CN222147589U - Active bypass circuit and device suitable for photovoltaic module quick shutoff device - Google Patents

Abstract

The utility model discloses an active bypass circuit and a device suitable for a photovoltaic module quick shutoff device, wherein the active bypass circuit comprises a state detection circuit, a bypass MOS tube and a first switch driving circuit, the state detection circuit is used for detecting the on-off state of the bypass diode and outputting a level signal according to the on-off state, the bypass MOS tube is connected with the bypass diode in parallel, and the first switch driving circuit is used for driving the bypass MOS tube to be conducted according to a control signal of a processor when the main switch tube is in an off state and the bypass diode is in an on state. Therefore, when the main switch tube is in a cut-off state and the bypass diode is in a conduction state, the current passing through the bypass diode can be effectively shared by controlling the conduction of the bypass MOS tube, the bypass diode is protected, and the reliability of the quick cut-off device is effectively improved.

Description

Active bypass circuit and device suitable for photovoltaic module quick shutoff device

Technical Field

The utility model relates to the technical field of safety protection equipment of photovoltaic power generation systems, in particular to an active bypass circuit and an active bypass device suitable for a quick shutoff device of a photovoltaic module.

Background

In recent years, the installed capacity of photovoltaic is rapidly increased year by year, and the photovoltaic power generation technology is rapidly developed. The string photovoltaic system is widely applied to the distributed photovoltaic systems such as balconies, roofs and the like in individual families due to the advantages of mature technology, high conversion efficiency, high integration level, low price and the like. When the photovoltaic power generation system is in a fire disaster, the direct-current high voltage of the series-connected photovoltaic power generation system can bring about arc discharge, fire starting and electric shock risks, and great potential safety hazards and difficulties are brought to fire extinguishing operation. In order to improve the safety degree of the string photovoltaic power generation system, a component-level quick turn-off device, such as a turn-off device, is configured for each photovoltaic cell, and when abnormal conditions such as fire disaster occur, the output of each photovoltaic cell is cut off through the turn-off device, so that the direct current output voltage of the photovoltaic system is reduced, and the construction risk of maintenance personnel is reduced.

The photovoltaic module shutoff device comprises a receiver, a control module and a main switching tube, wherein the control module controls the on and off of the main switching tube according to signals sent by the receiver, the receiver is responsible for detecting communication signals sent by the transmitter, the photovoltaic module shutoff device is provided with a bypass diode, and under the condition that the main switching tube of the module is disconnected or fails, other normally working photovoltaic module currents can keep flowing through the bypass diode, so that the shutoff purpose is realized.

Currently, two input ports are generally configured in a mainstream photovoltaic module shutoff device in the market, and two photovoltaic modules are connected. The technical scheme of the existing two-input shutoff is shown in fig. 1, and the shutoff comprises a sampling module, a control module, bypass diodes D1 and D2 and main switching tubes S1 and S2. When one of the photovoltaic modules is abnormal, the corresponding main switching tube is cut off, and a freewheeling channel is provided for the power bus current through the bypass diode. However, the diode voltage drop is large, and as the current flow increases, a great heat loss is generated, and in severe cases, the diode is damaged, so that the shutoff device is broken down. Loss is commonly shared by connecting a plurality of bypass diodes in parallel, but the problem cannot be fundamentally solved, and the current allowed to flow for a long time by the bypass diodes is often smaller than the rated current of the shutoff device.

Disclosure of utility model

Therefore, a technical scheme of a fast turn-off device suitable for a photovoltaic module is provided, so as to solve the problem that the bypass diode is easy to damage due to overlarge current when the bypass diode is turned on by the existing turn-off device.

In order to achieve the above objective, in a first aspect, the present application provides an active bypass circuit suitable for a fast shutdown device of a photovoltaic module, where the photovoltaic module is connected in series to form a photovoltaic string after being connected to the shutdown device, the fast shutdown device includes a main switching tube, a bypass diode and a processor, when the main switching tube is in an on state, the photovoltaic module corresponding to the main switching tube is connected to the photovoltaic string, and when the main switching tube is in an off state, the photovoltaic module corresponding to the main switching tube is separated from the photovoltaic string, and the bypass diode is used for bypassing the corresponding photovoltaic module when the main switching tube is in an off state;

the active bypass circuit includes:

The state detection circuit is used for detecting the on-off state of the bypass diode and outputting a level signal according to the on-off state;

A bypass MOS tube connected in parallel with the bypass diode;

And the first switch driving circuit is used for driving the bypass MOS tube to be conducted according to a control signal of the processor when the main switch tube is in an off state and the bypass diode is in an on state, and is used for driving the bypass MOS tube to be turned off according to the control signal of the processor before the main switch tube is conducted, and the control signal of the processor is generated according to a level signal output by the state detection circuit.

Further, the state detection circuit comprises a voltage stabilizing circuit and a comparison circuit, wherein the comparison circuit comprises a comparator, and the comparator comprises an inverting input end, a non-inverting input end and an output end;

The voltage stabilizing circuit is connected with the bypass diode in parallel and is used for outputting a voltage stabilizing value, one end of the voltage stabilizing circuit, which is used for outputting the voltage stabilizing value, is connected with the inverting input end of the comparator, and the other end of the voltage stabilizing circuit is grounded;

and the non-inverting input end of the comparator is used for receiving a comparison threshold value, and the output end of the comparator is connected with the processor.

Further, the voltage stabilizing circuit comprises a voltage stabilizing diode, a first resistor and a first diode, the voltage stabilizing diode is reversely connected with the first diode, the cathode of the first diode is grounded, the anode of the first diode is connected with the anode of the voltage stabilizing diode, the cathode of the voltage stabilizing diode is connected with the inverting input end, and the first resistor is respectively connected with the cathode of the bypass diode and the cathode of the voltage stabilizing diode.

Further, the comparison circuit further comprises a second resistor, a third resistor and a fourth resistor;

The comparator is powered by adopting a positive power supply and a negative power supply, the third resistor is connected between the non-inverting input end and the output end of the comparator, the fourth resistor is connected between the positive electrode of the positive power supply and the output end of the comparator, one end of the second resistor is grounded, and the other end of the second resistor is connected with the non-inverting input end of the comparator;

The comparison circuit further comprises a second diode and a fifth resistor, wherein the anode of the second diode is connected with the output end of the comparator, the other end of the second diode is connected with the processor, one end of the fifth resistor is connected with the cathode of the second diode, and the other end of the fifth resistor is grounded.

Further, the comparator is a hysteresis comparator.

In a second aspect, the present application also provides a photovoltaic module quick shutdown device with an active bypass circuit, the device comprising:

the active bypass circuit is suitable for the photovoltaic module quick shutoff device according to the first aspect of the application;

The main switch tube is connected in series with the photovoltaic module;

a receiver for receiving the control signal transmitted by the signal transmitter;

the processor is electrically connected with the receiver and is used for sending out a signal for driving the main switching tube to be turned on or turned off according to the control signal received by the receiver;

The second switch driving circuit is electrically connected with the processor and is used for receiving the signal for driving the main switch tube to be turned on or turned off and driving the main switch tube to be turned on or turned off, when the main switch tube is in a conducting state, the photovoltaic module corresponding to the main switch tube is connected into the photovoltaic serial, and when the main switch tube is in a cutting-off state, the photovoltaic module corresponding to the main switch tube is separated from the photovoltaic serial;

And the bypass diode is used for bypassing the corresponding photovoltaic module when the main switching tube is in a cut-off state.

Furthermore, each photovoltaic module corresponds to a bypass MOS tube, and the main switching tubes of all the different photovoltaic modules are driven to be opened and closed by the same second switch driving circuit;

further, each photovoltaic module corresponds to an active bypass circuit and the second switch driving circuit, the main switch tubes of the photovoltaic modules are driven to be opened and closed through the corresponding second switch driving circuits, and the bypass MOS tubes of different photovoltaic modules are driven to be opened and closed through the corresponding first switch driving circuits in the active bypass circuits.

Further, each photovoltaic module corresponds to an active bypass circuit;

The main switch tube is driven to be opened and closed by the second switch driving circuit, and the MOS tube in each active bypass circuit is driven to be opened and closed by the first switch driving circuit in the corresponding active bypass circuit;

The device comprises an anode output end and a cathode output end;

The photovoltaic module comprises a first photovoltaic module and a second photovoltaic module, the active bypass circuit comprises a first active bypass circuit and a second active bypass circuit, the main switch tube comprises a first main switch tube and a second main switch tube, and the bypass diode comprises a first bypass diode and a second bypass diode;

the first photovoltaic module corresponds to the first active bypass circuit, the first main switching tube and the first bypass diode, and the second photovoltaic module corresponds to the second active bypass circuit, the second main switching tube and the second bypass diode;

The first bypass diode is connected with the positive electrode output end, one end of the second bypass diode is grounded, and the other end of the second bypass diode is connected with the negative electrode output end.

Compared with the prior art, the active bypass circuit and the device suitable for the photovoltaic module quick shutoff device according to the technical scheme are different from the prior art, the active bypass circuit comprises a state detection circuit, a bypass MOS tube and a first switch driving circuit, the state detection circuit is used for detecting the on-off state of the bypass diode and outputting a level signal according to the on-off state, the bypass MOS tube is connected with the bypass diode in parallel, and the first switch driving circuit is used for driving the bypass MOS tube to be conducted according to a control signal of a processor when the main switch tube is in an off state and the bypass diode is in an on state, and is used for driving the bypass MOS tube to be turned off according to the control signal of the processor before the main switch tube is conducted. Therefore, when the main switch tube is in a cut-off state and the bypass diode is in a conduction state, the current passing through the bypass diode can be effectively shared by controlling the conduction of the bypass MOS tube, the bypass diode is protected, and the reliability of the quick cut-off device is effectively improved.

The foregoing summary is merely an overview of the present utility model, and may be implemented according to the text and the accompanying drawings in order to make it clear to a person skilled in the art that the present utility model may be implemented, and in order to make the above-mentioned objects and other objects, features and advantages of the present utility model more easily understood, the following description will be given with reference to the specific embodiments and the accompanying drawings of the present utility model.

Drawings

The drawings are only for purposes of illustrating the principles, implementations, applications, features, and effects of the present application and are not to be construed as limiting the application.

In the drawings of the specification:

FIG. 1 is a schematic diagram of a prior art shutoff bypass drive;

Fig. 2 is a schematic block diagram of an active bypass circuit suitable for use in a fast shutdown of a photovoltaic module according to a first exemplary embodiment of the present application;

fig. 3 is a schematic diagram of a photovoltaic module quick turn-off apparatus with an active bypass circuit according to a first exemplary embodiment of the present application;

fig. 4 is a schematic diagram of a photovoltaic module quick turn-off apparatus with an active bypass circuit according to a second exemplary embodiment of the present application;

Fig. 5 is a schematic diagram of a photovoltaic module quick turn-off apparatus with an active bypass circuit according to a third exemplary embodiment of the present application;

FIG. 6 is a schematic diagram illustrating the operation of a hysteresis comparator according to an exemplary embodiment of the present application;

fig. 7 is a schematic diagram of a photovoltaic module quick turn-off apparatus with an active bypass circuit according to a fourth exemplary embodiment of the present application;

fig. 8 is a schematic diagram of a photovoltaic module quick turn-off apparatus with an active bypass circuit according to a fifth exemplary embodiment of the present application.

Reference numerals referred to in the above drawings are explained as follows:

100. An active bypass circuit;

101. A state detection circuit;

103. A first switch driving circuit;

104. a MOS tube;

102. a processor;

201. A signal transmitter;

202. A receiver;

203. a second switch driving circuit;

204. A main switching tube;

205. bypass diode.

Detailed Description

In order to describe the possible application scenarios, technical principles, practical embodiments, and the like of the present application in detail, the following description is made with reference to the specific embodiments and the accompanying drawings. The embodiments described herein are only for more clearly illustrating the technical aspects of the present application, and thus are only exemplary and not intended to limit the scope of the present application.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of the phrase "in various places in the specification are not necessarily all referring to the same embodiment, nor are they particularly limited to independence or relevance from other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment may be combined in any manner to form a corresponding implementable technical solution.

Unless defined otherwise, technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application pertains, and the use of related terms herein is intended only to describe specific embodiments, not to limit the present application.

In the description of the present application, the term "and/or" is a representation for describing a logical relationship between objects, meaning that three relationships may exist, for example, a and/or B, meaning that there are a, B, and both a and B. In addition, the character "/" herein generally indicates that the front-to-back associated object is an "or" logical relationship.

In the present application, terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual number, order, or sequence of such entities or operations.

Without further limitation, the use of the terms "comprising," "including," "having," or other like terms in this specification is intended to cover a non-exclusive inclusion, such that a process, method, or article of manufacture that comprises a list of elements does not include additional elements but may include other elements not expressly listed or inherent to such process, method, or article of manufacture.

In the present application, the expressions "greater than", "less than", "exceeding" and the like are understood to exclude the present number, and the expressions "above", "below", "within" and the like are understood to include the present number, as well as the expressions "examining the guideline" and the like. Furthermore, in the description of embodiments of the present application, the meaning of "a plurality of" is two or more (including two), and similarly, the expression "a plurality of" is also to be understood as such, for example, "a plurality of" and the like, unless specifically defined otherwise.

In the description of embodiments of the present application, spatially relative terms such as "center," "longitudinal," "transverse," "length," "width," "thickness," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counter-clockwise," "axial," "radial," "circumferential," etc., are used herein as a basis for the description of the embodiments or as a basis for the description of the embodiments, and are not intended to indicate or imply that the devices or components referred to must have a particular position, a particular orientation, or be configured or operated in a particular orientation and therefore should not be construed as limiting the embodiments of the present application.

Unless specifically stated or limited otherwise, the terms "mounted," "connected," "affixed," "disposed," and the like as used in the description of embodiments of the application should be construed broadly. For example, the "connection" may be a fixed connection, a detachable connection, or an integral connection, may be a mechanical connection, an electrical connection, or a communication connection, may be a direct connection or an indirect connection through an intermediary, or may be a communication between two elements or an interaction relationship between two elements. The specific meaning of the above terms in the embodiments of the present application can be understood by those skilled in the art to which the present application pertains according to circumstances.

As shown in fig. 2, in a first aspect, the present application provides an active bypass circuit suitable for a fast shutdown device of a photovoltaic module, where the photovoltaic module is connected in series to form a photovoltaic string after being connected to the shutdown device, the fast shutdown device includes a main switching tube, a bypass diode and a processor, when the main switching tube is in an on state, the photovoltaic module corresponding to the main switching tube is connected to the photovoltaic string, and when the main switching tube is in an off state, the photovoltaic module corresponding to the main switching tube is separated from the photovoltaic string, and the bypass diode is used for bypassing the corresponding photovoltaic module when the main switching tube is in an off state;

the active bypass circuit includes:

A state detection circuit 101, configured to detect an on-off state of the bypass diode, and output a level signal according to the on-off state;

a bypass MOS transistor 104 connected in parallel with the bypass diode;

And the first switch driving circuit 103 is used for driving the bypass MOS tube to be conducted according to a control signal of the processor 102 when the main switch tube is in an off state and the bypass diode is in an on state, and is used for driving the bypass MOS tube to be turned off according to the control signal of the processor 102 before the main switch tube is conducted, and the control signal of the processor 102 is generated according to a level signal output by the state detection circuit.

Preferably, the processor is a microcontroller (i.e., MCU), the microcontroller (Microcontroller Unit, MCU), also called a single-chip Microcomputer (SINGLE CHIP Microcomputer) or a single-chip Microcomputer, which is to properly reduce the frequency and specification of the central processing unit (Central Process Unit, CPU), integrate peripheral interfaces such as memory (Timer), USB, a/D conversion, UART, PLC, DMA, etc., and even the LCD first switch driving circuit on a single chip to form a chip-level computer, and perform different combination control for different application occasions. The MCU is adopted as a processor of the control module, so that the whole area of the transmitting device can be effectively reduced, and the production cost is reduced.

In this embodiment, the bypass MOS transistor 104 is a MOS transistor for performing a bypass function, and the MOS transistor is a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET for short), which is also called a MOS field effect transistor. The working principle of the MOS tube is based on the electronic characteristics in a semiconductor, and mainly comprises three areas of a grid electrode, a source electrode and a drain electrode of the MOS tube. When a positive bias is applied to the gate of the MOS transistor, a conductive region is formed under the gate, which forms a conducting channel between the drain and the source, so that current can flow from the source to the drain through the MOS transistor. In other words, when the gate voltage is higher than the source voltage, the MOS transistor is in an on state, and a current can flow through the MOS transistor. On the other hand, when a negative bias is applied to the gate of the MOS transistor, an electric field appears under the gate, which impedes the flow of current between the drain and the source. In other words, when the gate voltage is lower than the source voltage, the MOS transistor is in an off state, and current cannot pass through the MOS transistor. When the MOS transistor is switched between the on state and the off state, the charge in the MOS transistor is modulated, which causes movement of the charge through the MOS transistor and electron flow. This feature makes the MOS transistor very useful in digital and analog signal processing, as it can amplify and process signals.

In the present embodiment, the first switch driving circuit 103 is a circuit for controlling a switching element (such as a transistor) to realize switching of on and off states of the switching element. Specifically, the first switch driving circuit may be a driving transistor circuit for controlling on and off states of the MOS transistor or the BJT transistor. It typically includes a control signal source (e.g., a microprocessor or logic gate) and a cascaded driver circuit. The driving circuit ensures that the switching element is switched quickly and stably by increasing the current or voltage.

In this embodiment, when the main switch tube is in an off state and the bypass diode is in an on state, the first switch driving circuit 103 is configured to drive the bypass MOS tube to be turned on according to a control signal of the processor 102, and before the main switch tube is turned on, the first switch driving circuit is configured to drive the bypass MOS tube to be turned off according to a control signal of the processor 102, and the control signal of the processor 102 is generated according to a level signal output by the state detection circuit. For example, when the main switch tube is in an off state and the state detection circuit detects that the bypass diode is in an on state, a high-level signal can be sent to the processor, the processor receives the high-level signal and then sends a corresponding control signal to the first switch driving circuit so as to control the first switch driving circuit to drive the bypass MOS tube to be on, otherwise, before the main switch tube is on, the processor can send a signal for driving to be off to the first switch driving circuit so as to control the first switch driving circuit to drive the bypass MOS tube to be off.

In some embodiments, the state detection circuit includes a voltage stabilizing circuit and a comparison circuit including a comparator including an inverting input, a non-inverting input, and an output;

The voltage stabilizing circuit is connected with the bypass diode in parallel and is used for outputting a voltage stabilizing value, one end of the voltage stabilizing circuit, which is used for outputting the voltage stabilizing value, is connected with the inverting input end of the comparator, and the other end of the voltage stabilizing circuit is grounded;

and the non-inverting input end of the comparator is used for receiving a comparison threshold value, and the output end of the comparator is connected with the processor.

Further, the voltage stabilizing circuit comprises a voltage stabilizing diode, a first resistor and a first diode, the voltage stabilizing diode is reversely connected with the first diode, the cathode of the first diode is grounded, the anode of the first diode is connected with the anode of the voltage stabilizing diode, the cathode of the voltage stabilizing diode is connected with the inverting input end, and the first resistor is respectively connected with the cathode of the bypass diode and the cathode of the voltage stabilizing diode.

Further, the comparison circuit further comprises a second resistor, a third resistor and a fourth resistor;

The comparator is powered by adopting a positive power supply and a negative power supply, the third resistor is connected between the non-inverting input end and the output end of the comparator, the fourth resistor is connected between the positive electrode of the positive power supply and the output end of the comparator, one end of the second resistor is grounded, and the other end of the second resistor is connected with the non-inverting input end of the comparator.

As shown in fig. 5, the comparison circuit further includes a second diode (i.e., D ₃ in fig. 5) whose anode is connected to the output terminal of the comparator and whose other end is connected to the processor, and a fifth resistor (i.e., R ₅ in fig. 5) whose one end is connected to the cathode of the second diode and whose other end is grounded. Thus, the signal single item output by the output end of the comparator can be ensured to be conducted.

In this embodiment, the Zener Diode is also called a voltage drop Diode (Zener Diode), which is a special Diode. Unlike a normal diode, which can only be turned on when forward biased, a zener diode can stably output a fixed voltage when reverse biased. The principle of operation of a Zener diode is based on the Zener effect, i.e. when the reverse voltage exceeds a certain value, called the Zener breakdown voltage, the Zener diode will enter the breakdown region and the reverse current increases dramatically, thus keeping the voltage of the Zener diode at a stable level. Since zener diode is capable of providing a relatively stable voltage upon reverse breakdown, it is often used as a voltage stabilizer or reference voltage source in a circuit. When the voltage in the circuit changes or fluctuates, the zener diode automatically adjusts its reverse current to maintain the stability of the output voltage.

In this embodiment, the comparator is preferably a hysteresis comparator. The hysteresis comparator (HYSTERESIS COMPARATOR) is a circuit for comparing voltages and has hysteresis (hysteresis) characteristics. It is often used in applications that are resistant to interference and eliminate voltage noise. The basic principle of a hysteresis comparator is to change the threshold of the comparator by using positive feedback so that it has hysteresis characteristics. A positive feedback is connected between the output of the comparator and the non-inverting input, and feeds back to the input when the output state changes. In the hysteresis comparator, the output will flip to a high level when the input voltage exceeds a high threshold and to a low level when the input voltage is below a low threshold. The difference is that when the input voltage changes between a high threshold and a low threshold, the output will remain unchanged until the input voltage breaks through the threshold that has flipped. The hysteresis characteristics enable the hysteresis comparator to provide a more stable output in the presence of noise or disturbances in the input signal. By setting a suitable hysteresis amount, the interference immunity of the comparator can be improved, and meanwhile, reliable switching behavior is provided.

As shown in fig. 5, the voltage stabilizing circuit specifically includes a voltage stabilizing diode Dz (i.e. the voltage stabilizing diode described above) and a common diode D2 (i.e. the first diode described above) connected in anti-series, and the resistor R1 (i.e. the first resistor described above) can limit the maximum reverse current of the voltage stabilizing diode, prevent the voltage stabilizing diode from being overheated and damaged, and break down and conduct when the voltage loaded on the voltage stabilizing diode exceeds the voltage stabilizing value of the voltage stabilizing diode, thereby playing the role of voltage stabilizing. V _i is a voltage stabilizing value and is used as the input of a hysteresis comparator in the comparison circuit, compared with a single-threshold comparator, the hysteresis comparator has strong anti-interference capability, and the bypass diode can be judged to be conducted only when the conduction voltage drop of the bypass diode reaches a set threshold.

The two voltage threshold calculation formulas of the hysteresis comparator are as follows:

Wherein V _h represents an upper voltage threshold of the hysteresis comparator, V _l represents a lower voltage threshold of the hysteresis comparator, V _cc represents voltages at both ends of the hysteresis comparator, R ₂ represents a second resistor, R ₃ represents a third resistor, and R ₄ represents a fourth resistor.

As shown in fig. 6, the hysteresis comparator has input/output characteristics such that the threshold values of the positive and negative voltages can be set by selecting an appropriate feedback network, i.e., adjusting the values of the resistors R2, R3, and R4 to change the threshold voltage. When V _i>V_h shows that the bypass diode is cut off, the hysteresis comparator outputs a low level, and IO outputs a low level, and when V _i<V_l shows that the bypass diode is turned on, the hysteresis comparator outputs a high level, and IO outputs a high level. The IO processor (such as MCU) generates a control signal of the MOS tube, and the MOS tube is controlled to be turned on through the first switch driving circuit.

As shown in fig. 3 and 4, in a second aspect, the present application provides a photovoltaic module quick turn-off apparatus with an active bypass circuit, the apparatus comprising:

The active bypass circuit 100 is an active bypass circuit suitable for a photovoltaic module quick shutoff device according to the first aspect of the present application;

A main switching tube 204 connected in series with the photovoltaic module;

a receiver 202 for receiving the control signal transmitted by the signal transmitter;

the processor 102 is electrically connected with the receiver and is used for sending out a signal for driving the main switching tube to be turned on or turned off according to a control signal received by the receiver;

The second switch driving circuit 203 is electrically connected with the processor, and is configured to receive the signal for driving the main switch tube to be turned on or turned off, and drive the main switch tube to be turned on or turned off, when the main switch tube is in a conducting state, the photovoltaic module corresponding to the main switch tube is connected to the photovoltaic string, and when the main switch tube is in a cutting-off state, the photovoltaic module corresponding to the main switch tube is separated from the photovoltaic string;

Bypass diode 205 is used for bypassing the corresponding photovoltaic module when the main switching tube is in the off state.

The working principle of the device is that the main switch tube 204 is controlled by a communication signal sent by the signal transmitter 201, the communication signal can be a power line carrier signal or a wireless communication signal, the receiver 202 receives the communication signal sent by the signal transmitter 201, and the processor 102 generates a corresponding driving control signal according to the communication signal to control the second switch driving circuit 203 (in fig. 4, the second switch driving circuit is a driving circuit communicatively connected with the receiver near the left side) to drive the on-off of the main switch tube. For example, when the main switch tube is in an off state and the bypass diode is in an on state, the bypass MOS tube is controlled to be conducted through the processor, so that the current passing through the bypass diode is effectively shared, the bypass diode is protected, and the reliability of the quick turn-off device is effectively improved. When the photovoltaic module needs to be restored to work, the bypass MOS tube can be closed before the main light-opening tube is opened, so that short circuit is avoided.

In some embodiments, each photovoltaic module corresponds to a bypass MOS transistor, the main switching transistors of all the different photovoltaic modules are driven to be turned on and turned off by the same second switch driving circuit, and all the different bypass MOS transistors are driven to be turned on and turned off by the same first switch driving circuit.

As shown in fig. 7, the receiver is responsible for receiving the communication signal sent by the signal transmitter, and this communication signal is used to control the on and off of the main switching tubes S1 (i.e., the main switching tube 1) and S2 (i.e., the main switching tube 2), so as to implement a function of quick turn-off. The communication signal may be a power line carrier signal or a wireless communication signal. The state detection circuit is used for detecting the on-off state of the bypass diode D1, and when the conduction voltage drop of the bypass diode reaches a set threshold value, the bypass diode D1 is stabilized at Vi through the current-limiting resistor R1, the voltage-stabilizing diode Dz and the diode D2. Vi is then used as the input of the hysteresis comparator, vh is the high threshold of the hysteresis comparator, vl is the low threshold, according to the calculation formula of the threshold, when Vi > Vh, the bypass diode is indicated to be cut off, the hysteresis comparator outputs a low level, IO outputs a low level, when Vi < Vl, the bypass diode is indicated to be conducted, when the hysteresis comparator outputs a high level, IO outputs a high level, and the bypass MOS transistor Q1 is controlled to be opened through a processor (such as a microcontroller, MCU) by a first switch driving circuit (which is a driving circuit connected with two MOS transistors on the right side in FIG. 7). The voltage stabilizing tube with 1V is taken, the conduction voltage drop of the diode D2 is 0.5V, when the bypass diode is conducted, the Vi voltage is stabilized at-1.5V, when the bypass diode is cut off, the Vi voltage is stabilized at 1.5V, vcc is the power supply voltage of the hysteresis comparator, 3.3V is taken, and in order to ensure that the voltage stabilizing tube can work in the effective rated working current, the current limiting resistor R1=8.2kΩ. Let r2=2kΩ be set, r3=60 kΩ of the total number of the samples, r4=10kΩ of the total number of the components, vh=0.092v, vl= -0.106V.

Through the design, when the bypass diode D1 is detected to be conducted, the parallel bypass MOS transistors Q1 and Q2 are driven to be turned on simultaneously, and the bypass MOS transistors Q1 and Q2 are turned off before the main light-on tubes S1 and S2 are turned on.

Of course, in other embodiments, each photovoltaic module corresponds to an active bypass circuit and the second switch driving circuit, the main switch tube of the photovoltaic module is driven to be turned on or turned off by the corresponding second switch driving circuit, and the bypass MOS tubes of the different photovoltaic modules are driven to be turned on or turned off by the corresponding first switch driving circuits in the active bypass circuits.

Further, each photovoltaic module corresponds to an active bypass circuit;

The main switch tube is driven to be opened and closed by the second switch driving circuit, and the MOS tube in each active bypass circuit is driven to be opened and closed by the first switch driving circuit in the corresponding active bypass circuit;

The device comprises an anode output end and a cathode output end;

The photovoltaic module comprises a first photovoltaic module and a second photovoltaic module, the active bypass circuit comprises a first active bypass circuit and a second active bypass circuit, the main switch tube comprises a first main switch tube and a second main switch tube, and the bypass diode comprises a first bypass diode and a second bypass diode;

the first photovoltaic module corresponds to the first active bypass circuit, the first main switching tube and the first bypass diode, and the second photovoltaic module corresponds to the second active bypass circuit, the second main switching tube and the second bypass diode;

The first bypass diode is connected with the positive electrode output end, one end of the second bypass diode is grounded, and the other end of the second bypass diode is connected with the negative electrode output end.

Fig. 8 is a schematic diagram of a photovoltaic module rapid shutdown device with an active bypass circuit according to a fifth exemplary embodiment of the present application. Compared with the fourth embodiment of fig. 7, the bypass switch driving signal for driving the bypass MOS transistor Q2 in this example is controlled by detecting the turn-on voltage of the bypass diode D4 (i.e., the second bypass diode), and the control circuit can control the on and off of the main switch transistors S1 (i.e., the first main switch transistor) and S2 (i.e., the second main switch transistor) according to the communication signal detected by the receiver, respectively. When the first photovoltaic module is abnormal in communication, the main switch tube S1 is disconnected, the bypass diode D1 (namely the first diode) is conducted, and a follow current channel is provided for power bus current. When the voltage detection circuit detects that the conduction voltage drop of the bypass diode D1 reaches a set threshold value, the parallel bypass MOS transistor Q1 is driven to be turned on, so that the purposes of reducing the loss of the bypass diode D1 and improving the reliability are achieved. When the second photovoltaic module is abnormal, the state detection circuit detects that the conduction voltage drop of the bypass diode D4 reaches a set threshold value, a low level is output through the hysteresis comparator, and the opening of the bypass MOS tube Q2 is controlled through a processor (such as a microcontroller, MCU) and a driving circuit. In this embodiment, the flexibility of the quick-cut-off can be enhanced by providing the respective state detection circuits for the different bypass diodes, respectively, with respect to the fourth embodiment shown in fig. 7.

Of course, the embodiment shown in fig. 7 and 8 only takes the active bypass circuit of two input ports as an example, but the number of the active bypass circuits is not limited thereto, and may be other numbers, such as three, four, etc.

It should be noted that, although the foregoing embodiments have been described herein, the scope of the present utility model is not limited thereby. Therefore, based on the innovative concepts of the present utility model, alterations and modifications to the embodiments described herein, or equivalent structures or equivalent flow transformations made by the present description and drawings, apply the above technical solutions directly or indirectly to other relevant technical fields, all of which are included in the scope of protection of the present patent.

Claims (9)

1. An active bypass circuit suitable for a fast shutoff device of a photovoltaic module is characterized in that,

The photovoltaic module is connected in series after being connected into the shutoff device to form a photovoltaic serial, the quick shutoff device comprises a main switch tube, a bypass diode and a processor, the processor is a microcontroller, when the main switch tube is in a conducting state, the photovoltaic module corresponding to the main switch tube is connected into the photovoltaic serial, when the main switch tube is in a cut-off state, the photovoltaic module corresponding to the main switch tube is separated from the photovoltaic serial, and the bypass diode is used for bypassing the corresponding photovoltaic module when the main switch tube is in the cut-off state;

the active bypass circuit includes:

The state detection circuit is used for detecting the on-off state of the bypass diode and outputting a level signal according to the on-off state;

A bypass MOS tube connected in parallel with the bypass diode;

And the first switch driving circuit is used for driving the bypass MOS tube to be conducted according to a control signal of the processor when the main switch tube is in an off state and the bypass diode is in an on state, and is used for driving the bypass MOS tube to be turned off according to the control signal of the processor before the main switch tube is conducted, and the control signal of the processor is generated according to a level signal output by the state detection circuit.

2. The active bypass circuit for a fast shutdown of a photovoltaic module of claim 1, wherein the state detection circuit comprises a voltage stabilizing circuit and a comparison circuit, the comparison circuit comprising a comparator comprising an inverting input, a non-inverting input, and an output;

The voltage stabilizing circuit is connected with the bypass diode in parallel and is used for outputting a voltage stabilizing value, one end of the voltage stabilizing circuit, which is used for outputting the voltage stabilizing value, is connected with the inverting input end of the comparator, and the other end of the voltage stabilizing circuit is grounded;

and the non-inverting input end of the comparator is used for receiving a comparison threshold value, and the output end of the comparator is connected with the processor.

3. The active bypass circuit for a fast shutdown of a photovoltaic module according to claim 2, wherein the voltage stabilizing circuit comprises a voltage stabilizing diode, a first resistor and a first diode, the voltage stabilizing diode and the first diode are reversely connected, a cathode of the first diode is grounded, an anode of the first diode is connected with an anode of the voltage stabilizing diode, a cathode of the voltage stabilizing diode is connected with the inverting input terminal, and the first resistor is respectively connected with a cathode of the bypass diode and a cathode of the voltage stabilizing diode.

4. The active bypass circuit for a fast shutdown of a photovoltaic module of claim 2, wherein the comparison circuit further comprises a second resistor, a third resistor, and a fourth resistor;

The comparator is powered by adopting a positive power supply and a negative power supply, the third resistor is connected between the non-inverting input end and the output end of the comparator, the fourth resistor is connected between the positive electrode of the positive power supply and the output end of the comparator, one end of the second resistor is grounded, and the other end of the second resistor is connected with the non-inverting input end of the comparator;

The comparison circuit further comprises a second diode and a fifth resistor, wherein the anode of the second diode is connected with the output end of the comparator, the other end of the second diode is connected with the processor, one end of the fifth resistor is connected with the cathode of the second diode, and the other end of the fifth resistor is grounded.

5. The active bypass circuit for a fast shutdown of a photovoltaic module according to any one of claims 2 to 4, wherein the comparator is a hysteretic comparator.

6. A photovoltaic module quick shut down device with an active bypass circuit, the device comprising:

An active bypass circuit as claimed in any one of claims 1 to 5, adapted for use in a fast shutdown of a photovoltaic module;

The main switch tube is connected in series with the photovoltaic module;

a receiver for receiving the control signal transmitted by the signal transmitter;

the processor is electrically connected with the receiver and is used for sending out a signal for driving the main switching tube to be turned on or turned off according to the control signal received by the receiver;

The second switch driving circuit is electrically connected with the processor and is used for receiving the signal for driving the main switch tube to be turned on or turned off and driving the main switch tube to be turned on or turned off, when the main switch tube is in a conducting state, the photovoltaic module corresponding to the main switch tube is connected into the photovoltaic serial, and when the main switch tube is in a cutting-off state, the photovoltaic module corresponding to the main switch tube is separated from the photovoltaic serial;

And the bypass diode is used for bypassing the corresponding photovoltaic module when the main switching tube is in a cut-off state.

7. The photovoltaic module quick turn-off apparatus with active bypass circuit according to claim 6,

Each photovoltaic module corresponds to a bypass MOS tube, the main switching tubes of all different photovoltaic modules are driven to be opened and closed by the same second switch driving circuit, and all different bypass MOS tubes are driven to be opened and closed by the same first switch driving circuit.

8. The rapid turn-off apparatus of photovoltaic modules with active bypass circuits according to claim 6, wherein each photovoltaic module corresponds to an active bypass circuit and the second switch driving circuit, the main switching tube of the photovoltaic module is driven to be turned on or turned off by the corresponding second switch driving circuit, and the bypass MOS tube of different photovoltaic modules is driven to be turned on or turned off by the corresponding first switch driving circuit in the active bypass circuit.

9. The photovoltaic module quick turn-off apparatus with active bypass circuit according to claim 6, wherein each photovoltaic module corresponds to an active bypass circuit;

The main switch tube is driven to be opened and closed by the second switch driving circuit, and the MOS tube in each active bypass circuit is driven to be opened and closed by the first switch driving circuit in the corresponding active bypass circuit;

The device comprises an anode output end and a cathode output end;

The photovoltaic module comprises a first photovoltaic module and a second photovoltaic module, the active bypass circuit comprises a first active bypass circuit and a second active bypass circuit, the main switch tube comprises a first main switch tube and a second main switch tube, and the bypass diode comprises a first bypass diode and a second bypass diode;

the first photovoltaic module corresponds to the first active bypass circuit, the first main switching tube and the first bypass diode, and the second photovoltaic module corresponds to the second active bypass circuit, the second main switching tube and the second bypass diode;

The first bypass diode is connected with the positive electrode output end, one end of the second bypass diode is grounded, and the other end of the second bypass diode is connected with the negative electrode output end.