Power extraction circuit, parallel-connected photovoltaic power generation assembly control device, and photovoltaic power generation string distribution system

Abstract

To provide a power extraction circuit, a parallel-connected photovoltaic power generation assembly control device, and a photovoltaic power generation string power distribution system suitable for use in combination with a bypass circuit of a photovoltaic power generation assembly.SOLUTION: In a parallel-connected photovoltaic power generation assembly control device 200, a power extraction circuit 10 performs an energy discharge output to generate a first internal voltage when a bypass circuit 20 is turned on, and generates the first internal voltage based on the output voltage of a photovoltaic power generation assembly 300 when the bypass circuit is cut off, and the pump-type voltage clamp circuit that stores energy generates a first control signal based on the first internal voltage, so that when the first control signal is enabled, if the first internal voltage meets the energy storage condition, the bypass circuit is cut off based on the first control signal, and if the first internal voltage meets the energy discharge condition, the bypass circuit is turned on based on the first control signal.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present application relates to the technical field of photovoltaic power generation, and in particular to a power extraction circuit, a parallel-connected photovoltaic assembly controller, and a photovoltaic string power distribution system. [Background technology]

[0002] A photovoltaic assembly control device (such as a photovoltaic assembly quick circuit breaker) is an important component in a photovoltaic power distribution system, and is mainly used to control the power supply output of a photovoltaic assembly. Thus, when a safety problem exists in the photovoltaic power distribution system or a safety failure occurs, for example, when an abnormality occurs in the output voltage and temperature of a photovoltaic assembly in the photovoltaic power distribution system or a fire occurs, the photovoltaic assembly control device can control the photovoltaic assembly to respond quickly and stop (i.e., turn off) the normal output of electrical energy from the photovoltaic assembly, thereby realizing a rapid shut-off and ensuring the safe and effective operation of the photovoltaic power distribution system.

[0003] Therefore, it is important how to ensure a continuous and stable power supply to the solar power assembly control device, and how to ensure a stable power supply to the solar power assembly control device so that it can operate normally when the solar power assembly is turned off. Summary of the Invention [Problem to be solved by the invention]

[0004] In view of this, in order to solve at least one problem in the background art, embodiments of the present application provide a power extraction circuit suitable for use in combination with a bypass circuit of a photovoltaic power generation assembly, a parallel-connection photovoltaic power generation assembly control device, and a photovoltaic power generation string power distribution system. [Means for solving the problem]

[0005] According to a first aspect, an embodiment of the present application provides a power extraction circuit suitable for use in combination with a bypass circuit of a photovoltaic assembly, comprising: a pumped voltage clamp circuit configured to provide an energy discharging output to generate a first internal voltage when a bypass circuit is conductive, and to generate the first internal voltage based on an output voltage of a photovoltaic assembly and to store energy when the bypass circuit is interrupted, the first internal voltage being used to provide a power supply voltage; a comparison circuit configured to generate a first control signal based on the first internal voltage, and to control the bypass circuit to be turned off based on the first control signal when the first control signal is enabled if the first internal voltage satisfies an energy storage condition, and to control the bypass circuit to be turned on based on the first control signal when the first internal voltage satisfies an energy release condition.

[0006] In connection with the first aspect, in one optional embodiment, the pumped voltage clamp circuit includes a clamp capacitance circuit and a clamp diode circuit; the clamp capacitance circuit is configured to form a discharge circuit together with the bypass circuit when the bypass circuit is conductive, and to form a charge circuit together with the positive electrode and the negative electrode of the photovoltaic assembly when the bypass circuit is interrupted, and has first ports located in the discharge circuit and the charge circuit, respectively, for outputting the first internal voltage; The clamp diode circuit is configured to perform reverse clamping when the clamp capacitance circuit performs energy dissipation output to obtain the first internal voltage.

[0007] In conjunction with the first aspect, in one optional embodiment, the pumped voltage clamp circuit further comprises a sampling circuit; The sampling circuit is configured to sample the first internal voltage to obtain a second internal voltage, and output for the comparison circuit to generate the first control signal.

[0008] In one alternative embodiment of the first aspect, the comparison circuit includes a hysteresis comparator; The hysteresis comparator is configured to generate the first control signal based on the second internal voltage to control the conduction and cut-off of the bypass circuit.

[0009] In one alternative embodiment, the comparison circuit further comprises a voltage stabilization circuit; The voltage regulation circuit is configured to provide a reference voltage to the hysteresis comparator.

[0010] In one alternative embodiment, the power extraction circuit further includes a voltage regulation / voltage stabilization circuit; The voltage regulation / voltage stabilization circuit is configured to convert the first internal voltage into a power supply voltage having one or more different voltage values ​​and output the power supply voltage.

[0011] According to a second aspect, an embodiment of the present application provides a parallel-connected photovoltaic assembly control device, the control device comprising a bypass circuit and a power extraction circuit suitable for use in combination with the bypass circuit of the photovoltaic assembly, The bypass circuit is configured to be connected between the positive and negative poles of the photovoltaic assembly and to be turned on or off under common control of a second control signal and a first control signal output by the power extraction circuit, and the second control signal is used to provide information including whether the photovoltaic assembly needs to be bypassed.

[0012] In connection with the second aspect, in one optional embodiment, the bypass circuit includes a reverse protection circuit and a controllable switch circuit; the controllable switch circuit is configured to be turned on or off under the control of a bypass control signal to realize the turning on or off of the bypass circuit, the bypass control signal being determined based on the first control signal and the second control signal; The reverse protection circuit is connected in series with the controllable switch circuit and configured to limit reverse current flow into the positive terminal of the photovoltaic assembly.

[0013] In conjunction with the second aspect, in one optional embodiment, the parallel connected photovoltaic assembly controller further includes a drive circuit configured to determine and generate the bypass control signal based on the first control signal and the second control signal.

[0014] In connection with the second aspect, in one optional embodiment, the parallel-connected photovoltaic assembly control device further includes a controller, a voltage detection circuit, and a temperature detection circuit; the voltage detection circuit is configured to acquire and output an output voltage of the solar power assembly; the temperature detection circuit is configured to obtain and output a temperature of the photovoltaic assembly; The controller is configured to determine and output the second control signal based on the output voltage and the temperature.

[0015] According to a third aspect, an embodiment of the present invention provides a photovoltaic string power distribution system, comprising: an array of photovoltaic photovoltaic assemblies; and one or more of the parallel-connected photovoltaic assembly controllers described above; the photovoltaic assembly array includes one or more series-parallel connections of photovoltaic assemblies; The parallel-connected photovoltaic assembly controller provides a photovoltaic string power distribution system configured to control the output of one or more photovoltaic assemblies. [Effects of the Invention]

[0016] The beneficial effects of the technical solutions according to the embodiments of the present application are as follows: The pump-type voltage clamp circuit and the comparator circuit can provide a continuous and stable power supply voltage in both the normal power output and the off-state of the photovoltaic assembly, avoiding overvoltage and undervoltage and improving the power supply stability of each internal circuit of the control device; and the parallel-connected photovoltaic assembly control device can overcome the drawbacks of the series-connected photovoltaic assembly control device, eliminating the energy loss caused by the normally-on state of the series-connected switch transistors, increasing the output power of the photovoltaic assembly, and independently removing a faulty photovoltaic assembly without affecting the normal operation of the system, thereby improving the reliability and stability of the system.

[0017] Additional aspects and advantages of embodiments of the invention will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned through the practice of embodiments of the invention. [Brief explanation of the drawings]

[0018] The drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments that fit the present application, and are used to explain the principles of the present application together with the specification. In order to more clearly explain the technical solutions of the embodiments of the present application, the following will briefly describe the drawings that need to be used in the description of the embodiments, and it is obvious that those skilled in the art can derive other drawings based on these drawings without any creative effort. These drawings and written descriptions are not intended to limit the scope of the concept of the present application in any way, but to explain the concept of the present application to those skilled in the art by referring to specific embodiments. In the drawings, [Figure 1]FIG. 1 is a principle block diagram of a series-connected photovoltaic power generation assembly control device. [Figure 2] FIG. 2 is a principle block diagram of one specific example of a power extraction circuit suitable for use in combination with a bypass circuit of a photovoltaic assembly in an embodiment of the present application. [Figure 3] FIG. 2 is a circuit diagram of one specific example of a pumped voltage clamp circuit in an embodiment of the present application. [Figure 4] 1 is a circuit diagram of a specific example of a step-down circuit in an embodiment of the present application. [Figure 5] FIG. 2 is a circuit diagram of one specific example of a voltage regulator in an embodiment of the present application. [Figure 6] FIG. 2 is a block diagram illustrating the principle of one specific example of a bypass circuit in an embodiment of the present application. [Figure 7] 1 is an operational flowchart of one specific example of a parallel-connected photovoltaic power generation assembly control device in an embodiment of the present application. [Figure 8] 1 is a principle block diagram of one specific example of a single-control type photovoltaic power generation string power distribution system according to an embodiment of the present application. [Figure 9] 1 is a principle block diagram of one specific example of a multiple control type solar power generation string power distribution system in an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0019] In order to make the technical solutions and beneficial effects of the embodiments of the present application more clearly understandable, the following detailed description will be given by listing specific embodiments. Here, the drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of local features. Unless otherwise defined, technical and scientific terms used herein have the same meaning as those in the technical field to which the embodiments of the present application belong.

[0020] It should be noted that terms such as "first," "second," and the like may be used to describe various elements herein, but these elements are not limited to these terms. These terms are used only to distinguish a first element from another element. When describing a "first," a "second" is not necessarily present. When discussing a "second," it does not necessarily imply the presence of a "first" in this application. The singular forms "a," "one," and "the" may also be intended to include the plural unless the context clearly indicates otherwise. The term "comprising" is used to determine the presence of an included feature but does not exclude the presence or addition of one or more other features. The term "and / or" includes any and all combinations of the associated listed items. The term "plurality" means two or more. The term "connection" may refer to a direct connection between two components, an indirect connection established by another component, internal communication between two components, or any other possible form of connection.

[0021] As shown in Figure 1, the series-connected photovoltaic assembly control device includes series-connected switch transistors S1, S2, ..., Sn to control the on / off of the power supply output of the photovoltaic assembly and thereby protect the photovoltaic assembly and the power system. When the switch transistors are in a normally-off state under the control of the control circuit, the photovoltaic assembly corresponding to the switch transistor (e.g., the photovoltaic assembly corresponding to switch transistor S1 may be photovoltaic assembly 1, and other correspondences can be inferred in this manner) operates normally. If a safety issue or safety failure occurs in the photovoltaic assembly, the switch transistors are turned off under the control of the control circuit to shut down the photovoltaic assembly corresponding to the switch transistor, thereby protecting the safety of the photovoltaic assembly and the system. Therefore, the power supply circuit can stably, continuously, and reliably supply power supply voltage to each circuit within the control device, ensuring the normal operation of the control device and effectively protecting the safety of the photovoltaic assembly and the system.

[0022] In addition, the series-connected photovoltaic assembly control device also has at least the following defects: during normal operation of the photovoltaic assembly, the conducting switch transistor consumes a large amount of energy, the requirements for turn-off logic and timing control are high, a complex control system needs to be implemented, which increases costs, and when the switch transistor is first turned off, it needs to bear the high voltage stress of the photovoltaic string, which poses a risk of overvoltage breakdown.

[0023] Therefore, in the embodiment of the present application, a parallel-connected photovoltaic power generation assembly control device is used to overcome the defects of the series-connected photovoltaic power generation assembly control device, and a power extraction circuit suitable for use in combination with a bypass circuit of a photovoltaic power generation assembly is proposed, which can provide a continuous and stable power supply voltage to the parallel-connected photovoltaic power generation assembly control device when the photovoltaic power generation assembly is normally outputting power and when it is bypassed, ensuring stable power supply and allowing it to operate normally. As shown in Figure 2, the power extraction circuit 10 suitable for use in combination with the bypass circuit 20 of the photovoltaic power generation assembly 300 is a pumped voltage clamp circuit (11) configured to perform energy discharging output to generate a first internal voltage Vc when the bypass circuit (20) is conducting, and to generate the first internal voltage Vc based on the output voltage of the photovoltaic power generation assembly and perform energy storage when the bypass circuit (20) is interrupted, wherein the first internal voltage Vc is used to provide a power supply voltage; and a comparison circuit (12) configured to generate a first control signal (ctr1) based on a first internal voltage (Vc), and to control the bypass circuit (20) to be turned off based on the first control signal (ctr1) when the first control signal (ctr1) is enabled if the first internal voltage (Vc) satisfies an energy storage condition, and to control the bypass circuit (20) to be turned on based on the first control signal (ctr1) when the first internal voltage (Vc) satisfies an energy release condition.

[0024] In an embodiment of the present application, the parallel-connection type photovoltaic assembly control device 200 may include a bypass circuit 20. The bypass circuit 20 can be connected in parallel to the photovoltaic assembly 300, and can be connected between the positive electrode PV+ and the negative electrode PV- of the photovoltaic assembly 300, and can be controlled to be turned on or off so that the photovoltaic assembly 300 can be bypassed or can normally output power. For example, a voltage input terminal of the bypass circuit 20 may be connected to the positive electrode PV+ of the photovoltaic assembly 300, and a voltage output terminal of the bypass circuit 20 may be connected to the negative electrode PV- of the photovoltaic assembly 300.

[0025] The bypass circuit 20 may be configured to be turned on or off under the common control of the first control signal ctr1 and the second control signal ctr2. For example, the first control signal ctr1 and the second control signal ctr2 may have an "AND" logical relationship. When the second control signal ctr2 maintains a high level, the first control signal ctr1 can be enabled, i.e., the conduction or cut-off of the bypass circuit 20 can be controlled according to changes in the level of the first control signal ctr1. In the parallel-connected photovoltaic assembly control device 200, the controller 30 can provide the second control signal ctr2 as a control signal for switching the parallel-connected photovoltaic assembly control device 200 between a "bypass state" and a "non-bypass state." For example, when the second control signal ctr2 is at a high level, it can indicate that the parallel-connected photovoltaic assembly control device 200 is in the "bypass state," and when the second control signal ctr2 is at a low level, it can indicate that the parallel-connected photovoltaic assembly control device 200 is in the "non-bypass state." That is, when the first control signal ctr1 is enabled, the parallel-connected photovoltaic power generation assembly controller 200 is in a "bypass state", and at this time, the first control signal ctr1 can control the conduction and cut-off of the bypass circuit 20. Conversely, when the second control signal ctr2 is at a low level, a change in the level of the first control signal ctr1 does not result in the combination of the first control signal ctr1 and the second control signal ctr2, so that the first control signal ctr1 is not enabled, the bypass circuit 20 remains cut-off, and the parallel-connected photovoltaic power generation assembly controller 200 is in a "non-bypass state".

[0026] When the parallel-connection type photovoltaic power generation assembly control device 200 is in the "non-bypass state," the photovoltaic power generation assembly 30 outputs power normally. For example, the output voltage of the photovoltaic power generation assembly 300 may be between 17 V and 60 V. At this time, the bypass circuit 20 is cut off, and the pumped voltage clamp circuit 11 uses the output voltage of the photovoltaic power generation assembly 300 to generate the first internal voltage Vc to provide a power supply voltage, thereby ensuring a continuous and stable power supply. At this time, the pumped voltage clamp circuit 11 may also reach saturation during or after the energy storage process.

[0027] When the parallel-connection type photovoltaic assembly control device 200 is in a "bypass state," the photovoltaic assembly 300 is bypassed (it can be considered as being turned off, and the normal power supply output is turned off), i.e., the output voltage between the positive electrode PV+ and the negative electrode PV- of the photovoltaic assembly 300 depends on the voltage difference between the voltage input terminal and the voltage output terminal of the bypass circuit 20. At this time, the output voltage of the photovoltaic assembly 300 is almost zero, and a voltage deficiency is formed. If the power supply voltage is still provided based on the output voltage of the photovoltaic assembly 300, it is likely to cause an unstable power supply problem for the photovoltaic assembly control device. Therefore, at this time, the energy release (e.g., discharge) of the pump-type voltage clamp circuit 11 is used to generate the first internal voltage Vc, and the power supply voltage is provided based on the first internal voltage Vc, thereby maintaining a stable power supply. As the energy release continues, the first internal voltage Vc gradually decreases. When the first internal voltage Vc satisfies the energy storage condition (for example, when the first internal voltage Vc is lower than the minimum voltage threshold, e.g., 7 V), stable power supply cannot be guaranteed, and energy storage (e.g., charging) is required in the pumped voltage clamp circuit 11. Therefore, the bypass circuit 20 is controlled to be turned off to store energy in the pumped voltage clamp circuit 11, and the voltage output characteristics of the photovoltaic assembly 300 are used to generate the first internal voltage Vc, thereby achieving continuous and stable power supply. The output voltage of the photovoltaic assembly 300 gradually increases. When the first internal voltage Vc generated based on the output voltage of the photovoltaic assembly 300 increases to a level that satisfies the energy release condition (for example, when the first internal voltage Vc is higher than the high voltage threshold, e.g., 13 V), the bypass circuit 20 is controlled to be conductive again to prevent overvoltage.The time it takes for the pumped voltage clamp circuit 11 to store the required electrical energy is usually shorter than the time it takes to generate the first internal voltage Vc using the output voltage of the photovoltaic assembly 300. That is, during the period when the first internal voltage Vc is generated based on the output voltage of the photovoltaic assembly 300, the pumped voltage clamp circuit 11 can store enough electrical energy to obtain the desired first internal voltage Vc at the time of energy release output. For example, the first internal voltage Vc can vary between 7V and 13V, and its waveform exhibits a zigzag shape.

[0028] The specific configuration of the comparison circuit 12 can be set according to actual needs, and may be realized, for example, by designing an algorithm using a chip such as a DSP or FPGA, or may be realized using an analog circuit consisting of an operational amplifier, for example, a hysteresis comparator.

[0029] In the embodiment of the present application, the pump-type voltage clamp circuit and the comparator circuit can provide a continuous and stable power supply voltage in two cases: when the photovoltaic assembly is in a normal power output state and when it is turned off, thereby avoiding overvoltage and undervoltage and improving the power supply stability of each internal circuit of the control device. Furthermore, the parallel-connected photovoltaic assembly control device can be combined to overcome the drawbacks of the series-connected photovoltaic assembly control device, eliminate the energy loss caused by the normally-on state of the series-connected switch transistors, increase the output power of the photovoltaic assembly, and independently remove a faulty photovoltaic assembly without affecting the normal operation of the system, thereby improving the reliability and stability of the system.

[0030] The photovoltaic assembly 300 may include multiple battery sheet units. The positive electrode of each battery sheet unit may be connected to the cathode of a diode, and the negative electrode of the battery sheet unit may be connected to the anode of the diode to form a reverse-parallel connection of diodes and a unidirectional channel for the photovoltaic assembly power supply. Reverse-parallel connection of each battery sheet unit to a diode forms a unidirectional channel for power supply protection. For example, as shown in FIG. 2 , the photovoltaic assembly 300 includes three battery sheet units. The first battery sheet unit and the first diode D1 are reverse-parallel connected, the second battery sheet unit and the second diode D2 are reverse-parallel connected, and the third battery sheet unit and the third diode D3 are reverse-parallel connected. The reverse-parallel connected diodes may be replaced by other devices with unidirectional conduction capability to protect the battery sheet units. The diodes are not limited to diodes. In the first aspect of the parallel-connection type photovoltaic power generation assembly control device 200, the diodes connected in parallel in the reverse direction may not be included, for example, the first diode D1, the second diode D2, and the third diode D3 may not be included. In the second aspect of the parallel-connection type photovoltaic power generation assembly control device 200, the diodes connected in parallel in the reverse direction may be included.

[0031] In one alternative embodiment, as shown in FIG. 3, the pumped voltage clamp circuit 11 includes a clamp capacitance circuit 111 and a clamp diode circuit 112; the clamp capacitance circuit 111 is configured to form a discharge circuit together with the bypass circuit 20 when the bypass circuit 20 is conductive, and to form a charge circuit together with the positive and negative electrodes of the photovoltaic power generation assembly when the bypass circuit 20 is interrupted, and is configured to have a first port PT1 located in the discharge circuit and the charge circuit, respectively, and to output a first internal voltage Vc; The clamp diode circuit 112 is configured to perform reverse clamping when the clamp capacitance circuit 111 performs energy release output, and to obtain the first internal voltage Vc.

[0032] In the embodiment of the present application, the clamp capacitance circuit 111 and the clamp diode circuit 112 can be provided according to actual needs. For example, the clamp capacitance circuit 111 may include one or more parallel-connected capacitors. The clamp diode circuit 112 may include one or more series-connected diodes. The diodes in the clamp diode circuit 112 are reverse-biased during the energy release discharge process, thereby clamping the voltage output by the first port PT1 to the first internal voltage Vc and improving power supply stability. As a specific example, the clamp capacitance circuit 111 includes a fourteenth capacitor C14, a fifteenth capacitor C15, and a sixteenth capacitor C16, and the clamp diode circuit 112 includes a fifth diode D5. A first terminal of the parallel-connected fourteenth capacitor C14, the fifteenth capacitor C15, and the sixteenth capacitor C16 is connected to the negative terminal of the fifth diode D5, and a second terminal of the parallel-connected fourteenth capacitor C14, the fifteenth capacitor C15, and the sixteenth capacitor C16 is connected to the negative terminal PV- of the solar power generation assembly. The positive terminal of the fifth diode D5 is connected to a first terminal of a controllable switch circuit 22 in the bypass circuit 20, and a second terminal of the controllable switch circuit 22 is connected to the negative terminal PV- of the solar power generation assembly. Thus, when the controllable switch circuit 22 is controlled to be conductive, the bypass circuit 20 is made conductive, the discharge circuit is made conductive, and the fourteenth capacitor C14, the fifteenth capacitor C15, and the sixteenth capacitor C16 can perform energy release discharge. For example, the controllable switch circuit 22 may be configured with a controllable semiconductor switch device, etc., and the controllable semiconductor switch device may include at least one of devices such as a BJT (transistor), an SCR (thyristor), a GTO (gate turn-off thyristor), a MOSFET (metal-oxide-semiconductor field-effect transistor, abbreviated as MOS transistor), an IGBT (insulated gate bipolar transistor), an MCT (MOS-controlled thyristor), and an SIT (static induction transistor). Accordingly, when the controllable switch circuit 22 is controlled to be cut off, the bypass circuit 20 is cut off, the charging circuit is made conductive, and the fourteenth capacitor C14, the fifteenth capacitor C15, and the sixteenth capacitor C16 can perform charging energy storage.

[0033] In one alternative embodiment, the pumped voltage clamp circuit 11 further includes a sampling circuit 113; The sampling circuit 113 is configured to sample the first internal voltage Vc to obtain the second internal voltage Vcheck, and output the comparison circuit 12 to generate the control signal ctr1.

[0034] In the embodiment of the present application, the sampling circuit 113 can be configured according to actual needs, for example, by using a voltage dividing resistor network to perform voltage dividing resistance sampling on the first internal voltage Vc to obtain the second internal voltage Vcheck, thereby reducing the voltage amplitude value and improving impedance matching.

[0035] In one alternative embodiment, the comparison circuit 12 includes a hysteresis comparator 121, The hysteresis comparator 121 is configured to generate a first control signal ctr1 based on the second internal voltage Vcheck to control the conduction and cut-off of the bypass circuit 20.

[0036] In the embodiment of the present application, the hysteresis range of the hysteresis comparator 121 can be set according to actual needs, for example, between 1.8V and 3.1V. When the second internal voltage Vcheck is greater than 3.1V, the hysteresis comparator 121 outputs a first control signal ctr1 at a first level to control the bypass circuit 20 to be conductive. When the second internal voltage Vcheck is less than 1.8V, the hysteresis comparator 121 outputs a first control signal ctr1 at a second level to control the bypass circuit 20 to be cut off. The first level may be different from the second level; for example, the first level may be a high level and the second level may be a low level. The high level and low level in the present application may be relative values ​​and are not limited to absolute values.

[0037] In one alternative embodiment, the comparison circuit 12 further includes a voltage stabilization circuit 122; The voltage stabilization circuit 122 is configured to provide a reference voltage Vref to the hysteresis comparator 121 .

[0038] In the embodiment of the present application, the voltage stabilization circuit 122 converts the power supply voltage (e.g., 3.3V) provided by the power extraction circuit 10 to obtain and output a more stable reference voltage as the reference voltage for the hysteresis comparator, thereby improving the operational stability of the hysteresis comparator. The voltage stabilization circuit 122 can be configured according to actual needs, for example, a three-terminal voltage stabilization circuit. For example, the three-terminal voltage stabilization circuit can use a TL431 chip.

[0039] In one alternative embodiment, as shown in FIG. 2, the power extraction circuit 10 further includes a voltage regulation / voltage stabilization circuit 13; The voltage adjusting / voltage stabilizing circuit 13 is configured to convert the first internal voltage Vc into a power supply voltage having one or more different voltage values ​​and output the converted power supply voltage.

[0040] In the embodiment of the present application, the voltage regulating / voltage stabilizing circuit 13 can be configured according to actual needs to obtain the required voltage values ​​of power supply voltages Vd1, Vd2, ..., Vdn, where n is a natural number, e.g., 5.0 V, 3.3 V, etc., thereby fulfilling the roles of voltage regulation and voltage stabilization. The voltage regulation of the voltage regulating / voltage stabilizing circuit 13 can be implemented as a step-up and / or step-down, i.e., the one or more different voltage values ​​output thereby can be greater than the first internal voltage Vc or less than the first internal voltage Vc, and can be configured according to actual needs. Each of the power supply voltages Vd1, Vd2, ..., Vdn can supply power to each internal circuit in the parallel-connected photovoltaic power generation assembly control device 200, such as the controller 30 and the voltage stabilizing circuit 122, thereby further improving the stability of the power supply voltage and ensuring stable and continuous power supply. As a specific example, as shown in FIG. 4, the voltage regulating / voltage stabilizing circuit 13 can include a step-down circuit 131.The step-down circuit 131 may be composed of a step-down integrated chip or the like, and can output a first stable voltage 5V0. The step-down circuit 131 may include a step-down integrated chip U1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, a twelfth capacitor C12, a fifth capacitor C5, an eleventh capacitor C11, a first inductance L1, a seventh voltage stabilizing diode D7, a sixth diode D6, and an eighth light-emitting diode D8. The VIN terminal of the step-down integrated chip U1 is respectively connected to the first terminal of the first resistor R1 and the first terminal of the twelfth capacitor C12 and is configured to input the first internal voltage Vc. The EN terminal of the step-down integrated chip U1 is respectively connected to the second terminal of the first resistor R1 and the first terminal of the third resistor R3. The BST of the step-down integrated chip U1 The first end of the buck integrated chip U1 is connected to the first end of the first capacitor C1, the SW end of the buck integrated chip U1 is connected to the second end of the first capacitor C1, the negative electrode of the seventh voltage stabilizing diode D7, and the first end of the first inductor L1, the FB end of the buck integrated chip U1 is connected to the first end of the fourth resistor R4 and the first end of the fifth resistor R5, the second end of the first inductor L1 is connected to the first end of the fifth capacitor C5 and the second end of the fourth resistor R4, and is configured to output the first voltage 5VIN, and the second end of the twelfth capacitor C12, the second end of the third resistor R3, the GND end of the buck integrated chip U1, the second end of the fifth resistor R5, the positive electrode of the seventh voltage stabilizing diode D7, and the second end of the fifth capacitor C5 are connected to the negative electrode PV- of the photovoltaic assembly. The buck integrated chip U1 can be selected according to actual needs.

[0041] To stabilize the first voltage 5VIN output by the step-down circuit 131, a sixth diode D6 is connected to its output terminal to form a one-way charge clamp voltage stabilization circuit, providing a first stabilized voltage 5V0 as one of the power supply voltages. For example, the first stabilized voltage 5V0 may be 5.0V. The second resistor R2 and the eighth light-emitting diode D8 form a one-way discharge circuit to prevent overvoltage of the output power supply. When the eighth light-emitting diode D8 emits light, the first stabilized voltage 5V0 maintains a constant electrical energy, and the eleventh capacitor C11 filters and stabilizes the first stabilized voltage 5V0. The twelfth capacitor C12 is an input voltage stabilization capacitor, performing filtering and voltage stabilization functions. The first resistor R1 and the third resistor R3 are series-connected voltage divider resistors, providing an enable signal to the EN terminal to control the operating state of the step-down integrated chip U1. For example, when the enable signal is high, the buck integrated chip U1 operates; conversely, when the enable signal is low, the buck integrated chip U1 does not operate. A first capacitor C1 (bootstrap capacitor) is connected in series between the BST terminal and the SW terminal to provide a driving voltage for the power switch transistor in the buck integrated chip U1. The seventh voltage stabilization diode D7 stabilizes the voltage of the output port. The first inductance L1 is a filtering inductance, and together with the fifth capacitor C5, forms an LC filtering structure to filter harmonics, thereby stabilizing the first voltage 5VIN of the output DC voltage. The fourth resistor R4 and the fifth resistor R5 sample the first voltage 5VIN and feed it back to the buck integrated chip U1 via the FB terminal.

[0042] 5, the voltage regulation / voltage stabilization circuit 13 may include a step-down circuit 131 and may further include a voltage regulator 132. The voltage regulator 132 may be configured with a linear voltage stabilization chip or the like, and may continue to convert based on the first stable voltage 5V0 to obtain a second stable voltage 3V3 as another power supply voltage. For example, the second stable voltage 3V3 may be 3.3V. The voltage regulator 132 may include a linear voltage stabilizing chip U2, a second capacitor C2, and a fourth capacitor C4. The VIN terminal of the linear voltage stabilizing chip U2 is connected to the CE terminal and the first terminal of the fourth capacitor C4, respectively, and configured to input the first stabilized voltage 5V0. The VOUT terminal of the linear voltage stabilizing chip U2 is connected to the first terminal of the second capacitor C2 and configured to output the second stabilized voltage 3V3. The second terminal of the fourth capacitor C4, the second terminal of the second capacitor C2, and the GND terminal of the linear voltage stabilizing chip U2 are respectively connected to the negative electrode PV- of the photovoltaic assembly. The linear voltage stabilizing chip U2 can be selected according to actual needs. The fourth capacitor C4 is an input filtering capacitor that can stabilize the input power supply. The CE terminal is an enable port of the linear voltage stabilizing chip U2 and is connected to the first stabilized voltage 5V0. The second capacitor C2 is an output filtering capacitor that is connected to the VOUT terminal and can stabilize the output DC power supply.

[0043] An embodiment of the present application further provides a parallel-connected photovoltaic assembly control device. As shown in Figure 2, the parallel-connected photovoltaic assembly control device 200 includes a bypass circuit 20 and a power extraction circuit 10 suitable for use in combination with the bypass circuit of the photovoltaic assembly, The bypass circuit 20 is configured to be connected between the positive pole PV+ and the negative pole PV- of the photovoltaic assembly 300 and to be turned on or off under the common control of a second control signal ctr2 and a first control signal ctr1 output by the power extraction circuit 10, and the second control signal ctr2 is used to provide information including whether the photovoltaic assembly 300 needs to be bypassed.

[0044] In the embodiment of the present application, the second control signal CTR2 may be provided by the controller 30, or by a control circuit made of a CMOS circuit, or by other methods, and can be set according to actual needs. The process of controlling and operating the bypass circuit 20 can be referred to above and will not be further described here. In the embodiment of the present application, the voltage-current characteristics of the photovoltaic assembly and the unidirectional voltage clamp characteristics of the diode are comprehensively considered, and a pump-type voltage clamp power extraction method is used to prevent overvoltage or undervoltage of the power supply voltage and ensure the power supply stability of the parallel-connected photovoltaic assembly control device.

[0045] FIG. 2 shows the first and second embodiments of the parallel-connected solar power generation assembly control device 200, and the main difference between them is whether they include diodes connected in parallel in the reverse direction, which can be seen from the above and will not be further described here.

[0046] In one alternative embodiment, as shown in FIG. 6, the bypass circuit 20 includes a reverse protection circuit 21 and a controllable switch circuit 22; The controllable switch circuit 22 is configured to be turned on or off under the control of a bypass control signal cp to realize the turning on or off of the bypass circuit 20, and the bypass control signal cp is determined based on the first control signal ctr1 and the second control signal ctr2; The reverse current protection circuit 21 is connected in series with the controllable switch circuit 22 and is configured to limit the flow of reverse current into the positive electrode PV+ of the photovoltaic assembly 300 .

[0047] In one optional embodiment, the parallel-connected photovoltaic power generation assembly control device 200 further includes a drive circuit 40 configured to determine and generate a bypass control signal cp based on the first control signal ctr1 and the second control signal ctr2.

[0048] In the embodiment of the present application, the controllable switch circuit 22 can be directly or indirectly controlled by the first control signal CTR1 and the second control signal CTR2 depending on the internal circuit structure, and can be set according to actual needs. The configuration of the controllable switch circuit 22 can be referred to above, and will not be further described here. For example, the above discloses that the driver circuit 40 determines and generates the bypass control signal Cp based on the first control signal CTR1 and the second control signal CTR2 to control the conduction and cut-off of the controllable switch circuit 22, thereby realizing indirect control of the controllable switch circuit 22, thereby integrating the control of the power extraction circuit 10, improving the defects of the series-connected photovoltaic power generation assembly control device, and further providing a continuous and stable power supply voltage for the parallel-connected photovoltaic power generation assembly control device, preventing overvoltage and undervoltage, and improving the overall stability of the control device and the system.

[0049] As a specific example, as shown in FIG. 3 , the reverse bias protection circuit 21 may include a fourth diode D4, and the controllable switch circuit 22 may include a switch transistor Q1, where the positive electrode of the fourth diode D4 is connected to the positive electrode PV+ of the photovoltaic assembly, the negative electrode of the fourth diode D4 is connected to the first terminal of the switch transistor Q1, and the second terminal of the switch transistor Q1 is connected to the negative electrode PV− of the photovoltaic assembly, and the control terminal of the switch transistor Q1 is configured to input a bypass control signal cp. The driving circuit 40 may include a driving chip U3, a resistor R25, a resistor R31, a resistor R32, and a capacitor C32. The ENA terminal of the driving chip U3 is connected to the first terminal of the resistor R25, and the second terminal of the resistor R25 is configured to input a first control signal CTR1. The INA terminal of the driving chip U3 is configured to input a second control signal CTR2. The OUT terminal of the driving chip U3 is connected to the first terminal of the resistor R31, and the second terminal of the resistor R31 is connected to the first terminal of the resistor R32 and the first terminal of the capacitor C32, respectively, and is configured to output a bypass control signal CTR. The second terminal of the resistor R32, the second terminal of the capacitor C32, and the GND terminal of the driving chip U3 are respectively connected to the negative pole PV- of the photovoltaic assembly. The VDD terminal of the driving chip U3 is configured to input a first regulated voltage 5V0. The driver chip U3 can be selected according to actual needs, for example, a logic circuit chip can be used to implement the AND operation of the first control signal ctr1 and the second control signal ctr2.

[0050] The positive electrode PV+ of the photovoltaic assembly is connected in series with a reverse blocking power diode (i.e., the fourth diode D4) to form a controllable unidirectional bypass conduction channel. The fourth diode D4 controls the current flow in the forward direction in the bypass circuit of the photovoltaic assembly and limits reverse current flow, preventing the original protection diodes (e.g., the first diode D1, the second diode D2, and the third diode D3 in Figure 2) from failing due to reverse current flow through the body diode of the MOS transistor. Furthermore, using only one main power diode (i.e., the fourth diode D4) as a unidirectional current clamp reduces the voltage drop power loss that occurs when multiple diodes are connected in series, solves the problem of temperature rise due to voltage drop loss, improves system stability, and reduces the cost of the product's base components. Resistor R25 is a current-limiting resistor. Resistor R31 is an output resistor, which can improve impedance matching. Resistor R32 is a charge / discharge resistor, and capacitor C32 is a charge / discharge capacitor.

[0051] In one alternative embodiment, the parallel-connected photovoltaic assembly control device 200 further includes a controller 30, a voltage detection circuit 50, and a temperature detection circuit 60. The voltage detection circuit 50 is configured to acquire and output a voltage Vbat output by the solar power generation assembly 300; The temperature detection circuit 60 is configured to acquire and output a temperature Tpv of the photovoltaic assembly 300; The controller 30 is configured to determine and output a second control signal ctr2 based on the voltage Vbat output by the photovoltaic assembly 300 and the temperature Tpv.

[0052] In the present embodiment, the power supply for the controller 30, the voltage detection circuit 50, and the temperature detection circuit 60 may all be one of the power supply voltages Vd1, Vd2, ..., Vdn output by the power extraction circuit to enhance operational stability. The controller 30 can realize local control of the power generation of the solar power generation assembly 300. When the solar power generation assembly 300 generates power, the illuminance and the temperature of the battery panel affect the current of the battery panel. Within a certain range, the stronger the illuminance, the larger the output current, and the higher the temperature, the smaller the output voltage. When the solar power generation assembly 300 fails, the solar power generation curve voltage is small. Therefore, a failure can be determined based on the voltage Vbat acquired by the voltage detection circuit 50 and the temperature Tpv acquired by the temperature detection circuit 60. For example, in the event of a failure, the controller 30 can output a second control signal (e.g., high level) containing information indicating that the solar power generation assembly needs to be bypassed, and control the bypass circuit 20 to conduct in one direction, thereby protecting the solar power generation assembly 300. Therefore, the condition monitoring of a single assembly of the photovoltaic assembly can be realized, and the protection of the photovoltaic assembly can be more accurate.

[0053] In one alternative embodiment, the parallel-connected photovoltaic assembly control device 200 may further include a communication module. For example, the communication module and the controller 30 may be packaged on a single chip. Remote control of the photovoltaic assembly 300 can be achieved by receiving a remote control signal through the communication module. For example, when a special situation, such as a house fire, occurs and the photovoltaic assembly 300 needs to be remotely controlled to be turned off, the controller 30 can receive the remote control signal through the communication module and control the bypass circuit 20 to be conductive to bypass the photovoltaic assembly 300. The communication module may be a short-range communication module or a remote communication module. The short-range communication module may include at least one of a Bluetooth module, a Wi-Fi module, a ZigBee module, an Ethernet module, a serial module, a Centronics module, etc., and the remote communication module may include at least one of a GPRS module, a 2G module, a 3G module, a 4G module, a 5G module, an LTE module, etc.

[0054] 7 shows the operation flow of the parallel-connected photovoltaic assembly control device. When the photovoltaic assembly (PV assembly) 300 starts up or operates, the voltage detection circuit 50 measures the voltage Vbat output by the photovoltaic assembly, the temperature detection circuit outputs the photovoltaic assembly temperature Tpv, and inputs communication commands and / or sampling signals to the controller 30 to determine the off state of the switch transistor Q1. The conduction signal drives the switch transistor Q1 to conduct, the control device enters a "bypass state," the pumped voltage clamp circuit 11 operates, and when the voltage across the capacitances (C14, C15, and C16) is greater than the highest voltage threshold (e.g., 13 V), the capacitances (C14, C15, and C16) discharge to provide the power supply voltage. When the voltage across the capacitances (C14, C15, and C16) is less than the lowest voltage threshold (e.g., 7 V), the drive circuit outputs an off signal, the switch transistor Q1 is turned off, and the photovoltaic assembly charges the capacitances (C14, C15, and C16). When receiving the OFF signal, the control device enters a "non-bypass state" and provides a power supply voltage to step down the output voltage of the photovoltaic assembly, for example, the power supply voltage can output a first stable voltage 5V0, or a second stable voltage 3V3 through a voltage regulator.

[0055] Whether the parallel-connected photovoltaic assembly control device is in the "bypass state" or the "non-bypass state", the first internal voltage Vc generated by the pump-type voltage clamp circuit is greater than the first stable voltage 5V0, and the first stable voltage 5V0 is continuously stepped down and output to power the driving circuit, the temperature detection circuit, etc. At the same time, the voltage regulator outputs the second stable voltage 3V3 to power the chips, etc., to ensure the normal operation of the PV assembly control device.

[0056] An embodiment of the present application further provides a photovoltaic power generation string power distribution system, as shown in FIG. 8 and FIG. 9 , the photovoltaic power generation string power distribution system 001 includes: a photovoltaic power generation assembly array; and one or more of the above-mentioned parallel-connected photovoltaic power generation assembly control devices 200; The photovoltaic assembly array includes one or more photovoltaic assemblies 300 connected in series or parallel; The parallel-connected photovoltaic assembly controller 200 is configured to control the output of one or more photovoltaic assemblies 300 .

[0057] In the embodiment of the present application, in the single-control type solar power string distribution system 001, one solar power assembly 300 can control the power supply output by one parallel-connected solar power assembly controller 200. For example, as shown in FIG. 8 , a solar power assembly array may include an eleventh solar power assembly PV11, a twenty-first solar power assembly PV21, ..., the nm-th solar power assembly PVnm, and there are a total of n x m solar power assembly 300, where n and m are both natural numbers. Each solar power assembly 300 corresponds one-to-one to one parallel-connected solar power assembly controller 200, i.e., includes an eleventh controller 211, a twenty-first controller 221, ..., the nm-th controller 2nm, and there are a total of n x m solar power assembly controllers constituting a solar power assembly controller array. The solar power string distribution system 001 can control the power supply output of the solar power assembly array by the solar power assembly controller array, and transmit it to the power system to provide energy to the power system. In the event of an unexpected accident occurring in the photovoltaic assembly, the bypass circuit can be quickly turned on to short-circuit the photovoltaic assembly, thereby protecting the photovoltaic assembly and ensuring the safety of the power system.

[0058] In the multiple-control type solar power generation string power distribution system 001, the power supply outputs of multiple solar power generation assemblies 300 can be controlled by one parallel-connected solar power generation assembly controller 200. For example, as shown in Fig. 9, a solar power generation assembly array may include an eleventh solar power generation assembly PV11, a twenty-first solar power generation assembly PV21, ..., an nm-th solar power generation assembly PVnm, and there are a total of n x m solar power generation assemblies 300, where n and m are both natural numbers. One string of solar power generation assemblies 300 corresponds one-to-one to one parallel-connected solar power generation assembly controller 200, i.e., includes a 2001st controller 2001, ..., a 200mth controller 200m, and there are a total of m solar power generation assemblies 300, which constitute a solar power generation assembly controller array.

[0059] The embodiments of the present application relate to the fields of new energy photovoltaic technology and semiconductor microelectronics, and to the technical field of protection using a new energy photovoltaic assembly-level rapid circuit breaker, suitable for power systems protecting photovoltaic assemblies and photovoltaic assembly arrays. The parallel-connected photovoltaic assembly control device (abbreviated as "circuit breaker") of the embodiments of the present application can be applied to photovoltaic assembly arrays of different sizes, and the bypass protection mechanism eliminates conduction restrictions between series-connected assemblies, maximizing the power generation of the photovoltaic assembly array. Furthermore, the bypass protection mechanism eliminates energy loss due to normally-on switch transistors connected in series in a series-connected photovoltaic assembly control device, fully utilizing solar power generation and maximizing light energy utilization. The bypass protection mechanism solves the high-voltage stress problem when series-connected switch transistors in a photovoltaic assembly array are initially turned off, improving the safety performance of the circuit breaker.

[0060] The bypass circuit in the embodiment of the present application provides a bypass unidirectional conduction technology, and the power extraction circuit used in combination with the bypass circuit provides a bypass low voltage DC power extraction technology, which solves the problem of bypass low voltage DC power extraction, provides a stable auxiliary power supply for the circuit breaker, ensures the stability of the photovoltaic assembly array, and makes the power generation of the photovoltaic power system safe and efficient.

[0061] The power extraction circuit of the embodiment of the present application uses a pump-type voltage clamp mechanism to extract energy from the photovoltaic assembly, avoiding overvoltage or undervoltage of the power supply, ensuring the stability of the voltage output by the power extraction circuit and the safety of the power supply, and improving the control stability and safety performance of the circuit breaker.

[0062] It should be understood that the above examples are merely illustrative and are not intended to encompass all possible embodiments encompassed by the claims. Various modifications and variations may be made based on the above examples without departing from the scope of the present disclosure. Similarly, the technical features of the above examples may be arbitrarily combined to form further embodiments of the present application that may not be explicitly described. Therefore, the above examples represent only some embodiments of the present application and do not limit the scope of protection of the patent application.

Claims

1. 1. A power extraction circuit suitable for use in combination with a bypass circuit of a photovoltaic assembly, comprising: a pumped voltage clamp circuit configured to perform an energy discharging output to generate a first internal voltage when a bypass circuit is conductive, and to generate the first internal voltage based on an output voltage of a photovoltaic power generation assembly and perform energy storage when the bypass circuit is interrupted, the first internal voltage being used to provide a power supply voltage; a comparison circuit configured to generate a first control signal based on the first internal voltage, and to control the bypass circuit to be turned off based on the first control signal when the first internal voltage satisfies an energy storage condition when the first control signal is enabled, and to control the bypass circuit to be turned on based on the first control signal when the first internal voltage satisfies an energy release condition.

2. the pumped voltage clamp circuit includes a clamp capacitance circuit and a clamp diode circuit; the clamp capacitance circuit is configured to form a discharge circuit together with the bypass circuit when the bypass circuit is conductive, and to form a charge circuit together with the positive electrode and the negative electrode of the photovoltaic assembly when the bypass circuit is interrupted, and has a first port located in the discharge circuit and the charge circuit, respectively, for outputting the first internal voltage; 2. The power extraction circuit according to claim 1, wherein the clamp diode circuit is configured to perform reverse clamping when the clamp capacitance circuit performs energy dissipation output to obtain the first internal voltage.

3. the pumped voltage clamp circuit further includes a sampling circuit; 3. The power extraction circuit according to claim 2, wherein the sampling circuit is configured to sample the first internal voltage to obtain a second internal voltage, and output the comparison circuit to generate the first control signal.

4. the comparison circuit includes a hysteresis comparator; 4. The power extraction circuit according to claim 3, wherein the hysteresis comparator is configured to generate the first control signal based on the second internal voltage to control conduction and cut-off of the bypass circuit.

5. the comparison circuit further includes a voltage stabilization circuit; 5. The power extraction circuit of claim 4, wherein the voltage stabilization circuit is configured to provide a reference voltage to the hysteresis comparator.

6. the power extraction circuit further includes a voltage regulation and voltage stabilization circuit; 2. The power extraction circuit according to claim 1, wherein the voltage adjustment / voltage stabilization circuit is configured to convert the first internal voltage into a power supply voltage of one or more different voltage values ​​and output the power supply voltage.

7. A parallel-connected photovoltaic power generation assembly control device, comprising: a bypass circuit; and a power extraction circuit according to any one of claims 1 to 6; The bypass circuit is configured to span between the positive and negative poles of the photovoltaic assembly and to be turned on or off under common control of a second control signal and a first control signal output by the power extraction circuit, and the second control signal is used to provide information including whether the photovoltaic assembly needs to be bypassed.

8. the bypass circuit includes a reverse protection circuit and a controllable switch circuit; the controllable switch circuit is configured to be turned on or off under control of a bypass control signal to realize turning on or off of the bypass circuit, the bypass control signal being determined based on the first control signal and the second control signal; 8. The parallel-connection type photovoltaic power assembly control device according to claim 7, wherein the reverse current protection circuit is connected in series with the controllable switch circuit and configured to limit reverse current flow into the positive terminal of the photovoltaic power assembly.

9. 9. The parallel connected photovoltaic power assembly control device of claim 8, further comprising a driver circuit configured to determine and generate the bypass control signal based on the first control signal and the second control signal.

10. a controller, a voltage detection circuit, and a temperature detection circuit; the voltage detection circuit is configured to acquire and output an output voltage of the solar power assembly; the temperature detection circuit is configured to obtain and output a temperature of the photovoltaic assembly; 8. The parallel-connected photovoltaic power assembly control device according to claim 7, wherein the controller is configured to determine and output the second control signal based on the output voltage and the temperature.

11. 10. A photovoltaic string power distribution system comprising: a photovoltaic assembly array; and one or more parallel-connected photovoltaic assembly controllers according to claim 7; the photovoltaic assembly array includes one or more series-parallel connections of photovoltaic assemblies; The photovoltaic string power distribution system, wherein the parallel-connected photovoltaic assembly controller is configured to control the output of one or more photovoltaic assemblies.

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