Analog chip of power converter and power converter

Abstract

The present application discloses an analog chip of a power converter and a power converter. The analog chip includes: a sampling circuit for collecting electrical parameters of the power converter, and an input end of the power converter for connecting a photovoltaic module; a maximum power tracking circuit obtains the input power and / or output power of the power converter according to the electrical parameters, performs maximum power tracking according to the input power or output power, and obtains an adjustment signal to a multiplexer; when a fast shutdown circuit receives a fast shutdown instruction sent from the outside of the analog chip, it generates a fast shutdown signal to the multiplexer; when the electrical parameters of the power converter exceed a first preset threshold, the protection circuit generates a protection signal to the multiplexer; the multiplexer selects one of the fast shutdown signal, the protection signal or the adjustment signal as a control signal to control the power device in the power converter. The analog chip can control the operation of the power converter, and can greatly reduce the cost of the photovoltaic power generation system compared to the digital chip.

Description

Technical Field

[0001] The present application relates to the technical field of photovoltaic power generation, and in particular to an analog chip of a power converter and a power converter. Background Art

[0002] A photovoltaic power generation system generally includes a photovoltaic module and a power converter, wherein the photovoltaic module can convert solar energy into electrical energy.

[0003] At present, a photovoltaic module includes multiple photovoltaic substrings, and each photovoltaic substring includes multiple photovoltaic cells. Multiple photovoltaic modules can be connected in series or in parallel to form a photovoltaic array. A diode is connected in parallel at both ends of each photovoltaic substring of the photovoltaic module. When the photovoltaic substring is blocked by shadows and cannot output sufficient current, the diode can bypass the photovoltaic substring, and the current of other photovoltaic substrings can flow through the diode, thereby ensuring that other photovoltaic substrings can continue to generate electricity. However, this way of completely bypassing the blocked photovoltaic substring by the diode makes the blocked photovoltaic substring completely unable to generate electricity, wasting the power generation capacity of the photovoltaic substring.

[0004] In order to continue to generate electricity when the photovoltaic substring is shaded, a power converter can be connected at both ends of the photovoltaic substring or the photovoltaic module, and the power converter can be used to replace the parallel diode. When the photovoltaic substring is shaded, the output current of the photovoltaic substring is reduced but it can still output power. The power converter can convert the output power of the photovoltaic substring and adjust its own output current to be equal to the current of the remaining photovoltaic substrings or the power converter connected to the photovoltaic substring, thereby improving the power generation efficiency of the entire photovoltaic power generation system.

[0005] At present, the control of power converters is achieved by digital chips. However, if the number of photovoltaic sub-strings in the photovoltaic power generation system is large, the number of power converters required is also large. Each power converter requires a digital chip, and a large number of digital chips are required, resulting in a higher cost for the entire photovoltaic power generation system. Summary of the invention

[0006] In order to solve the above technical problems, the present application provides an analog chip of a power converter and a power converter, which can control the operation of the power converter, thereby reducing the cost of a photovoltaic power generation system.

[0007] The present application provides an analog chip of a power converter, which is used to control the operation of the power converter, and specifically can control the switch state of the power device in the power converter. The present application is introduced by applying the power converter to a photovoltaic system. The analog chip includes: a sampling circuit, a maximum power tracking circuit, a protection circuit, a fast shutdown circuit and a multiplexer; the sampling circuit collects the electrical parameters of the power converter, and the input end of the power converter is used to connect the photovoltaic module; the maximum power tracking circuit obtains the input power and / or output power of the power converter according to the electrical parameters, performs maximum power tracking according to the input power or output power, and obtains an adjustment signal to the multiplexer; the fast shutdown circuit generates a fast shutdown signal to the multiplexer when receiving a fast shutdown instruction sent from the outside of the analog chip; the protection circuit generates a protection signal to the multiplexer when the electrical parameters of the power converter exceed a first preset threshold; the multiplexer selects one of the fast shutdown signal, the protection signal or the adjustment signal as a control signal to control the power device in the power converter. Among them, the electrical parameters may include the input voltage, input current, output voltage, output current and temperature of the power converter. The electrical parameters collected by the sampling circuit will be sent to the maximum power tracking circuit and the protection circuit at the same time.

[0008] Each circuit in the analog chip provided by the present application is built by an analog circuit, that is, the analog chip is implemented by an analog integrated circuit, and what is processed is an analog signal. Through the analog chip, the MPPT of the photovoltaic module can be realized, so that the photovoltaic system works at a higher power generation efficiency; and the analog chip can also realize the protection function and the fast shutdown function of the power converter, that is, when the electrical parameters of the power converter exceed the threshold, timely protection is performed to reduce the electrical parameters to avoid damage to the power converter; for example, overvoltage, overcurrent, and overtemperature protection of the power converter are realized in abnormal situations to prevent damage to the power converter or further spread of the fault. In addition, when a quick shutdown is required, the power converter is controlled to stop working. Since the analog chip has high integration and low cost, even if the photovoltaic system includes a large number of photovoltaic modules, the cost will not be too high, which can reduce the system cost compared to the digital chip.

[0009] A possible implementation method is that the controller of the analog chip can also control the power devices according to the priority of each signal, specifically for selecting control signals from fast shutdown signals, protection signals and adjustment signals from high to low priority to control the power devices in the power converter. In addition, when fast shutdown is required, the power converter is controlled to stop working. The level of fast shutdown is higher than the level of protection, and the level of protection is higher than the level of MPPT. The multiplexer can realize priority shutdown and cessation of work when the power converter needs to be shut down, and secondly, protection when an abnormal situation occurs in the power converter, while maintaining the operation of the power converter under normal circumstances. The controller outside the analog chip can send a fast shutdown instruction to the analog chip. Among them, the external controller can be a controller of the inverter or a controller of the combiner box, or it can be other host computers.

[0010] In a possible implementation, the analog chip further includes: a communication circuit connected to both the fast shutdown circuit and the sampling circuit; the communication circuit is bidirectional, and can forward commands sent by a controller outside the analog chip to each circuit inside the analog chip, and can forward the working status of each circuit inside the analog chip to the controller, so that the controller monitors the operation of the analog chip. The communication circuit is used to forward the fast shutdown instruction sent by the controller to the fast shutdown circuit, and is also used to send the electrical parameters of the power converter collected by the sampling circuit to the controller; the controller is used to monitor the operation of the power converter according to the electrical parameters.

[0011] In a possible implementation, the communication circuit is also connected to a multiplexer; the communication circuit sends the control signal of the multiplexer and / or the selection result of the control signal to the controller, and / or the communication circuit sends the forced selection instruction sent by the controller to the multiplexer, and the multiplexer selects the control signal from the fast shutdown signal, the protection signal and the adjustment signal according to the forced selection instruction. The forced selection instruction sent by the controller through the communication circuit is the adjustment signal, and the multiplexer will abandon the protection signal and control the operation of the power converter according to the adjustment signal sent by the controller.

[0012] In a possible implementation, the maximum power tracking circuit includes: a multiplier, a maximum power tracker and a voltage processor; the multiplier is used to obtain input power and / or output power according to the voltage and current in the electrical parameters; the maximum power tracker is used to obtain a voltage reference value by performing maximum power tracking according to the input power or output power; the voltage processor is used to obtain a regulation signal according to the voltage reference value and the input voltage or output voltage in the electrical parameters.

[0013] In one possible implementation, the maximum power tracking circuit also includes: a voltage simulator; a voltage simulator, used to obtain a voltage preset value based on a preset coefficient and a voltage in an electrical parameter, where the voltage in the electrical parameter includes an input voltage or an output voltage; a voltage processor, specifically used to compare a voltage reference value with the voltage preset value to obtain a comparison result, and obtain a regulation signal based on the comparison result and the input voltage or the output voltage in the electrical parameter.

[0014] In a possible implementation, the maximum power tracker is also used to store the input power or output power sent by the multiplier as the memory power, and compare the real-time power of the photovoltaic module with the memory power to obtain the voltage reference value, that is, the maximum power tracker has a memory function. The maximum power tracker is also used to receive and store the input power or output power sent by the multiplier, that is, the input power or output power sent by the multiplier is used as the memory power, and the real-time power of the photovoltaic module is compared with the memory power to obtain the voltage reference value. Among them, the real-time power of the photovoltaic module is also the power obtained by the multiplier. In addition, the embodiment of the present application does not limit the specific MPPT tracking method. For example, in a possible implementation, the method for the maximum power tracker to obtain the voltage reference value can use the perturbation observation method, that is, the voltage reference value increases or decreases, and the size of the real-time power and the memory power of the photovoltaic module when the voltage reference value changes is observed. If the real-time power is greater than the memory power, the voltage reference value continues to increase or decrease in the original direction of change, otherwise the voltage reference value increases or decreases in the opposite direction of the original direction of change. For example, when the voltage reference value increases, the real-time power is greater than the memory power, then the voltage reference value continues to increase, otherwise the voltage reference value is reduced.

[0015] In a possible implementation, the voltage processor is further configured to control the power converter to operate in a pass-through mode through a control signal when the parameter represented by the adjustment signal exceeds a second preset threshold.

[0016] In one possible implementation, the communication circuit is also connected to the maximum power tracking circuit; the communication circuit is also used to send the power or regulation signal of the power converter obtained by the maximum power tracking circuit to the controller; and / or to send the controller's power adjustment instruction for the maximum power tracking circuit to the maximum power tracking circuit, and the power adjustment instruction is used to adjust the power or regulation signal of the power converter in the maximum power tracking circuit; wherein the power of the power converter is input power and / or output power.

[0017] In a possible implementation, the communication circuit is also connected to the maximum power tracking circuit; the communication circuit is also used to send the voltage reference value to the controller; and / or the communication circuit is used to forward the instruction sent by the controller to adjust the voltage reference value to the voltage processor.

[0018] In one possible implementation, the communication circuit is also connected to the maximum power tracking circuit; the communication circuit is also used to send at least one of the preset coefficient, the preset voltage value or the voltage reference value to the controller; and / or, to forward the instruction sent by the controller to adjust at least one of the preset coefficient, the preset voltage value or the voltage reference value to the voltage processor.

[0019] In one possible implementation, the communication circuit is also connected to the protection circuit; the communication circuit is also used to send the first preset threshold and protection signal of the protection circuit to the controller; and is also used to receive an adjustment protection instruction sent by the controller to the protection circuit, the adjustment protection instruction is used to adjust the first preset threshold or the protection signal.

[0020] Since each circuit inside the analog chip provided by the present application is connected to the communication circuit, the communication circuit can receive instructions sent by the external controller, so that the external controller can force the adjustment of the working parameters of each circuit. In addition, the communication circuit can also send the working status and parameters of each circuit to the controller outside the analog chip, and the external controller can monitor the working status of each circuit, so as to achieve double guarantee of monitoring. The analog chip includes a communication circuit, which can expand the transmission range of each signal, enhance the availability of the analog chip, and enable the photovoltaic power generation system to monitor the working parameters and electrical parameters of the photovoltaic module and the power converter, improve the communication range of the adjustment signal, the fast shutdown signal and the protection signal, and help to further reduce the cost of the photovoltaic power generation system.

[0021] In one possible implementation, the control signal is a protection signal, and the control signal is used to control the power converter to perform wave-by-wave current limiting, or to control the power converter to stop working. Taking the power converter as a BUCK topology as an example, the specific implementation of wave-by-wave current limiting is explained. The control signal output by the analog chip controls the conduction time of the main switch tube to decrease cycle by cycle until it is not conducting. During this process, the current flowing from the input end of the power converter to the output end gradually decreases, thereby realizing the protection of the main switch tube and the passive switch tube. The wave-by-wave current limiting protection can prevent the switch tube in the power converter from temporarily overvoltage or overcurrent during the protection process, thereby protecting the switch tube. According to different application scenarios and circuit topologies, if the switch tube will not experience overvoltage or overcurrent during the protection process, the protection signal can also directly stop the power converter from working for protection.

[0022] In a possible implementation, when an abnormality occurs in the communication between the fast shutdown module and the controller, the fast shutdown circuit is used to generate a fast shutdown signal to the multiplexer.

[0023] In a possible implementation, the control signal is a fast shut-off signal, and the control signal is used to control the power converter to discharge quickly, or to control the power converter to stop working.

[0024] A possible implementation method also includes: a curve scanning circuit; a curve scanning circuit, which is used to generate a curve scanning start signal to a multiplexer when a scanning instruction is received; the multiplexer is used to select a control signal from a fast shutdown signal, a protection signal, a curve scanning start signal and an adjustment signal according to a priority from high to low; when the curve scanning start signal is used as a control signal, the control signal is used to control the power converter to perform a curve scanning on the input voltage and input current or to perform a curve scanning on the output voltage and output current.

[0025] In a possible implementation, the communication circuit is also connected to the curve scanning circuit; the communication circuit is used to send the curve scanning start signal and the curve scanning mode of the curve scanning circuit to the controller, and is also used to send the scanning adjustment instruction sent by the controller to the curve scanning circuit, and the scanning adjustment instruction is used to adjust the curve scanning mode and the curve scanning start signal. The analog chip provided in the present application also has an IV curve scanning function, for example, it can realize the curve scanning of the input current and input voltage of the power converter, and it can also realize the curve scanning of the output current and output voltage of the power converter, so that the voltage and current characteristics of the photovoltaic module can be monitored, and the monitoring and adjustment capabilities of the photovoltaic power generation system can be improved.

[0026] The present application also provides a power converter, including: a power conversion circuit and the analog chip introduced above; the input end of the power converter is used to connect to the photovoltaic module, and the output end of the power converter is used to connect to the junction box or inverter; the analog chip is used to output a control signal to the power converter, and the control signal is used to control the power conversion circuit.

[0027] This application has at least the following advantages:

[0028] The analog chip includes a sampling circuit, a maximum power tracking circuit, a protection circuit, a fast shutdown circuit and a multiplexer; each circuit included in the analog chip is constructed by an analog circuit, that is, an analog integrated circuit, which processes analog signals. Through the analog chip, the MPPT of the photovoltaic module can be realized, so that the photovoltaic system works at a higher power generation efficiency; and the analog chip can also realize the protection function and fast shutdown function of the power converter, that is, when the electrical parameters of the power converter exceed the threshold, timely protection is performed to reduce the electrical parameters to avoid damage to the power converter; in addition, when fast shutdown is required, the power converter is controlled to stop working. The level of fast shutdown is higher than the level of protection, and the level of protection is higher than the level of MPPT. Since the analog chip has high integration and low cost, even if the photovoltaic system includes a large number of photovoltaic modules, the cost will not be too high, which can reduce the system cost compared with digital chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of a photovoltaic module provided in an embodiment of the present application;

[0030] Figure 2 A schematic diagram of an analog chip of a power converter provided in an embodiment of the present application;

[0031] Figure 3 A schematic diagram of an analog chip of a power converter provided in an embodiment of the present application;

[0032] Figure 4 A schematic diagram of another analog chip provided in an embodiment of the present application;

[0033] Figure 5 A schematic diagram of another analog chip provided in an embodiment of the present application;

[0034] Figure 6 A schematic diagram of a maximum power tracking circuit provided in an embodiment of the present application;

[0035] Figure 7 A schematic diagram of another maximum power tracking circuit provided in an embodiment of the present application;

[0036] Figure 8 A schematic diagram of a power converter provided in an embodiment of the present application;

[0037] Fig. 9 A schematic diagram of another analog chip provided in an embodiment of the present application;

[0038] Fig.10 A schematic diagram of a photovoltaic power generation system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0040] The terms "first", "second", etc. in the following description are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0041] In this application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. In addition, the term "coupling" can be a way of achieving electrical connection for signal transmission. "Coupling" can be a direct electrical connection or an indirect electrical connection through an intermediate medium.

[0042] In order to enable those skilled in the art to better understand the technical solution provided by the embodiments of the present application, the application scenarios of the technical solution are first introduced below in conjunction with the accompanying drawings.

[0043] The embodiment of the present application relates to an analog chip of a power converter, which is used to control the operation of the power converter, that is, the analog chip can output a driving signal to a switch tube in the power converter, such as a driving signal in a pulse width modulation mode, to drive the switching action of the switch tube, so that the power converter can realize the conversion of electric energy. Among them, the power converter connection is used to connect a photovoltaic module or a photovoltaic substring, and is used to convert electric energy to the photovoltaic module or the photovoltaic substring. In addition, the power converter can also be connected to multiple photovoltaic modules. The power converter is a direct current (DC-DC, Direct Current) converter or a direct current (DC-AC, Alternating Current) converter, for example, the voltage of the photovoltaic module can be boosted or bucked, or bucked or converted into an alternating current voltage.

[0044] See also Figure 1 , which is a schematic diagram of a photovoltaic component provided in an embodiment of the present application.

[0045] This embodiment is only one possible implementation of a photovoltaic module. A photovoltaic module includes three photovoltaic sub-strings. The specific implementation of the photovoltaic sub-string is that after a single photovoltaic cell is divided into two halves, the half photovoltaic cells are connected in series and then in parallel to form a photovoltaic sub-string inside the photovoltaic module. Figure 1 It can be seen that the first photovoltaic sub-string includes half-cell battery string 11 and half-cell battery string 12 connected in parallel, the second photovoltaic sub-string includes half-cell battery string 21 and half-cell battery string 22 connected in parallel, and the third photovoltaic sub-string includes half-cell battery string 31 and half-cell battery string 32 connected in parallel.

[0046] Three photovoltaic substrings are connected in series to form a photovoltaic module, and the two ports in series are external output ports, namely port A and port B. Multiple photovoltaic modules can also be connected in series or in parallel to form a photovoltaic array, thereby realizing external power generation.

[0047] The embodiment of the present application does not limit the number of photovoltaic modules corresponding to a power converter, for example Figure 1 The photovoltaic assembly shown may correspond to one power converter, or each photovoltaic substring may correspond to one power converter, for example, three photovoltaic substrings may correspond to three power converters in total.

[0048] For the convenience of description, the following embodiments of the present application are introduced by taking one photovoltaic component corresponding to one power converter as an example.

[0049] Analog Chip Embodiment

[0050] Since a photovoltaic power generation system includes a large number of photovoltaic modules, a large number of power converters are required. If the power converter is controlled by a digital chip, the price of the digital chip is high and the cost of the entire photovoltaic power generation system is high. In order to reduce the cost, an embodiment of the present application provides an analog chip of a power converter, which is described in detail below in conjunction with the accompanying drawings.

[0051] See also Figure 2 , which is a schematic diagram of an application scenario of an analog chip of a power converter provided in an embodiment of the present application.

[0052] The power converter 200 includes an input end and an output end. The output end of the photovoltaic module 100 is connected to the input end of the power converter 200. The power converter 200 converts the power of the photovoltaic module 100 and transmits it to the output end.

[0053] The analog chip 300 is a single integrated circuit chip used to control the power converter, that is, to send a drive signal to the switch tube in the power converter 200 to control the switching state of the switch tube. For example, when the level of the drive signal is high, the switch tube is turned on; when the level of the drive signal is low, the switch tube is turned off.

[0054] See also Figure 3 , which is a schematic diagram of an analog chip of a power converter provided in an embodiment of the present application.

[0055] The analog chip 300 of the power converter provided in this embodiment includes: a sampling circuit 31, a maximum power tracking circuit 32, a protection circuit 33, a fast shutdown circuit 34 and a multiplexer 35;

[0056] The sampling circuit 31 is used to collect electrical parameters of the power converter, and the input end of the power converter is used to connect the photovoltaic module; wherein the electrical parameters may include the input voltage Vin, input current Iin, output voltage Vout, output current Iout and temperature T of the power converter. Since the input end of the power converter is connected to the photovoltaic module, the input voltage Vin and the input current Iin are the output voltage and output current of the photovoltaic module respectively. The electrical parameters collected by the sampling circuit 31 will be sent to the maximum power tracking circuit 32 and the protection circuit 33 at the same time.

[0057] The maximum power tracking circuit 32 is used to obtain the input power and / or output power of the power converter according to the electrical parameters, and perform maximum power point tracking (MPPT) according to the input power or output power to obtain an adjustment signal S1 to the multiplexer 35;

[0058] The input voltage Vin and the input current Iin of the power converter are multiplied to obtain the input power, and the output voltage Vout and the output current Iout are multiplied to obtain the output power. The maximum power tracking circuit 32 can perform MPPT according to the input power, or according to the output power, or according to the input power and the output power, which is not specifically limited in this embodiment. When ignoring power loss, the maximum power tracking circuit 32 can also obtain the real-time power of the photovoltaic module according to the input voltage Vin and the input current Iin.

[0059] The maximum power tracking circuit 32 can obtain the voltage reference value required to track the maximum power of the photovoltaic module according to the MPPT algorithm to achieve maximum power tracking.

[0060] The protection circuit 33 is used to generate a protection signal S2 to the multiplexer 35 when the electrical parameter of the power converter exceeds a first preset threshold;

[0061] When the input voltage of the power converter exceeds the preset first voltage threshold, or the input current of the power converter exceeds the preset first current threshold, or the output voltage of the power converter exceeds the preset second voltage threshold, or the output current of the power converter exceeds the preset second current threshold, or the temperature of the power converter exceeds the preset temperature threshold, an effective protection signal S2 is generated and sent to the multiplexer 35; when the multiplexer 35 selects the protection signal S2 as the control signal, overvoltage, overcurrent and overtemperature protection of the power converter is implemented in abnormal situations to prevent damage to the power converter or further spread of the fault.

[0062] The above is only an example. In addition, the protection circuit 33 can detect only one or more of the input voltage, input current, output voltage, output current, and temperature for protection according to actual needs.

[0063] The fast shutdown circuit 34 is used to generate a fast shutdown signal S3 to the multiplexer 35 when receiving a fast shutdown instruction S4 sent from the outside of the analog chip; the controller outside the analog chip can send the fast shutdown instruction S4 to the analog chip. The controller can be a controller of the inverter or a controller of the combiner box, or other host computers.

[0064] The fast shutdown signal S3 may be a normally closed signal.

[0065] When the multiplexer 35 selects the fast shutdown signal S3 as the control signal, the output voltage of the power converter is quickly reduced to below the safety voltage. If the connection between the input end of the power converter and the photovoltaic module also poses a risk of being exposed to personnel or other equipment, the input voltage of the power converter is also quickly reduced to below the safety voltage. Therefore, when the photovoltaic power generation system requires the power converter to be quickly shut down, the voltage of the power converter is quickly reduced and the power converter is eventually stopped to protect personnel and other equipment.

[0066] The multiplexer 35 is used to select one of the fast shutdown signal S3, the protection signal S2 or the adjustment signal S1 as a control signal S5 for controlling the power devices in the power converter. That is, S5 can be one of S1, S2 or S3, which can be selected according to actual needs.

[0067] One possible implementation is to set the priority according to actual needs, for example, select the control signal S5 from the fast shutdown signal S3, the protection signal S2 and the adjustment signal S1 from high to low priority, that is, S3 has the highest priority, S2 is the second, and S1 has the lowest priority. That is, when S1, S2 and S3 are valid at the same time, the multiplexer 35 selects S3 as the control signal output, that is, S5=S3. When S2 and S1 are both valid, the multiplexer 35 selects S2 as the control signal output, that is, S5=S2. When only S1 is valid, the multiplexer 35 selects S1 as the control signal output, that is, S5=S1.

[0068] The multiplexer 35 can realize the priority of shutting down and stopping the power converter when it is necessary to shut down, and secondly, protecting the power converter when an abnormal situation occurs, and maintaining the operation of the power converter under normal circumstances.

[0069] The analog chip provided in the embodiment of the present application includes various circuits built by analog circuits, that is, analog integrated circuits. Through the analog chip, MPPT of photovoltaic modules can be realized, so that the photovoltaic system works at a higher power generation efficiency; and the analog chip can also realize the protection function and fast shutdown function of the power converter, that is, when the electrical parameters of the power converter exceed the threshold, even if protection is performed, the electrical parameters are reduced to avoid damage to the power converter; in addition, when fast shutdown is required, the power converter is controlled to stop working. The level of fast shutdown is higher than the level of protection, and the level of protection is higher than the level of MPPT. Since the analog chip has high integration and low cost, even if the photovoltaic system includes a large number of photovoltaic modules, the cost will not be too high, which can reduce the system cost compared to digital chips.

[0070] In addition to the specific MPPT power, protection function and fast shutdown function, the analog chip provided in the embodiment of the present application also has a communication function, which is described in detail below in conjunction with the accompanying drawings.

[0071] See also Figure 4 , which is a schematic diagram of another analog chip provided in an embodiment of the present application.

[0072] The analog chip 300 also includes: a communication circuit 36 ​​connected to both the fast shutdown circuit 34 and the sampling circuit 31; the communication of the communication circuit 36 ​​is bidirectional, which can forward the commands sent by the controller outside the analog chip to the various circuits inside the analog chip, and can forward the working status of the various circuits inside the analog chip to the controller, so that the controller can monitor the operation of the analog chip.

[0073] The communication circuit 36 ​​is connected to the fast shutdown circuit 34, and is used to forward the fast shutdown instruction S4 sent by the controller to the fast shutdown circuit 34; in addition, the communication circuit 36 ​​is also connected to the sampling circuit 31, and is also used to send the electrical parameters of the power converter collected by the sampling circuit 31 to the controller; the controller monitors the operation of the power converter according to the electrical parameters.

[0074] In addition, the communication circuit 36 ​​is also connected to the multiplexer 35;

[0075] The communication circuit 36 ​​is used to send the control signal and / or the selection result of the control signal selected by the multiplexer 35 to the controller, and is also used to send the forced selection instruction sent by the controller to the multiplexer 35, and the multiplexer 35 selects the control signal from the fast shutdown signal, the protection signal and the adjustment signal according to the forced selection instruction. For example, the multiplexer 35 selects the protection signal output by the protection circuit 33 as the control signal, but the forced selection instruction sent by the controller through the communication circuit 36 ​​is a fast shutdown signal. At this time, the multiplexer 35 will abandon the protection signal and control the operation of the power converter according to the fast shutdown signal sent by the controller. Or for example, the multiplexer 35 selects the protection signal output by the protection circuit 33 as the control signal, but the forced selection instruction sent by the controller through the communication circuit 36 ​​is an adjustment signal. At this time, the multiplexer 35 will abandon the protection signal and control the operation of the power converter according to the adjustment signal sent by the controller.

[0076] See also Figure 5 , which is a schematic diagram of another analog chip provided in an embodiment of the present application.

[0077] The maximum power tracking circuit provided in the embodiment of the present application may include: a multiplier 32a, a maximum power tracker 32b and a voltage processor 32c.

[0078] The multiplier 32a is used to receive the electrical parameters sent by the sampling circuit 31. For example, the multiplier 32a multiplies the input voltage and input current of the power converter to obtain the input power of the power converter, that is, the power of the photovoltaic module. Alternatively, the multiplier 32a multiplies the output voltage and output current of the power converter to obtain the output power of the power converter. Under the condition of ignoring the power converter loss, the power of the photovoltaic module can also be approximately obtained; this power is the real-time power of the photovoltaic module.

[0079] The maximum power tracker 32b can obtain the voltage reference value required to track the maximum power of the photovoltaic module according to the power of the photovoltaic module and the MPPT control algorithm, and send the voltage reference value to the voltage processor 32c. The maximum power tracker 32b performs maximum power tracking according to the input power or output power of the power converter to obtain the voltage reference value.

[0080] The voltage processor 32c obtains a regulation signal according to the voltage reference value and the input voltage or the output voltage in the electrical parameter.

[0081] When the analog chip controls the input voltage of the power converter, the voltage processor 32c compares the voltage reference value with the input voltage of the power converter and adjusts it to obtain a regulation signal. When the analog chip controls the output voltage of the power converter, the voltage processor 32c compares the voltage reference value with the output voltage of the power converter and adjusts it to obtain a regulation signal; at the same time, the voltage processor 32c sends the regulation signal S1 to the multiplexer 35. In normal operation, the multiplexer 35 selects the regulation signal S1 as the control signal, thereby realizing the power conversion control of the power converter by the analog chip 300.

[0082] In addition, the communication circuit 36 ​​in the analog chip 300 provided in this embodiment is also connected to the protection circuit 33 and the maximum power tracking circuit.

[0083] Among them, the communication circuit 36 ​​is also used to send the power or regulation signal of the power converter obtained by the maximum power tracking circuit to the controller; it is also used to send the controller's power adjustment instruction for the maximum power tracking circuit to the maximum power tracking circuit, and the power adjustment instruction is used to adjust the power or regulation signal of the power converter in the maximum power tracking circuit; wherein the power of the power converter is input power and / or output power.

[0084] That is, the controller outside the analog chip can send instructions for adjusting the maximum power tracking circuit to the analog chip. When the communication circuit receives the communication signal containing the adjustment instruction, it can force the maximum power tracking circuit to adjust the working state, that is, force the power of the photovoltaic module or the adjustment signal.

[0085] The communication circuit 36 ​​is further used to send the voltage reference value of the voltage processor 32c to the controller; and is further used to forward the instruction for adjusting the voltage reference value sent by the controller to the voltage processor 32c.

[0086] The communication circuit 36 ​​is also used to send the first preset threshold and protection signal of the protection circuit to the controller; and is also used to receive the protection adjustment instruction sent by the controller to the protection circuit, and the protection adjustment instruction is used to adjust the first preset threshold or the protection signal.

[0087] The communication circuit 36 ​​can also send the working state of the protection circuit 33 as a communication signal to the outside of the analog chip to monitor the working state of the power converter in the photovoltaic power generation system; the working state of the protection circuit 33 is one or more of the current first voltage threshold, first current threshold, second voltage threshold, second current threshold, temperature threshold, and protection signal. At the same time, the controller outside the analog chip 300 can also send an instruction to adjust the working state to the protection circuit 33. When the communication circuit 36 ​​receives the communication signal containing the adjustment instruction, it can force the protection circuit 33 to adjust the working state, that is, force the adjustment of the first voltage threshold, the first current threshold, the second voltage threshold, the second current threshold, the temperature threshold or the protection signal.

[0088] The analog chip provided in this embodiment has each internal circuit connected to the communication circuit, and can receive instructions sent by an external controller through the communication circuit, so that the external controller can force the adjustment of the working parameters of each circuit. In addition, the communication circuit can also send the working status and parameters of each circuit to the controller outside the analog chip, and the external controller can monitor the working status of each circuit, so as to achieve double guarantee of monitoring. The analog chip including the communication circuit can expand the transmission range of each signal, enhance the availability of the analog chip, and enable the photovoltaic power generation system to monitor the working parameters and electrical parameters of the photovoltaic components and power converters, improve the communication range of the adjustment signal, the fast shutdown signal and the protection signal, which is conducive to further reducing the cost of the photovoltaic power generation system.

[0089] The maximum power tracker in the maximum power tracking circuit provided in the embodiment of the present application also has a power memory function, which is described in detail below in conjunction with the accompanying drawings.

[0090] See also Figure 6 , which is a schematic diagram of a maximum power tracking circuit provided in an embodiment of the present application.

[0091] The maximum power tracker 32b is also used to receive and store the input power or output power sent by the multiplier 32a, that is, to use the input power or output power sent by the multiplier 32a as the memory power, and to compare the real-time power of the photovoltaic module with the memory power to obtain a voltage reference value. The real-time power of the photovoltaic module is also the power obtained by the multiplier 32a.

[0092] In addition, the embodiments of the present application do not limit the specific MPPT tracking method. For example, in one possible implementation method, the method for the maximum power tracker 32b to obtain the voltage reference value can use the perturbation observation method, that is, the voltage reference value increases or decreases, and the real-time power and memory power of the photovoltaic module are observed when the voltage reference value changes. If the real-time power is greater than the memory power, the voltage reference value continues to increase or decrease in the original direction of change, otherwise the voltage reference value increases or decreases in the opposite direction of the original direction of change. For example, when the voltage reference value increases, the real-time power is greater than the memory power, then the voltage reference value continues to increase, otherwise it decreases.

[0093] See also Figure 7 , which is a schematic diagram of another maximum power tracking circuit provided in an embodiment of the present application.

[0094] The maximum power tracking circuit further includes: a voltage simulator 32d;

[0095] The voltage simulator 32d is used to obtain a preset voltage value according to a preset coefficient and a voltage in an electrical parameter, wherein the voltage in the electrical parameter includes an input voltage or an output voltage; wherein the preset coefficient may be obtained according to a proportional relationship or a curve relationship, which is not specifically limited here. For example, the preset voltage value is obtained according to a proportional relationship, i.e., a linear function relationship, i.e., the voltage simulator 32d may obtain the preset voltage value according to the ratio of the input voltage to the first preset voltage, or may obtain the preset voltage value according to the ratio of the output voltage to the second preset voltage. There is no necessary relationship between the first preset voltage ratio and the second preset voltage ratio.

[0096] The voltage processor 32c is specifically used to compare the voltage reference value with the voltage preset value to obtain a comparison result, and obtain a regulation signal according to the comparison result and the input voltage or the output voltage in the electrical parameter.

[0097] The voltage simulator 32d obtains the voltage preset value required for the simulated voltage according to the ratio of the input voltage to the first preset voltage; the voltage reference value obtained by the maximum power tracker 32b is compared with the voltage preset value obtained by the voltage simulator 32d, and the voltage processor 32c compares the comparison result of the two with the output voltage of the power converter again and adjusts it to obtain a regulation signal, thereby realizing the control of the output voltage of the power converter.

[0098] Or, the voltage simulator 32d obtains the voltage preset value required for the simulated voltage based on the ratio of the output voltage and the second preset voltage; the voltage reference value obtained by the maximum power tracker 32b is compared with the voltage reference value obtained by the voltage simulator 32d, and the voltage processor 32c compares the comparison result of the two with the input voltage of the power converter again and adjusts it to obtain a regulation signal, thereby realizing the control of the input voltage of the power converter.

[0099] Or, the voltage simulator 32d obtains the voltage preset value required for the simulated voltage based on the ratio of the input voltage to the first preset voltage; the voltage reference value obtained by the maximum power tracker 32b is compared with the voltage preset value obtained by the voltage simulator 32d, and the voltage processor 32c compares the comparison result of the two with the input voltage of the power converter again and adjusts it to obtain a regulation signal, thereby realizing the control of the input voltage of the power converter.

[0100] Or, the voltage simulator 32d obtains the voltage preset value required for the simulated voltage based on the ratio of the output voltage and the second preset voltage; the voltage reference value obtained by the maximum power tracker 32b is compared with the voltage reference value obtained by the voltage simulator 32d, and the voltage processor 32c compares the comparison result of the two with the output voltage of the power converter again and adjusts it to obtain a regulation signal, thereby realizing the control of the output voltage of the power converter.

[0101] In this embodiment, specific values ​​of the first preset voltage ratio and the second preset voltage ratio are not limited, and the two may be the same or different.

[0102] The communication circuit is also connected to the maximum power tracking circuit; the communication circuit is also used to send at least one of the preset coefficient, the preset voltage value or the voltage reference value to the controller; and / or, is also used to forward the instruction sent by the controller to adjust at least one of the preset coefficient, the preset voltage value or the voltage reference value to the voltage processor.

[0103] In this embodiment, when the power converter operates in a non-maximum power tracking state, the voltage of the power converter can still be controlled to a voltage value proportional to the voltage of the photovoltaic module, thereby simulating the voltage of the photovoltaic module, which is beneficial to the overall control of the photovoltaic power generation system.

[0104] The voltage processor is also used for controlling the power converter to operate in a pass-through mode when the parameter represented by the adjustment signal exceeds a second preset threshold value. The adjustment signal may be a pulse signal, and the parameter represented by the adjustment signal may be a pulse width, a duty cycle, a pulse frequency or a pulse amplitude of the adjustment signal, that is, one of the above parameters may be selected to judge that when the second preset threshold value is exceeded, the power converter is controlled to operate in a pass-through mode, that is, the input end and the output end are directly connected without power conversion in between.

[0105] See also Figure 8 , which is a schematic diagram of a power converter provided in an embodiment of the present application.

[0106] In this embodiment, the topology of the power converter is a BUCK circuit as an example for introduction, and other topology circuit structures can also be used, which is not specifically limited here. The BUCK circuit includes a main switch tube S1, a passive switch tube S2, an inductor L and an output capacitor C, wherein the main switch tube S1 is activated to realize power conversion.

[0107] The embodiments of the present application do not limit the specific types of S1 and S2. For example, they may be metal-oxide-semiconductor field-effect transistors (MOSFET), insulated gate bipolar transistors (IGBT), or diodes.

[0108] When the multiplexer selects the adjustment signal as the control signal and the adjustment signal does not exceed the preset threshold, the analog chip controls the power converter to work in a normal state, that is, the power converter converts the voltage and current of the photovoltaic module into different levels of voltage and current according to actual needs and transmits them to the output end of the power converter. When the multiplexer selects the adjustment signal as the control signal and the adjustment signal exceeds the preset threshold, the control power converter enters the pass-through mode. Figure 8 If the main switch tube S1 in the power converter is kept normally on and the passive switch tube S2 is kept normally off, the output voltage of the power converter is equal to the input voltage, and the output current is equal to the input current, that is, the power of the photovoltaic module is directly transmitted to the output end of the power converter.

[0109] In this embodiment, the analog chip has the function of controlling the power converter to operate in a pass-through mode. When the photovoltaic module is not blocked, the power converter can be allowed not to perform power conversion, but to transmit the power of the photovoltaic module directly to the output end, thereby reducing the loss caused by the power converter and improving the power generation efficiency of the entire photovoltaic power generation system.

[0110] In this embodiment, the circuit topology and its corresponding direct-pass mode take the BUCK step-down circuit as an example, and can also be applied to the case where the power converter is a BOOST step-up circuit, etc. The direct-pass mode control method can also be adjusted accordingly according to different circuit topologies.

[0111] When the multiplexer selects the protection signal as the control signal, the control signal is used to control the power converter to perform wave-by-wave current limiting, or to control the power converter to stop working.

[0112] by Figure 8 The power converter topology example shown illustrates the specific implementation of the wave-by-wave current limiting. The control signal output by the analog chip controls the conduction time of the main switch tube S1 to decrease cycle by cycle until it is not conducting. During this process, the current flowing from the input end of the power converter to the output end gradually decreases, thereby achieving protection for the main switch tube S1 and the passive switch tube S2.

[0113] In this embodiment, the wave-by-wave current limiting protection can prevent the switch tube in the power converter from experiencing temporary overvoltage or overcurrent during the protection process, thereby protecting the switch tube. Depending on different application scenarios and circuit topologies, if the switch tube will not experience overvoltage or overcurrent during the protection process, the protection signal can also directly stop the power converter from working to perform protection.

[0114] In addition, the analog chip provided in the embodiment of the present application can also protect the power converter by generating a fast shutdown signal to the multiplexer when an abnormality occurs in the communication between the fast shutdown circuit and the controller outside the analog chip.

[0115] In this embodiment, the communication link between the fast shutdown circuit and the outside of the analog chip is abnormal. When the analog chip does not include a communication circuit, the fast shutdown circuit itself determines that the communication link is abnormal. When the analog chip includes a communication circuit, the communication circuit can determine that the communication link between the fast shutdown circuit and the outside is abnormal, or the fast shutdown circuit itself can determine that the communication link is abnormal.

[0116] When the control signal output by the analog chip is a fast shut-off signal, the control signal is used to control the power converter to discharge quickly, or to control the power converter to stop working.

[0117] Continue with Figure 8 The BUCK circuit shown is used as an example for introduction. When the multiplexer selects the adjustment signal as the control signal, the control signal discharges the capacitor of the power converter according to the adjustment signal, that is, the control signal controls the passive switch tube S2 in the power converter to remain turned on or turned on for a long time, thereby discharging the output capacitor C and quickly reducing the output voltage of the power converter to below the safe voltage.

[0118] If the input end of the power converter is connected to the photovoltaic module through a cable or other potentially exposed means, such as being exposed to staff or other equipment, the control signal output by the analog chip can control the active tube S1 to remain turned on or turned on for a long time, discharge the photovoltaic module, and quickly reduce the input voltage of the power converter to below the safe voltage. In this process, it is necessary to ensure that the passive switch tube S2 and the main switch tube S1 are not damaged by overcurrent or overheating. After the output voltage and input voltage of the power converter drop, the power converter can be stopped, and finally the power converter can be quickly shut down, thereby ensuring the safety of staff and equipment.

[0119] Depending on the application scenarios and circuit topologies, the regulation signal can also directly stop the power converter from working and ensure that the output voltage and input voltage of the power converter can be reduced to below the safe voltage in a short time.

[0120] The analog chip provided in the embodiment of the present application also has the function of IV curve scanning, which is described in detail below with reference to the accompanying drawings.

[0121] See also Fig. 9 , which is a schematic diagram of another analog chip provided in an embodiment of the present application.

[0122] Since the input end of the power converter is connected to the photovoltaic module, the analog chip can realize curve scanning of the voltage and current of the photovoltaic module.

[0123] In this embodiment, the analog chip 300 further includes: a curve scanning circuit 37;

[0124] The curve scanning circuit 37 is used to generate a curve scanning start signal to the multiplexer when receiving a scanning instruction;

[0125] The multiplexer 35 is used to select a control signal from the fast shutdown signal, the protection signal, the curve scanning start signal and the adjustment signal according to the priority from high to low; when the curve scanning start signal is used as the control signal, the control signal is used to control the power converter to perform a curve scanning on the input voltage and input current or to perform a curve scanning on the output voltage and output current.

[0126] In addition, in the analog chip 300 provided in this embodiment, the communication circuit 36 ​​is also connected to the curve scanning circuit 37;

[0127] The communication circuit 36 ​​is used to send the curve scanning start signal and the curve scanning mode of the curve scanning circuit 37 to the controller, and is also used to send the scanning adjustment instruction sent by the controller to the curve scanning circuit 37, and the scanning adjustment instruction is used to adjust the curve scanning mode and the curve scanning start signal.

[0128] The following is an example of the scanning instruction generated by the external controller of the analog chip, that is, when the curve scanning circuit 37 receives the scanning instruction from the outside of the analog chip 300, it generates a valid curve scanning start signal and sends it to the multiplexer 35; when the multiplexer 35 does not receive a valid adjustment signal or a valid protection signal, and receives a valid curve scanning start signal, it uses the curve scanning start signal as a control signal, and controls the power converter to scan the input current input voltage curve or the output current output voltage curve of the power converter according to the curve scanning mode preset by the curve scanning circuit 37. The multiplexer 35 is also used to select the control signal S5 from the fast shutdown signal S3, the protection signal S2, the curve scanning start signal S7 and the adjustment signal S1 according to the priority from high to low, so as to ensure the reliable operation of the power converter; the control signal S5 is used to control the power device in the power converter. That is, S5 can be one of S1 or S7 or S2 or S3, where S3 has the highest priority, S2 is second, S7 is third, and S1 has the lowest priority. That is, when S1, S7, S2, and S3 are all valid at the same time, the multiplexer 35 selects S3 as the control signal output, that is, S5 = S3. When S2, S7, and S1 are all valid, the multiplexer 35 selects S2 as the control signal output, that is, S5 = S2. When S7 and S1 are both valid, the multiplexer 35 selects S7 as the control signal output, that is, S5 = S7. When only S1 is valid, the multiplexer 35 selects S1 as the control signal output, that is, S5 = S1.

[0129] When the analog chip 300 includes a communication circuit 36, the curve scanning circuit 37 can also be connected to the communication circuit 36. The communication circuit 36 ​​can send the working state of the curve scanning circuit 37 to the outside of the analog chip 300 as a communication signal; the working state of the curve scanning circuit 37 includes the current curve scanning mode and the curve scanning start signal. At the same time, the controller outside the analog chip 300 can also send a scan adjustment instruction for adjusting the working state of the curve scanning circuit 37 to the chip. When the communication circuit 36 ​​receives the communication signal containing the scan adjustment instruction, it can force the curve scanning circuit 37 to adjust the working state, that is, force the curve scanning mode and the curve scanning start signal to be adjusted.

[0130] The curve scanning mode may be: the entire IV scanning curve starts from the open circuit voltage with the same scanning step length; or, the scanning step lengths are different, or segmented IV curve scanning, etc.

[0131] The analog chip provided in the embodiment of the present application also has an IV curve scanning function, for example, it can realize the curve scanning of the input current and input voltage of the power converter, and it can also realize the curve scanning of the output current and output voltage of the power converter, so as to monitor the voltage and current characteristics of the photovoltaic module and improve the monitoring and adjustment capabilities of the photovoltaic power generation system.

[0132] Power Converter Embodiment

[0133] Based on the analog chip of a power converter provided in the above embodiment, the embodiment of the present application also provides a power converter, which integrates the analog chip, that is, the power converter includes a power conversion circuit and an analog chip, which is described in detail below in conjunction with the accompanying drawings.

[0134] See also Fig.10 , which is a schematic diagram of a photovoltaic power generation system provided in an embodiment of the present application.

[0135] The photovoltaic power generation system provided in the embodiment of the present application includes: a power conversion circuit 200a and the analog chip 300 introduced in the above embodiment;

[0136] The input end of the power conversion circuit 200a is used to connect to the photovoltaic module, and the output end of the power conversion circuit 200a is used to connect to the inverter 400;

[0137] The analog chip 300 is used to output a control signal to the power conversion circuit 200a. The control signal is used to control the power conversion circuit 200a to perform power conversion. That is, the control signal output by the analog chip 300 can be a PWM signal to control the action of the switch tube in the power conversion circuit 200a. For example, when the topology of the power conversion circuit 200a is Figure 8 In the circuit shown, the control signal is used to control the action of S1 and S2.

[0138] In this embodiment, the output end of the power conversion circuit 200 a is connected to the inverter 400 as an example. In addition, a combiner box may be included between the power conversion circuit 200 a and the inverter 400 .

[0139] The photovoltaic power generation system provided in this embodiment includes an analog chip, which can not only control the power converter to perform normal power conversion and provide the power of the photovoltaic module to the inverter, but also realize protection, fast shutdown, curve scanning and other functions. Since there are many power converters in the photovoltaic power generation system provided in the embodiment of the present application, and each power converter needs to be configured with a control chip, if it is realized by using a digital chip, the cost is high, and the use of the analog chip provided in the above embodiment will greatly reduce the cost of the photovoltaic power generation system.

[0140] It should be understood that in this application, "at least one (item)" means one or more, and "more" means two or more. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of this application without departing from the content of the technical solution of this application shall still fall within the scope of protection of the technical solution of this application.

Claims

1. An analog chip for a power converter, characterized in that: include: Sampling circuit, maximum power tracking circuit, protection circuit, fast shutdown circuit and multiplexer; The sampling circuit is used to collect electrical parameters of the power converter, the input end of the power converter is used to connect the photovoltaic module; the electrical parameters include the input voltage and input current of the power converter, and / or the electrical parameters include the output voltage and output current of the power converter; The maximum power tracking circuit is used to obtain the input power and / or output power of the power converter according to the electrical parameters, perform maximum power tracking according to the input power or the output power, and obtain an adjustment signal to the multiplexer; The fast shutdown circuit is used to generate a fast shutdown signal to the multiplexer when receiving a fast shutdown instruction sent from outside the analog chip; The protection circuit is used to generate a protection signal to the multiplexer when the electrical parameter of the power converter exceeds a first preset threshold; The multiplexer is used to select one of the fast shutdown signal, the protection signal or the adjustment signal as a control signal to control the power device in the power converter; The maximum power tracking circuit includes: a voltage processor; The voltage processor is used to control the power converter to operate in a pass-through mode through the control signal when the parameter represented by the adjustment signal exceeds a second preset threshold.

2. The analog chip according to claim 1, characterized in that: The multiplexer is specifically used to select a control signal from the fast shutdown signal, the protection signal and the adjustment signal in order of priority from high to low, so as to control the power device in the power converter.

3. The analog chip according to claim 1, characterized in that: Also includes: a communication circuit connected to both the fast shutdown circuit and the sampling circuit; The communication circuit is used to forward the fast shutdown instruction sent by the controller to the fast shutdown circuit, and is also used to send the electrical parameters of the power converter collected by the sampling circuit to the controller; the controller is used to monitor the operation of the power converter according to the electrical parameters.

4. The analog chip according to claim 3, characterized in that: The communication circuit is also connected to the multiplexer; The communication circuit is used to send the control signal of the multiplexer and / or the selection result of the control signal to the controller, and / or to send the forced selection instruction sent by the controller to the multiplexer, and the multiplexer selects the control signal from the fast shutdown signal, the protection signal and the adjustment signal according to the forced selection instruction.

5. The analog chip according to any one of claims 3 to 4, characterized in that: The maximum power tracking circuit also includes: a multiplier and a maximum power tracker; The multiplier is used to obtain the input power and / or the output power according to the voltage and current in the electrical parameters; The maximum power tracker is used to perform maximum power tracking according to the input power or the output power to obtain a voltage reference value; The voltage processor is further used to obtain the adjustment signal according to the voltage reference value and the input voltage or the output voltage in the electrical parameter.

6. The analog chip according to claim 5, characterized in that: The maximum power tracking circuit also includes: a voltage simulator; The voltage simulator is used to obtain a preset voltage value according to a preset coefficient and a voltage in the electrical parameter, wherein the voltage in the electrical parameter includes an input voltage or an output voltage; The voltage processor is specifically used to compare the voltage reference value with the voltage preset value to obtain a comparison result, and obtain the adjustment signal according to the comparison result and the input voltage or the output voltage in the electrical parameter.

7. The analog chip according to claim 5, characterized in that: The maximum power tracker is further used to store the input power or the output power sent by the multiplier as memory power, and compare the real-time power of the photovoltaic component with the memory power to obtain the voltage reference value.

8. The analog chip according to claim 5, characterized in that: The communication circuit is also connected to the maximum power tracking circuit; The communication circuit is also used to send the power of the power converter or the regulation signal obtained by the maximum power tracking circuit to the controller; and / or to send the controller's power adjustment instruction for the maximum power tracking circuit to the maximum power tracking circuit, and the power adjustment instruction is used to adjust the power of the power converter or the regulation signal in the maximum power tracking circuit; wherein the power of the power converter is input power and / or output power.

9. The analog chip according to claim 5, characterized in that: The communication circuit is also connected to the maximum power tracking circuit; The communication circuit is further used to send the voltage reference value to the controller; and / or to forward the instruction sent by the controller to adjust the voltage reference value to the voltage processor.

10. The analog chip according to claim 6, characterized in that: The communication circuit is also connected to the maximum power tracking circuit; The communication circuit is also used to send at least one of the preset coefficient, the preset voltage value or the voltage reference value to the controller; and / or to forward an instruction sent by the controller to adjust at least one of the preset coefficient, the preset voltage value or the voltage reference value to the voltage processor.

11. The analog chip according to any one of claims 3 to 4, characterized in that: The communication circuit is also connected to the protection circuit; The communication circuit is also used to send the first preset threshold and the protection signal of the protection circuit to the controller; and is also used to receive an adjustment protection instruction sent by the controller to the protection circuit, wherein the adjustment protection instruction is used to adjust the first preset threshold or the protection signal.

12. The analog chip according to any one of claims 1 to 4, characterized in that: The control signal is the protection signal, and the control signal is used to control the power converter to perform wave-by-wave current limiting, or to control the power converter to stop working.

13. The analog chip according to any one of claims 1 to 4, characterized in that: When an abnormality occurs in the communication between the fast shutdown module and the controller, the fast shutdown circuit is used to generate a fast shutdown signal to the multiplexer.

14. The analog chip according to any one of claims 1 to 4, characterized in that: The control signal is the fast shutdown signal, and the control signal is used to control the power converter to discharge quickly, or to control the power converter to stop working.

15. The analog chip according to any one of claims 3 to 4, characterized in that: Also includes: a curve scanning circuit; The curve scanning circuit is used to generate a curve scanning start signal to the multiplexer when receiving a scanning instruction; The multiplexer is used to select a control signal from the fast shutdown signal, the protection signal, the curve scanning start signal and the adjustment signal according to the priority from high to low; when the curve scanning start signal is used as the control signal, the control signal is used to control the power converter to perform a curve scanning on the input voltage and input current or to perform a curve scanning on the output voltage and output current.

16. The analog chip according to claim 15, characterized in that: The communication circuit is also connected to the curve scanning circuit; The communication circuit is used to send the curve scanning start signal and the curve scanning mode of the curve scanning circuit to the controller, and is also used to send the scanning adjustment instruction sent by the controller to the curve scanning circuit, and the scanning adjustment instruction is used to adjust the curve scanning mode and the curve scanning start signal.

17. A power converter, characterized in that: include: A power conversion circuit and an analog chip as described in any one of claims 1 to 16; The input end of the power converter is used to connect to a photovoltaic module, and the output end of the power converter is used to connect to a combiner box or an inverter; the analog chip is used to output a control signal to the power converter, and the control signal is used to control the power conversion circuit.

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