Optimizer, control method and photovoltaic system

Abstract

The present disclosure provides an optimizer, a control method, and a related apparatus. The optimizer comprises an optimizer main circuit and a protection circuit, wherein the protection circuit is connected in parallel to an output end of the optimizer main circuit; when an input end of the optimizer main circuit is in an open-circuit state, the protection circuit is in a closed-circuit state; and when the input end of the optimizer main circuit is in a closed-circuit state, the protection circuit is in an open-circuit state. In this way, when the input end of the optimizer is in an open-circuit state, the protection circuit connected in parallel to the output end of the optimizer main circuit is in a closed-circuit state, so that the output end of the optimizer main circuit is short-circuited, thereby reducing the possibility of energy backfeeding, and improving the safety of photovoltaic systems.

Description

Optimizer, control method and photovoltaic system

[0001] The present disclosure claims the priority of the Chinese patent publication No. 2024113534405, published on September 25, 2024, entitled "Optimizer, control method and photovoltaic system", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates to an optimizer, a control method and a photovoltaic system. BACKGROUND

[0003] Generally, in a photovoltaic system, one of the solutions to solve the mismatch of components is to use an optimizer. By connecting the optimizer and the string of photovoltaic modules in series, the optimizer adopts a predictive current and voltage technology to ensure that the photovoltaic module string is always in an optimal working state, solves the impact of the photovoltaic power station on power generation due to shadow shielding, inconsistent orientation or differences in electrical specifications of components, realizes the maximum power output of the components, and improves the power generation of the system.

[0004] However, in the actual use of the optimizer, the input end of the optimizer may be open due to problems such as loose input end interface of the optimizer, failure of the photovoltaic module string, aging, etc. When the input end of the optimizer is open, the energy at the output end may flow back to the optimizer, thereby causing damage to the optimizer, and further reducing the safety of the photovoltaic system. SUMMARY

[0005] Therefore, the present disclosure provides an optimizer, a control method and a photovoltaic system to improve the safety of the optimizer.

[0006] The present disclosure provides the following technical solutions:

[0007] In a first aspect, the present disclosure provides an optimizer, which comprises an optimizer main circuit and a protection circuit; wherein the protection circuit is connected in parallel with the output end of the optimizer main circuit;

[0008] When the input end of the optimizer main circuit is open, the protection circuit is a pass;

[0009] When the input end of the optimizer main circuit is a pass, the protection circuit is open.

[0010] In combination with the first aspect, in some implementations of the first aspect, the protection circuit comprises a driving circuit and a switching circuit; wherein the output end of the driving circuit is connected to the input end of the switching circuit;

[0011] The driving circuit is configured to drive the switch circuit to be open when the input end of the optimizer main circuit is in a pass-through state, and is configured to drive the switch circuit to be in a pass-through state when the input end of the optimizer main circuit is in an open circuit state.

[0012] With reference to the first aspect, in some implementations of the first aspect, the switch circuit is a short circuit.

[0013] When the input end of the optimizer main circuit is disconnected from the DC power supply of the driving circuit, the driving circuit does not output a driving signal, and the short circuit is in a pass-through state.

[0014] When the input end of the optimizer main circuit is connected to the DC power supply of the driving circuit, the driving circuit outputs a driving signal to drive the short circuit to be in an open state.

[0015] With reference to the first aspect, in some implementations of the first aspect, the protection circuit includes a driving circuit and a switch circuit; the optimizer further includes a controller; an output end of the controller is connected to an input end of the driving circuit, and an output end of the driving circuit is connected to an input end of the switch circuit.

[0016] When it is determined that the input end of the optimizer main circuit is in an open circuit state, the controller controls the driving circuit to send a first driving signal to the switch circuit; the first driving signal is configured to control the switch circuit to be in a pass-through state.

[0017] With reference to the first aspect, in some implementations of the first aspect, the controller is further configured to:

[0018] After sending the first driving signal, it is determined whether a voltage value of the input end of the optimizer main circuit is greater than a preset voltage value.

[0019] If the voltage value of the input end of the optimizer main circuit is greater than the preset voltage value, the controller controls the driving circuit to send a second driving signal to the switch circuit; the second driving signal is configured to control the switch circuit to be in a pass-through state.

[0020] With reference to the first aspect, in some implementations of the first aspect, the protection circuit includes a switch circuit; the optimizer further includes a controller; an auxiliary power supply of the controller is provided by the input end of the optimizer main circuit.

[0021] The controller is configured to determine whether a voltage of the input end of the optimizer main circuit is greater than a preset voltage, and is configured to control the switch circuit to be in a pass-through state when the voltage of the input end of the optimizer main circuit is greater than the preset voltage.

[0022] In some implementations of the first aspect, the protection circuit includes a driving circuit and a switch circuit, the switch circuit being an open circuit; the optimizer further includes a judging circuit; an output terminal of the judging circuit is connected to an input terminal of the driving circuit; an output terminal of the driving circuit is connected to an input terminal of the protection circuit.

[0023] When the voltage value of the output terminal of the optimizer main circuit is greater than the standard voltage value, the judging circuit outputs a first output signal to the driving circuit.

[0024] The driving circuit sends a third driving signal to the switch circuit based on the first output signal; the third driving signal is configured to drive the switch circuit to be a pass-through circuit.

[0025] In some implementations of the first aspect, the judging circuit includes a comparison circuit and a voltage acquisition circuit; a first input terminal of the comparison circuit is connected to a reference source, a second input terminal of the comparison circuit is connected to an output terminal of the voltage acquisition circuit; an output terminal of the comparison circuit is connected to an input terminal of the driving circuit; the reference source is configured to provide the standard voltage value to the comparison circuit.

[0026] The voltage acquisition circuit is configured to acquire an acquisition voltage value of the output terminal of the optimizer main circuit; and is configured to input the acquisition voltage value to the comparison circuit.

[0027] The comparison circuit is configured to output a first output signal or a second output signal to the driving circuit based on the standard voltage value and the acquisition voltage value; the first output signal is a high-level signal, and the second output signal is a low-level signal.

[0028] The driving circuit sends the third driving signal to the protection circuit based on the first output signal.

[0029] In some implementations of the first aspect, the protection circuit includes a driving circuit and a switch circuit; the driving circuit is connected to a first terminal of the switch circuit; a second terminal and a third terminal of the switch circuit are respectively connected to a positive electrode and a negative electrode of the output terminal.

[0030] The driving circuit is configured to drive the switch circuit to be an open circuit when the voltage of the input terminal of the optimizer main circuit is less than or equal to the preset voltage; and is further configured to drive the switch circuit to be a pass-through circuit when the voltage of the input terminal of the optimizer main circuit is greater than the preset voltage.

[0031] In some implementations of the first aspect, the switch circuit is a MOS tube or a thyristor.

[0032] In a second aspect, the present disclosure provides a photovoltaic system, comprising at least one inverter and at least one optimizer;

[0033] The output of the optimizer is connected to the input of the corresponding inverter; the input of the optimizer is connected to the output of the corresponding photovoltaic module; the optimizer is the optimizer as described in the first aspect; the inverter is configured to receive the direct current output by the corresponding optimizer and convert the direct current into alternating current to supply power to the load.

[0034] The optimizer provided by the present disclosure comprises an optimizer main circuit and a protection circuit; the protection circuit is connected in parallel to the output of the optimizer main circuit; when the input of the optimizer main circuit is open, the protection circuit is in a conducting state; when the input of the optimizer main circuit is in a conducting state, the protection circuit is in an open state. In this way, when the input of the optimizer is open, the protection circuit connected in parallel to the output of the optimizer main circuit is in a conducting state, so that the output of the optimizer main circuit is short-circuited, thereby improving the safety of the photovoltaic system.

[0035] BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the drawings used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0037] FIG. 1a is a schematic diagram of an open circuit of an optimizer;

[0038] FIG. 1b is a schematic diagram of an equivalent circuit of an optimizer provided by the present disclosure;

[0039] FIG. 2 is a schematic diagram of a first structure of an optimizer provided by the present disclosure;

[0040] FIG. 3 is a schematic diagram of a second structure of an optimizer provided by the present disclosure;

[0041] FIG. 4 is a schematic diagram of a third structure of an optimizer provided by the present disclosure;

[0042] FIG. 5 is a schematic diagram of a fourth structure of an optimizer provided by the present disclosure;

[0043] FIG. 6 is a schematic diagram of a fifth structure of an optimizer provided by the present disclosure;

[0044] FIG. 7 is a schematic diagram of a sixth structure of an optimizer provided by the present disclosure;

[0045] FIG. 8 is a seventh structure of an optimizer according to an embodiment of the present disclosure;

[0046] FIG. 9 is a first structure of a driving circuit according to an embodiment of the present disclosure;

[0047] FIG. 10 is a second structure of a driving circuit according to an embodiment of the present disclosure;

[0048] FIG. 11 is a third structure of a driving circuit according to an embodiment of the present disclosure;

[0049] FIG. 12 is a fourth structure of a driving circuit according to an embodiment of the present disclosure;

[0050] FIG. 13 is a fifth structure of a driving circuit according to an embodiment of the present disclosure;

[0051] FIG. 14 is a sixth structure of a driving circuit according to an embodiment of the present disclosure;

[0052] FIG. 15 is a flowchart of a control method of an optimizer according to an embodiment of the present disclosure;

[0053] FIG. 16 is a schematic diagram of a photovoltaic system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0054] As described above, in the research of the optimizer, it is found that in the photovoltaic system, one of the solutions to the component mismatch is to use an optimizer. By connecting the input end of the optimizer with the output end of the corresponding photovoltaic component, further connecting the output ends of the optimizers in series as the output end of the photovoltaic string, and adopting the predicted current and voltage technology to ensure that the photovoltaic component is always in the optimal working state, the influence of the photovoltaic power station on the power generation due to the shadow shielding, inconsistent orientation or component electrical specification difference is solved, the maximum power output of the photovoltaic string is realized, and the system power generation is improved.

[0055] Referring to FIG. 1a, which is a schematic diagram of an open circuit of an optimizer.

[0056] In the actual use of the optimizer, the input end of the optimizer may be open due to the loose input end interface of the optimizer, the failure of the photovoltaic string, aging and other problems. When the input end of the optimizer is open, the output end of the optimizer may be backflowed with energy due to the inverter voltage or the voltage circulation of another string in the parallel string, thereby causing damage to the optimizer, and further reducing the safety of the photovoltaic system.

[0057] In combination with FIG. 1a, for the convenience of understanding, the optimizer main circuit can be equivalent to the schematic diagrams shown in a of FIG. 1a and b of FIG. 1a. When the input end of the optimizer is open, that is, the input end of the optimizer main circuit is open, there is a possibility of energy mutual transmission between photovoltaic strings or between the inverter and the optimizer. When energy is continuously transmitted to the optimizer with the open input end, the optimizer main circuit can be damaged due to overvoltage, that is, the energy at the output end of the optimizer main circuit can flow back to the input end of the optimizer main circuit in the direction A shown in a of FIG. 1a or in the direction B shown in b of FIG. 1a.

[0058] In order to improve the safety of the optimizer, the present disclosure provides an optimizer, a control method and a photovoltaic system. The optimizer in the above embodiment comprises an optimizer main circuit and a protection circuit. The protection circuit is connected in parallel with the output end of the optimizer main circuit. When the input end of the optimizer main circuit is open, the protection circuit is in a conduction state. When the input end of the optimizer main circuit is in a conduction state, the protection circuit is in an open state.

[0059] In this way, when the input end of the optimizer is open, the protection circuit connected in parallel with the output end of the optimizer main circuit is in a conduction state, so that the output end of the optimizer main circuit is short-circuited. At this time, the energy at the output end of the optimizer main circuit cannot flow back to the optimizer main circuit from the output end, thereby improving the safety of the photovoltaic system.

[0060] In order to enable those skilled in the art to better understand the present disclosure, the technical solutions in the embodiments of the present disclosure will be described clearly and completely below with reference to the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, not all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present disclosure.

[0061] The optimizer is briefly introduced below. The optimizer is a power electronic device installed between the photovoltaic module and the inverter, configured to improve the efficiency and performance of the photovoltaic power generation system. In a possible implementation, the topology of the optimizer main circuit includes but is not limited to one or more of a Boost circuit, a Buck circuit, a Buck-Boost circuit, a high-frequency isolation inverter topology, a pseudo-direct-current bus interleaved flyback topology, etc.

[0062] The Boost circuit (boost chopper circuit or boost circuit) has the characteristics of high efficiency, easy control and low cost, but only has the function of boosting. Among them, the Boost circuit is often configured in the optimizer to boost the output voltage of the photovoltaic module, so that it is more suitable for the input requirements of the inverter.

[0063] Buck circuit (buck converter or buck chopper circuit) is opposite to Boost circuit, and has voltage reduction function. In some specific scenarios, such as when the output voltage of the photovoltaic module is too high, the Buck circuit can be used for voltage reduction.

[0064] Buck-Boost circuit (buck-boost converter or buck-boost chopper circuit) combines the characteristics of Boost and Buck circuits, which can both step up and step down. Among them, Buck-Boost circuit provides more flexibility in the optimizer, which can adjust the output voltage of the photovoltaic module according to the actual situation.

[0065] In an implementation manner, in order to reduce the volume, the above-mentioned optimizer can also use high-frequency isolated inverter topology. Among them, this topology structure realizes the isolation and conversion between direct current and alternating current through high-frequency transformer, which improves the safety and reliability of the system.

[0066] The pseudo-direct-current bus interleaved flyback topology does not have a direct-current bus, and converts the direct-current signal into a positive half-cycle sine wave through an interleaved flyback structure, and then adjusts it into a full-cycle sine wave through a thyristor. Among them, this topology structure can realize efficient electric energy conversion and transmission in the optimizer, while saving a large number of high-voltage capacitors.

[0067] Based on the structure of each optimizer main circuit proposed above, in order to analyze the optimizer main circuit later, the optimizer main circuit can be simplified, and the embodiment takes the Boost circuit as an example to illustrate the simplification process of the optimizer main circuit. The Boost circuit is a direct current conversion circuit, and the key components of the Boost circuit include the switch tube VQ, the inductor L, the input filter capacitor Cs, the output filter capacitor C, the diode VD and the load R.

[0068] The main function of the optimizer main circuit is to realize the smoothing and stability of the voltage, and at the same time, the protection circuit components can be realized, so in the embodiment of the present disclosure, the behavior of the switch tube VQ, the inductor L, the input filter capacitor Cs and the load R can not be involved, therefore the simplification and analysis of the switch tube VQ, the inductor L, the input filter capacitor Cs and the load R can be ignored, and only the output filter capacitor C and the diode VD are simplified and equivalent.

[0069] Combining the equivalent circuit schematic diagram of the optimizer main circuit shown in FIG. 1b, the capacitor C-1 and the capacitor C-2 can represent the equivalent representation of the output filter capacitor C in the Boost circuit, and the diode D represents the diode VD in the Boost circuit.

[0070] Capacitor C-1 and capacitor C-2 are connected in parallel, representing the output filter capacitor C in the Boost circuit, and this parallel connection can simulate the total capacity of capacitor C, and further when the photovoltaic panel output current fluctuates, the capacitor can release or absorb charges to maintain the stability of the output voltage. Diode D is reversely connected between the first end of capacitor C-1 and the first end of capacitor C-2, which simulates the reverse blocking behavior of diode VD in the Boost circuit, that is, when the switch tube VQ is turned on, diode VD is in a reverse blocking state, thereby protecting the capacitor and other circuit elements.

[0071] By equivalent the optimizer main circuit to the equivalent circuit shown in Figure 1b, the basic functions of the optimizer main circuit can be realized, that is, to realize the smoothing and stability of the voltage, and to realize the protection circuit device.

[0072] In the embodiments of the present disclosure, only the topology of the optimizer main circuit is taken as an example of the Boost circuit to describe the equivalent process of the optimizer main circuit, but it is not limited to the topology of the optimizer main circuit of each of the following embodiments. The topology of the optimizer main circuit is also the Boost circuit, and can also be any circuit described above, which is not limited here. The equivalent circuit of the optimizer main circuit shown in each of the following embodiments is only illustrative and cannot be used as a basis for limiting the protection scope of the present disclosure.

[0073] Referring to Figure 2, which is a first structural schematic diagram of an optimizer provided by an embodiment of the present disclosure, in combination with Figure 2, the optimizer 200 provided by the embodiment of the present disclosure can include: an optimizer main circuit 201 and a protection circuit 202; wherein the protection circuit 202 is connected in parallel with the output end of the optimizer main circuit 201.

[0074] When the input end of the optimizer main circuit 201 is open, the protection circuit 202 is a pass.

[0075] When the input end of the optimizer main circuit 201 is a pass, the protection circuit 202 is open.

[0076] When the input end of the optimizer is open, the protection circuit 202 can be controlled to be a pass, so that the output end of the optimizer is in a short-circuit state, so that energy cannot flow back to the optimizer through the output end of the optimizer, thereby improving the safety of the photovoltaic system. When the input end of the optimizer is a pass, the optimizer is in a normal working state, and at this time the protection circuit can be controlled to be open.

[0077] The protection circuit provided by the embodiments of the present disclosure aims to realize a closed circuit when the input end of the optimizer main circuit is open, and an open circuit when the input end of the optimizer main circuit is closed. In a possible implementation, the protection circuit can be a device such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), a contactor, a relay or a transistor, or a circuit structure realizing a closed circuit or an open circuit.

[0078] As an example, assuming that the protection circuit is a normally open relay, when the input end of the optimizer main circuit is closed, the disconnection of the contacts can be realized by controlling the disconnection of the coil, thereby ensuring that the optimizer main circuit can work normally; when the input end of the optimizer main circuit is open, the closing of the contacts can be realized by controlling the connection of the coil, thereby short-circuiting the output end of the optimizer main circuit and reducing the possibility of energy backflow.

[0079] As another example, assuming that the protection circuit is a normally open contactor, when the input end of the optimizer main circuit is closed, the contacts of the normally open contactor are in a disconnected state, thereby enabling the optimizer main circuit to work normally; when the input end of the optimizer main circuit is open, the contacts of the normally open contactor are closed, thereby short-circuiting the output end of the optimizer main circuit.

[0080] As an example, assuming that the protection circuit is a MOSFET, when the input end of the optimizer main circuit is closed, the gate voltage of the MOSFET is less than the threshold voltage, at this time, the MOSFET is open, thereby ensuring that the optimizer main circuit can work normally; when the input end of the optimizer main circuit is open, the gate voltage of the MOSFET is controlled to be greater than the threshold voltage, thereby enabling the MOSFET to be closed, so as to short-circuit the output end of the optimizer main circuit.

[0081] As an example, assuming that the protection circuit is a switch circuit, when the input end of the optimizer main circuit is closed, the switch circuit is open, thereby ensuring that the optimizer main circuit can work normally; when the input end of the optimizer main circuit is open, the switch circuit is closed, thereby short-circuiting the output end of the optimizer main circuit and reducing the possibility of energy backflow from the output end to the input end of the optimizer, thereby providing safety of the system.

[0082] In the embodiments of the present disclosure, when the input end of the optimizer main circuit is open, the protection circuit of the output end of the optimizer main circuit is set to be closed, at this time, since the protection circuit is closed, the output end of the optimizer main circuit is short-circuited, and the energy of the output end will not backflow to the input end of the optimizer main circuit, thereby achieving the purpose of protecting the optimizer.

[0083] Referring to FIG. 3, which is a second structural schematic diagram of an optimizer provided by the embodiments of the present disclosure.

[0084] In combination with FIG. 3, the optimizer 300 provided by the embodiments of the present disclosure can include an optimizer main circuit 201 and a protection circuit 202, the protection circuit 202 including a driving circuit 301 and a switching circuit 302; wherein an output end of the driving circuit 301 is connected to an input end of the switching circuit 302.

[0085] The driving circuit refers to a circuit configured to drive the switching circuit to be in an open path or a closed path. The switching circuit refers to a circuit configured to serve as a switching device to achieve the purpose of being open or closed, and the switching circuit can be but is not limited to a MOS tube or a thyristor. The MOS tube (Metal-Oxide-Semiconductor Field-Effect Transistor) is also called MOSFET (sometimes written as MOS-FET), which is a unipolar semiconductor device. The thyristor, also known as silicon controlled rectifier, is a high-power switching semiconductor device.

[0086] In the embodiments of the present disclosure, the switching circuit can include one or more MOS tubes or thyristors. As an example, when the switching circuit includes multiple MOS tubes or thyristors, the multiple MOS tubes or thyristors can be connected in series, or, in order to reduce the failure of the switching circuit caused by the unavailability of a single MOS tube or thyristor, the multiple MOS tubes or thyristors can also be connected in parallel, or the multiple MOS tubes or thyristors can be connected in series and parallel, which is not limited herein. As an example, the switching circuit can also include multiple MOS tubes and thyristors, and the multiple MOS tubes and thyristors can be connected in series, in parallel, or in series and parallel, which is not limited herein.

[0087] In a possible implementation, the driving circuit 301 is connected to a first end of the switching circuit 302; a second end and a third end of the switching circuit 302 are respectively connected to a positive electrode and a negative electrode of the output end.

[0088] The driving circuit 301 is configured to drive the switching circuit 302 to be in an open path when the voltage at the input end of the optimizer main circuit is less than or equal to a preset voltage, or to be in a closed path when the voltage at the input end of the optimizer main circuit is greater than the preset voltage. When the voltage of the optimizer main circuit is greater than the preset voltage, it can be considered that the input end of the optimizer main circuit is in an open path, at this time, the output end of the optimizer main circuit can be short-circuited by driving the switching circuit to be in a closed path, so as to reduce the possibility of energy backflow and achieve the purpose of protecting the optimizer.

[0089] When the input end of the optimizer main circuit 201 is a pass-through, the optimizer is in a normal working state, at this time, the switch circuit 302 can be driven to be open by the driving circuit 301, so that the optimizer main circuit 201 can work normally. When the input end of the optimizer main circuit 201 is open, it can be considered that the optimizer main circuit 201 fails, at this time, the switch circuit 302 can be driven to be a pass-through by the driving circuit 301, so that the output end of the optimizer 201 is short-circuited, preventing energy from flowing back to the input end of the optimizer main circuit, and achieving the purpose of protecting the optimizer.

[0090] Referring to FIG. 4, FIG. 4 is a third structural schematic diagram of an optimizer provided by an embodiment of the present disclosure.

[0091] In combination with FIG. 4, the optimizer 400 provided by an embodiment of the present disclosure can include an optimizer main circuit 201, a driving circuit 301, and a switch circuit, wherein the switch circuit is a short-circuit circuit 401.

[0092] Embodiments of the present disclosure have the same components or devices as the above-mentioned embodiments, and the above-mentioned reference signs are used, and thus will not be described here.

[0093] The short-circuit circuit means a normally closed straight-through circuit, as an example, the short-circuit circuit is any one of a depletion mode metal-oxide semiconductor field effect transistor (MOSFET) tube, a normally closed contactor, and a normally closed relay, including but not limited to the above-mentioned three short-circuit circuits, and the short-circuit circuit can be integrated with a single device or multiple devices.

[0094] The normally closed means that the contacts on the device are in a closed state when the device is not powered on, and only after the device is powered on can the contacts be in an open state. In the embodiment of the present disclosure, the driving circuit 203 is connected to the input end of the optimizer main circuit 201, and the driving circuit 203 is powered by the optimizer main circuit 201.

[0095] When the input end of the optimizer main circuit 201 is disconnected from the DC power supply of the driving circuit 301, the input end of the optimizer main circuit 201 does not provide voltage for the driving circuit 301, the input end of the optimizer main circuit 201 is in an open state, and the driving circuit 301 does not output a driving signal, at this time, the short-circuit circuit 401 is a pass-through due to the lack of control of the driving circuit 301, so that the output end of the optimizer main circuit is short-circuited, reducing the possibility of energy backflow, protecting the optimizer, and improving the safety of the photovoltaic system.

[0096] When the input end of the optimizer main circuit 201 is connected to the DC power supply of the driving circuit 301, the input end of the optimizer main circuit 201 is in a normal working state, at this time, the driving circuit 301 can output a driving signal to drive the short-circuit circuit 401 to be open, so as to ensure the normal use of the optimizer.

[0097] When the optimizer accesses the photovoltaic module, due to the characteristics of the diode of the main circuit of the optimizer, the voltage at the input end of the optimizer is not clamped by the short circuit circuit. In addition, when the optimizer is working normally, the voltage provided by the input end can be used to power the driving circuit, so that the driving circuit controls the short circuit circuit to be open.

[0098] Referring to FIG. 5, it is a fourth structural schematic diagram of an optimizer provided by an embodiment of the present disclosure.

[0099] In combination with FIG. 5, the optimizer 500 provided by an embodiment of the present disclosure can include a main circuit 201 of the optimizer, a protection circuit 202 and a controller 501, the protection circuit 202 including a driving circuit 301 and a switching circuit 302. The output end of the controller 501 is connected with the input end of the driving circuit 301, and the output end of the driving circuit 301 is connected with the input end of the switching circuit 302.

[0100] Embodiments of the present disclosure have the same components or devices as the above-mentioned embodiments, and the above-mentioned embodiments use the same reference numerals, which will not be described here.

[0101] The controller is responsible for receiving signals from various input devices and processing these signals according to pre-set logic or programs, and then generating corresponding control signals to drive or adjust other parts of the circuit. The controller can work with power supply, sensors, actuators, etc. to complete specific functions or tasks.

[0102] Among them, the controller can receive signals from various input devices, such as sensors, switches, buttons, etc. These signals can be analog signals (such as temperature, pressure, light intensity, etc.) or digital signals (such as switch state, encoder, etc.). The controller converts these signals into an internal processable format and performs necessary filtering, amplification, comparison, etc.

[0103] Further, according to the pre-set logic or program, the controller judges and decides the input signal. For example, when the voltage reaches a certain set value, the controller may decide to send a control signal to the driving circuit; when a certain switch is pressed, the controller may change the working mode of the circuit, etc.

[0104] Then, according to the result of logical judgment, the controller generates corresponding control signals to drive or adjust other parts of the circuit. These control signals can be analog signals (such as voltage, current, etc.), or digital signals (such as PWM signals, pulse signals, etc.). The control signals are sent to actuators, relays, motors, controllable switches, etc. through output ports or interfaces to achieve specific control targets.

[0105] There are many types of controllers, including but not limited to analog controllers, digital controllers, programmable logic controllers (PLC), etc. These controllers differ in structure, function and performance, but have similar basic principles and functions.

[0106] When it is determined that the input end of the optimizer main circuit 201 is open, the controller 501 can control the driving circuit 301 to send a first driving signal to the switching circuit 302 to control the switching circuit 302 to be in a pass-through state by the first driving signal.

[0107] In the embodiments of the present disclosure, whether the input end of the optimizer main circuit is open can be determined by determining the voltage value of the input end of the optimizer main circuit. As an example, a voltage sensor, a current sensor or other acquisition circuit can be used to obtain the voltage value of the input end of the optimizer main circuit 201. When a current sensor is used, the current value of the optimizer main circuit can be obtained first, and then the voltage value can be determined according to the current value.

[0108] In actual application scenarios, when the voltage value of the input end of the optimizer main circuit 201 is not 0, it can be that the optimizer main circuit is working normally, or that the energy of the output end of the optimizer main circuit flows back to the input end of the optimizer main circuit, resulting in a voltage at the input end of the optimizer main circuit. Therefore, in order to reduce the voltage generated by the energy backflow at the input end of the optimizer main circuit, which can cause the optimizer main circuit to be mistakenly considered as working normally, in one possible implementation, the controller 501 can be configured to:

[0109] After sending the first driving signal, it is determined whether the voltage value of the input end of the optimizer main circuit 201 is greater than a preset voltage value. If the voltage value of the input end of the optimizer main circuit 201 is greater than the preset voltage value, the driving circuit 301 is controlled to send a second driving signal to the switching circuit 302. The second driving signal is configured to control the switching circuit 302 to be in a pass-through state.

[0110] The input end of the optimizer main circuit will be in a relatively fixed voltage range when it is working normally. If the voltage of the input end of the optimizer main circuit exceeds the preset voltage value, it can be considered that the optimizer main circuit is in an open state and the energy has flowed back to the input end of the optimizer main circuit. At this time, in order to improve the safety of the optimizer, the driving circuit can be controlled to send a second driving signal to the switching circuit to make the switching circuit in a pass-through state, so as to realize the output end circuit of the optimizer main circuit and reduce the possibility of energy flowing back to the input end.

[0111] Referring to FIG. 6, which is a fifth structural schematic diagram of an optimizer provided by an embodiment of the present disclosure.

[0112] In combination with FIG. 6, the optimizer 600 provided by the embodiment of the present disclosure can include the optimizer main circuit 201, the controller 501, and the protection circuit 202, wherein the protection circuit 202 is the switch circuit 302. The auxiliary power supply of the controller 501 is provided by the input end of the optimizer main circuit 201.

[0113] The same components or devices in the above embodiments are used with the same reference numerals, and will not be described here.

[0114] The controller 501 is configured to determine whether the voltage at the input end of the optimizer main circuit is greater than a preset voltage, and to control the switch circuit 302 to be turned on when the voltage at the input end of the optimizer main circuit is greater than the preset voltage.

[0115] In the embodiment of the present disclosure, the auxiliary power supply of the controller is generally powered by the voltage at the input end of the optimizer main circuit. When the voltage at the output end of the optimizer main circuit backflows to the input end of the optimizer, the auxiliary power supply is powered to start, and after the controller starts, whether the voltage at the input end of the optimizer main circuit is greater than a preset voltage is determined. When the voltage at the input end of the optimizer main circuit is greater than the preset voltage, the switch circuit is controlled to be in an on state, so that the output end of the optimizer main circuit is short-circuited, to prevent energy from continuing to backflow to the input end, and to achieve the purpose of protecting the optimizer.

[0116] Referring to FIG. 7, which is a sixth structural schematic diagram of an optimizer provided by an embodiment of the present disclosure.

[0117] In combination with FIG. 7, the optimizer 700 provided by the embodiment of the present disclosure can include the optimizer main circuit 201, the protection circuit 202, and the determination circuit 701. The protection circuit 302 includes the drive circuit 301 and the switch circuit 302, and the switch circuit 302 is the open circuit 702. The output end of the determination circuit 701 is connected to the input end of the drive circuit 301, and the output end of the drive circuit 301 is connected to the input end of the protection circuit 202.

[0118] The same components or devices in the above embodiments are used with the same reference numerals, and will not be described here.

[0119] The open circuit means a normally open circuit. As a possible implementation, the GIA open circuit can be any one of a metal-oxide semiconductor field effect transistor (MOSFET) tube, a normally open contactor, and a normally open relay, including but not limited to the above three circuits.

[0120] When the voltage value at the output end of the optimizer main circuit 201 is greater than the standard voltage value, it can be considered that the optimizer main circuit has a fault, and the input end of the optimizer main circuit is open circuit. At this time, the first output signal can be output to the driving circuit 301 by the judgment circuit 701, and the third driving signal is sent to the switch circuit 302 by the driving circuit 301 based on the first output signal, so as to drive the switch circuit 302 to be a passway by the third driving signal.

[0121] In the embodiments of the present disclosure, the judgment circuit is used to judge whether the voltage at the output end of the optimizer main circuit is greater than the standard voltage value. When the voltage at the output end of the optimizer main circuit is greater than the standard voltage value, it can be considered that the input end of the optimizer main circuit is open circuit. At this time, the first output signal can be sent to the driving circuit by the judgment circuit, so as to make the driving circuit send the third driving signal to the switch circuit based on the first output signal, so as to drive the switch circuit to be a passway, so that the output end of the optimizer main circuit is short-circuited, the possibility of energy backflow is reduced, and the purpose of protecting the optimizer is achieved.

[0122] Referring to FIG. 8, FIG. 8 is a seventh structure schematic diagram of an optimizer provided by an embodiment of the present disclosure.

[0123] In combination with FIG. 8, the optimizer 800 provided by the embodiment of the present disclosure can include an optimizer main circuit 201, a protection circuit 202, and a judgment circuit 701. The protection circuit 302 includes a driving circuit 301 and a switch circuit 302. The switch circuit 302 is an open circuit 702. The judgment circuit 701 can include a comparison circuit 801 and a voltage acquisition circuit 802. The first input end of the comparison circuit 801 is connected with a reference source. The second input end of the comparison circuit 801 is connected with the output end of the voltage acquisition circuit 802. The output end of the comparison circuit 801 is connected with the input end of the driving circuit 301. The reference source is configured to provide a standard voltage value to the comparison circuit.

[0124] The voltage acquisition circuit 802 is configured to acquire an acquisition voltage value at the output end of the optimizer main circuit 201, and input the acquisition voltage value to the comparison circuit.

[0125] In some possible implementation manners, the voltage acquisition circuit can be a voltage sensor, a current sensor, or a resistance sampling circuit, etc. When it is a current sensor, the acquisition voltage value is determined according to the acquired acquisition current value. When it is a resistance sampling circuit, two series resistors can be set, and the common end of the two resistors is used as the output to acquire the voltage value at the input end of the optimizer main circuit.

[0126] The comparison circuit 801 is configured to output a first output signal or a second output signal to the driving circuit 301 based on the standard voltage value and the acquisition voltage value. The first output signal is a high-level signal, and the second output signal is a low-level signal.

[0127] The driving circuit 301 sends a third driving signal to the protection circuit 202 based on the first output signal.

[0128] When the input end of the optimizer main circuit is open, the output end of the optimizer main circuit can backflow energy, so that the input end and the output end of the optimizer main circuit both have a voltage, and the voltage gradually increases, causing the optimizer to be damaged. Therefore, whether the voltage of the input end or the output end of the optimizer main circuit is greater than a preset voltage value can be determined by the judgment circuit, so as to determine whether the input end of the optimizer is open, so that the open circuit is in a path when the input end of the optimizer is open.

[0129] In the above embodiments, the protection circuit, the driving circuit, the controller, the comparison circuit and the voltage acquisition circuit are integrated in the interior of the optimizer. In other possible implementation manners, the protection circuit, the driving circuit, the controller, the comparison circuit and the voltage acquisition circuit can also be integrated outside the optimizer, and when the above devices are integrated outside the optimizer, the functions or effects that can be achieved by any of the above embodiments can be achieved, which are not limited here. For the related explanations and descriptions of the above devices, reference can be made to the explanations and descriptions in the above embodiments, which are not repeated here.

[0130] Based on the optimizer provided in the above embodiments, some possible circuit structures of the driving circuit 301 and the switching circuit 302 are introduced below.

[0131] Referring to FIG. 9, which is a first structure schematic diagram of a driving circuit provided in an embodiment of the present disclosure.

[0132] In combination with FIG. 9, the driving circuit 301 provided in an embodiment of the present disclosure can include a voltage stabilizing tube D1 and a first capacitor C1. The first end of the voltage stabilizing tube D1 is connected with the first end of the switching circuit 302, the second end of the voltage stabilizing tube D1 is connected with the positive pole OUT+ of the output end of the optimizer main circuit, the first end of the voltage stabilizing tube D1 is connected with the first end of the first capacitor C1, the second end of the first capacitor C1 is connected with the negative pole OUT- of the output end of the optimizer main circuit, the second end of the switching circuit 302 is connected with the positive pole OUT+ of the output end of the optimizer main circuit, and the third end of the switching circuit 302 is connected with the negative pole OUT- of the output end of the optimizer main circuit.

[0133] In an embodiment of the present disclosure, the driving circuit 301 can be configured in parallel with the first specified port, the second end of the switching circuit 302 is connected with the positive pole of the second specified port, the third end of the switching circuit 302 is connected with the negative pole of the second specified port, the first specified port is at least one of the input end or the output end of the optimizer main circuit, and the second specified port is at least one of the input end or the output end of the optimizer main circuit.

[0134] The driving circuit 301 can be arranged at the input end, the output end, the input end and the output end of the optimizer main circuit, and the switching circuit 302 can be arranged at the input end, the output end, the input end and the output end of the power conversion device. The combination of the driving circuit 301 and the switching circuit 302 can include various arrangements, which will not be described here.

[0135] In the embodiments of the present disclosure, Vo+ and Vo- of the driving circuit are the positive and negative electrodes of the input end of the optimizer main circuit, or Vo+ and Vo- of the driving circuit are the positive and negative electrodes of the output end of the optimizer main circuit, which is arranged according to the actual situation and is not limited here.

[0136] The voltage stabilizing tube, also known as voltage stabilizer, electronic voltage stabilizer or voltage stabilizing diode (Zener diode), is a kind of semiconductor device that can automatically adjust the resistance value in the circuit to keep the output voltage constant. The voltage stabilizing tube has a stable breakdown voltage. When the reverse voltage exceeds the value of the breakdown voltage, the voltage stabilizing tube enters the breakdown state, but its voltage will remain at the breakdown voltage value, thereby maintaining the voltage in the circuit constant. The voltage stabilizing tube can normally conduct like a diode at the forward working voltage; but when the reverse voltage exceeds its breakdown voltage, it can exhibit voltage stabilization characteristics.

[0137] The voltage stabilizing tube can be replaced by devices that can realize voltage stabilization function, such as transistor voltage stabilizer, integrated circuit voltage stabilizer, switching voltage stabilizer and linear voltage stabilizer, but considering the cost, for example, the voltage stabilizing tube.

[0138] The embodiments of the present disclosure utilize the PN junction structure and reverse breakdown voltage characteristics of the voltage stabilizing tube. When the input voltage of the second end of the voltage stabilizing tube D1 is less than or equal to the stable voltage value, the voltage stabilizing tube D1 is not conductive, i.e. the second end and the third end of the switching circuit 302 are not connected; when the input voltage of the second end of the voltage stabilizing tube D1 is greater than the stable voltage value, the voltage stabilizing tube D1 is broken down, so that the voltage of the first end and the second end of the voltage stabilizing tube D1 is equal, at this time the voltage stabilizing tube D1 can drive the switching circuit 302 to make the second end and the third end of the switching circuit 302 connected. The stable voltage value of the voltage stabilizing tube D1 can be set as the voltage value of the preset voltage, and the arrangement manner is not limited here.

[0139] When the input voltage exceeds the stable voltage value of the voltage stabilizing tube, the voltage stabilizing tube will start to conduct and limit the further increase of the voltage, thereby playing the role of clamping to limit the input voltage within a certain voltage range. By limiting the input voltage within a certain voltage range, the optimizer main circuit can be effectively protected from high voltage damage, and the stability and reliability of the circuit can be ensured.

[0140] In order to improve the safety of the driving circuit, the capacitor C1 can absorb or release part of the energy, so as to slow down the rate of voltage change and prevent the sudden change of voltage from damaging the switching circuit.

[0141] In the embodiment of the present disclosure, by using the reverse breakdown characteristic of the voltage stabilizing tube in the driving circuit, when the input voltage of the second end of the voltage stabilizing tube is greater than the stable voltage value, that is, the input end is open, the voltage of the output end is increased, at this time, the voltage stabilizing tube D1 is turned on, and then the switching circuit 302 is driven to be turned on to short the output end of the optimizer main circuit, so as to form a temporary current loop and achieve the protection of the optimizer.

[0142] Referring to FIG. 10, it is a second structure schematic diagram of a driving circuit provided by the embodiment of the present disclosure.

[0143] In combination with FIG. 10, the driving circuit 301 includes a voltage stabilizing tube D1, a capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a second voltage stabilizing tube D2, a first switching device Q1 and a second switching device Q2.

[0144] The first end of the first resistor R1 is connected to the second end of the second resistor R2 and the first end of the first switching device Q1, the second end of the first resistor R1 is connected to the positive electrode of the output end of the optimizer main circuit, the first end of the second resistor R2 is connected to the third end of the second switching device Q2, the first end of the third resistor R3 is connected to the second end of the fourth resistor R4 and the first end of the voltage stabilizing tube D1, the second end of the third resistor R3 is connected to the third end of the first switching device Q1, the first end of the fourth resistor R4 is connected to the first end of the capacitor C1 and the first end of the second switching device Q2, the second end of the first switching device Q1 is connected to the second end of the voltage stabilizing tube D1 and the positive electrode of the output end of the optimizer main circuit, the second end of the second switching device Q2 is connected to the second end of the capacitor C1, the second end of the capacitor C1 is connected to the second end of the second voltage stabilizing tube D2 and the negative electrode of the output end of the optimizer main circuit, and the first end of the voltage stabilizing tube D1 is connected to the second end of the second voltage stabilizing tube D2 and the first end of the switching circuit 302.

[0145] The protection circuit composed of the driving circuit 301 and the switching circuit 302 is connected in parallel to the output end of the optimizer main circuit, when the voltage of Vo+ is higher than the stable voltage value of D1, the voltage stabilizing tube D1 is broken down, at this time, the voltage stabilizing tube D1 is turned on, and then the second switching device Q2 is driven to be turned on through D1 and R4, and then the first switching device Q1 is turned on, and the voltage of Vo+ reaches the first end of the switching circuit 302 through the current limiting resistor R3, so as to drive the switching circuit 302 to be turned on, so as to achieve the short circuit protection effect.

[0146] In the embodiment of the present disclosure, the stable voltage value of the voltage stabilizing tube D1 can be greater than the rated output voltage of the power conversion device, so as to reduce the influence on the power conversion device. In addition, when the first switching device Q1 is turned on, the voltage of Vo+ will reach the first end (such as the G pole of the MOS tube) of the switching circuit 302 through the first switching device Q1 and the current limiting resistor R4. Since the voltage value of Vo+ is high, and the voltage Vgs (voltage difference between the gate and the source) that the first end of the switching circuit 302 can withstand is generally not more than 20V, the second voltage stabilizing tube D2 can be used for protection. By adjusting the stable voltage value of the second voltage stabilizing tube D2, the switching circuit 302 can be prevented from being damaged due to overvoltage of Vgs.

[0147] If the switching circuit 302 is a MOS tube, when the driving circuit drives the MOS tube to be turned on, the MOS tube will pull down the voltage of Vo+, and the MOS tube will be turned off due to the loss of driving voltage, and be in a kind of belching protection state, but the purpose of protecting the device can be achieved. In addition, the stable voltage value of the voltage stabilizing tube can be greater than or equal to the rated output voltage value of the optimizer, otherwise it may affect the normal work of the optimizer.

[0148] Referring to FIG. 11, FIG. 11 is a third structural schematic diagram of a driving circuit provided by an embodiment of the present disclosure.

[0149] In combination with FIG. 11, the driving circuit 301 comprises a voltage stabilizing tube D1, a capacitor C1, and a fifth resistor R5.

[0150] The first end of the voltage stabilizing tube D1 is connected to the first end of the fifth resistor R5, the second end of the voltage stabilizing tube D1 is connected to the positive pole of the output end of the optimizer main circuit, the second end of the fifth resistor R5 is connected to the first end of the capacitor C1 and the first end of the switching circuit 302, and the second end of the capacitor C1 is connected to the negative pole of the output end of the optimizer main circuit.

[0151] The fifth resistor R5 can limit the current passing through the voltage stabilizing tube D1 and the switching circuit 302, so as to prevent the voltage stabilizing tube D1 from being damaged due to excessive current. In addition, the fifth resistor R5 and the voltage stabilizing tube D1 are connected in series, and can jointly function as voltage division, so as to ensure that the voltage between the two ends of the voltage stabilizing tube D1 is within the normal working range.

[0152] When the voltage of Vo+ (the positive pole of the output end of the optimizer main circuit) appears, the input voltage of the second end of the voltage stabilizing tube D1 is the voltage of Vo+. When the voltage of Vo+ is greater than the stable voltage value of the voltage stabilizing tube D1, the voltage stabilizing tube D1 is broken down, so that the voltage of the first end and the second end of the voltage stabilizing tube D1 is equal. At this time, the voltage stabilizing tube D1 can drive the switching circuit 302, so that the second end and the third end of the switching circuit 302 are connected, and then the output end of the optimizer main circuit is short-circuited, so as to achieve the purpose of protecting the device.

[0153] Referring to FIG. 12, which is a fourth structural schematic diagram of a driving circuit provided by an embodiment of the present disclosure.

[0154] In combination with FIG. 12, the driving circuit 301 includes a voltage stabilizing tube D1, a capacitor C1, a sixth resistor R6, and a diode D3.

[0155] The first end of the voltage stabilizing tube D1 is connected to the first end of the sixth resistor R6 and the first end of the diode D3, the second end of the voltage stabilizing tube D1 is connected to the positive pole of the output end of the optimizer main circuit, the second end of the diode D3 is connected to the first end of the switch circuit 302, the first end of the capacitor C1 is connected to the first end of the diode, and the second end of the capacitor C1 is connected to the second end of the sixth resistor R6 and the negative pole of the output end of the optimizer main circuit.

[0156] When the voltage Vo+ (the positive pole of the output end of the optimizer main circuit) appears, the input voltage of the second end of the voltage stabilizing tube D1 is the voltage of Vo+, and when the voltage of Vo+ is greater than the stable voltage value of the voltage stabilizing tube D1, the voltage stabilizing tube D1 is broken down, so that the voltages of the first end and the second end of the voltage stabilizing tube D1 are equal. At this time, the voltage stabilizing tube D1 can drive the switch circuit 102, so that the second end and the third end of the switch circuit 102 are connected, and the output end of the optimizer main circuit is short-circuited, thereby achieving the protection of the equipment.

[0157] When the switch circuit 302 is a thyristor, as long as there is a trigger pulse at the gate under certain voltage conditions, the thyristor can be turned on, and after the trigger pulse disappears, the thyristor can still maintain the on state. Only when the current is less than the holding current of the thyristor can the thyristor be turned off. It can be configured as a protection circuit without a stable power supply, which can alleviate the problem that the switch circuit 302 can only be protected by hiccup when it is a MOS tube.

[0158] As an example, when the switch circuit 302 is a thyristor, when the voltage Vo+ appears, the second switch device Q2 is turned on through the high resistance R2 and R5, and then the first switch device Q1 is turned on. The current limiting resistor R4 with a small resistance value achieves the effect of amplifying the driving current. The voltage drop on the resistor R4 is very small, so the voltage at the second end of the D1 is almost equal to Vo+. When the voltage of Vo+ is greater than the stable voltage value of the voltage stabilizing tube D1, the voltage stabilizing tube D1 is broken down, and the thyristor is driven to be turned on, so as to achieve the short-circuit protection effect of the thyristor. After the short-circuit protection is achieved, even if the voltage of Vo+ is pulled down, as long as there is a certain current, the second switch device Q2 can continuously maintain the on state to protect, until the output end energy current is too small to maintain the thyristor on, the second switch device Q2 returns to the off state, and the hiccup frequency is significantly reduced.

[0159] In order to further illustrate the connection relationship between the controller 501, the driving circuit 301 and the switching circuit 302, referring to FIG. 13, which is a fifth structural schematic diagram of a driving circuit provided in the embodiment of the present disclosure.

[0160] In combination with FIG. 13, the driving circuit 301 provided in the embodiment of the present disclosure can include a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a third switching device Q3, a fourth switching device Q4, a fifth switching device Q5, a voltage stabilizing tube D1, a diode D3 and a second capacitor C2.

[0161] The first end of the seventh resistor R7 is connected to the positive pole of the output end of the optimizer main circuit, the second end of the seventh resistor R7 is connected to the third end of the fifth switching device Q5 and the second end of the diode D3, the first end and the second end of the eighth resistor R8 are respectively connected to the third end of the third switching device Q3 and the first end of the ninth resistor R9, the common end of the eighth resistor R8 and the ninth resistor R9 is connected to the second end of the diode D3, the second end of the ninth resistor R9 is connected to the first end of the fourth switching device Q4 and the first end of the second capacitor C2, the first end of the third switching device Q3 is connected to the positive pole of the output end of the optimizer main circuit, the first end of the third switching device Q3 is connected to the third end of the fourth switching device Q4, the second end of the third switching device Q3 is connected to the positive pole of the output end of the optimizer main circuit, the second end of the fourth switching device Q4 is connected to the second end of the second capacitor C2, the second end of the fifth switching device Q5 is connected to the negative pole of the output end of the optimizer main circuit, the first end of the fifth switching device Q5 is connected to the output end of the controller 501, the first end of the voltage stabilizing tube D1 is connected to the first end of the switching circuit 302, the second end of the voltage stabilizing tube D1 is connected to the positive pole of the output end of the optimizer main circuit, the first end of the diode D3 is connected to the first end of the voltage stabilizing tube D1, and the second capacitor C2 is connected to the negative pole of the output end of the optimizer main circuit.

[0162] The third switching device Q3 and the fourth switching device Q4 shown in FIG. 13 are driving circuits configured to provide sufficient current to drive the switching circuit 302 to be conductive, the diode D3 is connected in series with the switching circuit 302, and the conduction voltage drop needs to be ensured to be greater than 0.7V, and the function of the diode D3 is to raise the voltage at the upper end of the resistor R9, so that when the voltage of Vo+ is greater than the preset voltage, the current is preferentially passed through R7 and R9, so that the fourth switching device Q4 is conductive. The driving circuit provided in the embodiment of the present disclosure performs different actions under three working conditions, which are as follows:

[0163] When the input end of the optimizer main circuit is open, the electrical equipment cannot start, and when Vo+ has voltage backflow into the driving circuit, the current passes through R7 and R9 to turn on the fourth switch device Q4, and then turn on the third switch device Q3, at which time the driving circuit works. At this time, the current of Vo+ mainly passes through the third switch device Q3, the fourth resistor R8, and the diode D3 to reach the switch circuit 302, so as to turn on the switch circuit 302, thereby playing a role in overvoltage protection.

[0164] When the input end of the optimizer main circuit is normally connected, the input end of the optimizer main circuit is normally connected with the photovoltaic module, and after the electrical equipment starts, the MCU gives a signal to pull up the OVP_EN1 pin to turn on the fifth switch device Q5 to ground, the Vce of the fifth switch device Q5 is almost 0V, the fourth switch device Q4 will not be turned on, and the switch circuit 302 will not be turned on, at which time the normal output voltage Vo+ will only pass through the seventh resistor R7 and the fifth switch device Q5 to discharge. Among them, selecting a suitable resistance value of the eighth resistor R8 can realize lower loss.

[0165] When the input end of the optimizer main circuit is normal and the output end of the optimizer main circuit is abnormally overvoltage, the input end of the optimizer main circuit is not open, the machine is normally running, and the protection circuit cannot be started. If the output end of the optimizer main circuit has a voltage exceeding the preset voltage at this time, the voltage stabilizing tube D1 will discharge to drive the switch circuit 302 to conduct short circuit protection. The voltage stabilizing value of the voltage stabilizing tube D1 can be selected according to actual needs, and is generally greater than the rated output voltage of the electrical equipment.

[0166] Among them, the switch circuit 302 can be a thyristor, a MOSFET, etc., and the diode D3 in the circuit can be a diode, a voltage stabilizing tube or a resistor, etc., which can be combined and matched to ensure that the switch circuit 302 is turned on.

[0167] Referring to FIG. 14, the sixth structure of the driving circuit provided by the embodiment of the present disclosure is shown.

[0168] In combination with FIG. 14, the driving circuit 301 provided by the embodiment of the present disclosure can include a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a third switch device Q3, a fourth switch device Q4, a fifth switch device Q5, a voltage stabilizing tube D1, a diode D3, a second capacitor C2, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, and a thirteenth resistor R13.

[0169] The first end of the tenth resistor R10 is connected to the positive pole of the output end of the main circuit of the optimizer, the second end of the tenth resistor R10 is connected to the first end of the third switch Q3, the first end and the second end of the eleventh resistor R11 are respectively connected to the first end of the third switch Q3 and the third end of the fourth switch Q4, the first end and the second end of the twelfth resistor R12 are respectively connected to the first end of the fifth switch Q5 and the output end of the controller 501, the first end of the thirteenth resistor R13 is connected to the first end of the fifth switch Q5, and the second end of the thirteenth resistor R13 is connected to the negative pole of the output end of the main circuit of the optimizer.

[0170] Based on the overvoltage protection circuit provided in the above embodiment, the switch circuit 302 can be any one of the following: a depletion mode metal oxide field effect transistor (MOSFET) tube, a junction field effect transistor (JFET) tube, and a gallium nitride high electron mobility transistor (GaN HEMT) tube.

[0171] The positions of the protection circuits provided in different electrical devices can be different, that is, the connection relationships between different electrical devices and the protection circuits can be different, and the same electrical device can include multiple connection relationships with the protection circuit. Therefore, in the following embodiments, different connection modes are provided for three different electrical devices, but the following connection modes are only examples and are not limited herein.

[0172] In addition, in some possible implementations, the protection circuit can include a driving circuit and a switch circuit, and in another possible implementation, the driving circuit in the protection circuit can be controlled by a control unit (MCU). Therefore, although the connection relationship between the driving circuit in the protection circuit and the control unit is not described in the following embodiments, it can be understood that the output end of the control unit is connected to the driving circuit to control the driving circuit.

[0173] Referring to FIG. 15, which is a flowchart of a control method of an optimizer provided in an embodiment of the present disclosure. In combination with FIG. 15, the optimizer provided in the embodiment of the present disclosure is the optimizer shown in FIG. 2, and the control method is as follows:

[0174] S1501: determining whether the input end of the main circuit of the optimizer is open.

[0175] When the optimizer is working, whether the input end of the optimizer is open can be determined by determining whether the main circuit of the optimizer is open.

[0176] S1502: when the input end of the main circuit of the optimizer is open, the protection circuit is controlled to be in a pass-through state.

[0177] S1503: when the input end of the main circuit of the optimizer is in a pass-through state, the protection circuit is open.

[0178] As an example, the protection circuit includes a driving circuit and a switching circuit; the optimizer can include a controller; an output end of the controller is connected with an input end of the driving circuit, and an output end of the driving circuit is connected with an input end of the switching circuit.

[0179] The step S1502 can include:

[0180] When it is determined that the input end of the optimizer main circuit is open circuit, the driving circuit is controlled to send a first driving signal to the switching circuit; the first driving signal is configured to control the switching circuit to be in conduction.

[0181] As an example, the protection circuit includes a driving circuit and a switching circuit; the optimizer can include a controller; an output end of the controller is connected with an input end of the driving circuit, and an output end of the driving circuit is connected with an input end of the switching circuit.

[0182] After sending the first driving signal, it is judged whether the voltage value of the input end of the optimizer main circuit is greater than a preset voltage value;

[0183] If the voltage value of the input end of the optimizer main circuit is greater than the preset voltage value, the driving circuit is controlled to send a second driving signal to the switching circuit; the second driving signal is configured to control the switching circuit to be in conduction.

[0184] As an example, the protection circuit includes a switching circuit; the optimizer can include a controller; an auxiliary power supply of the controller is provided by an input end of the optimizer main circuit;

[0185] The step S1502 can include:

[0186] It is judged whether the voltage of the input end of the optimizer main circuit is greater than a preset voltage; and the switching circuit is configured to be controlled to be in conduction when the voltage of the input end of the optimizer main circuit is greater than the preset voltage.

[0187] As an example, the protection circuit includes a driving circuit and a switching circuit, and the switching circuit is an open circuit; the optimizer can include a judging circuit; an output end of the judging circuit is connected with an input end of the driving circuit; and an output end of the driving circuit is connected with an input end of the protection circuit;

[0188] The step S1502 includes:

[0189] When the voltage value of the output end of the optimizer main circuit is greater than a standard voltage value, the judging circuit outputs a first output signal to the driving circuit;

[0190] The driving circuit sends a third driving signal to the switching circuit based on the first output signal; the third driving signal is configured to drive the switching circuit to be in conduction.

[0191] As an example, the judgment circuit includes a comparison circuit and a voltage acquisition circuit; a first input end of the comparison circuit is connected with a reference source, a second input end of the comparison circuit is connected with an output end of the voltage acquisition circuit; an output end of the comparison circuit is connected with an input end of the driving circuit; the reference source is configured to provide a standard voltage value to the comparison circuit;

[0192] The control method can include:

[0193] acquiring a collection voltage value of an output end of the optimizer main circuit;

[0194] outputting a first output signal or a second output signal to the driving circuit based on the standard voltage value and the collection voltage value; the first output signal is a high-level signal, and the second output signal is a low-level signal;

[0195] sending a third driving signal to the protection circuit based on the first output signal.

[0196] The control method of the optimizer provided by the embodiments of the present disclosure has the same beneficial effects as the optimizer provided by the above embodiments, and will not be described here.

[0197] In combination with FIG. 16, the embodiments of the present disclosure provide a photovoltaic system 1600, including at least one optimizer 1601 and at least one inverter 1602;

[0198] The output end of each optimizer 1601 is connected with the input end of the corresponding inverter 1602; the input end of the optimizer 1601 is connected with the output end of the corresponding photovoltaic module; and the optimizer 1601 is the optimizer described in any of the above embodiments.

[0199] The inverter 1602 is configured to receive direct current output by the corresponding optimizer 1601, and convert the direct current into alternating current to supply power to a load.

[0200] The inverter is the core equipment of the photovoltaic system, and its main function is to convert the direct current output by the optimizer into alternating current suitable for use in the power grid. In some possible implementations, the inverter can be responsible for monitoring parameters such as current, voltage, and frequency in the solar photovoltaic system, and adjusting according to system requirements to ensure normal operation of the system.

[0201] The output ends of the optimizers are connected in series as an output end, and the output end is connected with the corresponding inverter. Here, the number of optimizers is not limited, and the connection relationship between the optimizer and the inverter is not limited to one-to-one or multiple-to-one. The connection relationship between the optimizer and the inverter in the photovoltaic system in the art is within the protection scope of the present disclosure.

[0202] The various embodiments in the present disclosure are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the difference from other embodiments. The "first", "second" (if any) in the names mentioned in the embodiments of the present disclosure are only used for name identification, and do not represent the first and second in order.

[0203] The above is only one embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

An optimizer characterized in that The optimizer comprises an optimizer main circuit and a protection circuit; wherein the protection circuit is connected in parallel with an output end of the optimizer main circuit; When an input end of the optimizer main circuit is open, the protection circuit is a pass; When the input end of the optimizer main circuit is a pass, the protection circuit is open. The optimizer of claim 1, wherein The protection circuit comprises a driving circuit and a switch circuit; wherein an output end of the driving circuit is connected with an input end of the switch circuit; The driving circuit is configured to drive the switch circuit to be open when the input end of the optimizer main circuit is a pass; and is configured to drive the switch circuit to be a pass when the input end of the optimizer main circuit is open. The optimizer according to claim 2, characterized in that The switch circuit is a short circuit; When the input end of the optimizer main circuit is disconnected from a direct current power supply of the driving circuit, the driving circuit does not output a driving signal, and the short circuit is a pass; When the input end of the optimizer main circuit is connected to the direct current power supply of the driving circuit, the driving circuit outputs a driving signal to drive the short circuit to be open. The optimizer of claim 1, wherein The protection circuit comprises a driving circuit and a switch circuit; the optimizer further comprises a controller; an output end of the controller is connected with an input end of the driving circuit, and an output end of the driving circuit is connected with an input end of the switch circuit; When it is determined that the input end of the optimizer main circuit is open, the controller controls the driving circuit to send a first driving signal to the switch circuit; the first driving signal is configured to control the switch circuit to be a pass. The optimizer according to claim 4, characterized in that The controller is further configured to: After sending the first driving signal, judge whether a voltage value of the input end of the optimizer main circuit is greater than a preset voltage value; If the voltage value of the input end of the optimizer main circuit is greater than the preset voltage value, control the driving circuit to send a second driving signal to the switch circuit; The second driving signal is configured to control the switch circuit to be a pass. The optimizer of claim 1, wherein The protection circuit comprises a switch circuit; the optimizer further comprises a controller; an auxiliary power supply of the controller is provided by an input end of the optimizer main circuit; The controller is configured to judge whether a voltage of the input end of the optimizer main circuit is greater than a preset voltage; and is configured to control the switch circuit to be conductive when the voltage of the input end of the optimizer main circuit is greater than the preset voltage. The optimizer of claim 1, wherein The protection circuit comprises a driving circuit and a switch circuit, and the switch circuit is an open circuit; the optimizer further comprises a judgment circuit; an output end of the judgment circuit is connected with an input end of the driving circuit; and an output end of the driving circuit is connected with an input end of the protection circuit; When a voltage value of an output end of the optimizer main circuit is greater than a standard voltage value, the judgment circuit outputs a first output signal to the driving circuit; The driving circuit sends a third driving signal to the switch circuit based on the first output signal; and the third driving signal is configured to drive the switch circuit to be a pass. The optimizer according to claim 7, characterized in that The judgment circuit comprises a comparison circuit and a voltage acquisition circuit; a first input end of the comparison circuit is connected with a reference source, a second input end of the comparison circuit is connected with an output end of the voltage acquisition circuit; an output end of the comparison circuit is connected with an input end of the driving circuit; the reference source is configured to provide the standard voltage value to the comparison circuit; The voltage acquisition circuit is configured to acquire an acquisition voltage value of an output end of the optimizer main circuit; and configured to input the acquisition voltage value to the comparison circuit; The comparison circuit is configured to output a first output signal or a second output signal to the driving circuit based on the standard voltage value and the acquisition voltage value; the first output signal is a high-level signal, and the second output signal is a low-level signal; The driving circuit is configured to send the third driving signal to the protection circuit based on the first output signal. The optimizer of claim 1, wherein The protection circuit comprises a driving circuit and a switching circuit; the driving circuit is connected with a first end of the switching circuit; a second end and a third end of the switching circuit are connected with a positive electrode and a negative electrode of the output end respectively; The driving circuit is configured to drive the switching circuit to be open circuit when a voltage of an input end of the optimizer main circuit is less than or equal to the preset voltage; and is further configured to drive the switching circuit to be closed circuit when the voltage of the input end of the optimizer main circuit is greater than the preset voltage. The optimizer according to claims 2-9, characterized in that The switching circuit is a MOS tube or a thyristor. A control method of an optimizer, characterized in that, The optimizer comprises an optimizer main circuit and a protection circuit; wherein the protection circuit is connected in parallel with an output end of the optimizer main circuit; The control method comprises: controlling the protection circuit to be closed circuit when an input end of the optimizer main circuit is open circuit; controlling the protection circuit to be open circuit when the input end of the optimizer main circuit is closed circuit. A photovoltaic system characterized by The system comprises at least one inverter and at least one optimizer; wherein an output end of the optimizer is connected with an input end of a corresponding inverter; an input end of the optimizer is connected with an output end of a corresponding photovoltaic module; the optimizer is the optimizer according to any one of claims 1-10; the inverter is configured to receive direct current output by the corresponding optimizer, and to convert the direct current into alternating current to supply power to the load.

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