Direct current converter

Abstract

The present application provides a direct current converter, comprising a first buck circuit, a second buck circuit, a charge pump circuit, a driving circuit, a controller, and a power conversion circuit. A photovoltaic module is connected to the power conversion circuit, and the power conversion circuit is connected to an inverter. A direct current outputted by the power conversion circuit is converted by means of the inverter into an alternating current to be connected to a power grid. The direct current converter achieves maximum power tracking of the photovoltaic module. The first buck circuit provides a first power supply for the driving circuit and provides a power supply for the charge pump circuit. The charge pump circuit provides a second power supply for the driving circuit. The second buck circuit provides a power supply for the controller. The first buck circuit and the charge pump circuit supply power to the driving circuit as two independent power supplies, so that switch tubes in the power conversion circuit are separately controlled, thereby reducing electromagnetic interference and noise and improving the efficiency and stability of the power conversion circuit.

Description

A DC converter

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on June 16, 2023, with application number 202310722567.9 and invention name "A DC Converter", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of photovoltaic power generation, and in particular to a DC converter. Background Art

[0004] Photovoltaic systems convert the DC power generated by photovoltaic panels into AC power that meets grid requirements through power conversion circuits before being connected to the public grid. These systems require multiple low-voltage DC power sources to operate. Furthermore, to implement the synchronous rectification function of the power conversion circuit, two independent driver power supplies and a half-bridge driver are required. However, the circuit structure required to implement these functions is complex, involving a large number of chips, resulting in high system costs. Therefore, a new circuit structure is needed to reduce the cost of photovoltaic systems and simplify the overall power supply design.

[0005] Summary of the Invention

[0006] The present application provides a DC converter, which uses a first BUCK circuit and a charge pump circuit to provide two independent power supplies for powering a driving circuit, thereby separately controlling the switching tubes in the power conversion circuit to reduce electromagnetic interference and noise and improve the efficiency and stability of the power conversion circuit.

[0007] In a first aspect, the present application provides a DC converter, which includes a first BUCK circuit, a second BUCK circuit, a charge pump circuit and a drive circuit. The input end of the first BUCK circuit is used to connect to a photovoltaic module, the output end of the first BUCK circuit is connected to the input end of the second BUCK circuit, the input end of the charge pump circuit and the first power supply end of the drive circuit, the output end of the charge pump circuit is connected to the second power supply end of the drive circuit, the input end of the power conversion circuit is used to connect to the photovoltaic module, the output end of the power conversion circuit is used to connect to an inverter, and the DC power output by the power conversion circuit is converted into AC power through the inverter and connected to the power grid. The control signal input end of the drive circuit is connected to the controller, and the drive signal output end of the drive circuit is connected to the control end of the power conversion circuit. The DC converter is used to achieve maximum power tracking of the photovoltaic module, wherein: the first BUCK circuit is used to provide a first power supply for the drive circuit and provide power for the charge pump circuit; the charge pump circuit is used to provide a second power supply for the drive circuit; and the second BUCK circuit is used to provide power for the controller.

[0008] Because the drive circuit needs to provide an isolated drive power supply for some of the switching tubes in the power conversion circuit, the present application provides a charge pump circuit to provide power to the drive circuit. The charge pump circuit converts the voltage output by the first buck circuit into an independent power supply. The first buck circuit and the charge pump circuit can serve as two independent power supplies to simultaneously power the drive circuit. This approach can provide two power supplies to the drive circuit, thereby independently controlling the switching tubes in the power conversion circuit, reducing electromagnetic interference and noise, and improving the efficiency and stability of the power conversion circuit.

[0009] As a possible implementation, the first buck circuit includes: at least one switching tube, a first inductor, and a first capacitor; the second buck circuit includes: at least one switching tube, a second inductor, and a second capacitor; each switching tube in the first buck circuit, each switching tube in the second buck circuit, the charge pump circuit, and the drive circuit are placed in a packaged chip; the packaged chip includes a first pin, a second pin, a third pin, and a fourth pin, the first pin is connected to the first inductor, the second pin is connected to the first capacitor, the third pin is connected to the second inductor, and the fourth pin is connected to the second capacitor.

[0010] This application places the inductor and capacitor outside the package, reducing the volume of the packaged chip and achieving a more complex circuit design when the design space is limited. In addition, placing the inductor and capacitor outside the package makes it easier to repair and replace the inductor and capacitor without disassembling the packaged chip. Since the inductor itself generates heat during operation, placing the inductor outside the packaged chip can transfer heat to the surrounding environment more quickly, thereby reducing the temperature of the packaged chip and improving the reliability and life of the DC converter. In addition, placing the inductor outside the packaged chip can reduce electromagnetic interference problems, so that the magnetic field and electric field of the inductor will not interfere with other circuit components.

[0011] Furthermore, placing each switch tube in the first buck circuit, each switch tube in the second buck circuit, the charge pump circuit, and the drive circuit in the same package structure of the packaged chip can reduce the physical connection distance between the various circuits and improve the reliability of the entire DC converter. Placing the above-mentioned devices and circuits in the same package can also play a role in physical protection, reducing the failure rate of circuit components. In addition, integrating multiple circuits in the same package can also reduce the number of devices in the circuit because some devices can be shared.

[0012] The first BUCK circuit can be composed of components such as a switching tube, a first inductor located outside the packaged chip, and a first capacitor located outside the packaged chip. The switching tube is used to convert the input voltage of the photovoltaic module into a current through the first inductor, which is then stored in the first capacitor. Finally, the energy in the first capacitor is released by periodic switching of the switching tube. The second BUCK circuit can be composed of components such as a switching tube, a second inductor located outside the packaged chip, and a second capacitor located outside the packaged chip. The switching tube is used to convert the input voltage of the first BUCK circuit into a current through the second inductor, which is then stored in the second capacitor. Finally, the energy in the second capacitor is released by periodic switching of the switching tube, thereby providing power supplies of multiple different voltages through the first BUCK circuit and the second BUCK circuit.

[0013] As a possible implementation, the power conversion circuit includes: a first switching tube, a second switching tube, a third inductor and a third capacitor; one end of the first switching tube is connected to the positive input terminal of the photovoltaic module, the other end of the first switching tube is connected to one end of the second switching tube, the other end of the second switching tube is connected to the negative input terminal of the photovoltaic module, one end of the third inductor is connected to the other end of the first switching tube, the other end of the third inductor is connected to one end of the second switching tube, and the other end of the third capacitor is connected to the other end of the second switching tube; the driving circuit is used to control the conduction state of the first switching tube and the second switching tube to adjust the output power of the photovoltaic module.

[0014] As a possible implementation, the charge pump circuit includes: a fourth switching tube, a fifth switching tube, a sixth switching tube, a first diode, a fourth capacitor, and a fifth capacitor; one end of the fourth switching tube is connected to the output end of the first buck circuit, the other end of the fourth switching tube is respectively connected to one end of the fourth capacitor and the positive electrode of the first diode, the other end of the fourth capacitor is connected to the first end of the fifth switching tube, the second end of the fifth switching tube is grounded, the other end of the fourth capacitor is connected to the first end of the sixth switching tube, the cathode of the first diode is connected to one end of the fifth capacitor, and the second end of the sixth switching tube is connected to the other end of the fifth capacitor.

[0015] By controlling the on / off states of the fourth switch tube and the fifth switch tube, the fourth capacitor is charged, and then by controlling the on / off states of the third switch tube, the energy stored in the fourth capacitor is transferred to the fifth capacitor, so that the fifth capacitor provides driving power for the driving circuit.

[0016] Since reverse connection of photovoltaic modules may cause many hazards and risks, as a possible implementation method, the packaged chip also includes a detection circuit within the package. The detection circuit includes a sixth switching tube and a detection resistor. The detection circuit is connected in parallel on both sides of the output end of the power conversion circuit. The detection circuit is used to detect whether the photovoltaic module is reverse connected.

[0017] As a possible implementation, the first buck circuit includes: at least one switching tube, a first inductor, and a first capacitor; the second buck circuit includes: at least one switching tube, a second inductor, and a second capacitor; each switching tube in the first buck circuit, each switching tube in the second buck circuit, the charge pump circuit, the drive circuit, and the reverse connection detection circuit are placed in the packaged chip.

[0018] The present application places the reverse connection detection circuit inside the packaged chip, which can reduce the size of the DC converter and achieve a more complex circuit design when the design space is limited.

[0019] As a possible implementation method, after determining that the photovoltaic component is powered on, the third switch tube is controlled to be turned on to detect whether the photovoltaic component is reversely connected; or, when determining that there is residual charge on the third capacitor, the third switch tube is controlled to be turned on to release the residual charge on the third capacitor.

[0020] After the PV system is powered on, the third switch is pulled high, turning it on. At this point, if any PV module is reversely connected, the circuit's resistance will change. A multimeter can then be used to measure the resistance across the PV module's output to detect reverse connection. This allows the system to stop the module immediately and then inspect any reversed modules to avoid potential damage. Furthermore, closing the third switch can also release residual charge from capacitors in the power conversion circuit.

[0021] As a possible implementation method, the positive output terminal of the first BUCK circuit is connected to the power input terminal of the driving circuit, the negative output terminal of the first BUCK circuit is connected to the ground terminal of the driving circuit, the cathode of the first diode of the charge pump circuit is connected to the high-side half-bridge driving power input terminal of the driving circuit, the second end of the sixth switch tube of the charge pump circuit is connected to the high-side half-bridge driving power ground terminal of the driving circuit, the high-side driving signal input terminal of the driving circuit is used to receive the high-side control signal sent by the controller, the low-side driving signal input terminal of the driving circuit is used to receive the low-side control signal sent by the controller, the high-side driving signal output terminal of the driving circuit is used to output the driving signal to the first switching tube according to the high-side control signal, and the low-side driving signal output terminal of the driving circuit is used to output the driving signal to the second switching tube according to the low-side control signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a schematic structural diagram of a DC converter;

[0023] FIG2 is a schematic diagram of a packaging structure of a DC converter;

[0024] FIG3A is a schematic structural diagram of a power conversion circuit;

[0025] FIG3B is a schematic structural diagram of a charge pump circuit;

[0026] FIG4 is a connection diagram of a driving circuit;

[0027] FIG5 is a connection diagram of a reverse connection detection circuit;

[0028] FIG6 is a schematic diagram of the complete structure of a DC converter. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be understood as being limited to the embodiments set forth herein; on the contrary, these embodiments are provided to make the present application more comprehensive and complete, and to fully convey the concepts of the example embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted. The words expressing position and direction described in this application are all explained using the accompanying drawings as examples, but changes can be made as needed, and all changes are included in the scope of protection of this application. The drawings in this application are only used to illustrate relative position relationships and do not represent true proportions.

[0030] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. The specific operating methods in the method embodiments can also be applied to device embodiments or system embodiments. It should be noted that in the description of the present application, "at least one" refers to one or more, wherein multiple refers to two or more. In view of this, "multiple" can also be understood as "at least two" in the embodiments of the present invention. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the previous and next associated objects are in an "or" relationship. In addition, it should be understood that in the description of the present application, words such as "first" and "second" are only used to distinguish the purpose of description, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order.

[0031] It should be noted that in the embodiments of the present application, "connection" refers to electrical connection, and the connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be either a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components. For example, the connection between A and B can also be a direct connection between A and C, and C and B can be directly connected, with A and B connected through C.

[0032] To implement synchronous rectification in the power conversion circuit, the photovoltaic system requires two independent drive power supplies and a half-bridge driver. However, the circuit structure required to implement these functions is complex, involving a large number of chips, resulting in high photovoltaic system costs. Therefore, a new circuit structure is needed to reduce photovoltaic system costs and simplify the overall power supply design.

[0033] In view of this, the present application provides a DC converter that can reduce the cost of a photovoltaic system and simplify the power supply design of the photovoltaic system. Referring to FIG1 , FIG1 is a schematic structural diagram of a DC converter, wherein the DC converter 100 includes a first BUCK circuit 101, a second BUCK circuit 102, a charge pump circuit 103, a drive circuit 104, a controller 105, and a power conversion circuit 106. The input end of the first BUCK circuit 101 is used to connect to a photovoltaic module 107, the output end of the first BUCK circuit 101 is connected to the input end of the second BUCK circuit 102, the input end of the charge pump circuit 103, and the first power supply end of the drive circuit 104, and the output end of the charge pump circuit 103 is connected to the output end of the drive circuit 104. The second power supply end is connected, the control signal input end of the drive circuit 104 is connected to the controller 105, the input end of the power conversion circuit 106 is used to connect to the photovoltaic module, and the output end of the power conversion circuit 106 is used to connect to the inverter 108. The DC power output by the power conversion circuit 106 is converted into AC power through the inverter 108 and connected to the power grid 109. The control signal input end of the drive circuit 104 is connected to the controller 105, and the drive signal output end of the drive circuit 104 is connected to the control end of the power conversion circuit 106. The DC converter 100 is used to achieve maximum power tracking of the photovoltaic module 107.

[0034] The first BUCK circuit 101 is used to provide a first power supply for the driving circuit 104 and a power supply for the charge pump circuit 103 ; the charge pump circuit 103 is used to provide a second power supply for the driving circuit 104 ; and the second BUCK circuit 102 is used to provide a power supply for the controller 105 .

[0035] The operating principle of the first buck circuit 101 is to use a switching transistor to convert the input voltage of the photovoltaic panel 107 through an inductor into a current, which is then stored in a capacitor. Finally, the energy in the capacitor is released by periodically switching the switching transistor to achieve the purpose of voltage reduction. For example, if the input voltage of the photovoltaic panel 107 is approximately 30V, the first buck circuit 101 can convert the input voltage of the photovoltaic panel 107 to a voltage of approximately 12V, thereby powering the charge pump circuit 103 and the driver circuit 104.

[0036] The operating principle of the second buck circuit 102 is to use a switching transistor to convert the input voltage of the first buck circuit 101 through an inductor into a current, which is then stored in a capacitor. Finally, the energy in the capacitor is released by periodically switching the switching transistor to achieve the purpose of voltage reduction. For example, if the input voltage of the first buck circuit 101 is approximately 12V, the second buck circuit 102 can convert the input voltage of the first buck circuit 101 to a voltage of approximately 3.3V, thereby powering the controller 105.

[0037] The switches in the first BUCK circuit 101 and the second BUCK circuit 102 may include, but are not limited to, a metal oxide semiconductor field effect transistor (MOSFET) driver, an insulated gate bipolar transistor (IGBT) driver, a gate driver, and other driving structures.

[0038] In addition, the weak power supplies provided by the first BUCK circuit 101 and the second BUCK circuit 102 can also provide power for the controller 105 and other devices in the DC converter 100. Those skilled in the art can make connections according to specific needs, thereby further reducing power supply costs.

[0039] Because the driver circuit needs to provide isolated drive power for some of the switches in the power conversion circuit 106, a charge pump circuit 103 is provided to provide power to the driver circuit. The charge pump circuit 103 converts the voltage output by the first buck circuit 101 into an independent power supply. The first buck circuit 101 and the charge pump circuit 103 can simultaneously power the driver circuit 104. This approach provides two power supplies for the driver circuit 104, allowing for separate control of the switches in the power conversion circuit 106, reducing electromagnetic interference and noise, and improving the efficiency and stability of the power conversion circuit 106.

[0040] It should be noted that the charge pump circuit 103 can also be a flyback Buck-Boost circuit, which can also achieve isolated and adjustable DC conversion and has lower electromagnetic interference (EMI). The specific circuit structure and control method will not be described here in detail, and people in this field should know it.

[0041] The drive circuit 104 may include multiple modules, such as a control input module, an isolation module, a logic control module, and a drive output module. The control input module is generally used to receive input signals sent by the controller 105, such as PWM signals. The isolation module can provide electrical isolation to protect the controller 105 and semiconductor devices within the drive circuit 104. The logic control module is used to process the input signals sent by the controller 105. The drive output module is used to generate drive signals, thereby providing drive signals to the power conversion circuit 106.

[0042] The controller 105 may be a general-purpose central processing unit (CPU), a general-purpose processor, a digital signal processing (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The aforementioned processors may also be a combination that implements computing functions. For example, the controller 105 may also include a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and the like.

[0043] Power conversion circuit 106 is used to convert the direct current (DC) generated by photovoltaic modules 107 into AC (alternating current) that meets grid requirements before being connected to the public grid. Power conversion circuit 106 may include a buck (buck) step-down circuit, a boost (boost) circuit, or a buck-boost (buck-boost) step-down / boost circuit, a dual active bridge converter (DAB), and an inverter. The specific possible circuit types and circuit combinations are well known to those skilled in the art and are not detailed here.

[0044] Exemplarily, the power conversion circuit 106 may also include: a maximum power point tracking (MPPT) circuit. The MPPT circuit detects the input voltage and current in real time, calculates the input power, and enables the photovoltaic system to track the maximum power point of the input according to certain pre-set algorithms, so that the photovoltaic system can output more electrical energy to the power grid and increase power generation.

[0045] Referring to FIG. 2 , FIG. 2 is a schematic diagram of the package structure of a DC converter, wherein the first buck circuit 101 includes: at least one switch, a first inductor 201, and a first capacitor 202; the second buck circuit 102 includes: at least one switch, a second inductor 203, and a second capacitor 204; each switch in the first buck circuit, each switch in the second buck circuit, the charge pump circuit 103, and the drive circuit 104 are disposed within a packaged chip 200; the packaged chip 200 includes a first pin 205, a second pin 206, a third pin 207, and a fourth pin 208. The first pin 205 is connected to the first inductor 201, the second pin 206 is connected to the first capacitor 202, the third pin 207 is connected to the second inductor 203, and the fourth pin 208 is connected to the second capacitor 204.

[0046] The input end of the packaged chip 200 is used to connect to the photovoltaic module 107. The positive output end of the photovoltaic module 107 is connected to the positive input end of the first buck circuit 101. The negative output end of the photovoltaic module 107 is connected to the negative input end of the first buck circuit 101. The positive output end of the first buck circuit 101 is connected to the positive input end of the second buck circuit 102. The negative output end of the first buck circuit 101 is connected to the negative input end of the second buck circuit 102. The output end of the packaged chip 200 provides a drive signal to the power conversion circuit 106 and provides power to the controller 105 and other components of the DC converter 100. The first pin 205 to the fourth pin 208 each include two connection ports. For example, the first end of the first inductor 201 can be connected to the first connection port of the first pin 205, and the second end of the first inductor 201 can be connected to the second connection port of the first pin 205.

[0047] The present application places the inductor and capacitor outside the packaged chip 200, which can more easily achieve the required inductance and capacitance values, reduce the volume of the DC converter 100, and achieve a more complex circuit design when the design space is limited. In addition, if the inductor and capacitor are placed outside the package, the maintenance or replacement of the inductor and capacitor becomes easier, and there is no need to disassemble and replace them. In addition, the inductor itself will generate heat during operation. Placing the inductor outside the packaged chip 200 can transfer heat to the surrounding environment more quickly, thereby reducing the temperature of the packaged chip 200 and improving the reliability and life of the DC converter 100. In addition, placing the inductor outside the packaged chip 200 can reduce electromagnetic interference (EMI) problems, so that the magnetic field and electric field of the inductor will not interfere with other circuit components.

[0048] Furthermore, placing each switch tube in the first BUCK circuit 101, each switch tube in the second BUCK circuit 102, the charge pump circuit 103, and the drive circuit in the same package structure of the packaged chip 200 can reduce the physical connection distance between the various circuits and improve the reliability of the entire DC converter 100. Placing the above-mentioned devices and circuits in the same package can provide physical protection and reduce the failure rate of circuit elements. In addition, integrating multiple circuits in the same package can also reduce the number of devices in the circuit because some devices can be shared.

[0049] As a possible implementation, refer to Figure 3A, which is a structural schematic diagram of a power conversion circuit. The power conversion circuit includes: a first switching tube 301, a second switching tube 302, a third inductor 303 and a third capacitor 304; one end of the first switching tube 301 is connected to the positive input terminal of the photovoltaic component 107, the other end of the first switching tube 301 is connected to one end of the second switching tube 302, the other end of the second switching tube 302 is connected to the negative input terminal of the photovoltaic component 107, one end of the third inductor 303 is connected to the other end of the first switching tube 301, the other end of the third inductor 303 is connected to one end of the second switching tube 301, and the other end of the third capacitor is connected to the other end of the second switching tube 302; the driving circuit 104 is used to control the conduction state of the first switching tube 301 and the second switching tube 302 to adjust the output power of the photovoltaic component 107.

[0050] Among them, the first switch tube 301 and the second switch tube 302 can be one or more of various types of switching devices such as MOSFET, bipolar junction transistor (BJT), IGBT, silicon carbide (SiC) power tube, etc., which are not listed one by one in the embodiments of the present application. Each switch tube can include a first end, a second end and a control end, wherein the control end is used to control the closing or opening of the switch tube. When the switch tube is closed, current can be transmitted between the first end and the second end of the switch tube. When the switch tube is disconnected, current cannot be transmitted between the first end and the second end of the switch tube. Taking MOSFET as an example, the control end of the switch tube is the gate, the first end of the switch tube can be the source of the switch tube, and the second end can be the drain of the switching device, or the first end can be the drain of the switch tube, and the second end can be the source of the switch tube.

[0051] As a possible implementation, refer to FIG. 3B , which is a schematic diagram of the structure of a charge pump circuit. The charge pump circuit 103 includes: a fourth switch 311, a fifth switch 312, a sixth switch 313, a first diode 314, a fourth capacitor 315, and a fifth capacitor 316. One end of the fourth switch 311 is connected to the output end of the first buck circuit 101, the other end of the fourth switch 311 is connected to one end of the fourth capacitor 315 and the anode of the first diode 314, the other end of the fourth capacitor 315 is connected to the first end of the fifth switch 312, the second end of the fifth switch 312 is grounded, the other end of the fourth capacitor 315 is connected to the first end of the sixth switch 313, the cathode of the first diode 314 is connected to one end of the fifth capacitor 316, and the second end of the sixth switch 313 is connected to the other end of the fifth capacitor 316.

[0052] The controller 105 is used to control the fourth switch tube 311 and the fifth switch tube 312 to be turned on and the sixth switch tube 313 to be turned off, so that the fourth capacitor 315 is charged. The controller 105 controls the fourth switch tube 311 and the fifth switch tube 312 to be turned on and the sixth switch tube 313 to be turned off, so that the first buck circuit 101 and the fourth capacitor 315 charge the fifth capacitor 316, and the fifth capacitor 316 provides driving power for the driving circuit 104.

[0053] The controller 105 is further configured to control the first switch 301 and the fourth switch 311 to be turned on simultaneously, and / or to control the first switch 301 and the fourth switch 311 to be turned off simultaneously, so as to place the power conversion circuit 106 in the pass-through mode. In this manner, by controlling the first switch 301 and the fourth switch 311 in the power conversion circuit 106 to be turned on simultaneously, the controller 105 enables the charge pump circuit 103 to provide an isolated driving power supply for the first switch 301 of the power conversion circuit 106 when only one power supply is available, thereby satisfying the pass-through turn-on requirement of the first switch 301. In this manner, even if the second switch 302 of the power conversion circuit 106 is not operating, the power conversion circuit 106 can remain in the pass-through mode.

[0054] As a possible embodiment, referring to FIG4 , FIG4 is a connection diagram of the drive circuit, and the drive circuit may include the following interface terminals: a power input terminal (VDD), a ground terminal (VSS), a high-side half-bridge drive power input terminal (high side bridge, HB), a high-side half-bridge drive power ground terminal (high side, HS), a high-side drive signal output terminal (high side output, HO), a high-side drive signal input terminal (high side input, HI), a low-side drive signal input terminal (low side input, LI), and a low-side drive signal output terminal (low side output, LO). The positive output terminal of the first BUCK circuit 101 is connected to the VDD terminal of the drive circuit, and the negative output terminal of the first BUCK circuit 101 is connected to the VSS terminal of the drive circuit 104. In this way, the first BUCK circuit 101 can provide an operating voltage for the drive circuit. The cathode of the first diode 314 of the charge pump circuit 103 is connected to the HB of the driving circuit, and the second end of the sixth switch tube 313 of the charge pump circuit 103 is connected to the HS end of the driving circuit. By driving the HB end and the HS end, an isolated driving power supply can be provided for the first switch tube 301 of the power conversion circuit 106 when there is only one power supply, thereby meeting the turning-on requirement of the first switch tube 301.

[0055] The HI and LI terminals of the driving circuit are connected to the controller 105. The HI terminal is used to receive a high-side control signal, and the LI terminal receives a low-side control signal. The above control signals are used to respectively control the opening and closing of the first switching tube 301 and the second switching tube 302 in the power conversion circuit 106, thereby controlling the output voltage of the power conversion circuit 106.

[0056] The HO terminal of the driving circuit is used to output a driving signal to the first switch tube 301 of the power conversion circuit 106 based on the high-side control signal, and the LO terminal of the driving circuit is used to output a driving signal to the second switch tube 302 of the power conversion circuit 106 based on the low-side control signal.

[0057] PV modules 107 typically have a string-type structure. If PV modules 107 are reversely connected internally, numerous hazards and risks may arise. For example, reverse connection of PV modules 107 can cause reverse current flow, potentially damaging electronic components within PV modules 107, thereby reducing the performance and lifespan of PV modules 107. Reverse connection of PV modules 107 can cause current to flow in the opposite direction, reducing the power generation capacity of PV modules 107 or even preventing it from generating any power at all. Furthermore, if PV modules 107 are reversely connected and connected to the power grid, reverse current flow can result, potentially posing safety risks such as fire and electric shock. As a possible implementation, refer to FIG. 5 , which is a schematic diagram of a reverse connection detection circuit. The DC converter 100 further includes a reverse connection detection circuit 500, which includes a third switch 501 and a detection resistor 502. The reverse connection detection circuit 500 is connected in parallel to both sides of the third capacitor 304.

[0058] As a possible implementation, each switch in the first BUCK circuit 101 , each switch in the second BUCK circuit 102 , the charge pump circuit 103 , the drive circuit 104 , and the reverse connection detection circuit 500 are placed in the packaged chip 200 .

[0059] As a possible implementation, the controller 105 is used to: after determining that the photovoltaic component 107 is powered on, control the third switch tube 501 to turn on to detect whether the photovoltaic component 107 is reversely connected; or when determining that there is residual charge on the third capacitor 304, control the third switch tube 501 to turn on to release the residual charge on the third capacitor 304.

[0060] After the photovoltaic system is powered on, the controller 105 pulls the third switch 501 high, turning it on. At this point, if any photovoltaic module is reversely connected, the circuit's resistance value will change. By measuring the circuit's resistance with a multimeter, it is possible to detect the reverse connection in that photovoltaic module 107. This allows the system to promptly stop the operation of the photovoltaic module 107 and inspect the reversed photovoltaic module 107, thereby preventing any damage caused by reverse connection.

[0061] In addition, the capacitors in the power conversion circuit 106 are used to filter out the DC component of the circuit. However, after power is turned off, residual charge may still remain on the capacitors in the power conversion circuit 106. If these residual charges are not released, they may generate a short-term high voltage when they are turned on next time, thereby potentially damaging components in the circuit. Therefore, by providing the reverse connection detection circuit 500 in the packaged chip 200, when it is necessary to release the residual charge of the capacitors in the power conversion circuit 106, the controller 105 can release the residual charge by closing the third switch tube 501. The reverse connection detection circuit 500 is connected to the output terminal of the power conversion circuit 106 to form a loop. When the power conversion circuit 106 is turned off, if there is still residual charge in the capacitor, the magnitude of the residual charge can be detected by the detection resistor 502. When it is detected that the magnitude of the residual charge exceeds a safety threshold, the controller 105 releases the residual charge to the ground line through the third switch tube 501 by turning on the third switch tube 501, thereby avoiding damaging components in the circuit.

[0062] Referring to Figure 6 , which is a schematic diagram of the complete structure of a DC converter provided in an embodiment of the present application, the input end of the first buck circuit is used to connect to the photovoltaic module 107, the output end of the first buck circuit 101, and the input end of the second buck circuit 102. Specifically, the first buck circuit 101 may include: a sixth switch 601, a seventh switch 602, a first inductor 201, and a first capacitor 202; the second buck circuit 102 may include: an eighth switch 603, a ninth switch 604, a second inductor 203, and a second capacitor 204.

[0063] In which, the positive electrode of the photovoltaic component 107 is connected to the first end of the sixth switching tube 601, the second end of the sixth switching tube 601 is respectively connected to the first end of the first inductor 201 and the first end of the seventh switching tube 602, the third end of the sixth switching tube 601 is used to input a signal for controlling the state of the sixth switching tube 601, the second end of the seventh switching tube 602 is respectively connected to the negative electrode of the photovoltaic component 107 and the first end of the first capacitor 202, the third end of the seventh switching tube 602 is used to input a signal for controlling the state of the seventh switching tube 602, and the second end of the second inductor 203 is connected to the second end of the second capacitor 204.

[0064] The first end of the first capacitor 202 is connected to the first end of the eighth switching tube 603, the second end of the eighth switching tube 603 is respectively connected to the first end of the second inductor 203 and the first end of the ninth switching tube 604, the third end of the eighth switching tube 603 is used to input a signal for controlling the state of the eighth switching tube 603, the second end of the ninth switching tube 604 is respectively connected to the second end of the first capacitor 202 and the first end of the second capacitor 204, the third end of the ninth switching tube 604 is used to input a signal for controlling the state of the ninth switching tube 604, and the second end of the second inductor 203 is connected to the second end of the second capacitor 204.

[0065] The output end of the first BUCK circuit 101 is connected to the input end of the charge pump circuit 103 , wherein the first end of the fourth switch tube 311 is connected to the first end of the first capacitor 202 .

[0066] The output terminal of the first buck circuit 101 is also connected to the first power supply terminal of the driving circuit 104 , wherein the first terminal of the first capacitor 202 is connected to the VDD terminal of the driving circuit 104 , and the second terminal of the first capacitor 202 is connected to the VSS terminal of the driving circuit 104 .

[0067] The output terminal of the charge pump circuit 103 is connected to the second power supply terminal of the driving circuit 104 , wherein the first terminal of the fourth capacitor 315 is connected to the HB terminal of the driving circuit 104 , and the second terminal of the fourth capacitor 315 is connected to the HS terminal of the driving circuit 104 .

[0068] The output end of the controller 105 is used to input a high-side control signal and a low-side control signal to the HI end and the LI end of the drive circuit 104. The HO end of the drive circuit 104 is used to output a drive signal to the first switch tube 301 of the power conversion circuit 106 based on the high-side control signal. The LO end of the drive circuit 104 is used to output a drive signal to the second switch tube 302 of the power conversion circuit 106 based on the low-side control signal.

[0069] In the DC converter provided herein, the charge pump circuit converts the voltage output by the first buck circuit into an independent power supply. The first buck circuit and the charge pump circuit can function as two independent power supplies to simultaneously power the driver circuit. This approach provides two power supplies for the driver circuit, allowing independent control of the switches in the power conversion circuit, reducing electromagnetic interference and noise and improving the efficiency and stability of the power conversion circuit. By placing the inductor and capacitor outside the package of the packaged chip, it is easier to meet the required inductor and capacitor sizes for the buck circuit, thereby reducing the size of the packaged chip and enabling more complex circuit designs when design space is limited. Furthermore, placing the inductor and capacitor outside the package makes it easier to repair and replace the inductor and capacitor, without disassembling the packaged chip; only the external inductor and capacitor need to be accessed. Furthermore, because the charge pump circuit can provide an isolated drive power supply to the first switch of the power conversion circuit, even if the second switch is not working, the first switch can be in direct-through mode, meeting the first switch's on-state requirements. Furthermore, placing the switching transistors of the first and second buck circuits, the charge pump circuit, and the driver circuit in the same packaged chip reduces the failure rate of circuit components and the number of components in the circuit. The reverse connection detection circuit in the packaged chip detects reverse connection of the photovoltaic module and releases any residual charge in the capacitors of the power conversion circuit, thereby preventing damage to components in the circuit.

[0070] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A DC converter, characterized in that: The DC converter includes a first BUCK circuit, a second BUCK circuit, a charge pump circuit, a drive circuit, a controller and a power conversion circuit. The input end of the first BUCK circuit is used to connect the photovoltaic module. The output end of the first BUCK circuit is connected to the input end of the second BUCK circuit, the input end of the charge pump circuit and the first power supply end of the drive circuit. The output end of the charge pump circuit is connected to the second power supply end of the drive circuit. The input end of the power conversion circuit is used to connect the photovoltaic module. The output end of the power conversion circuit is used to connect the inverter. The inverter converts the DC power output by the power conversion circuit into AC power and connects it to the power grid. The control signal input end of the drive circuit is connected to the controller. The drive signal output end of the drive circuit is connected to the control end of the power conversion circuit. The DC converter is used to achieve maximum power tracking of the photovoltaic module, wherein: The first BUCK circuit is used to provide a first power supply for the driving circuit and provide power for the charge pump circuit; The charge pump circuit is used to provide a second power supply for the driving circuit; The second BUCK circuit is used to provide power to the controller.

2. The DC converter according to claim 1, characterized in that: The first BUCK circuit includes: at least one switch tube, a first inductor and a first capacitor; The second BUCK circuit includes: at least one switch tube, a second inductor and a second capacitor; Each switch tube in the first BUCK circuit, each switch tube in the second BUCK circuit, the charge pump circuit and the drive circuit are placed in a packaged chip; The packaged chip includes a first pin, a second pin, a third pin and a fourth pin, the first pin is connected to the first inductor, the second pin is connected to the first capacitor, the third pin is connected to the second inductor, and the fourth pin is connected to the second capacitor.

3. The DC converter according to claim 1 or 2, characterized in that: The power conversion circuit includes: a first switch tube, a second switch tube, a third inductor and a third capacitor; One end of the first switch tube is connected to the positive input end of the photovoltaic module, the other end of the first switch tube is connected to one end of the second switch tube, the other end of the second switch tube is connected to the negative input end of the photovoltaic module, one end of the third inductor is connected to the other end of the first switch tube, the other end of the third inductor is connected to one end of the second switch tube, and the other end of the third capacitor is connected to the other end of the second switch tube; The driving circuit is used to control the conduction state of the first switch tube and the second switch tube to adjust the output power of the photovoltaic component.

4. The DC converter according to claim 3, characterized in that: The DC converter further includes: a reverse connection detection circuit, which includes a third switch tube and a detection resistor, and the reverse connection detection circuit is connected in parallel on both sides of the third capacitor.

5. The DC converter according to claim 4, characterized in that: The first BUCK circuit includes: at least one switch tube, a first inductor and a first capacitor; The second BUCK circuit includes: at least one switch tube, a second inductor and a second capacitor; Each switch tube in the first BUCK circuit, each switch tube in the second BUCK circuit, the charge pump circuit, the drive circuit and the reverse connection detection circuit are placed in a packaged chip.

6. The DC converter according to claim 4, characterized in that: The controller is used to: After determining that the photovoltaic assembly is powered on, controlling the third switch tube to be turned on to detect whether the photovoltaic assembly is reversely connected; or When it is determined that there is residual charge on the third capacitor, the third switch tube is controlled to be turned on to release the residual charge on the third capacitor.

7. The DC converter according to any one of claims 3 to 6, characterized in that: The charge pump circuit comprises: a fourth switch tube, a fifth switch tube, a sixth switch tube, a first diode, a fourth capacitor and a fifth capacitor; One end of the fourth switch tube is connected to the output end of the first BUCK circuit, and the other end of the fourth switch tube is connected to the output end of the first BUCK circuit. One end of the fourth capacitor is connected to the positive electrode of the first diode, the other end of the fourth capacitor is connected to the first end of the fifth switch tube, the second end of the fifth switch tube is grounded, the other end of the fourth capacitor is connected to the first end of the sixth switch tube, the cathode of the first diode is connected to one end of the fifth capacitor, and the second end of the sixth switch tube is connected to the other end of the fifth capacitor.

8. The DC converter according to claim 7, characterized in that: The controller is used to: Controlling the fourth switch tube and the fifth switch tube to be turned on and the sixth switch tube to be turned off, so that the first BUCK circuit charges the fourth capacitor; The fourth switch tube and the sixth switch tube are controlled to be turned on, and the fifth switch tube is turned off, so that the first BUCK circuit and the fourth capacitor charge the fifth capacitor.

9. The DC converter according to claim 7, characterized in that: The controller is used to: The first switch tube and the fourth switch tube are controlled to be turned on at the same time, or the first switch tube and the fourth switch tube are controlled to be turned off at the same time, so that the power conversion circuit is in a direct-pass mode.

10. The DC converter according to claim 7, characterized in that: The positive output end of the first BUCK circuit is connected to the power input end of the drive circuit, the negative output end of the first BUCK circuit is connected to the ground end of the drive circuit, the cathode of the first diode of the charge pump circuit is connected to the high-side half-bridge drive power input end of the drive circuit, the second end of the sixth switch tube of the charge pump circuit is connected to the high-side half-bridge drive power ground end of the drive circuit, the high-side drive signal input end of the drive circuit is used to receive the high-side control signal sent by the controller, the low-side drive signal input end of the drive circuit is used to receive the low-side control signal sent by the controller, the high-side drive signal output end of the drive circuit is used to output the drive signal to the first switch tube according to the high-side control signal, and the low-side drive signal output end of the drive circuit is used to output the drive signal to the second switch tube according to the low-side control signal.

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