circuit and a cathode voltage dividing resistor circuit, the anode voltage dividing resistor circuit comprises a pull-up resistor R11 and a pull-down resistor R4, one end of the pull-up resistor R11 is connected with the anode output of the photovoltaic module, and the other end of the pull-up resistor R11 is connected with an anode functional pin of the metering chip ADC 1; one end of the pull-down resistor R4 is connected with one end of the pull-up resistor R11 and then connected with the positive electrode functional pin of the metering chip ADC1, the other end of the pull-down resistor R4 is grounded, the negative electrode voltage dividing resistor circuit comprises a resistor R5, one end of the negative electrode voltage dividing resistor circuit is grounded, and the other end of the negative electrode voltage dividing resistor circuit is connected with the negative electrode functional pin of the metering chip ADC 1.

2. The quick shutoff device supporting two-way photovoltaic module input with the monitoring function according to claim 1, wherein the voltage sampling unit samples the output voltage of the photovoltaic module after receiving the sampling instruction of the logic control unit.

3. The quick shutoff device supporting two-way photovoltaic module input and having a monitoring function according to any one of claims 1-2, wherein an inductor is arranged on a negative electrode line of the second photovoltaic module, and one end of the inductor is connected with a negative electrode output of the second photovoltaic module through a group of MOS switches.

4. The quick shutoff device supporting two-way photovoltaic module input with a monitoring function according to claim 3, wherein the logic control unit is in communication connection with the inductance carrier; further, the logic control unit receives a carrier signal between the positive electrode and the negative electrode of the inductance differential circuit.

5. The quick shutoff device supporting two-way photovoltaic module input with the monitoring function according to claim 1, wherein a current sampling unit is arranged on a negative output line of the second photovoltaic module, and the current sampling unit is in communication connection with the logic control unit; further, the current sampling unit samples the current flowing through the second photovoltaic module after receiving the sampling instruction of the logic control unit.

6. The quick shutoff device supporting two-way photovoltaic module input with the monitoring function according to claim 1, wherein the anode of the bypass diode is connected with the first photovoltaic module or the second photovoltaic module through a group of MOS switches, and the cathode of the bypass diode is connected with the anode output of the first photovoltaic module or the second photovoltaic module.

7. A photovoltaic power generation system, characterized in that it comprises the rapid shutoff device supporting two-way photovoltaic module input with monitoring function according to any one of claims 1-6, and further comprises a plurality of photovoltaic modules; four input ports of the quick shutoff device are respectively connected with the positive electrode output and the negative electrode output of the two photovoltaic modules; at least one of the output ports of the quick turnoff device is connected in series with the output ports of other quick turnoff devices to form a photovoltaic group string; a plurality of photovoltaic groups are connected in series-parallel to form a photovoltaic array; and the photovoltaic array and the rear-stage photovoltaic module are connected to form the photovoltaic power generation system.

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