阅读说明：本技术 光伏发电系统以及电子设备 (Photovoltaic power generation system and electronic device ) 是由 孟令孔 王浩 刘荣 石孙节 付世强 于 2021-09-15 设计创作，主要内容包括：本发明提供了一种光伏发电系统以及电子设备,其中的系统包括,一个或多个光伏模块、光伏逆变模块,光伏模块的两端连接光伏逆变模块,或多个光伏模块并联后的两端连接光伏逆变模块；光伏模块包括串联的n个第一光伏单元和i个第二光伏单元,第一光伏单元包括第一光伏组件、关断装置,第一光伏组件的第一端和第二端连接关断装置,关断装置连接对应的上一个光伏单元和对应的下一个光伏单元；第二光伏单元包括第二光伏组件,第二光伏组件的第一端连接上一个光伏单元,第二光伏组件的第二端连接下一个光伏单元,i个第二光伏单元的开路电压之和匹配于光伏逆变模块的电压阈值。本发明可以实现系统搭配的灵活性,提高光伏逆变模块的利用率。(The invention provides a photovoltaic power generation system and electronic equipment, wherein the system comprises one or more photovoltaic modules and photovoltaic inversion modules, wherein two ends of each photovoltaic module are connected with the photovoltaic inversion modules, or two ends of each photovoltaic module after being connected in parallel are connected with the photovoltaic inversion modules; the photovoltaic module comprises n first photovoltaic units and i second photovoltaic units which are connected in series, each first photovoltaic unit comprises a first photovoltaic assembly and a turn-off device, the first end and the second end of each first photovoltaic assembly are connected with the turn-off devices, and the turn-off devices are connected with the corresponding last photovoltaic unit and the corresponding next photovoltaic unit; the second photovoltaic unit comprises a second photovoltaic assembly, the first end of the second photovoltaic assembly is connected with the previous photovoltaic unit, the second end of the second photovoltaic assembly is connected with the next photovoltaic unit, and the sum of the open-circuit voltages of the i second photovoltaic units is matched with the voltage threshold of the photovoltaic inverter module. The invention can realize the flexibility of system collocation and improve the utilization rate of the photovoltaic inverter module.)

1. A photovoltaic power generation system is characterized by comprising one or more photovoltaic modules and photovoltaic inversion modules, wherein two ends of each photovoltaic module are connected with the photovoltaic inversion modules, or two ends of each photovoltaic module after being connected in parallel are connected with the photovoltaic inversion modules;

the photovoltaic module comprises n first photovoltaic units and i second photovoltaic units which are connected in series, the first photovoltaic unit comprises a first photovoltaic assembly and a turn-off device, and the first end and the second end of the first photovoltaic assembly are connected with the turn-off device;

the turn-off device is connected with the corresponding last photovoltaic unit and the corresponding next photovoltaic unit, or the turn-off device is connected with the photovoltaic inversion module and the corresponding next photovoltaic unit, wherein n is more than or equal to 1, and i is more than or equal to 1;

the second photovoltaic unit comprises a second photovoltaic assembly, the first end of the second photovoltaic assembly is connected with the previous photovoltaic unit, the second end of the second photovoltaic assembly is connected with the next photovoltaic unit, or the second end of the second photovoltaic assembly is connected with the photovoltaic inverter module;

the sum of the open-circuit voltages of the i second photovoltaic units is matched with the voltage threshold of the photovoltaic inverter module;

the photovoltaic inverter module is configured to: when the photovoltaic inversion module starts to work, determining a control signal according to the voltage at two ends of the photovoltaic module, and sending the control signal to the turn-off device;

the turn-off device is used for: and receiving the control signal, and controlling the on-off state of the turn-off device according to the control signal so as to increase or decrease the voltage at two ends of the photovoltaic module.

2. The photovoltaic power generation system according to claim 1, wherein the turn-off device is configured to control the turn-off device to turn on or off according to the control signal, so that when the voltage across the photovoltaic module increases or decreases, the turn-off device is specifically configured to:

when the control signal received by the turn-off device forms a turn-on signal corresponding to the turn-off device, the turn-off device is turned on to enable the voltage at two ends of the photovoltaic module to be increased;

when the turn-off device does not receive the turn-on signal corresponding to the turn-off device within the target time period, the turn-off device is turned off, so that the voltage at two ends of the photovoltaic module is reduced.

3. The photovoltaic power generation system of claim 1, wherein the control signal comprises a coded sequence including at least one set of designated characters, and the number of designated characters corresponding to the turn-on signals of different turn-off devices is different.

4. The photovoltaic power generation system according to claim 3, wherein the photovoltaic inverter module is configured to, when determining the control signal according to the voltage across the photovoltaic module, specifically:

when the voltage difference value between the voltage threshold value and the voltage at two ends of the photovoltaic module is smaller than a first threshold value, reducing the number of the designated characters in the code sequence by 1 group;

when the voltage difference value is larger than a second threshold value, increasing the number of the specified characters in the code sequence by 1 group;

when the voltage difference is greater than the first threshold and less than the second threshold, the number of designated characters in the code sequence is unchanged.

5. The photovoltaic power generation system of claim 1, wherein the turn-off device comprises a switch, a microcontroller, a signal receiving circuit, a bypass diode; the photovoltaic inversion module comprises a photovoltaic inverter and a signal sending unit;

the first end of the photovoltaic inverter is connected with the first end of the photovoltaic module, the second end of the photovoltaic inverter is connected with the second end of the photovoltaic module, and the photovoltaic inverter is used for: receiving voltages at two ends of the photovoltaic module, and generating the control signal according to the voltages at the two ends of the photovoltaic module;

the signal transmitting unit is connected with the photovoltaic inverter and is used for: sending the received control signal to the signal receiving circuit;

the signal receiving circuit is connected with the microcontroller, and is used for: receiving the control signal, filtering and amplifying the control signal, and feeding the control signal back to the microcontroller,

the switch is connected in series with the first end of the first photovoltaic module, the control end of the switch is connected with the microcontroller, and the microcontroller is used for:

controlling the switch to be switched on or off according to the received control signal;

the negative pole of the bypass diode is connected with the second pole of the switch, and the positive pole of the bypass diode is connected with the second end of the first photovoltaic assembly.

6. The photovoltaic power generation system according to claim 5, wherein the signal receiving circuit comprises a first signal transformer, a PLC signal receiving sub-circuit, and the signal transmitting unit comprises a second signal transformer, a signal transmitting sub-unit, and an inverting capacitor;

the signal transmitting subunit is connected to the photovoltaic inverter, the signal transmitting subunit is connected to the first side of the second signal transformer, and the signal transmitting subunit is configured to: receiving the control signal and feeding the control signal back to the second signal transformer;

a first end of a second side of the second signal transformer is connected to a first end of the photovoltaic module through the inverter capacitor, and a second end of the second side of the second signal transformer is connected to a second end of the photovoltaic module; the second signal transformer is configured to: coupling the control signal to a power line and feeding back to the photovoltaic module through the power line;

the first end of the first side of the first signal transformer is connected with the second end of the first photovoltaic assembly, and the second end of the first side of the first signal transformer is connected with the corresponding photovoltaic unit; the second side of the first signal transformer is connected with the PLC signal receiving sub-circuit; the first signal transformer is configured to: decoupling the control signal from the power line and feeding the control signal back to the PLC signal receiving sub-circuit;

the PLC signal receiving sub-circuit is connected with the microcontroller, and is used for: feeding back the received control signal to the microcontroller.

7. The photovoltaic power generation system according to claim 5, wherein the signal transmitting unit and the signal receiving circuit realize transmission and reception of signals in a wireless communication manner.

8. The photovoltaic power generation system of claim 7, wherein the wireless communication means comprises any one of:

bluetooth communication, wifi communication, radio frequency communication.

9. The photovoltaic power generation system of claim 5, wherein the turn-off device further comprises a bypass capacitor, one end of the bypass capacitor is connected to the second pole of the switch, and the other end of the bypass capacitor is connected to the second end of the first photovoltaic module.

10. An electronic device characterized by comprising the photovoltaic power generation system according to any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of photovoltaic power generation, in particular to a photovoltaic power generation system and electronic equipment.

Background

The photovoltaic power generation is a technology for directly converting light energy into electric energy by utilizing a photovoltaic effect of a semiconductor interface, mainly comprises a photovoltaic module and a photovoltaic inverter, and solar battery units are connected in series and then are packaged and protected to form the large-area photovoltaic module. The photovoltaic inverter can control the power supply of a power grid through the implementation of the photovoltaic assembly.

The main control principle of the pv inverter is Maximum Power Point Tracking (MPPT), even if the module operates at the voltage Vmp point, that is, the module operates at the Maximum power point, when the system is configured, the open-circuit voltage Voc (as shown in fig. 2, for example) of the module must be considered, and the sum of the open-circuit voltages Voc of m modules in the string cannot exceed the Maximum voltage threshold of the pv inverter, that is, mwoc < Vinv, which limits the flexibility of configuration of the pv system.

Disclosure of Invention

The invention provides a photovoltaic power generation system and electronic equipment, and aims to solve the problems of inflexible system collocation and low photovoltaic inverter utilization rate.

According to a first aspect of the present invention, a photovoltaic power generation system is provided, which includes one or more photovoltaic modules and a photovoltaic inverter module, wherein two ends of the photovoltaic modules are connected to the photovoltaic inverter module, or two ends of the photovoltaic modules after being connected in parallel are connected to the photovoltaic inverter module;

the photovoltaic module comprises n first photovoltaic units and i second photovoltaic units which are connected in series, the first photovoltaic unit comprises a first photovoltaic assembly and a turn-off device, the first end and the second end of the first photovoltaic assembly are connected with the turn-off device,

the turn-off device is connected with the corresponding last photovoltaic unit and the corresponding next photovoltaic unit, or the turn-off device is connected with the photovoltaic inversion module and the corresponding next photovoltaic unit, wherein n is more than or equal to 1, and i is more than or equal to 1;

the second photovoltaic unit comprises a second photovoltaic assembly, the first end of the second photovoltaic assembly is connected with the previous photovoltaic unit, the second end of the second photovoltaic assembly is connected with the next photovoltaic unit, or the second end of the second photovoltaic assembly is connected with the photovoltaic inverter module;

the sum of the open-circuit voltages of the i second photovoltaic units is matched with the voltage threshold of the photovoltaic inverter module;

the photovoltaic inverter module is configured to: when the photovoltaic inversion module starts to work, determining a control signal according to the voltage at two ends of the photovoltaic module, and sending the control signal to the turn-off device;

the turn-off device is used for: and receiving the control signal, and controlling the on-off state of the turn-off device according to the control signal so as to increase or decrease the voltage at two ends of the photovoltaic module.

Optionally, the turn-off device is configured to control the turn-off device to turn on or off according to the control signal, so that when the voltage across the photovoltaic module increases or decreases, the turn-off device is specifically configured to:

when the control signal received by the turn-off device forms a turn-on signal corresponding to the turn-off device, the turn-off device is turned on to enable the voltage at two ends of the photovoltaic module to be increased;

when the turn-off device does not receive the turn-on signal corresponding to the turn-off device within the target time period, the turn-off device is turned off, so that the voltage at two ends of the photovoltaic module is reduced.

Optionally, the control signal includes a code sequence, the code sequence includes at least one group of designated characters, and the number of the designated characters corresponding to the on signals of different turn-off devices is different.

Optionally, when the photovoltaic inverter module is configured to determine the control signal according to the voltage at the two ends of the photovoltaic module, the photovoltaic inverter module is specifically configured to:

when the voltage difference value between the voltage threshold value and the voltage at two ends of the photovoltaic module is smaller than a first threshold value, reducing the number of the designated characters in the code sequence by 1 group;

when the voltage difference value is larger than a second threshold value, increasing the number of the specified characters in the code sequence by 1 group;

when the voltage difference is greater than the first threshold and less than the second threshold, the number of designated characters in the code sequence is unchanged.

Optionally, the turn-off device includes a switch, a microcontroller, a signal receiving circuit, and a bypass diode; the photovoltaic inversion module comprises a photovoltaic inverter and a signal sending unit;

the first end of the photovoltaic inverter is connected with the first end of the photovoltaic module, the second end of the photovoltaic inverter is connected with the second end of the photovoltaic module, and the photovoltaic inverter is used for: receiving voltages at two ends of the photovoltaic module, and generating the control signal according to the voltages at the two ends of the photovoltaic module;

the signal transmitting unit is connected with the photovoltaic inverter and is used for: sending the received control signal to the signal receiving circuit;

the signal receiving circuit is connected with the microcontroller, and is used for: receiving the control signal, filtering and amplifying the control signal, and feeding the control signal back to the microcontroller,

the switch is connected in series with the first end of the first photovoltaic module, the control end of the switch is connected with the microcontroller, and the microcontroller is used for:

controlling the switch to be switched on or off according to the received control signal;

the negative pole of the bypass diode is connected with the second pole of the switch, and the positive pole of the bypass diode is connected with the second end of the first photovoltaic assembly.

Optionally, the signal receiving circuit includes a first signal transformer and a PLC signal receiving sub-circuit, and the signal transmitting unit includes a second signal transformer, a signal transmitting sub-unit and an inverting capacitor;

the signal transmitting subunit is connected to the photovoltaic inverter, the signal transmitting subunit is connected to the first side of the second signal transformer, and the signal transmitting subunit is configured to: receiving the control signal and feeding the control signal back to the second signal transformer;

a first end of a second side of the second signal transformer is connected to a first end of the photovoltaic module through the inverter capacitor, and a second end of the second side of the second signal transformer is connected to a second end of the photovoltaic module; the second signal transformer is configured to: coupling the control signal to a power line and feeding back to the photovoltaic module through the power line;

the first end of the first side of the first signal transformer is connected with the second end of the first photovoltaic assembly, and the second end of the first side of the first signal transformer is connected with the corresponding photovoltaic unit; the second side of the first signal transformer is connected with the PLC signal receiving sub-circuit; the first signal transformer is configured to: decoupling the control signal from the power line and feeding the control signal back to the PLC signal receiving sub-circuit;

the PLC signal receiving sub-circuit is connected with the microcontroller, and is used for: feeding back the received control signal to the microcontroller.

Optionally, the signal sending unit and the signal receiving circuit implement sending and receiving of signals in a wireless communication manner.

Optionally, the wireless communication mode includes any one of:

bluetooth communication, wifi communication, radio frequency communication.

Optionally, the turn-off device further includes a bypass capacitor, one end of the bypass capacitor is connected to the second pole of the switch, and the other end of the bypass capacitor is connected to the second end of the first photovoltaic module.

According to a second aspect of the present invention, there is provided an electronic device comprising the photovoltaic power generation system according to the first aspect of the present invention and its optional aspects.

According to the photovoltaic power generation system and the electronic equipment, the voltage at two ends of the photovoltaic module is detected to control the on or off of the turn-off device in the photovoltaic module, compared with the situation that the number of the photovoltaic modules in the photovoltaic power generation system is designed according to the open-circuit voltage of the photovoltaic modules in part of schemes, the number of the photovoltaic modules connected into the photovoltaic power generation system can be increased or reduced according to the real-time voltage of the photovoltaic modules, the flexible collocation of the system is realized, meanwhile, part of the modules are connected with the system through the turn-off device, and the increase or reduction of the modules is facilitated;

in addition, the invention can also realize that more components are connected into the photovoltaic power generation system, and can improve the utilization rate of the photovoltaic inverter module.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a first schematic structural diagram of a photovoltaic power generation system according to an embodiment of the present invention;

FIG. 2 is a P-V plot of a photovoltaic module according to an embodiment of the present invention;

FIG. 3 is a flow chart illustrating the determination of a control signal according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a photovoltaic power generation system according to an embodiment of the present invention;

FIG. 5 is a first schematic circuit diagram of a turn-off device according to an embodiment of the present invention;

FIG. 6 is a second schematic circuit diagram of a turn-off device according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a photovoltaic power generation system according to an embodiment of the invention.

Reference numerals:

1-a photovoltaic module;

2-a photovoltaic inverter module;

11-a first photovoltaic unit;

12-a second photovoltaic unit;

111-a first photovoltaic module;

112-turn-off means;

1121-microcontroller;

1122-signal receiving circuit;

11221-a PLC signal receiving sub-circuit;

121-a second photovoltaic module;

21-a photovoltaic inverter;

22-a signal transmitting unit;

221-a signal transmitting subcircuit;

a Q-switch;

a D-bypass diode;

c1 — bypass capacitance;

c2-inverter capacitance;

t1 — first signal transformer;

t2-second signal transformer.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The technical solution of the present invention will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

Referring to fig. 1, an embodiment of the present invention provides a photovoltaic power generation system, including one or more photovoltaic modules 1 and a photovoltaic inverter module 2, where two ends of the photovoltaic module 1 are connected to the photovoltaic inverter module 2, or two ends of the photovoltaic modules 1 after being connected in parallel are connected to the photovoltaic inverter module 2;

the photovoltaic module 1 comprises n first photovoltaic units 11 and i second photovoltaic units 12 connected in series, the first photovoltaic unit 11 comprises a first photovoltaic component 111 and a turn-off device 112, a first end and a second end of the first photovoltaic component 111 are connected with the turn-off device 112,

the turn-off device 112 is connected with the corresponding last photovoltaic unit and the corresponding next photovoltaic unit, or the turn-off device 112 is connected with the photovoltaic inverter module 2 and the corresponding next photovoltaic unit, wherein n is greater than or equal to 1, and i is greater than or equal to 1;

the second photovoltaic unit 12 includes a second photovoltaic module 121, a first end of the second photovoltaic module 121 is connected to a previous photovoltaic unit, a second end of the second photovoltaic module 121 is connected to a next photovoltaic unit, or a second end of the second photovoltaic module is connected to the photovoltaic inverter module 2;

the number of the photovoltaic cells connected in series in the first photovoltaic module 111 and the second photovoltaic module 121 may be the same or different;

the sum of the open circuit voltages of the i second photovoltaic units 12 matches the voltage threshold of the photovoltaic inverter module 2;

the photovoltaic inverter module 2 is configured to: when the photovoltaic inverter module 2 starts to work, determining a control signal according to the voltage at two ends of the photovoltaic module 1, and sending the control signal to the turn-off device 112;

in a further example, the photovoltaic inverter module is further configured to control a photovoltaic module of the photovoltaic module to be at a maximum power point, and direct current electric energy generated by the photovoltaic module in the photovoltaic module is converted into fixed-frequency fixed-voltage or frequency-modulation voltage-regulation alternating current;

the turn-off device 112 is configured to: receiving the control signal, and controlling the on-off state of the turn-off device 112 according to the control signal, so as to increase or decrease the voltage at the two ends of the photovoltaic module 1, which can be understood as above, when the turn-off device is turned on, the first photovoltaic module corresponding to the turn-off device will be connected into the photovoltaic power generation system, and further, the number of the photovoltaic modules providing the voltage in the photovoltaic module increases, and the voltage at the two ends of the photovoltaic module will increase;

the initial states of the n turn-off devices are all turn-off states, and after the photovoltaic inverter module starts to work, the turn-off devices can be turned on or turned off according to received control signals.

The working principle and the positive effects in an embodiment of the present invention are described below with reference to fig. 2:

the change curve of the voltage and the current at two ends of the photovoltaic module can be seen from the graph, the photovoltaic module is not connected with a load, for example, when the photovoltaic inverter module does not work, the voltage generated by the photovoltaic module is not consumed by the load, the voltage is the highest, and the voltage is the open-circuit voltage V of the photovoltaic module at the moment_ocWhen the photovoltaic module is connected to a load, for example, the photovoltaic inverter module starts to work, the voltage at the two ends of the photovoltaic module will slowly decrease, then the photovoltaic inverter module will control the photovoltaic module to work at the maximum power point, and the voltage at the two ends of the photovoltaic module is V_mpAt the moment, the voltage at the two ends of the photovoltaic module is far smaller than the voltage threshold value of the photovoltaic inversion module, and the photovoltaic inversion module can generate corresponding control signals according to the voltage at the two ends of the photovoltaic module to control at least one turn-off device of the n turn-off devices to be turned on so as to improve the photovoltaic efficiencyThe voltage at the two ends of the module improves the utilization rate of the photovoltaic inversion module;

in addition, in the working process of the photovoltaic power generation system, when voltages at two ends of the photovoltaic module are changed due to sudden situations or other reasons, the photovoltaic inversion module can control part of the n turn-off devices to be turned on or off according to the detected voltages at the two ends of the photovoltaic module, so that the voltages at the two ends of the photovoltaic module are changed, the flexible control over the photovoltaic modules connected into the system is realized, the number of the photovoltaic modules connected into the system is controlled through the photovoltaic inversion module, and the photovoltaic inversion module is more flexible and convenient compared with manual adjustment;

compared with the method that the number of the photovoltaic modules in the photovoltaic power generation system is designed according to the open-circuit voltage of the photovoltaic modules in part of schemes, the method can increase or reduce the number of the photovoltaic modules connected into the photovoltaic power generation system according to the voltages at two ends of the photovoltaic modules, so that the flexible collocation of the system is realized, and meanwhile, part of the modules such as the second photovoltaic module are connected with the system through the turn-off device, so that the increase or reduction of the modules is facilitated;

in addition, the invention can also realize that more components are connected into the photovoltaic power generation system, and can improve the utilization rate of the photovoltaic inverter module.

In one embodiment, the turn-off device 112 is configured to control the turn-off device 112 to turn on or off according to the control signal, so that when the voltage across the photovoltaic module 1 increases or decreases, specifically:

when the control signal received by the turn-off device 112 forms a turn-on signal corresponding to the turn-off device 112, the turn-off device 112 is turned on, so that the voltage across the photovoltaic module 1 is increased;

when the turn-off device 112 does not receive the turn-on signal corresponding to the turn-off device 112 in the target time period, the turn-off device 112 is turned off, so that the voltage across the photovoltaic module 1 is reduced.

For further example, when determining that the turn-on signal corresponding to the turn-off device 112 is not received in the target time period, the turn-off device 112 specifically includes: the turn-off device turns off the photovoltaic module through the timing function of the turn-off device, for example, when the turn-off device receives a corresponding turn-on signal, the timing of the turn-off device is cleared, when the timing is restarted, and when the value of the timing of the turn-off device is matched with the target duration, the turn-off device controls the turn-off device to enter a turn-off state, so that the corresponding first photovoltaic module is opened from the system, and the voltage at two ends of the photovoltaic module is reduced.

In one example, the turn-on signals of different turn-off devices are the same, and then n turn-off devices may correspond to n numbers, each number corresponds to a part of the control signal, which may be a turn-on signal or a turn-off signal, and the turn-off devices implement the control of turn-on or turn-off according to the part of the control signals corresponding to the numbers in the received control signals;

in another example, the on signals of different turn-off devices are the same, and the control signal may include an on signal of at least one turn-off device, and when the turn-off device determines that the control signal includes the on signal corresponding to the turn-off device, the turn-off device is turned on.

In the above embodiment, the same control signal includes the turn-on signals or the turn-off signals of different turn-off devices, and it is not necessary to send the control signals to the corresponding turn-off devices, so that flexible control over the second photovoltaic modules corresponding to the plurality of turn-off devices is facilitated, time and work efficiency are saved, and an algorithm is simplified.

In one embodiment, the control signal comprises a code sequence, the code sequence comprises at least one group of designated characters, and the number of designated characters corresponding to the on signals of different turn-off devices is different.

Table 1:

numbering	Coding sequence	Opening ofShutoff device
			1	0x55000000000000000000	1 st one
2	0x55550000000000000000	1, 2 of
			3	0x55555500000000000000	Number 1, 2, 3
4	0x55555555000000000000	Number 1, 2, 3, 4
			5	0x55555555550000000000	Number 1, 2, 3, 4, 5
6	0x55555555555500000000	Number 1, 2, 3, 4, 5, 6
			7	0x55555555555555000000	1, 2, 3, 4, 5, 6, 7
8	0x55555555555555550000	1, 2, 3, 4, 5, 6, 7 and 8
			9	0x55555555555555555500	1, 2, 3, 4, 5, 6, 7, 8 and 9
10	0x55555555555555555555	1, 2, 3, 4, 5, 6, 7, 8, 9, 10

The control signals in one embodiment of the present invention are further illustrated below with reference to table 1:

assuming that the photovoltaic power generation system has 10 turn-off devices, each turn-off device is numbered from 1 to 10, one group of coding sequences is a control signal, the control signal has 10 bytes, the photovoltaic inversion module sends the control signal once per second, 00x55 is an on coding sequence (namely a designated character), the number of the continuous on coding sequences indicates the number of the turn-off devices needing to be turned on, the turn-off devices determine whether the turn-on is needed or not according to the number of the on codes in the received group of coding sequences and the number corresponding to the turn-off devices, for example, the turn-on device with the number of 1 receives 1 on coding sequence, the turn-on device with the number of 2 receives 2 continuous on coding sequences, the turn-off device with the number of 3 receives 3 continuous on coding sequences, and so on, the turn-off device with the number of m receives m continuous on coding sequences, therefore, the photovoltaic inversion module can flexibly control the voltages at the two ends of the photovoltaic module, if the voltages at the two ends of the photovoltaic module are close to the voltage threshold value of the photovoltaic inversion module, the number of the continuous on coding sequences is reduced, and if the voltages at the two ends of the photovoltaic module are far lower than the voltage threshold value of the photovoltaic inversion module, the continuous on coding sequences are gradually increased.

In one embodiment, the photovoltaic inverter module 2 is specifically configured to, when determining the control signal according to the voltage across the photovoltaic module:

when the voltage difference value between the voltage threshold value and the voltage at two ends of the photovoltaic module is smaller than a first threshold value, reducing the number of the designated characters in the code sequence by 1 group;

when the voltage difference value is larger than a second threshold value, increasing the number of the specified characters in the code sequence by 1 group;

when the voltage difference is greater than the first threshold and less than the second threshold, the number of designated characters in the code sequence is unchanged.

In an example, the first threshold may be an open-circuit voltage of one photovoltaic module, the second threshold is a sum of open-circuit voltages of 5 photovoltaic modules, or the second threshold is a sum of open-circuit voltages of 5 photovoltaic modules, and the like, and specifically, the first threshold and the second threshold may be set according to an actual application scenario and the open-circuit voltage of the photovoltaic module.

In one example, the control signal may be generated as shown in fig. 3, wherein Vinv represents a voltage threshold of the pv inverter module, Vstring represents a voltage across the pv module, V1 represents a first threshold, V2 represents a second threshold, and the number of consecutive on-coding sequences represents a number of groups of the designated characters, wherein, for the determination of the magnitude of the voltage difference value and the first threshold and the second threshold, the magnitude relationship between Vinv-Vstring and V2 may be compared, and then the magnitude relationship between Vinv-Vstring and V1 may be determined.

Referring to fig. 4 and fig. 5, in one embodiment, the turn-off device 112 includes a switch Q, a microcontroller 1121, a signal receiving circuit 1122, and a bypass diode D; the photovoltaic inversion module 2 comprises a photovoltaic inverter 21 and a signal sending unit 22;

the first end of the photovoltaic inverter 21 is connected to the first end of the photovoltaic module 1, the second end of the photovoltaic inverter 21 is connected to the second end of the photovoltaic module 2, and the photovoltaic inverter 21 is configured to: receiving voltages at two ends of the photovoltaic module, and generating the control signal according to the voltages at the two ends of the photovoltaic module;

the signal transmitting unit 22 is connected to the photovoltaic inverter 21, and the signal transmitting unit 22 is configured to: sending the received control signal to the signal receiving circuit 1122;

the signal receiving circuit 1122 is connected to the microcontroller 1121, and the signal receiving circuit 1122 is configured to: receiving the control signal, filtering and amplifying the control signal, and feeding the filtered control signal back to the microcontroller 1121,

the switch Q is connected in series to the first end of the first photovoltaic module 111, a control end of the switch Q is connected to the microcontroller 1121, and the microcontroller 1121 is configured to:

controlling the switch Q to be switched on or off according to the received control signal;

the cathode of the bypass diode D is connected to the second pole of the switch Q, and the anode of the bypass diode D is connected to the second end of the first photovoltaic module 1121;

OUT + and OUT-in fig. 5 may be understood as the outputs of the turn-off devices, connecting the corresponding last photovoltaic cell (e.g., the output of the last turn-off device) and the corresponding next photovoltaic cell (e.g., the output of the next turn-off device), or connecting the photovoltaic inverter module (e.g., the first terminal of the photovoltaic inverter 21) and the corresponding next photovoltaic cell.

In one embodiment, the turn-off device 112 further includes a bypass capacitor C1, one end of the bypass capacitor C1 is connected to the second pole of the switch Q, and the other end of the bypass capacitor C1 is connected to the second end of the first photovoltaic module 111.

Referring to fig. 6 and 7, in one embodiment, the signal receiving circuit 1122 includes a first signal transformer T1, a PLC signal receiving sub-circuit 11221, and the signal transmitting unit 22 includes a second signal transformer T2, a signal transmitting sub-unit 221, and an inverting capacitor C2;

the signal transmitting subunit 221 is connected to the photovoltaic inverter 21, the signal transmitting subunit 221 is connected to a first side of the second signal transformer T2, and the signal transmitting subunit 221 is configured to: receiving the control signal and feeding the control signal back to the second signal transformer T2;

a first terminal of a second side of the second signal transformer T2 is connected to a first terminal of the photovoltaic module 1 through the inverting capacitor C2, and a second terminal of a second side of the second signal transformer T2 is connected to a second terminal of the photovoltaic module 1; the second signal transformer T2 is configured to: coupling the control signal to a power line and feeding back to the photovoltaic module 1 through the power line;

a first end of a first side of the first signal transformer T1 is connected to a second end of the first photovoltaic module 111, and a second end of a first side of the first signal transformer T1 is connected to a corresponding photovoltaic cell; the second side of the first signal transformer T1 is connected with the PLC signal receiving sub-circuit 11221; the first signal transformer T1 is configured to: decoupling the control signal from the power line and feeding the control signal back to the PLC signal receiving sub-circuit 11221;

the PLC signal receiving sub-circuit 11221 is connected to the microcontroller 1121, and the PLC signal receiving sub-circuit 11221 is configured to: feeding back the received control signal to the microcontroller 1121.

In one example, the shutdown device further comprises a PLC signal transmitting circuit, wherein the PLC signal transmitting circuit is connected to the microcontroller to receive a shutdown signal sent by the microcontroller;

the PLC signal transmitting circuit is connected to both ends of the second side of the first signal transformer T1 to feed back the shutdown signal to the first signal transformer T1;

the first signal transformer T1 is also used to: the received shutdown signal is coupled to the power line and fed back to the second signal transformer T2 through the power line, and further fed back to the photovoltaic inverter 21, so that the photovoltaic inverter 21 can detect whether the corresponding shutdown device is turned on or off in real time, and the shutdown device can be accurately controlled.

In one embodiment, the signal transmitting unit 22 and the signal receiving circuit 1122 realize signal transmission and reception by wireless communication.

In a further example, the wireless communication means includes any one of:

bluetooth communication, wifi communication, radio frequency communication.

Further, the signal receiving circuit 1122 and the signal transmitting unit 22 include corresponding receiving and transmitting devices for radio signals, so as to realize wireless communication therebetween, and the receiving and transmitting devices may be designed according to a wireless communication manner.

An embodiment of the present invention further provides an electronic device, including the photovoltaic power generation system described above.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.