Active bypass circuit and device suitable for rapid turn-off device of photovoltaic module

Abstract

The utility model discloses an active bypass circuit and device suitable for a photovoltaic assembly rapid turn-off device, 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 a bypass diode and outputting a level signal according to the on-off state, and the first switch driving circuit is used for driving the bypass MOS tube to switch on and off. 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 the processor when the main switch tube is in a cut-off state and the bypass diode is in a conducting state. Thus, when the main switch tube is in a cut-off state and the bypass diode is in a conducting state, the current passing through the bypass diode can be effectively shared by controlling the bypass MOS tube to be conducted, the effect of protecting the bypass diode is achieved, and the reliability of the quick turn-off device is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of safety protection equipment for photovoltaic power generation systems, and in particular to an active bypass circuit and a device suitable for a photovoltaic component fast shut-off device. Background Art

[0002] In recent years, the installed capacity of photovoltaic power generation has increased rapidly year by year, and photovoltaic power generation technology has developed rapidly. Due to its mature technology, high conversion efficiency, high integration, and low price, string photovoltaic systems have been widely used in distributed photovoltaic systems such as balconies and roofs in individual households. When a fire occurs in a photovoltaic power generation system, the DC high voltage of the string photovoltaic power generation system will cause arcing, fire, and electric shock hazards, which will bring great safety hazards and difficulties to the fire fighting operation. In order to improve the safety of the string photovoltaic power generation system, each photovoltaic cell is equipped with a component-level fast shutdown device, such as a circuit breaker. In the event of an abnormal situation such as a fire, the circuit breaker is used to cut off the output of each photovoltaic cell, reduce the DC output voltage of the photovoltaic system, and thus reduce the construction risk of maintenance personnel.

[0003] The photovoltaic module shutdown device includes a receiver, a control module and a main switch tube. The control module controls the on and off of the main switch tube according to the signal sent by the receiver. The receiver is responsible for detecting the communication signal sent by the transmitter. The photovoltaic module shutdown device is equipped with a bypass diode. When the main switch tube of the module is disconnected or fails, the current of other normally operating photovoltaic modules can continue to flow through the bypass diode to achieve the purpose of shutdown.

[0004] The mainstream photovoltaic panel circuit breakers on the market are generally equipped with two input ports to connect two photovoltaic panels. Figure 1 As shown, the circuit breaker includes a sampling module, a control module, bypass diodes D1 and D2, and main switches S1 and S2. When one of the photovoltaic modules is abnormal, the corresponding main switch is cut off, and the bypass diode provides a freewheeling channel for the power bus current. However, the voltage drop of the diode is large, and it increases with the increase of the current flowing through it, which will generate a lot of heat loss. In severe cases, it will cause the diode to be damaged and cause the circuit breaker to malfunction. Usually, multiple bypass diodes are connected in parallel to share the loss, but this cannot fundamentally solve the problem. The current that the bypass diode allows to flow for a long time is often less than the rated current of the circuit breaker. Utility Model Content

[0005] Therefore, it is necessary to provide a technical solution for a fast switch for photovoltaic modules to solve the problem that the bypass diode is easily damaged due to excessive current when the bypass diode is turned on.

[0006] To achieve the above-mentioned purpose, in a first aspect, the present application provides an active bypass circuit suitable for a photovoltaic module fast shut-down device, wherein the photovoltaic modules are connected to the shut-down device and then connected in series to form a photovoltaic series, and the fast shut-down device comprises a main switch tube, a bypass diode and a processor, and when the main switch tube is in an on state, the photovoltaic module corresponding to the main switch tube is connected to the photovoltaic series, and when the main switch tube is in an off state, the photovoltaic module corresponding to the main switch tube is disconnected from the photovoltaic series, and the bypass diode is used to bypass the corresponding photovoltaic module when the main switch tube is in an off state;

[0007] The active bypass circuit comprises:

[0008] A state detection circuit, used for detecting the on-off state of the bypass diode and outputting a level signal according to the on-off state;

[0009] A bypass MOS tube connected in parallel with the bypass diode;

[0010] The first switch driving circuit is used to drive the bypass MOS tube to turn on according to the control signal of the processor when the main switch tube is in the off state and the bypass diode is in the on state. Before the main switch tube is turned on, the first switch driving circuit is used to drive the bypass MOS tube to turn off according to the control signal of the processor, and the control signal of the processor is generated according to the level signal output by the state detection circuit.

[0011] Further, the state detection circuit includes a voltage stabilizing circuit and a comparison circuit, the comparison circuit includes a comparator, and the comparator includes an inverting input terminal, a non-inverting input terminal and an output terminal;

[0012] The voltage stabilizing circuit is connected in parallel with the bypass diode and is used to output a regulated voltage value. One end of the voltage stabilizing circuit used to output the regulated voltage value is connected to the inverting input end of the comparator, and the other end of the voltage stabilizing circuit is grounded.

[0013] The non-inverting input terminal of the comparator is used to receive a comparison threshold, and the output terminal of the comparator is connected to the processor.

[0014] Furthermore, the voltage stabilizing circuit includes a voltage stabilizing diode, a first resistor and a first diode, the voltage stabilizing diode and the first diode are connected in reverse, the cathode of the first diode is grounded, the anode of the first diode is connected to the anode of the voltage stabilizing diode, the cathode of the voltage stabilizing diode is connected to the inverting input terminal, and the first resistor is respectively connected to the cathode of the bypass diode and the cathode of the voltage stabilizing diode.

[0015] Furthermore, the comparison circuit also includes a second resistor, a third resistor, and a fourth resistor;

[0016] The comparator is powered by a positive and negative power supply, the third resistor is connected between the in-phase input terminal and the output terminal of the comparator, the fourth resistor is connected between the positive electrode of the positive and negative power supply and the output terminal of the comparator, one end of the second resistor is grounded, and the other end is connected to the in-phase input terminal of the comparator;

[0017] The comparison circuit also includes a second diode and a fifth resistor, wherein an anode of the second diode is connected to the output end of the comparator and the other end is connected to the processor, and one end of the fifth resistor is connected to the cathode of the second diode and the other end is grounded.

[0018] Furthermore, the comparator is a hysteresis comparator.

[0019] In a second aspect, the present application also provides a photovoltaic assembly rapid shutdown device with an active bypass circuit, the device comprising:

[0020] An active bypass circuit is an active bypass circuit applicable to a photovoltaic module fast shut-down device as described in the first aspect of the present application;

[0021] The main switch tube is connected in series with the photovoltaic module;

[0022] A receiver, used for receiving a control signal sent by a signal transmitter;

[0023] A processor, electrically connected to the receiver, and configured to send a signal to drive the main switch tube to turn on or off according to a control signal received by the receiver;

[0024] A second switch driving circuit is electrically connected to the processor and is used to receive the signal for driving the main switch tube to be turned on or off, and drive the main switch tube to be turned on or off. When the main switch tube is in the on state, the photovoltaic component corresponding to the main switch tube is connected to the photovoltaic series, and when the main switch tube is in the off state, the photovoltaic component corresponding to the main switch tube is disconnected from the photovoltaic series;

[0025] The bypass diode is used to bypass the corresponding photovoltaic component when the main switch tube is in the cut-off state.

[0026] Furthermore, each photovoltaic module corresponds to a bypass MOS tube, and the main switch tubes of all different photovoltaic modules are driven to open and close by the same second switch driving circuit; and all different bypass MOS tubes are driven to open and close by the same first switch driving circuit;

[0027] Furthermore, each photovoltaic component corresponds to an active bypass circuit and the second switch driving circuit, and the main switch tube of the photovoltaic component is driven to open and close by the corresponding second switch driving circuit; and the bypass MOS tubes of different photovoltaic components are driven to open and close by the first switch driving circuit in the corresponding active bypass circuit.

[0028] Furthermore, each photovoltaic module corresponds to an active bypass circuit;

[0029] The main switch tube is driven to open and close by the second switch driving circuit, and the MOS tube in each active bypass circuit is driven to open and close by the first switch driving circuit in the corresponding active bypass circuit;

[0030] The device includes a positive output terminal and a negative output terminal;

[0031] The photovoltaic assembly includes a first photovoltaic assembly and a second photovoltaic assembly, the active bypass circuit includes a first active bypass circuit and a second active bypass circuit, the main switch tube includes a first main switch tube and a second main switch tube, and the bypass diode includes a first bypass diode and a second bypass diode;

[0032] The first photovoltaic assembly corresponds to the first active bypass circuit, the first main switch tube, and the first bypass diode, and the second photovoltaic assembly corresponds to the second active bypass circuit, the second main switch tube, and the second bypass diode;

[0033] The first bypass diode is connected to the positive output terminal, one end of the second bypass diode is grounded, and the other end is connected to the negative output terminal.

[0034] Different from the prior art, the active bypass circuit and device for the photovoltaic module fast shutoff device described in the above technical solution include a state detection circuit, a bypass MOS tube and a first switch driving circuit. The state detection circuit is used to detect the on-off state of the bypass diode and output a level signal according to the on-off state. The bypass MOS tube is connected in parallel with the bypass diode. When the main switch tube is in the off state and the bypass diode is in the on state, the first switch driving circuit is used to drive the bypass MOS tube to turn on according to the control signal of the processor, and before the main switch tube is turned on, the first switch driving circuit is used to drive the bypass MOS tube to turn off according to the control signal of the processor. In this way, when the main switch tube is in the off state and the bypass diode is in the on state, the current passing through the bypass diode can be effectively shared by controlling the bypass MOS tube to turn on, which plays a role in protecting the bypass diode and effectively improving the reliability of the fast shutoff device.

[0035] The above-mentioned records related to the content of the utility model are only an overview of the technical solution of the present application. In order to enable ordinary technicians in the field to more clearly understand the technical solution of the present application, and then implement it according to the text of the specification and the contents recorded in the drawings, and to make the above-mentioned purpose and other purposes, features and advantages of the present application easier to understand, the following is an explanation in combination with the specific implementation method and drawings of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings are only used to illustrate the principles, implementation methods, applications, characteristics and effects of the specific embodiments of the present application and other related contents, and shall not be considered as limitations of the present application.

[0037] In the drawings of the specification:

[0038] Figure 1 A schematic diagram of a circuit breaker bypass drive device according to the prior art;

[0039] Figure 2 This is a module schematic diagram of an active bypass circuit applicable to a photovoltaic module fast shutdown device according to a first exemplary embodiment of the present application;

[0040] Figure 3 A schematic diagram of a photovoltaic assembly rapid shutdown device with an active bypass circuit according to a first exemplary embodiment of the present application;

[0041] Figure 4 A schematic diagram of a photovoltaic assembly rapid shutdown device with an active bypass circuit according to a second exemplary embodiment of the present application;

[0042] Figure 5 A schematic diagram of a photovoltaic assembly rapid shutdown device with an active bypass circuit according to a third exemplary embodiment of the present application;

[0043] Figure 6 A schematic diagram of the working principle of a hysteresis comparator involved in an exemplary embodiment of the present application;

[0044] Figure 7 A schematic diagram of a photovoltaic assembly rapid shutdown device with an active bypass circuit according to a fourth exemplary embodiment of the present application;

[0045] Figure 8 It is a schematic diagram of a photovoltaic assembly rapid shutdown device with an active bypass circuit according to a fifth exemplary embodiment of the present application.

[0046] The reference numerals in the above drawings are described as follows:

[0047] 100. Active bypass circuit;

[0048] 101. Status detection circuit;

[0049] 103. A first switch driving circuit;

[0050] 104. MOS tube;

[0051] 102. Processor;

[0052] 201. Signal transmitter;

[0053] 202, receiver;

[0054] 203. A second switch driving circuit;

[0055] 204, main switch tube;

[0056] 205. Bypass diode. DETAILED DESCRIPTION

[0057] In order to explain in detail the possible application scenarios, technical principles, specific schemes that can be implemented, and the purposes and effects that can be achieved, the following is a detailed description of the specific embodiments listed in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0058] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0059] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0060] In the description of this application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that three relationships may exist, for example, A and / or B, which means: A exists, B exists, and A and B exist at the same time. In addition, the character " / " in this article generally indicates that the objects before and after are in an "or" logical relationship.

[0061] In the present application, terms such as “first” and “second” are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship of quantity, priority or sequence between these entities or operations.

[0062] Without further limitations, in this application, the words "include", "comprises", "has" or other similar expressions used in the sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product including the elements, so that the process, method or product including a series of elements may include not only those limited elements, but also other elements not explicitly listed, or also include elements inherent to such process, method or product.

[0063] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than", "less than", "exceed" and the like are understood to exclude the number itself; expressions such as "above", "below", "within" and the like are understood to include the number itself. In addition, in the description of the embodiments of this application, "multiple" means more than two (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups", "multiple times", etc., unless otherwise clearly and specifically limited.

[0064] In the description of the embodiments of the present application, space-related expressions used, such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or position relationship based on the orientation or position relationship shown in the specific embodiments or drawings, and are only for the convenience of describing the specific embodiments of the present application or facilitating the reader's understanding, and do not indicate or imply that the referred device or component must have a specific position, a specific orientation, or be constructed or operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0065] Unless otherwise expressly specified or limited, in the description of the embodiments of the present application, the terms such as "install", "connect", "connect", "fix", "set", etc. used should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integrated setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For technicians in the technical field to which the present application belongs, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0066] like Figure 2As shown, in the first aspect, the present application provides an active bypass circuit suitable for a photovoltaic component fast shut-off device, wherein the photovoltaic components are connected in series to form a photovoltaic string after being connected to the shut-off device, and the fast shut-off device comprises a main switch tube, a bypass diode and a processor, and when the main switch tube is in an on state, the photovoltaic component corresponding to the main switch tube is connected to the photovoltaic string, and when the main switch tube is in an off state, the photovoltaic component corresponding to the main switch tube is disconnected from the photovoltaic string, and the bypass diode is used to bypass the corresponding photovoltaic component when the main switch tube is in an off state;

[0067] The active bypass circuit comprises:

[0068] A state detection circuit 101, used for detecting the on-off state of the bypass diode and outputting a level signal according to the on-off state;

[0069] A bypass MOS tube 104 is connected in parallel with the bypass diode;

[0070] The first switch driving circuit 103 is used to drive the bypass MOS tube to turn on according to the control signal of the processor 102 when the main switch tube is in the off state and the bypass diode is in the on state. Before the main switch tube is turned on, the first switch driving circuit is used to drive the bypass MOS tube to turn off according to the control signal of the processor 102. The control signal of the processor 102 is generated according to the level signal output by the state detection circuit.

[0071] Preferably, the processor is a microcontroller (MCU), which is also called a single chip microcomputer or a single chip microcomputer. The frequency and specifications of the central processing unit (CPU) are appropriately reduced, and the peripheral interfaces such as memory, timer, USB, A / D conversion, UART, PLC, DMA, and even the LCD first switch drive circuit are integrated on a single chip to form a chip-level computer, which performs different combination controls for different application scenarios. Using MCU as the processor of the control module can effectively reduce the overall area of ​​the transmitting device and reduce production costs.

[0072] In this embodiment, the bypass MOS tube 104 refers to a MOS tube used to play a bypass function. The MOS tube is a metal-oxide-semiconductor field-effect transistor (Metal-Oxide-Semiconductor Field-Effect Transistor, referred to as MOSFET), also known as a MOS field effect tube. The working principle of the MOS tube is based on the electronic characteristics of semiconductors, and is mainly composed of three regions: the gate, source, and drain of the MOS tube. When a positive bias is applied to the gate of the MOS tube, a conductive region is formed under the gate, which forms a conduction channel between the drain and the source, so that the current can flow from the source to the drain through the MOS tube. In other words, when the gate voltage is higher than the source voltage, the MOS tube is in a conducting state, and the current can flow through the MOS tube. On the other hand, when a negative bias is applied to the gate of the MOS tube, an electric field appears under the gate, which will hinder the current flow between the drain and the source. In other words, when the gate voltage is lower than the source voltage, the MOS tube is in a cut-off state, and the current cannot pass through the MOS tube. When the MOS tube switches between the on state and the off state, the charge in the MOS tube will be modulated, which will cause the movement of charge through the MOS tube and the flow of electrons. This characteristic makes the MOS tube very useful in digital and analog signal processing because it can amplify and process signals.

[0073] In this embodiment, the first switch driving circuit 103 is a circuit for controlling a switch element (such as a transistor, etc.) to switch between the on and off states of the switch element. Specifically, the first switch driving circuit may be a driving transistor circuit, which is used to control the on and off states of a MOS tube or a BJT transistor. It generally includes a control signal source (such as a microprocessor or a logic gate) and a cascaded driving circuit. The driving circuit ensures that the switch element switches quickly and stably by increasing the current or voltage.

[0074] In this embodiment, when the main switch tube is in the off state and the bypass diode is in the on state, the first switch driving circuit 103 is used to drive the bypass MOS tube to turn on according to the control signal of the processor 102. Before the main switch tube is turned on, the first switch driving circuit is used to drive the bypass MOS tube to turn off according to the control signal of the processor 102. The control signal of the processor 102 is generated according to the level signal output by the state detection circuit. For example, when the main switch tube is in the off state and the state detection circuit detects that the bypass diode is in the on state, a high level signal can be sent to the processor. After receiving the high level signal, the processor sends a corresponding control signal to the first switch driving circuit to control the first switch driving circuit to drive the bypass MOS tube to turn on. Conversely, before the main switch tube is turned on, the processor can send a signal for driving the turn-off to the first switch driving circuit to control the first switch driving circuit to drive the bypass MOS tube to turn off.

[0075] In some embodiments, the state detection circuit includes a voltage stabilization circuit and a comparison circuit, the comparison circuit includes a comparator, and the comparator includes an inverting input terminal, a non-inverting input terminal, and an output terminal;

[0076] The voltage stabilizing circuit is connected in parallel with the bypass diode and is used to output a regulated voltage value. One end of the voltage stabilizing circuit used to output the regulated voltage value is connected to the inverting input end of the comparator, and the other end of the voltage stabilizing circuit is grounded.

[0077] The non-inverting input terminal of the comparator is used to receive a comparison threshold, and the output terminal of the comparator is connected to the processor.

[0078] Furthermore, the voltage stabilizing circuit includes a voltage stabilizing diode, a first resistor and a first diode, the voltage stabilizing diode and the first diode are connected in reverse, the cathode of the first diode is grounded, the anode of the first diode is connected to the anode of the voltage stabilizing diode, the cathode of the voltage stabilizing diode is connected to the inverting input terminal, and the first resistor is respectively connected to the cathode of the bypass diode and the cathode of the voltage stabilizing diode.

[0079] Furthermore, the comparison circuit also includes a second resistor, a third resistor, and a fourth resistor;

[0080] The comparator is powered by positive and negative power supplies, the third resistor is connected between the in-phase input terminal and the output terminal of the comparator, the fourth resistor is connected between the positive pole of the positive and negative power supplies and the output terminal of the comparator, one end of the second resistor is grounded, and the other end is connected to the in-phase input terminal of the comparator.

[0081] like Figure 5As shown, the comparison circuit also includes a second diode (i.e. Figure 5 D 3 ) and the fifth resistor (i.e. Figure 5 R 5 ), the anode of the second diode is connected to the output end of the comparator, and the other end is connected to the processor, one end of the fifth resistor is connected to the cathode of the second diode, and the other end is grounded. In this way, it can ensure that the signal output from the output end of the comparator is unidirectionally conducted.

[0082] In this embodiment, the Zener diode is also called a voltage drop diode (Zener Diode), which is a special diode. Unlike ordinary diodes that can only be turned on when forward biased, the Zener diode can stably output a fixed voltage when reverse biased. The working principle of the Zener diode is based on the Zener effect, that is, 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 will increase sharply, so that the voltage of the Zener diode is maintained at a stable level. Since the Zener diode can provide a relatively stable voltage when it breaks down in reverse, it is often used as a voltage stabilizer or reference voltage source in the circuit. When the voltage in the circuit changes or fluctuates, the Zener diode will automatically adjust its reverse current to maintain the stability of the output voltage.

[0083] In this embodiment, the comparator is preferably a hysteresis comparator. A hysteresis comparator is a circuit for comparing voltages and has a hysteresis characteristic. It is often used in applications for anti-interference and voltage noise elimination. The basic principle of a hysteresis comparator is to change the threshold of the comparator by using positive feedback, so that it has a hysteresis characteristic. The positive feedback is connected between the output terminal and the non-inverting input terminal of the comparator, and is fed back to the input terminal when the output state changes. In a hysteresis comparator, when the input voltage exceeds a high threshold, the output will flip to a high level; and when the input voltage is lower than a low threshold, the output will flip to a low level. 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 been flipped. The hysteresis characteristic enables the hysteresis comparator to provide a more stable output when there is noise or interference in the input signal. By setting an appropriate hysteresis amount, the anti-interference performance of the comparator can be improved while providing reliable switching behavior.

[0084] like Figure 5As shown, in the voltage stabilizing circuit, it specifically includes: a voltage stabilizing diode Dz (i.e., the voltage stabilizing diode mentioned above) and a common diode D2 (i.e., the first diode mentioned above) are connected in anti-series, and the resistor R1 (i.e., the first resistor mentioned above) can limit the maximum reverse current of the voltage stabilizing diode to prevent the voltage stabilizing diode from overheating and damage. When the voltage loaded on the voltage stabilizing diode exceeds the voltage stabilizing value of the voltage stabilizing diode, the voltage stabilizing diode will be broken down and turned on, thereby playing a role in voltage stabilization. V i It is the regulated voltage value and also serves as the input of the hysteresis comparator in the comparison circuit. Compared with the single threshold comparator, the hysteresis comparator has a strong anti-interference ability. Only when the conduction voltage drop of the bypass diode reaches the set threshold, the bypass diode will be judged to be turned on.

[0085] The two voltage thresholds of the hysteresis comparator are calculated as follows:

[0086]

[0087]

[0088] Among them, V h Represents the upper voltage threshold of the hysteresis comparator, V l Represents the lower voltage threshold of the hysteresis comparator, V cc Represents the voltage across the hysteresis comparator, R 2 Represents the second resistor, R 3 Represents the third resistor, R 4 represents the fourth resistor.

[0089] like Figure 6 As shown, the input-output characteristics of the hysteresis comparator are as follows: the thresholds of the positive and negative voltages can be set by selecting a suitable feedback network, that is, adjusting the values ​​of the resistors R2, R3 and R4 to change the threshold voltage. i >V h When V i <V l When , it indicates that the bypass diode is turned on, at this time, the hysteresis comparator outputs a high level, and the IO outputs a high level. The IO processor (such as MCU) generates a control signal of the MOS tube, and controls the opening of the MOS tube through the first switch driving circuit.

[0090] like Figure 3 and Figure 4 As shown, in a second aspect, the present application provides a photovoltaic assembly rapid shutdown device with an active bypass circuit, the device comprising:

[0091] The active bypass circuit 100 is an active bypass circuit applicable to a photovoltaic module fast shutdown device as described in the first aspect of the present application;

[0092] A main switch tube 204 is connected in series with the photovoltaic module;

[0093] The receiver 202 is used to receive the control signal sent by the signal transmitter;

[0094] A processor 102, electrically connected to the receiver, and configured to send a signal for driving the main switch tube to turn on or off according to a control signal received by the receiver;

[0095] The second switch driving circuit 203 is electrically connected to the processor and is used to receive the signal for driving the main switch tube to be turned on or off, and drives the main switch tube to be turned on or off. When the main switch tube is in the on state, the photovoltaic component corresponding to the main switch tube is connected to the photovoltaic series, and when the main switch tube is in the off state, the photovoltaic component corresponding to the main switch tube is disconnected from the photovoltaic series;

[0096] The bypass diode 205 is used to bypass the corresponding photovoltaic assembly when the main switch is in the cut-off state.

[0097] The working principle of the device is as follows: the main switch tube 204 is controlled by the communication signal sent by the signal transmitter 201, and 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 drive control signal according to the communication signal to control the second switch drive circuit 203 (in Figure 4 In the embodiment, the second on-drive circuit is a drive circuit connected to the receiver on the left side for communication to drive the on and off of the main switch tube. For example, when the main switch tube is in the off state and the bypass diode is in the on state, the bypass MOS tube can be controlled by the processor to be turned on, thereby effectively sharing the current passing through the bypass diode, protecting the bypass diode, and effectively improving the reliability of the fast shut-off device. When it is necessary to resume the operation of the photovoltaic module, the bypass MOS tube can be turned off before the main switch tube is turned on to avoid a short circuit.

[0098] In some embodiments, each photovoltaic component corresponds to a bypass MOS tube, the main switch tubes of all different photovoltaic components are driven to open and close by the same second switch driving circuit; and all different bypass MOS tubes are driven to open and close by the same first switch driving circuit.

[0099] like Figure 7As shown in the figure, the receiver is responsible for receiving the communication signal sent by the signal transmitter. This communication signal is used to control the turning on and off of the main switch tubes S1 (i.e., main switch tube 1) and S2 (i.e., main switch tube 2), thereby realizing the function of fast turn-off. The communication signal can be a power line carrier signal or a wireless communication signal. The state detection circuit is used to detect the on-off state of the bypass diode D1. When the conduction voltage drop of the bypass diode reaches the set threshold, it is stabilized at Vi through the current-limiting resistor R1, the voltage-regulating 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, and Vl is the low threshold. According to the aforementioned threshold calculation formula, when Vi > Vh, it indicates that the bypass diode is cut off. At this time, the hysteresis comparator outputs a low level, and IO outputs a low level; when Vi < Vl, it indicates that the bypass diode is conducting. At this time, the hysteresis comparator outputs a high level, and IO outputs a high level. The processor (such as a microcontroller, MCU) controls the bypass MOS tube Q1 to turn on through the first switch drive circuit (the drive circuit connected to the two MOS tubes on the right side in Figure 7 ). Here, a voltage-regulating diode of 1V is selected, and the conduction voltage drop of the diode D2 is 0.5V. When the bypass diode is conducting, Vi is stabilized at -1.5V. When the bypass diode is cut off, Vi is stabilized at 1.5V. Vcc is the supply voltage of the hysteresis comparator, taking 3.3V. To ensure that the voltage-regulating diode can work within the effective rated working current, the current-limiting resistor R1 = 8.2 kΩ. Let R2 = 2 kΩ, R3 = 60 kΩ, R4 = 10 kΩ, then Vh = 0.092V, Vl = -0.106V.

[0100] Through the above design, it is possible to realize that when it is detected that the bypass diode D1 is conducting, the parallel-connected bypass MOS tubes Q1 and Q2 are simultaneously driven to turn on, and the bypass MOS tubes Q1 and Q2 are turned off before the main switch tubes S1 and S2 are turned on.

[0101] Of course, in some other embodiments, each photovoltaic module corresponds to an active bypass circuit and the second switch drive circuit. The main switch tube of the photovoltaic module is driven to turn on and off through the corresponding second switch drive circuit; and the bypass MOS tubes of different photovoltaic modules are driven to turn on and off through the first switch drive circuit in their respective corresponding active bypass circuits.

[0102] Furthermore, each photovoltaic module corresponds to an active bypass circuit;

[0103] The main switch tube is driven to turn on and off through the second switch drive circuit, and the MOS tubes in each active bypass circuit are driven to turn on and off through the first switch drive circuit in the corresponding active bypass circuit;

[0104] The device includes a positive output terminal and a negative output terminal;

[0105] The photovoltaic assembly includes a first photovoltaic assembly and a second photovoltaic assembly, the active bypass circuit includes a first active bypass circuit and a second active bypass circuit, the main switch tube includes a first main switch tube and a second main switch tube, and the bypass diode includes a first bypass diode and a second bypass diode;

[0106] The first photovoltaic assembly corresponds to the first active bypass circuit, the first main switch tube, and the first bypass diode, and the second photovoltaic assembly corresponds to the second active bypass circuit, the second main switch tube, and the second bypass diode;

[0107] The first bypass diode is connected to the positive output terminal, one end of the second bypass diode is grounded, and the other end is connected to the negative output terminal.

[0108] like Figure 8 FIG. 1 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. Figure 7 Compared with the fourth embodiment of the present invention, the bypass switch driving signal for driving the bypass MOS tube Q2 in this example is controlled by detecting the conduction voltage of the bypass diode D4 (i.e., the second bypass diode). The control circuit can control the opening and closing of the main switch tube S1 (i.e., the first main switch tube) and S2 (i.e., the second main switch tube) respectively according to the communication signal detected by the receiver. When the communication of the first photovoltaic component is abnormal, the main switch tube S1 is disconnected, and the bypass diode D1 (i.e., the first diode) is turned on to provide a freewheeling channel for the power bus current. When the voltage detection circuit detects that the conduction voltage drop of the bypass diode D1 reaches the set threshold, it drives the parallel bypass MOS tube Q1 to turn on, thereby achieving the purpose of reducing the loss of the bypass diode D1 and improving reliability. When the second photovoltaic component is abnormal, when the state detection circuit detects that the conduction voltage drop of the bypass diode D4 reaches the set threshold, it outputs a low level through the hysteresis comparator, and controls the opening of the bypass MOS tube Q2 through the drive circuit through the processor (such as a microcontroller, MCU). Relative to Figure 7 As for the fourth embodiment shown, in this embodiment, respective state detection circuits are provided for different bypass diodes, which can enhance the flexibility of the fast shutdown device.

[0109] certainly, Figure 7 and Figure 8 The illustrated embodiment only takes the active bypass circuit of two input ports as an example, but is not limited thereto. The number of active bypass circuits may also be other numbers, such as three, four, etc.

[0110] It should be noted that although the above embodiments have been described in this article, this does not limit the scope of patent protection of the utility model. Therefore, based on the innovative concept of the utility model, changes and modifications to the embodiments described in this article, or equivalent structural or equivalent process changes made using the contents of the utility model specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields are all included in the scope of protection of the utility model patent.

Claims

1. An active bypass circuit suitable for a photovoltaic module fast shutdown device, characterized in that: The photovoltaic components are connected to the switch and connected in series to form a photovoltaic string. The fast switch comprises a main switch tube, a bypass diode and a processor, and the processor is a microcontroller. When the main switch tube is in the on state, the photovoltaic component corresponding to the main switch tube is connected to the photovoltaic string. When the main switch tube is in the off state, the photovoltaic component corresponding to the main switch tube is disconnected from the photovoltaic string. The bypass diode is used to bypass the corresponding photovoltaic component when the main switch tube is in the off state. The active bypass circuit comprises: A state detection circuit, 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; The first switch driving circuit is used to drive the bypass MOS tube to turn on according to the control signal of the processor when the main switch tube is in the off state and the bypass diode is in the on state. Before the main switch tube is turned on, the first switch driving circuit is used to drive the bypass MOS tube to turn off according to the control signal of the processor, and the control signal of the processor is generated according to the level signal output by the state detection circuit.

2. The active bypass circuit suitable for a photovoltaic module rapid shutdown device according to claim 1, characterized in that: The state detection circuit includes a voltage stabilizing circuit and a comparison circuit, the comparison circuit includes a comparator, and the comparator includes an inverting input terminal, a non-inverting input terminal and an output terminal; The voltage stabilizing circuit is connected in parallel with the bypass diode and is used to output a regulated voltage value. One end of the voltage stabilizing circuit used to output the regulated voltage value is connected to the inverting input end of the comparator, and the other end of the voltage stabilizing circuit is grounded. The non-inverting input terminal of the comparator is used to receive a comparison threshold, and the output terminal of the comparator is connected to the processor.

3. The active bypass circuit suitable for a photovoltaic module rapid shutdown device according to claim 2, characterized in that: The voltage stabilizing circuit includes a voltage stabilizing diode, a first resistor and a first diode. The voltage stabilizing diode and the first diode are connected in reverse, the cathode of the first diode is grounded, the anode of the first diode is connected to the anode of the voltage stabilizing diode, the cathode of the voltage stabilizing diode is connected to the inverting input terminal, and the first resistor is respectively connected to the cathode of the bypass diode and the cathode of the voltage stabilizing diode.

4. The active bypass circuit suitable for a photovoltaic module fast shutdown device according to claim 2, characterized in that: The comparison circuit also includes a second resistor, a third resistor, and a fourth resistor; The comparator is powered by a positive and negative power supply, the third resistor is connected between the in-phase input terminal and the output terminal of the comparator, the fourth resistor is connected between the positive electrode of the positive and negative power supply and the output terminal of the comparator, one end of the second resistor is grounded, and the other end is connected to the in-phase input terminal of the comparator; The comparison circuit also includes a second diode and a fifth resistor, wherein an anode of the second diode is connected to the output end of the comparator and the other end is connected to the processor, and one end of the fifth resistor is connected to the cathode of the second diode and the other end is grounded.

5. The active bypass circuit suitable for a photovoltaic module rapid shutdown device according to any one of claims 2 to 4, characterized in that: The comparator is a hysteresis comparator.

6. A photovoltaic module rapid shutdown device with an active bypass circuit, characterized in that: The device comprises: An active bypass circuit, which is an active bypass circuit applicable to a photovoltaic module fast shutdown device as claimed in any one of claims 1 to 5; The main switch tube is connected in series with the photovoltaic module; A receiver, used for receiving a control signal sent by a signal transmitter; A processor, electrically connected to the receiver, and configured to send a signal to drive the main switch tube to turn on or off according to a control signal received by the receiver; A second switch driving circuit is electrically connected to the processor and is used to receive the signal for driving the main switch tube to be turned on or off, and drive the main switch tube to be turned on or off. When the main switch tube is in the on state, the photovoltaic component corresponding to the main switch tube is connected to the photovoltaic series, and when the main switch tube is in the off state, the photovoltaic component corresponding to the main switch tube is disconnected from the photovoltaic series; The bypass diode is used to bypass the corresponding photovoltaic component when the main switch tube is in the cut-off state.

7. The photovoltaic module rapid shutdown device with active bypass circuit according to claim 6, characterized in that: Each photovoltaic component corresponds to a bypass MOS tube, the main switch tubes of all different photovoltaic components are driven to open and close by the same second switch driving circuit; and all different bypass MOS tubes are driven to open and close by the same first switch driving circuit.

8. The photovoltaic module rapid shutdown device with active bypass circuit according to claim 6, characterized in that: Each photovoltaic component corresponds to an active bypass circuit and the second switch driving circuit, and the main switch tube of the photovoltaic component is driven to open and close by the corresponding second switch driving circuit; and the bypass MOS tubes of different photovoltaic components are driven to open and close by the first switch driving circuit in the corresponding active bypass circuit.

9. The photovoltaic module rapid shutdown device with active bypass circuit according to claim 6, characterized in that: Each photovoltaic module corresponds to an active bypass circuit; The main switch tube is driven to open and close by the second switch driving circuit, and the MOS tube in each active bypass circuit is driven to open and close by the first switch driving circuit in the corresponding active bypass circuit; The device includes a positive output terminal and a negative output terminal; The photovoltaic assembly includes a first photovoltaic assembly and a second photovoltaic assembly, the active bypass circuit includes a first active bypass circuit and a second active bypass circuit, the main switch tube includes a first main switch tube and a second main switch tube, and the bypass diode includes a first bypass diode and a second bypass diode; The first photovoltaic assembly corresponds to the first active bypass circuit, the first main switch tube, and the first bypass diode, and the second photovoltaic assembly corresponds to the second active bypass circuit, the second main switch tube, and the second bypass diode; The first bypass diode is connected to the positive output terminal, one end of the second bypass diode is grounded, and the other end is connected to the negative output terminal.

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