Virtual voltage detection circuit, method, system and equipment
By coordinating the detection and processing modules in the photovoltaic system, and controlling the switching transistor to construct a voltage relief circuit, the problem of virtual voltage at the output of the Boost circuit is solved, thereby improving the reliability and stability of the system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOLAR POWER NETWORK TECHNOLOGY (ZHEJIANG) CO LTD
- Filing Date
- 2025-08-05
- Publication Date
- 2026-04-17
AI Technical Summary
In photovoltaic systems, the output of the Boost circuit still has voltage when the photovoltaic module stops generating electricity, which causes reverse leakage current to form a virtual voltage, affecting the reliability and logic judgment of the system.
By coordinating the detection and processing modules, the switching transistor is turned on to construct a pressure relief circuit at the input of the DC-DC converter module, thereby identifying and eliminating false pressure.
It improves the reliability of photovoltaic systems, prevents interference and misjudgment of the system by virtual voltage, and reduces unnecessary stress and standby power consumption of devices.
Smart Images
Figure CN121878291A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of photovoltaic power generation, and in particular to a voltage detection circuit, method, system and device. Background Technology
[0002] A photovoltaic (PV) system is a power generation system that uses photovoltaic modules to convert solar energy into electrical energy. It is widely used in grid-connected power generation, off-grid power supply, residential energy storage, industrial and commercial energy storage, and integrated PV-energy storage systems. In a typical PV system, a boost circuit (DC-to-voltage converter) is often used to increase the DC voltage output by the PV modules to meet the input requirements of the inverter or energy storage battery.
[0003] When the photovoltaic modules stop generating electricity at night, there is no voltage at the input of the Boost circuit. However, the inverter system connected to the output may still be running, such as charging / discharging the battery or in standby mode, resulting in a certain voltage remaining at the output of the Boost circuit. This output voltage reverse-biases the output diode in the Boost circuit, causing reverse leakage current in the diode. This reverse leakage current causes voltage to flow backward from the Boost circuit output into the photovoltaic module side, creating a virtual voltage input. This can lead to sampling anomalies and potential problems with system display and logic. Summary of the Invention
[0004] This application provides a false pressure detection circuit, method, system, and device to improve system reliability.
[0005] In a first aspect, embodiments of this application provide a false voltage detection circuit, including: a detection module and a processing module; the detection module is connected to a DC-DC converter module and is used to detect the input voltage of the DC-DC converter module; wherein, the DC-DC converter module includes a switching transistor; the processing module is connected to the control terminal of the switching transistor and is used to control the switching transistor to conduct when the input voltage detected by the detection module is within a first threshold range; the processing module is further used to determine whether the input voltage drops to a second threshold range after the switching transistor is conducted, and if so, determine that the input voltage is a false voltage.
[0006] In one possible implementation, the DC-DC converter module further includes: a first energy storage unit and a unidirectional conduction unit; the first energy storage unit is connected between the positive input terminal and the negative input terminal of the DC-DC converter module; the anode of the unidirectional conduction unit is connected to the positive input terminal of the DC-DC converter module, and the cathode is connected to the positive output terminal of the DC-DC converter module; the first end of the switching transistor is connected to the positive input terminal of the DC-DC converter module, and the other end is grounded.
[0007] In one possible implementation, the DC-DC converter module further includes: a second energy storage unit; the positive input terminal of the DC-DC converter module is connected to one end of the switching transistor and the anode of the unidirectional conduction unit through the second energy storage unit.
[0008] In one possible implementation, the input of the DC-DC converter is connected to a photovoltaic module, and the output is connected to an inverter.
[0009] Secondly, embodiments of this application provide a method for detecting false voltage, based on the processing module described above; the method includes: acquiring the input voltage detected by the detection module; when the input voltage is within a first threshold range, controlling the switching transistor in the DC-DC converter to turn on; after the switching transistor is turned on, determining whether the input voltage drops to a second threshold range; if so, determining that the input voltage is a false voltage.
[0010] In one possible implementation, controlling the switching transistor in the DC-DC converter module to turn on includes: sending a pulse width modulation signal with a fixed duty cycle to the switching transistor during a first preset time period to turn on the switching transistor.
[0011] In one possible implementation, after determining whether the input voltage has dropped to the second threshold range, the method further includes: if the input voltage has not dropped to the second threshold range, then stopping the control of the switching transistor in the DC-DC converter module to turn on.
[0012] In one possible implementation, after stopping the switching transistor in the DC-DC converter module from conducting, the process further includes: after a second preset time period, returning to execute the input voltage detected by the detection module and subsequent steps.
[0013] In one possible implementation, after determining that the input voltage is a false voltage, the method further includes: continuously sending a pulse width modulation signal with a fixed duty cycle to the switching transistor until the input voltage is less than a first threshold range.
[0014] Thirdly, embodiments of this application provide a photovoltaic system, including a photovoltaic module, the aforementioned voltage detection circuit, and a DC-DC conversion module; wherein the positive output terminal of the photovoltaic module is connected to the positive input terminal of the DC-DC conversion module, and the negative output terminal of the photovoltaic module is connected to the negative input terminal of the DC-DC conversion module.
[0015] Fourthly, embodiments of this application provide an electronic device, including: a memory and a processor;
[0016] The memory stores the instructions that the computer executes;
[0017] The processor executes computer execution instructions stored in memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.
[0018] The false voltage detection circuit, method, system, and device provided in this application include a detection module and a processing module. The detection module detects the input voltage of the DC-DC converter module, and the processing module is connected to the control terminal of the switching transistor in the DC-DC converter module. The processing module controls the switching transistor to turn on when the input voltage detected by the detection module is within a first threshold range. The processing module also determines whether the input voltage drops to a second threshold range after the switching transistor is turned on; if so, it determines that the input voltage is a false voltage. This solution constructs a voltage relief loop at the input terminal of the DC-DC converter module by controlling the switching transistor to turn on. If the input voltage drops after voltage relief, it is determined to be a false voltage. This simultaneously achieves the detection and partial elimination of false voltage, improving the reliability of the system. Attached Figure Description
[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0020] Figure 1 This is a schematic diagram of the structure of the false pressure detection circuit provided in the embodiments of this application;
[0021] Figure 2 This is a schematic diagram of the structure of the false pressure detection circuit provided in the embodiments of this application;
[0022] Figure 3 This is a schematic diagram of the structure of the false pressure detection circuit provided in the embodiments of this application;
[0023] Figure 4 This is a schematic diagram of the structure of the false pressure detection circuit provided in the embodiments of this application;
[0024] Figure 5 A schematic flowchart of the virtual pressure detection method provided in the embodiments of this application;
[0025] Figure 6 A schematic flowchart of the virtual pressure detection method provided in the embodiments of this application;
[0026] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.
[0027] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation
[0028] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.
[0029] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning. In addition, the terms "comprising" and "having," and any variations thereof, are intended to be omnipresent but not exclusive. For example, a product or device that comprises a series of components is not necessarily limited to those components that are explicitly listed, but may include other components that are not explicitly listed or that are inherent to such product or device.
[0030] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0031] The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.
[0032] A photovoltaic (PV) system, also known as a solar photovoltaic power generation system, is a device that directly converts sunlight into electrical energy using the photovoltaic effect of semiconductor materials. Its core component is the photovoltaic module, or solar panel, which is typically composed of multiple photovoltaic cells connected in series or parallel. PV systems are characterized by being clean and pollution-free, relatively simple to maintain, and capable of distributed deployment, making their applications extremely wide-ranging: such as distributed grid-connected systems installed on the roofs of residential and commercial buildings to supplement the grid or achieve partial self-consumption; and large-scale ground-mounted power plants that directly supply large amounts of clean electricity to the grid in centralized power plant systems. In addition, PV systems are widely used in the transportation sector, such as photovoltaic streetlights, traffic lights, agricultural photovoltaic water pumps, agricultural facility power supply, emergency power supplies, and charging of various portable electronic devices. Throughout the entire PV power generation chain, especially in grid-connected systems, to improve efficiency, achieve maximum power point tracking, and adapt to the inverter's input voltage range, a DC-DC conversion circuit is usually required between the PV module and the inverter. Among them, the boost circuit is one of the most important and commonly used topologies. It can boost the relatively low output voltage of photovoltaic modules, which fluctuates with light and temperature, to a more stable and higher DC bus voltage.
[0033] When it's nighttime or in extremely low light conditions, the photovoltaic modules stop generating electricity, and their output voltage approaches zero, causing the input of the Boost circuit to be essentially at zero or extremely low voltage. However, the inverter connected to the system output may not be completely de-energized. For example, in a hybrid energy storage system, it may be managing battery charging and discharging, or it may be in standby mode preparing for startup the next day. This results in a certain voltage maintained by the energy storage system or standby power supply at the output (DC bus) of the Boost circuit. At this time, the previously conducting switch in the Boost circuit is turned off. In this situation, the positive voltage at the Boost circuit output is directly applied to the cathode of the output rectifier diode, while the anode is close to zero potential due to the lack of voltage on the photovoltaic side. This causes the diode to experience a significant reverse voltage from cathode to anode, exceeding its ideal cutoff state. In actual semiconductor devices, this deep reverse bias inevitably induces a small reverse leakage current. The path of this leakage current is: starting from the positive bus voltage at the Boost circuit output, flowing through the reverse-biased diode, the inductor, and finally reaching the positive terminal of the photovoltaic module.
[0034] Because the internal impedance of photovoltaic modules is extremely high at night (in an open-circuit state), this tiny reverse leakage current charges parasitic components such as the junction capacitance and bypass diodes inside the photovoltaic module, forming a "virtual voltage" at the input that is much higher than zero but lower than the normal operating voltage. This virtual voltage may not only cause sampling anomalies and interfere with the monitoring of the module's true state, such as misjudging that there is still weak power generation and subsequent logic judgments, but if it exists for a long time or is too large, it will also increase unnecessary stress on the devices, reduce system reliability, and may lead to an increase in standby power consumption.
[0035] The technical content provided in this application aims to solve the aforementioned technical problems in related technologies. The false voltage detection circuit, method, system, and device provided in the embodiments of this application include a detection module and a processing module. The detection module is used to detect the input voltage of the DC-DC converter module. The processing module is connected to the control terminal of the switching transistor in the DC-DC converter module and is used to control the switching transistor to conduct when the input voltage detected by the detection module is within a first threshold range. The processing module is also used to determine whether the input voltage drops to a second threshold range after the switching transistor is conducted; if so, the input voltage is determined to be a false voltage. The solution of this application can construct a voltage relief circuit at the input terminal of the DC-DC converter module by controlling the switching transistor to conduct. If the input terminal voltage drops after voltage relief, it is determined to be a false voltage, thus realizing the detection and partial elimination of false voltage and improving the reliability of the system.
[0036] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.
[0037] Figure 1 This is a schematic diagram of the structure of the false pressure detection circuit provided in the embodiments of this application, as shown below. Figure 1 As shown, the circuit includes: a detection module 10 and a processing module 20;
[0038] The detection module 10 is connected to the DC-DC converter module 30 and is used to detect the input voltage of the DC-DC converter module 30; wherein, the DC-DC converter module 30 includes a switching transistor 31;
[0039] The processing module 20 is connected to the control terminal of the switching transistor 31 and is used to control the switching transistor 31 to conduct when the input voltage detected by the detection module 10 is within the first threshold range. The processing module 20 is also used to determine whether the input voltage drops to the second threshold range after the switching transistor 31 is conducted. If so, the input voltage is determined to be a false voltage.
[0040] For example, the detection module 10 and processing module 20 can be a core structure of a resistor voltage divider and an analog-to-digital converter. Specifically, the detection module 10 includes a high-precision resistors R1 and R2 connected in series for voltage division, and the input pin of the analog-to-digital converter in the processing module 20 is connected between R1 and R2. In practical applications, the processing module 20 can be a microprocessor with a built-in analog-to-digital converter. In addition to the analog-to-digital converter, the microprocessor may also include a driver chip for initiating a pulse width modulation signal output to drive the switch 31 to conduct based on the real-time sampling results of the analog-to-digital converter.
[0041] Optionally, the processing module 20 may also be an existing microprocessor in the DC-DC conversion module or an improved microprocessor, in order to achieve the reuse of circuit components.
[0042] In some optional embodiments, the detection module 10 may also be an isolated voltage sensor such as a linear optocoupler or a Hall voltage sensor, and the processing module 20 may also be a two-way comparator such as constructing a first threshold window comparison circuit, whose output triggers the generation of a fixed-width pulse width modulation signal; the second threshold is determined by another comparator, and finally outputs a false voltage determination signal through AND gate logic.
[0043] It should be noted that the DC-DC converter module 30 is a DC-DC boost converter module, i.e., a Boost circuit. In some embodiments, the input terminal of the DC-DC converter module 30 is connected to a DC power supply device such as a photovoltaic module, a battery pack, or a DC generator; the output terminal of the DC-DC converter module 30 is connected to a load such as an inverter or a DC load; the output terminal of the DC-DC converter module 30 can also be connected to energy storage such as a battery pack, a capacitor pack, or a pre-charge circuit.
[0044] In some embodiments, the DC-DC converter 30 includes a capacitor and / or an inductor to store the voltage input to the input terminal of the DC-DC converter 30 during normal operation; and to store the voltage input to the output terminal of the DC-DC converter 30 in the presence of reverse leakage current. Specifically, when the DC-DC converter 30 includes a capacitor, its internal structure can be such that the positive input terminal is connected to the detection module 10, one end of the capacitor, one end of the switching transistor 31, and the positive output terminal, and the other end of the capacitor and the other end of the switching transistor 31 are both connected to the negative input terminal, and the negative input terminal is grounded; when the DC-DC converter 30 includes an inductor, its internal structure can be such that the positive input terminal is connected to the detection module 10, one end of the inductor, the other end of the inductor, one end of the switching transistor 31, and the positive output terminal, and the other end of the switching transistor 31 is connected to the negative input terminal, and the negative input terminal is grounded.
[0045] For example, the first threshold range of the input voltage can be pre-defined as the range that affects the circuitry of the DC-DC converter module. This range is related to the output side of the DC-DC converter module and is affected by the output port voltage. Specifically, the first threshold range can be 50-200V. Optionally, the first threshold can be set based on the system's rated operating voltage and safety margin, for example, 5% of the rated voltage.
[0046] In practical applications, when the input voltage is within the first threshold range, the processing module 20 can output a pulse width modulation signal to control the conduction time of the switch 31 in order to release the input voltage; optionally, the processing module 20 can also directly output high and low level signals to control the conduction and cutoff of the switch 31.
[0047] Furthermore, after the processing module 20 controls the switch 31 to turn on, it is also necessary to determine whether the input voltage has dropped to the second threshold range. The second threshold range is typically lower than the first threshold range and is used to detect the decreasing trend of the input voltage. It can be set as the lower limit of the first threshold minus a certain margin. Optionally, the second threshold range can be set according to the system's sensitivity to false voltage, and is usually more stringent than the first threshold to improve the accuracy of false voltage detection. It should be understood that when the input voltage is a false voltage caused by reverse current, the input voltage detected by the detection module 10 should decrease after the switch 31 turns on. If the input voltage is a normal input voltage, the input voltage detected by the detection module 10 will maintain its magnitude due to continuous current replenishment after the switch 31 turns on.
[0048] The false voltage detection circuit provided in this application includes a detection module and a processing module. The detection module is used to detect the input voltage of the DC-DC converter module. The processing module is connected to the control terminal of the switching transistor in the DC-DC converter module and is used to control the switching transistor to conduct when the input voltage detected by the detection module is within a first threshold range. The processing module is also used to determine whether the input voltage drops to a second threshold range after the switching transistor is conducted. If so, the input voltage is determined to be a false voltage. The solution of this application can construct a voltage relief loop at the input terminal of the DC-DC converter module by controlling the switching transistor to conduct. If the input voltage drops after voltage relief, it is determined to be a false voltage. At the same time, false voltage detection and partial elimination are realized, improving the reliability of the system.
[0049] Figure 2 This is a schematic diagram of the structure of the false pressure detection circuit provided in the embodiments of this application, as shown below. Figure 2 As shown, the DC-DC converter module 30 also includes: a first energy storage unit 32 and a unidirectional conduction unit 33;
[0050] The first energy storage unit 32 is connected between the positive input terminal and the negative input terminal of the DC-DC converter module 30;
[0051] The anode of the unidirectional conduction unit 33 is connected to the positive input terminal of the DC-DC converter module 30, and the cathode is connected to the positive output terminal of the DC-DC converter module 30.
[0052] The first end of the switching transistor 31 is connected to the positive input terminal of the DC-DC converter module 30, and the other end is grounded.
[0053] In practical applications, the first energy storage unit 32 can be a single capacitor or a group of capacitors; the unidirectional conduction unit 33 can be a diode or a Schottky diode.
[0054] In this example, when there is a reverse-biased leakage current in the unidirectional conduction unit 33, the high voltage at the positive output terminal of the DC-DC converter module 30 causes the voltage of the first energy storage unit 32 connected to the input terminal of the DC-DC converter module 30 to rise along the path of the leakage current. Furthermore, the voltage of the first energy storage unit 32 is directly proportional to the magnitude of the leakage current and time, and inversely proportional to the capacitance value of the first energy storage unit 32.
[0055] Furthermore, when the processing module 20 turns on the switch 31 under certain conditions, the current path changes. At this time, current can flow directly to ground through the switch 31, forming a low-impedance loop. This process causes the charge in the first energy storage unit 32 to be released rapidly, resulting in a voltage drop. On one hand, if the input voltage drops rapidly to the second threshold range after the switch 31 is turned on, the input voltage can be determined to be a false voltage. A false voltage refers to a voltage rise caused by leakage current or other abnormal paths, rather than being provided by the actual power supply voltage. On the other hand, when the input voltage is not a false voltage, after the switch 31 is turned on, the power supply can continuously provide sufficient current to maintain a stable input voltage. Therefore, even if the switch 31 is turned on, the input voltage will not drop significantly because the power supply can compensate for the charge release caused by the switch 31 being turned on. In this case, the circuit can operate normally, and the input voltage is maintained within the first threshold range.
[0056] In this example, the reverse bias leakage current of the unidirectional conduction unit 33 causes an abnormal increase in the voltage of the first energy storage unit 32. By controlling the switching transistor 31 to conduct, a low-impedance current path can be constructed to release the abnormally increased leakage current, thereby realizing the detection of the false voltage of the first energy storage unit 32.
[0057] Figure 3 This is a schematic diagram of the structure of the false pressure detection circuit provided in the embodiments of this application, as shown below. Figure 3 As shown, the DC-DC converter module 30 also includes a second energy storage unit 34;
[0058] The positive input terminal of the DC-DC converter module 30 is connected to one end of the switching transistor 31 and the anode of the unidirectional conduction unit 33 through the second energy storage unit 34.
[0059] For example, the second energy storage unit 34 can be a single inductor or multiple inductors connected in series or parallel to achieve the required inductance value or current capacity.
[0060] In this example, the second energy storage unit 34 can store and release energy during the on and off processes of the switching transistor 31, thereby smoothing current changes. This feature helps provide a more stable current path during false voltage detection, enabling the detection module 10 to more accurately sense changes in the input voltage. Furthermore, the second energy storage unit 34 can reduce current ripple and mitigate the effects of electromagnetic interference, thereby improving the accuracy and reliability of false voltage detection. This stable energy transfer and current regulation capability ensures that the circuit can respond quickly when a false voltage is detected, avoiding misjudgments and malfunctions.
[0061] Figure 4 This is a schematic diagram of the structure of the false pressure detection circuit provided in the embodiments of this application, as shown below. Figure 4 As shown, the DC-DC conversion module includes switching transistors 31 (Q1 and D1 in the diagram), a first energy storage unit 32 (C1 in the diagram), a unidirectional conduction unit 33 (D2 in the diagram), and a second energy storage unit 34 (L1 in the diagram). The module also includes capacitor C2 for output filtering. In practical applications, the load terminal R1 can be a combination of the inverter and the power grid. When the input voltage Vi of the DC-DC conversion module is zero, the high voltage Vo of the output voltage reaches C1 through the reverse-biased leakage current of D2, raising the voltage of C1 and creating a false input voltage Vi. At this time, by controlling the conduction of the switching transistor Q1, a closed discharge circuit can be constructed using C1, L1, and Q1, thereby achieving the dual functions of false voltage detection and release.
[0062] As yet another example, based on any example, the input of the DC-DC converter module 30 is connected to a photovoltaic module, and the output is connected to an inverter.
[0063] In this example, when the photovoltaic module is exposed to sunlight, it generates DC voltage and current. This voltage is transmitted through the input terminal of the DC-DC converter module 30. The DC-DC converter module 30 adjusts the input voltage and current to meet the requirements of the inverter or the power grid. The regulated electrical energy is transmitted to the inverter or the power grid through the unidirectional conduction unit 33 to ensure that the current flows in one direction and prevents backflow from affecting the photovoltaic module. The inverter converts the DC power to AC power and synchronizes it with the grid frequency to ensure that the electrical energy can be effectively transmitted to the grid or supplied to the local load.
[0064] When the photovoltaic modules stop generating electricity at night, the input voltage of the DC-DC converter module 30 disappears. However, the inverter system connected to its output may still be operating, such as performing battery management or in standby mode, maintaining a certain DC voltage at the output. In this state, the unidirectional conduction unit 33 of the DC-DC converter module 30 will experience a significant reverse bias voltage. Even in the off state, the unidirectional conduction unit 33 will generate a small reverse leakage current. The path of this leakage current is: from the positive voltage at the output → through the output diode (reverse) → finally reaching the photovoltaic module side. This reverse-flowing current will charge the energy storage devices in the DC-DC converter module 30, or the parasitic capacitance inside the photovoltaic module that has stopped generating electricity, forming a "virtual voltage" at the input of the DC-DC converter module 30 that is not generated by electricity generation.
[0065] The solution in this example can monitor the reverse input voltage of the inverter when the photovoltaic modules are not generating electricity at night, and release the virtual voltage measurement when the voltage reaches a virtual voltage that affects the circuit operation of the DC-DC converter module 30, thereby improving the stability of the photovoltaic system.
[0066] The false voltage detection circuit provided in this application includes a detection module and a processing module. The detection module is used to detect the input voltage of the DC-DC converter module. The processing module is connected to the control terminal of the switching transistor in the DC-DC converter module and is used to control the switching transistor to conduct when the input voltage detected by the detection module is within a first threshold range. The processing module is also used to determine whether the input voltage drops to a second threshold range after the switching transistor is conducted. If so, the input voltage is determined to be a false voltage. The solution of this application can construct a voltage relief loop at the input terminal of the DC-DC converter module by controlling the switching transistor to conduct. If the input voltage drops after voltage relief, it is determined to be a false voltage. At the same time, false voltage detection and partial elimination are realized, improving the reliability of the system.
[0067] Figure 5 This is a flowchart illustrating a virtual pressure detection method provided in an embodiment of this application. This method is based on the processing module described in any of the above embodiments. Figure 5 As shown, the method includes:
[0068] S101. Obtain the input voltage detected by the detection module. When the input voltage is within the first threshold range, control the switching transistor in the DC-DC conversion module to turn on.
[0069] S102. After the switching transistor is turned on, determine whether the input voltage drops to the second threshold range. If so, determine that the input voltage is a false voltage.
[0070] In some embodiments, the processing module is the processing module in the false voltage detection circuit of any of the above embodiments, and the false voltage detection circuit further includes a detection module. The detection module is connected to the DC-DC converter module and is used to detect the input voltage of the DC-DC converter module; wherein the DC-DC converter module includes a switching transistor.
[0071] The processing module is connected to the control terminal of the switching transistor and is used to control the switching transistor to conduct when the input voltage detected by the detection module is within the first threshold range. The processing module is also used to determine whether the input voltage drops to the second threshold range after the switching transistor is conducted. If so, the input voltage is determined to be a false voltage.
[0072] For example, the detection module and processing module can be a core structure of a resistor voltage divider and an analog-to-digital converter (ADC). Specifically, the detection module includes a high-precision resistors R1 and R2 connected in series for voltage division, and the input pin of the ADC in the processing module is connected between R1 and R2. In practical applications, the processing module can be a microprocessor with a built-in ADC. In addition to the ADC, the microprocessor can also include a driver chip for initiating a pulse-width modulation signal output to drive the switching transistor to conduct based on the real-time sampling results of the ADC.
[0073] Optionally, the processing module may be an existing microprocessor in the DC-DC conversion module or an improved microprocessor, in order to achieve the reuse of circuit components.
[0074] In some optional embodiments, the detection module may also be an isolated voltage sensor such as a linear optocoupler or a Hall voltage sensor, and the processing module may also be a two-way comparator, such as constructing a first threshold window comparison circuit, whose output triggers the generation of a fixed-width pulse width modulation signal; the second threshold is determined by another comparator, and finally outputs a false voltage determination signal through AND gate logic.
[0075] It should be noted that the DC-DC converter module is a DC-DC boost converter module, i.e., a Boost circuit. In some embodiments, the input terminal of the DC-DC converter module is connected to a DC power supply device such as a photovoltaic module, a battery pack, or a DC generator; the output terminal of the DC-DC converter module is connected to a load such as an inverter or a DC load; the output terminal of the DC-DC converter module can also be connected to energy storage such as a battery pack, a capacitor pack, or a pre-charge circuit.
[0076] In some embodiments, the DC-DC converter module includes a capacitor and / or an inductor to store the voltage input to the input terminal of the DC-DC converter module during normal operation; and to store the voltage input to the output terminal of the DC-DC converter module in the presence of reverse leakage current. Specifically, when the DC-DC converter module includes a capacitor, its internal structure can be such that the positive input terminal is connected to the detection module, one end of the capacitor, one end of the switch, and the positive output terminal, and the other end of the capacitor and the other end of the switch are both connected to the negative input terminal, which is grounded; when the DC-DC converter module includes an inductor, its internal structure can be such that the positive input terminal is connected to the detection module, one end of the inductor, the other end of the inductor, one end of the switch, and the positive output terminal, and the other end of the switch is connected to the negative input terminal, which is grounded.
[0077] For example, the first threshold range of the input voltage can be pre-defined as the range that affects the circuitry of the DC-DC converter module. This range is related to the output side of the DC-DC converter module and is affected by the output port voltage. Specifically, the first threshold range can be 50-200V. Optionally, the first threshold can be set based on the system's rated operating voltage and safety margin, for example, 5% of the rated voltage.
[0078] In practical applications, when the input voltage is within the first threshold range, the processing module can output a pulse width modulation signal to control the conduction time of the switching transistor to release the input voltage; optionally, the processing module can also directly output high and low level signals to control the conduction and turn-off of the switching transistor.
[0079] Furthermore, after the processing module controls the switching transistor to turn on, it is also necessary to determine whether the input voltage has dropped to the second threshold range. The second threshold range is typically lower than the first threshold range and is used to detect the decreasing trend of the input voltage. It can be set as the lower limit of the first threshold minus a certain margin. Optionally, the second threshold range can be set according to the system's sensitivity to false voltage, and is usually more stringent than the first threshold to improve the accuracy of false voltage detection. It should be understood that when the input voltage is a false voltage caused by reverse current, the input voltage detected by the detection module should decrease after the switching transistor turns on. If the input voltage is a normal input voltage, the input voltage detected by the detection module will maintain its magnitude due to continuous current replenishment after the switching transistor turns on.
[0080] In practical applications, the processing module can obtain the input voltage detected by the detection module based on a fixed time period. For example, when the input terminal of the DC-DC converter module is connected to a photovoltaic module, this fixed time period would be during nighttime or when the local weather is not sunny. Optionally, when the input terminal of the DC-DC converter module is connected to a battery pack, this fixed time period could be when the resistor group is depleted, disconnected, or when power is supplied. For instance, when the processing module determines that the current input voltage is a false voltage, it can also notify relevant maintenance personnel or issue an alarm via an audible and visual alarm.
[0081] In the false voltage detection method provided in this application, the detection module is used to detect the input voltage of the DC-DC converter module, and the processing module is connected to the control terminal of the switching transistor in the DC-DC converter module. The processing module controls the switching transistor to conduct when the input voltage detected by the detection module is within a first threshold range. After the switching transistor is turned on, the processing module also determines whether the input voltage drops to a second threshold range; if so, it determines that the input voltage is a false voltage. This solution constructs a voltage relief circuit at the input terminal of the DC-DC converter module by controlling the switching transistor to conduct. If the input voltage drops after voltage relief, it is determined to be a false voltage. This simultaneously achieves the detection and partial elimination of false voltage, improving the reliability of the system.
[0082] As yet another example, based on any example, controlling the switching transistor in the DC-DC conversion module in S101 to turn on includes:
[0083] During the first preset time period, a pulse width modulation signal with a fixed duty cycle is sent to the switching transistor to turn it on.
[0084] For example, the transmission period of the first preset time period bit pulse width modulation signal can be 10 seconds. In practical applications, it can also be adjusted according to different circuit requirements.
[0085] In some embodiments, the duty cycle in the pulse width modulation signal with a fixed duty cycle sent to the switching transistor can be a low duty cycle, such as 0.1. Optionally, the low duty cycle can also be adjusted according to actual needs, such as between 0.05 and 0.15.
[0086] The solution in this example sends a pulse width modulation signal with a fixed duty cycle to the switching transistor, thereby detecting dummy voltages without deep discharge through short-time pulse testing. In addition, the extremely short conduction time can reduce thermal stress and extend the device life of the switching transistor.
[0087] As yet another example, building upon any previous example, after determining in S102 whether the input voltage has dropped to the second threshold range, the method further includes:
[0088] If the input voltage does not drop to the second threshold range, the step of controlling the switching transistor in the DC-DC converter module to turn on is stopped.
[0089] In this example, if the input voltage does not drop to the second threshold range, it indicates that the input voltage of the DC-DC converter module is not a false voltage. In this case, deep discharge can be avoided by stopping the switching transistor in the DC-DC converter module.
[0090] In some alternative embodiments, the system drive can also be enabled, that is, the periodic pulse width modulation drive function can be activated by the control system integrated in the DC-DC converter module itself.
[0091] In this example, when the input voltage of the DC-DC converter is not a false voltage, the scheme can avoid excessive regulation of the input voltage and reduce excessive release of the input voltage by stopping the switching transistor in the DC-DC converter.
[0092] As yet another example, based on any example, after the step of stopping the switching transistors in the DC-DC converter module from conducting, the following is also included:
[0093] After the second preset time period, return to execute the input voltage detected by the detection module and subsequent steps.
[0094] For example, when it is determined that the input voltage of the DC-DC converter module is not a false voltage, a time period during which it is not a false voltage can be set, which is the second preset time period. In practical applications, this second preset time period can be a relatively long period of 30 minutes. After 30 minutes, the processing module performs false voltage detection on the input voltage again.
[0095] In some optional examples, the second preset time period can also be flexibly adjusted, such as extending the second preset time period when the input of the DC-DC converter module is relatively stable.
[0096] The solution in this example reduces the power consumption caused by continuous detection of the input voltage of the DC-DC converter module by setting a second preset time period for judging the input voltage, and improves the reliability of the system by periodic detection.
[0097] As yet another example, after determining that the input voltage is a phantom voltage, based on any previous example, the following steps are also included:
[0098] A pulse width modulation signal with a fixed duty cycle is continuously sent to the switching transistor until the input voltage is less than the first threshold range.
[0099] In practical applications, when the virtual voltage is large, there may be insufficient virtual voltage release. The solution in this example continuously monitors the input voltage detected by the detection module and continuously sends a pulse width modulation signal with a fixed duty cycle to the switching transistor until the input voltage is less than the minimum value in the first threshold range.
[0100] In practical applications, multiple duty cycle pulse width modulation strategies can be set. For example, a relatively small duty cycle, such as 0.1, can be used to determine if the input voltage is a false voltage. After determining that the input voltage is a false voltage, the duty cycle can be increased to 0.2 or higher to improve the efficiency of false voltage release.
[0101] The scheme in this example continuously sends a pulse width modulation signal with a fixed duty cycle to the switching transistor until the input voltage is less than the first threshold range, which can fully release the false voltage and thus improve the reliability of the system.
[0102] Figure 6 This is a flowchart illustrating the virtual pressure detection method provided in the embodiments of this application, as shown below. Figure 6 As shown, the processing module executes the steps in the flowchart. Specifically, after acquiring the input voltage Vi detected by the detection module, it determines whether the input voltage is within the first threshold range. If it is not within the first threshold range, it returns to executing the steps for acquiring the input voltage detected by the detection module and its subsequent steps. If it is within the first threshold range, it drives the switching transistor with a duty cycle of 0.1 within a 10s pulse width modulation period. It further determines whether the input voltage drops to the second threshold range. If it drops to the second threshold range, it determines that the input voltage is a false voltage, and assumes that the 10s pulse width modulation period can release the false voltage, and returns to executing the steps for acquiring the input voltage detected by the detection module and its subsequent steps. If it does not drop to the second threshold range, it determines that the input voltage is not a false voltage and stops the drive control, and returns to executing the steps for acquiring the input voltage detected by the detection module and its subsequent steps after 30 minutes to perform cyclic detection.
[0103] In the false voltage detection method provided in this application, the detection module is used to detect the input voltage of the DC-DC converter module, and the processing module is connected to the control terminal of the switching transistor in the DC-DC converter module. The processing module controls the switching transistor to conduct when the input voltage detected by the detection module is within a first threshold range. After the switching transistor is turned on, the processing module also determines whether the input voltage drops to a second threshold range; if so, it determines that the input voltage is a false voltage. This solution constructs a voltage relief circuit at the input terminal of the DC-DC converter module by controlling the switching transistor to conduct. If the input voltage drops after voltage relief, it is determined to be a false voltage. This simultaneously achieves the detection and partial elimination of false voltage, improving the reliability of the system.
[0104] This application also provides a photovoltaic system, which includes a photovoltaic module, a voltage detection circuit as described in any of the above embodiments, and a DC-DC conversion module; wherein the positive output terminal of the photovoltaic module is connected to the positive input terminal of the DC-DC conversion module, and the negative output terminal of the photovoltaic module is connected to the negative input terminal of the DC-DC conversion module.
[0105] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 7As shown, the electronic device provided in this embodiment includes a processor 291 and a memory 292; it may also include a communication interface 293 and a bus 294. The processor 291, memory 292, and communication interface 293 can communicate with each other via the bus 294. The communication interface 293 can be used for information transmission. The processor 291 can call logical instructions in the memory 292 to execute the method described above.
[0106] Furthermore, the logic instructions in the aforementioned memory 292 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.
[0107] The memory 292, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this application. The processor 291 executes functional applications and data processing by running the software programs, instructions, and modules stored in the memory 292, that is, it implements the methods in the above method examples.
[0108] The memory 292 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 292 may include high-speed random access memory and may also include non-volatile memory.
[0109] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this application.
[0110] It should be further noted that although the steps in the flowchart are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.
[0111] It should be understood that the above-described device embodiments are merely illustrative, and the device of this application can also be implemented in other ways. For example, the division of units / modules in the above embodiments is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units, modules, or components may be combined, or integrated into another system, or some features may be ignored or not executed.
[0112] Furthermore, unless otherwise specified, the functional units / modules in the various embodiments of this application can be integrated into one unit / module, or each unit / module can exist physically separately, or two or more units / modules can be integrated together. The integrated units / modules described above can be implemented in hardware or in the form of software program modules.
[0113] If the integrated unit / module is implemented as a software program module and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.
[0114] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.
[0115] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.
[0116] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.
Claims
1. A virtual ground detection circuit, characterized by, include: Detection module and processing module; The detection module is connected to the DC-DC converter module and is used to detect the input voltage of the DC-DC converter module; wherein, the DC-DC converter module includes a switching transistor; The processing module is connected to the control terminal of the switching transistor and is used to control the switching transistor to turn on when the input voltage detected by the detection module is within the first threshold range. The processing module is also used to determine whether the input voltage drops to the second threshold range after the switching transistor is turned on. If so, the input voltage is determined to be a false voltage.
2. The circuit according to claim 1, characterized in that, The DC-DC converter module further includes: a first energy storage unit and a unidirectional conduction unit; The first energy storage unit is connected between the positive input terminal and the negative input terminal of the DC-DC converter module; The anode of the unidirectional conduction unit is connected to the positive input terminal of the DC-DC converter module, and the cathode is connected to the positive output terminal of the DC-DC converter module. The first end of the switching transistor is connected to the positive input terminal of the DC-DC converter module, and the other end is grounded.
3. The circuit according to claim 2, characterized in that, The DC-DC converter module further includes: a second energy storage unit; The positive input terminal of the DC-DC converter module is connected to one end of the switching transistor and the anode of the unidirectional conduction unit through the second energy storage unit.
4. The circuit according to any one of claims 1-3, characterized in that, The input of the DC-DC converter module is connected to the photovoltaic module, and the output is connected to the inverter.
5. A method for detecting false pressure, characterized in that, Based on the processing module as described in any one of claims 1-4; the method includes: The input voltage detected by the detection module is obtained, and when the input voltage is within the first threshold range, the switching transistor in the DC-DC conversion module is turned on. After the switch is turned on, it is determined whether the input voltage drops to the second threshold range. If so, the input voltage is determined to be a false voltage.
6. The method according to claim 5, characterized in that, The control of the switching transistor in the DC-DC conversion module includes: During a first preset time period, a pulse width modulation signal with a fixed duty cycle is sent to the switching transistor to turn it on.
7. The method according to claim 5, characterized in that, After determining whether the input voltage has dropped to the second threshold range, the method further includes: If the input voltage does not drop to the second threshold range, then the step of controlling the switching transistor in the DC-DC conversion module to turn on is stopped.
8. The method according to claim 7, characterized in that, After the step of stopping the switching transistor in the control DC-DC conversion module from conducting, the method further includes: After the second preset time period, the process returns to execute the input voltage detected by the acquisition and detection module and subsequent steps.
9. The method according to any one of claims 5-8, characterized in that, After determining that the input voltage is a false voltage, the method further includes: A pulse width modulation signal with a fixed duty cycle is continuously sent to the switching transistor until the input voltage is less than the first threshold range.
10. A photovoltaic system, characterized in that, Includes a photovoltaic module, a voltage detection circuit as described in any one of claims 1-4, and a DC-DC conversion module; wherein, The positive output terminal of the photovoltaic module is connected to the positive input terminal of the DC-DC converter module, and the negative output terminal of the photovoltaic module is connected to the negative input terminal of the DC-DC converter module.
11. An electronic device, characterized in that, include: Memory, processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the processor to perform the method as described in any one of claims 5-9.