WO2024078093A1 - 一种机壳接地检测方法及逆变器 - Google Patents
一种机壳接地检测方法及逆变器 Download PDFInfo
- Publication number
- WO2024078093A1 WO2024078093A1 PCT/CN2023/109357 CN2023109357W WO2024078093A1 WO 2024078093 A1 WO2024078093 A1 WO 2024078093A1 CN 2023109357 W CN2023109357 W CN 2023109357W WO 2024078093 A1 WO2024078093 A1 WO 2024078093A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- voltage
- casing
- inverter
- sub
- bus
- Prior art date
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 55
- 230000008439 repair process Effects 0.000 claims abstract description 34
- 238000010248 power generation Methods 0.000 claims abstract description 33
- 238000000034 method Methods 0.000 claims abstract description 28
- 230000007935 neutral effect Effects 0.000 claims description 22
- 238000005070 sampling Methods 0.000 claims description 17
- 230000008859 change Effects 0.000 abstract description 14
- 238000010586 diagram Methods 0.000 description 7
- 230000006870 function Effects 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 101001121408 Homo sapiens L-amino-acid oxidase Proteins 0.000 description 5
- 102100026388 L-amino-acid oxidase Human genes 0.000 description 5
- 238000012986 modification Methods 0.000 description 5
- 230000004048 modification Effects 0.000 description 5
- 238000004590 computer program Methods 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 101100233916 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) KAR5 gene Proteins 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 229910001415 sodium ion Inorganic materials 0.000 description 3
- 101000827703 Homo sapiens Polyphosphoinositide phosphatase Proteins 0.000 description 2
- 102100023591 Polyphosphoinositide phosphatase Human genes 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000001308 synthesis method Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 101100012902 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) FIG2 gene Proteins 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 238000004422 calculation algorithm Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000005022 packaging material Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
Definitions
- the present invention relates to the technical field of power electronics, and in particular to a casing grounding detection method and an inverter.
- the PID repair circuit is often used to apply voltage to the ground at the negative pole of the power generation component to reduce the impact of the PID effect of the power generation component on the power generation component. If the casing is not grounded, the PID repair circuit function will fail, and the power generation component will not be able to obtain the PID compensation voltage. If additional detection devices are added on the basis of the traditional inverter structure, the system risk will increase and the operation will be complicated.
- the present invention provides a casing grounding detection method and an inverter, which are used to solve the problem of detecting the casing grounding of an inverter without adding additional detection components.
- an embodiment of the present invention provides a casing grounding detection method, which is applied to an inverter, wherein the inverter includes a bus positive electrode, a bus negative electrode, a ground terminal, a PID potential induced attenuation repair circuit, a first detection resistor, a second detection resistor and a casing; wherein the first detection resistor is connected between the bus positive electrode and the casing, the second detection resistor is connected between the bus negative electrode and the casing, and the PID repair circuit is connected between the bus negative electrode and the casing; the inverter is connected to a power generation component; the method includes:
- the second voltage is adjusted by the PID repair circuit; wherein the second voltage is the voltage between the negative pole of the bus and the ground terminal;
- a third voltage is collected, where the third voltage is the voltage between the housing and the ground terminal after the second voltage is adjusted, and the third voltage is used to detect whether the housing is grounded when the absolute value of the difference between the third voltage and the first voltage is less than or equal to a set voltage difference threshold.
- the voltage between the negative pole of the busbar and the ground terminal is compared with the set voltage threshold to detect whether the casing is grounded; wherein the voltage threshold can be a voltage threshold set by considering the ground voltage of the casing or a voltage threshold set by comprehensively considering the ground voltage of the casing and the sampling error. In practical applications, there is an equivalent resistance of leakage current to the ground in the power generation component.
- the ratio of the equivalent resistance of the grounding of the positive pole of the power generation component to the equivalent resistance of the grounding of the negative pole of the power generation component is equal to the ratio of the resistance of the first detection resistor to the resistance of the second detection resistor, since the power generation voltage of the power generation component is approximately equal to the bus voltage, the voltage between the negative pole of the busbar and the ground terminal is equal to the voltage between the negative pole of the busbar and the casing. Therefore, even if the absolute value of the voltage between the casing and the ground terminal is less than or equal to the set voltage threshold, it cannot be proved that the casing is grounded.
- This solution changes the casing voltage to the ground by further adjusting the voltage between the negative pole of the busbar and the ground.
- Whether the casing is grounded can be accurately judged according to the voltage change value between the casing and the ground terminal.
- the technical solution proposed by the present invention does not require the addition of additional detection devices, and can accurately determine whether the housing is grounded by using the devices configured in the traditional inverter in combination with the grounding detection method proposed by the present invention.
- the first voltage is used to detect that the absolute value of the first voltage is greater than the voltage difference threshold.
- the third voltage is also used to detect whether the housing is grounded, and the absolute value of the difference between the third voltage and the first voltage is greater than the voltage threshold to detect whether the housing is grounded.
- the equivalent resistance to ground of the leakage current formed by the grounding of the power generation component only affects the detection of the grounding of the casing through the absolute value of the first voltage being less than or equal to the voltage threshold, and does not affect the detection of the casing not being grounded through the absolute value of the first voltage being greater than the voltage threshold.
- the absolute value of the casing's voltage to ground should be equal to the voltage threshold, so when the absolute value of the first voltage is greater than the voltage threshold, it can be detected that the casing is not grounded.
- the absolute value of the difference between the third voltage and the first voltage is greater than the voltage difference threshold, that is, after adjusting the bus negative pole voltage to ground, the casing voltage to ground changes accordingly, and it can also be detected that the casing is not grounded.
- the inverter further includes a live terminal and a neutral terminal, and collecting the first voltage includes:
- the first sub-voltage and the second sub-voltage are calculated to obtain the first voltage.
- the voltage at the neutral line terminal may not be zero when the three-phase voltage at the live line terminal is unbalanced, it is necessary to calculate the voltage between the neutral line terminal and the ground based on the voltage at the live line terminal.
- the voltage between the neutral line terminal and the ground terminal can be calculated by a vector synthesis method; further, the collected voltage between the housing and the neutral line terminal and the voltage between the neutral line terminal and the ground are calculated to obtain the voltage between the housing and the ground.
- the PID repair circuit includes a switch device and a compensation power supply; wherein the switch device and the compensation power supply are connected in series, and before collecting the first voltage, the method further includes:
- the switch device is controlled to be turned off.
- adjusting the second voltage by using the PID repair circuit includes:
- the switch device is controlled to be closed, and the compensation power supply is controlled to adjust the second voltage.
- the compensation power supply in order to adjust the voltage between the negative pole of the busbar and the ground and further determine the change in the voltage between the casing and the ground, it is necessary to change the working state of the PID repair circuit, that is, before collecting the first voltage, the compensation power supply does not provide compensation, and when the voltage between the negative pole of the busbar and the ground needs to be adjusted, the compensation power supply is used for compensation.
- the configuration device of the inverter in order not to add additional devices, it is necessary to use the configuration device of the inverter to adjust the voltage between the negative pole of the bus and the ground terminal.
- a PID repair circuit is designed to not compensate for the voltage between the negative pole of the bus and the ground under the condition of sufficient incident light, and to compensate for the voltage between the negative pole of the bus and the ground under the condition of insufficient incident light, so as to solve the problem of potential induced attenuation. Therefore, this solution can use the PID repair circuit of the photovoltaic inverter to adjust the voltage between the negative pole of the bus and the ground.
- the casing grounding detection method provided in the embodiment of the present invention can ensure the detection accuracy, is simple to operate, and does not require additional devices, thereby reducing costs.
- an embodiment of the present invention provides an inverter, the inverter comprising a bus positive electrode, a bus negative electrode, a ground terminal, a PID repair circuit, a first detection resistor, a second detection resistor and a casing; wherein the first detection resistor is connected between the bus positive electrode and the casing, the second detection resistor is connected between the bus negative electrode and the casing, and the PID repair circuit is connected between the bus negative electrode and the casing; the inverter is connected to a power generation component; the inverter further comprises:
- a sampling circuit used for collecting a first voltage; wherein the first voltage is a voltage between the housing and the ground terminal;
- a controller configured to adjust a second voltage through the PID repair circuit when the absolute value of the first voltage is less than or equal to a set voltage threshold; wherein the second voltage is the voltage between the negative pole of the busbar and the ground terminal;
- the sampling circuit is also used to collect a third voltage, where the third voltage is the voltage between the housing and the ground terminal after the second voltage is adjusted.
- the third voltage is used to detect whether the housing is grounded when the absolute value of the difference between the third voltage and the first voltage is less than or equal to a set voltage difference threshold.
- the absolute value of the difference between the third voltage and the first voltage is used, and the absolute value of the first voltage is greater than the voltage difference threshold to detect whether the casing is grounded; the third voltage is also used, and the absolute value of the difference between the third voltage and the first voltage is greater than the voltage threshold to detect whether the casing is grounded.
- the inverter further includes a live terminal and a neutral terminal, and the sampling circuit collects the first voltage by the following method:
- a second sub-voltage is calculated according to the live line voltage, where the second sub-voltage is the voltage between the neutral line terminal and the ground line terminal; and the first sub-voltage and the second sub-voltage are calculated to obtain the first voltage.
- the PID repair circuit includes a switch device and a compensation power supply; wherein the switch device and the compensation power supply are connected in series, and before the first voltage is collected, the inverter is further used for:
- the switch device is controlled to be turned off.
- the inverter is specifically used for:
- the switch device is controlled to be closed, and the second voltage is adjusted by the compensation power supply.
- FIG1 is a schematic diagram of the structure of an inverter system
- FIG2 is a schematic flow chart of a casing grounding detection method provided by an embodiment of the present invention.
- FIG3 is a schematic structural diagram of an inverter system provided by an embodiment of the present invention.
- FIG. 4 is a schematic diagram of the structure of an inverter provided in an embodiment of the present invention.
- PID Potential induced degradation
- the PID effect refers to the phenomenon that when there is a high bias voltage between the electrode and the frame of the photovoltaic module, the sodium ions in the glass migrate and adhere to the surface of the battery cell, causing the power of the photovoltaic module to decrease.
- the potential of the photovoltaic module frame is zero, which is higher than the potential of the battery cell.
- a charged water film will form on the surface of the module, and a simulated electric field will be formed between this charged water film and the battery cell due to the potential difference.
- the sodium ions themselves are positively charged.
- the sodium ions will migrate toward the battery through the packaging material, and a large amount of charge will accumulate on the surface of the battery cell, passivating the battery surface. Furthermore, the inverter power is sharply attenuated, reducing the output power of the power station and reducing the power generation.
- the impedance of photovoltaic modules to ground refers to the equivalent resistance of the leakage current of photovoltaic modules to ground in the photovoltaic inverter system.
- the photovoltaic inverter when the photovoltaic inverter is working, the DC input side is connected to the photovoltaic modules. Under ideal working conditions, the photovoltaic modules are floating, but under special working conditions such as rain, snow and fog, the equivalent resistance of photovoltaic modules to ground may be reduced.
- first and second in the embodiments of the present invention are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as “first” and “second” may explicitly or implicitly include one or more of the features. For example, “first voltage”, “second voltage” and “third voltage” are only exemplary to indicate different voltages, and do not mean that the importance or priority of the voltages are different.
- At least one means one or more, and “plurality” means two or more.
- “And/or” describes the association relationship of associated objects, indicating that three relationships may exist.
- a and/or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural.
- the character “/” generally indicates that the associated objects before and after are in an “or” relationship.
- “At least one of the following” or similar expressions refers to any combination of these items, including any combination of single or plural items.
- at least one of a, b, or c can mean: a, b, c, a and b, a and c, b and c, or a, b and c.
- the casing of electrical equipment with metal shells needs to be grounded. Problems such as missing grounding, wrong grounding or damage to the grounding wire terminal will cause various safety accidents.
- the power generation component is prone to PID effect in a humid environment and power attenuation occurs under the action of bias voltage, thus affecting the power output of the entire power generation system, the PID repair circuit is often used to apply voltage to the ground at the negative pole of the power generation component to reduce the impact of the PID effect of the power generation component on the power generation component. If the casing is not grounded, the PID compensation function will fail. Therefore, it is necessary to accurately detect whether the casing is grounded to avoid subsequent safety problems.
- the current detection scheme often uses the primary side of the optocoupler, an isolation device, to draw power between the mains live wire and the chassis.
- the secondary side of the optocoupler generates high and low level signals that are detected by the control circuit. If the secondary side of the optocoupler is detected as a low level, the chassis is grounded; if the secondary side of the optocoupler is detected as a high level, the chassis is not grounded.
- a non-isolated device transistor or MOS tube can be used instead of the optocoupler to detect whether the chassis is grounded.
- adding additional detection devices to the traditional inverter structure will increase system risks and complicate operations.
- an embodiment of the present invention provides a casing grounding detection method and an inverter, which are used to detect the casing grounding of the inverter without adding additional detection devices.
- FIG1 is a schematic diagram of the structure of an inverter system.
- the inverter system includes an inverter 101 and a power generation component 102.
- the inverter 101 includes a bus positive electrode BUS+, a bus negative electrode BUS-, a live line terminal L, a neutral line terminal N, a ground line terminal PE, a PID repair circuit 1011, a first detection resistor R1, a second detection resistor R2 and a housing 1012.
- the first detection resistor R1 is connected between the bus positive pole BUS+ and the housing 1012
- the second detection resistor R2 is connected between the bus negative pole BUS- and the housing 1012
- the PID repair circuit 1011 is connected between the bus negative pole BUS- and the housing 1012
- the inverter 101 is connected to the power generation component 102; wherein, the positive pole of the power generation component 102 is connected to the bus positive pole BUS+, and the negative pole of the power generation component 102 is connected to the bus negative pole BUS-.
- the inverter system also includes a first equivalent resistance R3 formed between the positive electrode of the power generation component 102 and the ground terminal PE, and a second equivalent resistance R4 formed between the negative electrode of the power generation component 102 and the ground terminal PE.
- the PID repair circuit 1011 includes a switch device 10111 and a compensation power supply 10112, and the switch device 10111 and the compensation power supply 10112 are connected in series.
- Fig. 2 is a schematic flow chart of a casing grounding detection method provided by an embodiment of the present invention. The method can be applied to the inverter 101 in the inverter system shown in Fig. 1, and the method includes:
- Step 201 The inverter controls the switch device of the PID repair circuit to be turned off.
- the compensation power supply 10112 Since the bus negative pole to ground voltage needs to be adjusted in subsequent steps to further determine the change in casing to ground voltage, it is necessary to control the switch device 10111 to change the working state of the PID repair circuit 1011, that is, before executing step 202, the compensation power supply 10112 does not provide compensation, and when the bus negative pole BUS- to ground voltage needs to be adjusted, the compensation power supply 10112 is used for compensation.
- the inverter 101 controls the switch device 10111 to be turned off by keeping the switch device 10111 in an off state or by turning off the closed switch device 10111.
- FIG3 is a structural schematic diagram of an inverter system provided by an embodiment of the present invention. As shown in FIG3, if the above-mentioned inverter system is a photovoltaic inverter system, the switch device 10111 can be a relay, and the compensation power supply 10112 is a voltage source.
- Step 202 The inverter collects a first voltage.
- the first voltage is the voltage between the housing 1012 and the ground terminal PE, and the first voltage is obtained through sampling and calculation.
- the inverter may collect the first voltage through the following steps A1-A3:
- the inverter 101 collects the live line voltage and the first sub-voltage; wherein the first sub-voltage is the voltage between the housing 1012 and the neutral line terminal N.
- the inverter 101 calculates the second sub-voltage according to the live line voltage; wherein the second sub-voltage is the voltage between the neutral line terminal N and the ground line terminal PE.
- the live line voltage is the mains voltage, and the calculation method can be applied according to the actual circuit situation. For example, in the case of three-phase imbalance, the second sub-voltage can be calculated according to the live line voltage by a vector synthesis method.
- A3 The inverter 101 calculates the first sub-voltage and the second sub-voltage to obtain a first voltage.
- the acquisition method of the third voltage hereinafter is similar to the acquisition method of the first voltage, and will not be described in detail later.
- Step 203 The inverter determines whether the absolute value of the first voltage is greater than the voltage threshold; if so, execute step 204; otherwise, execute step 205.
- the voltage threshold may be set according to the voltage between the housing 1012 and the ground terminal PE when the housing is grounded; or the voltage threshold may be set taking into account error factors such as voltage sampling. For example, in an ideal grounding state, the voltage between the housing 1012 and the ground terminal PE is zero, and the voltage threshold may be set to zero; or the voltage threshold may be set to approximately zero taking into account the sampling error.
- Step 204 The inverter detects that the housing is not grounded.
- the inverter may issue a warning through display or sound prompt.
- the warning process after detecting that the casing is grounded is similar to the following and will not be described in detail.
- Step 205 The inverter adjusts the second voltage through the PID repair circuit.
- the second voltage is the voltage between the negative electrode of the busbar BUS- and the ground terminal PE.
- the second voltage is obtained by sampling.
- the inverter 101 can determine the voltage between the bus negative electrode BUS- and the ground terminal PE by the following formula: Voltage between:
- U1 is the voltage between the bus negative electrode BUS- and the ground terminal PE
- U pv is the power generation voltage of the power generation component 102
- r3 is the resistance value of the first equivalent resistor R3
- r4 is the resistance value of the second equivalent resistor R4.
- the voltage between the negative electrode of the busbar BUS- and the housing 1012 can be determined by the following formula:
- U2 is the voltage between the negative electrode of the bus BUS- and the housing 1012
- U BUS is the total bus voltage
- r1 is the resistance value of the first detection resistor R1
- r2 is the resistance value of the second detection resistor R2.
- the voltage of U pv is equal to the voltage of the negative electrode of the busbar BUS-, and the ratio of r 2 to r 1 is not equal to the ratio of r 3 to r 4.
- the first voltage is less than or equal to the voltage threshold, the grounding of the housing 1012 can be detected.
- the ratio of r 2 to r 1 may be equal to the ratio of r 3 to r 4. Therefore, the first voltage is less than or equal to the voltage threshold, and it cannot be proved that the housing 1012 is grounded.
- the inverter may control the switching device 10111 to close and control the compensation power supply 10112 to adjust the second voltage.
- Step 206 The inverter collects the third voltage.
- the third voltage is the voltage between the housing and the ground terminal after the second voltage is adjusted.
- Step 207 The inverter determines whether the absolute value of the difference between the third voltage and the first voltage is greater than the voltage difference threshold; if so, execute step 204; otherwise, execute step 208.
- adjusting the voltage between the bus negative electrode BUS- and the ground terminal PE will change the voltage between the housing 1012 and the ground terminal PE.
- adjusting the voltage between the bus negative electrode BUS- and the ground terminal PE will not change the voltage between the housing 1012 and the ground terminal PE, or will change slightly (taking into account the error).
- the voltage difference threshold can be set according to the change value of the voltage between the housing 1012 and the ground terminal PE. For example, in an ideal grounding state, the voltage change value between the housing 1012 and the ground terminal PE is zero, and the voltage difference threshold can be set equal to zero; or considering the sampling error, the voltage difference threshold can be set approximately equal to zero.
- Step 208 The inverter detects that the housing is grounded.
- the technical solution provided by the present invention adjusts the voltage between the negative pole of the bus and the ground terminal through the configured devices of the inverter.
- the grounding state of the inverter casing can be accurately judged according to the change value of the voltage of the negative bus to the ground. Therefore, the casing grounding detection method disclosed in the present invention can ensure the detection accuracy, simple operation, and no additional devices are required, and the cost is low.
- an embodiment of the present invention further provides an inverter, which can be applied to the housing grounding detection method shown in FIG. 2 or a similar implementation to FIG. 2.
- the following further describes an inverter provided by the present invention in conjunction with the accompanying drawings and the housing grounding detection method.
- FIG4 is a schematic diagram of the structure of an inverter provided by an embodiment of the present invention.
- the inverter 101 further includes a sampling circuit 401 and a controller 402; the sampling circuit 401 is used to collect a first voltage and a third voltage; wherein the first voltage is the voltage between the housing and the ground terminal; wherein the third voltage is the voltage between the housing and the ground terminal after the second voltage is adjusted.
- the sampling circuit 401 collects the first voltage by the following method:
- the sampling circuit 401 collects the live line voltage and the first sub-voltage, wherein the first sub-voltage is the voltage between the housing and the neutral line terminal.
- the sampling circuit 401 calculates the second sub-voltage according to the live line voltage, and calculates the first sub-voltage and the second sub-voltage to obtain the first voltage, wherein the second sub-voltage is the voltage between the neutral line terminal and the ground line terminal.
- the controller 402 is used to control the switch device to be disconnected before collecting the first voltage; to detect whether the housing is grounded by the absolute value of the first voltage being greater than the voltage threshold; to control the switch device to be closed by the absolute value of the first voltage being less than or equal to the voltage threshold, and to adjust the second voltage by the compensation power supply; wherein the second voltage is the voltage between the negative pole of the busbar and the ground terminal.
- the absolute value of the voltage difference is less than or equal to the set voltage difference threshold to detect whether the chassis is grounded.
- modules, units and methods can be implemented in other ways.
- the module and unit embodiments described above are only schematic.
- the division of modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.
- Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of modules or units, which can be electrical, mechanical or other forms.
- the units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.
- each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.
- the above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.
- the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium.
- the technical solution of the embodiment of the present invention 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, which is stored in a storage medium and includes several instructions for a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to perform all or part of the steps of the methods of each embodiment of the present invention.
- the aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.
- the computer-executable instructions in the embodiment of the present invention may also be referred to as application program codes, which is not specifically limited in the embodiment of the present invention.
- the computer program product includes one or more computer instructions.
- the computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.
- the computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium.
- the various illustrative logic units and circuits described in the embodiments of the present invention can be implemented or operated by a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of the above.
- the general-purpose processor can be a microprocessor, and optionally, the general-purpose processor can also be any conventional processor, controller, microcontroller or state machine.
- the processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.
- the steps of the method or algorithm described in the embodiments of the present invention can be directly embedded in hardware, a software unit executed by a processor, or a combination of the two.
- the software unit can be stored in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other storage medium in the art.
- the storage medium can be connected to the processor so that the processor can read information from the storage medium and can write information to the storage medium.
- the storage medium can also be integrated into the processor.
- the processor and the storage medium can be arranged in an ASIC.
- These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Inverter Devices (AREA)
- Protection Of Static Devices (AREA)
Abstract
本发明公开了一种机壳接地检测方法及逆变器，逆变器包括母线正极和负极、地线端、PID修复电路、第一和第二检测电阻以及机壳；第一检测电阻与母线正极和机壳连接，第二检测电阻与母线负极和机壳连接，修复电路与母线负极和机壳连接；逆变器与发电组件连接；方法包括：采集第一电压，即机壳与地线端之间的电压；当第一电压的绝对值不大于电压阈值时，通过修复电路调整第二电压；其中，第二电压为母线负极与地线端之间的电压；采集第三电压，即第二电压调整后机壳与地线端之间的电压，第三电压与第一电压之差的绝对值不大于电压差阈值，以检测机壳是否接地。本发明根据机壳对地电压变化判断机壳是否接地，不增加额外检测器件，提高了系统安全性。
Description
相关申请的交叉引用
本申请要求在2022年10月11日提交中国专利局、申请号为202211243034.4、申请名称为“一种机壳接地检测方法及逆变器”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
本发明涉及电力电子技术领域，尤其涉及一种机壳接地检测方法及逆变器。
一般金属外壳的电气设备的机壳都需要接地，但在实际应用中，往往会出现机壳漏接地，接地错误或者接地线损坏等问题。此时如果电气设备发生内部故障将会引发各种安全事故，比如内部线缆与机壳短路导致机壳带电；机壳未接地导致电磁兼容设计(electro magnetic compatibility，EMC)的传导干扰或辐射干扰超标，对周围环境造成恶劣影响。
另外，由于发电组件在潮湿的环境中容易产生电势诱导衰减(potential induced degradation，PID)效应，并在偏置电压的作用下出现功率衰减的现象，从而影响整个发电系统的功率输出，因此，往往通过使用PID修复电路在发电组件负极对地施加电压降低发电组件的PID效应对发电组件的影响。若机壳未接地，将会导致PID修复电路功能失效，进而导致发电组件无法得到PID补偿电压。若在传统逆变器结构基础上增加额外检测器件，会导致系统风险增加并且操作复杂。
基于此，如何在不增加额外检测器件的前提下，检测逆变器的机壳是否接地是目前亟待解决的问题。
发明内容
本发明提供一种机壳接地检测方法及逆变器，用于解决在不增加额外检测器件的前提下，检测逆变器的机壳接地的问题。
第一方面，本发明实施例提供一种机壳接地检测方法，应用于逆变器，所述逆变器包括母线正极、母线负极、地线端、PID电势诱导衰减修复电路、第一检测电阻、第二检测电阻和机壳；其中，所述第一检测电阻连接在所述母线正极和所述机壳之间，所述第二检测电阻连接在所述母线负极和所述机壳之间，所述PID修复电路连接在所述母线负极和所述机壳之间；所述逆变器与发电组件连接；所述方法包括：
采集第一电压；其中，所述第一电压为所述机壳与所述地线端之间的电压；
当所述第一电压的绝对值小于或等于设定的电压阈值时，通过所述PID修复电路调整第二电压；其中，所述第二电压为所述母线负极与所述地线端之间的电压；
采集第三电压，所述第三电压为所述第二电压调整后所述机壳与所述地线端之间的电压，所述第三电压用于，所述第三电压与所述第一电压之间的差值的绝对值小于或等于设定的电压差阈值，以检测所述机壳是否接地。
基于本发明提供的技术方案，将母线负极与地线端之间的电压与设定的电压阈值进行比较，检测机壳是否接地；其中，电压阈值可以为考虑机壳接地电压设定的电压阈值或综合考虑机壳接地电压和采样误差设定的电压阈值。由于在实际应用中，发电组件存在漏电流对地等效电阻。若发电组件正极接地的等效电阻阻值与发电组件负极接地等效电阻阻值的比值，与第一检测电阻阻值和第二检测电阻阻值的比值相等，由于发电组件的发电电压和母线电压近似相等，则母线负极与地线端之间的电压等于母线负极与机壳之间的电压，因此，即使测得机壳与地线端之间的电压的绝对值小于或等于设定的电压阈值，也无法证明机壳接地，本方案通过进一步的调整母线负极对地电压改变机壳对地电压。根据机壳与地线端之间的电压变化值可以准确判断机壳是否接地。本发明提出的技术方案可以不增加额外检测器件，利用传统的逆变器中配置的器件结合本发明提出的接地检测方法即可准确判断机壳是否接地。
在一种可能的实施方式中，所述第一电压用于，所述第一电压的绝对值大于所述电压差阈值，以检
测所述机壳是否接地；所述第三电压还用于，所述第三电压与所述第一电压之间的差值的绝对值大于电压阈值，以检测所述机壳是否接地。
基于本发明提供的技术方案，由于发电组件接地形成的漏电流对地等效电阻，只影响通过第一电压的绝对值小于或等于电压阈值检测机壳接地，不影响通过第一电压的绝对值大于电压阈值检测机壳未接地。正常工作状态下，机壳的对地电压的绝对值应该等于电压阈值，因此在第一电压的绝对值大于电压阈值时，可以检测到机壳未接地。另外，当第三电压与第一电压之差的绝对值大于电压差阈值时，即在调整母线负极对地电压后，机壳对地电压跟随发生变化，也可以检测到机壳未接地。
在一种可能的实施方式中，所述逆变器还包括火线端和中性线端，所述采集第一电压，包括：
采集火线端电压和第一子电压；其中，所述第一子电压为所述机壳与所述中性线端之间的电压；
根据所述火线端电压计算第二子电压，所述第二子电压为所述中性线端与所述地线端之间的电压；
对所述第一子电压和所述第二子电压进行计算，得到所述第一电压。
基于本发明提供的技术方案，由于在火线端电压三相不平衡的情况下，中性线端电压可能不为零，因此需要根据火线端电压计算中性线端对地电压，比如，可以通过向量合成的方法计算中性线端与地线端之间的电压；进一步的，对采集到的机壳与中性线端之间的电压与中性线端对地电压进行计算，得到机壳对地电压。
在一种可能的实施方式中，所述PID修复电路包括开关器件和补偿电源；其中，所述开关器件和所述补偿电源串联，在所述采集第一电压之前，所述方法还包括：
控制所述开关器件断开。
在一种可能的实施方式中，所述通过所述PID修复电路调整所述第二电压，包括：
控制所述开关器件闭合，控制所述补偿电源调整所述第二电压。
基于本发明提供的技术方案，为调整母线负极对地电压，进一步判断机壳对地电压变化量，需要使得PID修复电路的工作状态存在变化，即采集第一电压之前，使补偿电源不提供补偿，在需要调整母线负极对地电压时，使用补偿电源进行补偿。
基于本发明提供的技术方案，为不增加额外器件，需要使用逆变器的配置器件调整母线负极与地线端之间的电压。比如，针对光伏逆变器，设计有PID修复电路，用于在入射光线充足的条件下，不对母线负极对地电压进行补偿，在入射光线不足的条件下，对母线负极对地电压进行补偿，解决电势诱导衰减问题，因此，本方案可以使用光伏逆变器的PID修复电路调整母线负极对地电压。本发明实施例提供的机壳接地检测方法可以保证检测精度，操作简单，且无需额外添加器件，降低成本。
第二方面，本发明实施例提供一种逆变器，所述逆变器包括母线正极、母线负极、地线端、PID修复电路、第一检测电阻、第二检测电阻和机壳；其中，所述第一检测电阻连接在所述母线正极和所述机壳之间，所述第二检测电阻连接在所述母线负极和所述机壳之间，所述PID修复电路连接在所述母线负极和所述机壳之间；所述逆变器与发电组件连接；所述逆变器还包括：
采样电路，用于采集第一电压；其中，所述第一电压为所述机壳与所述地线端之间的电压；
控制器，用于当所述第一电压的绝对值小于或等于设定的电压阈值时，通过所述PID修复电路调整第二电压；其中，所述第二电压为所述母线负极与所述地线端之间的电压；
所述采样电路，还用于采集第三电压，所述第三电压为所述第二电压调整后所述机壳与所述地线端之间的电压，所述第三电压用于，所述第三电压与所述第一电压之间的差值的绝对值小于或等于设定的电压差阈值，以检测所述机壳是否接地。
所述第三电压与所述第一电压之间的差值的绝对值在一种可能的实施方式中，所述第一电压用于，所述第一电压的绝对值大于所述电压差阈值，以检测所述机壳是否接地；所述第三电压还用于，所述第三电压与所述第一电压之间的差值的绝对值大于电压阈值，以检测所述机壳是否接地。
在一种可能的实施方式中，所述逆变器还包括火线端和中性线端，所述采样电路通过下述方法采集所述第一电压：
采集火线电压和第一子电压；其中，所述第一子电压为所述机壳与所述中性线端之间的电压；
根据所述火线电压计算第二子电压，所述第二子电压为所述中性线端与所述地线端之间的电压；对所述第一子电压和所述第二子电压进行计算，得到所述第一电压。
在一种可能的实施方式中，所述PID修复电路包括开关器件和补偿电源；其中，所述开关器件和所述补偿电源串联，在所述采集第一电压之前，所述逆变器还用于：
控制所述开关器件断开。
在一种可能的实施方式中，所述逆变器，具体用于：
控制所述开关器件闭合，通过所述补偿电源调整所述第二电压。
图1为一种逆变系统的结构示意图；
图2为本发明实施例提供的一种机壳接地检测方法的流程示意图；
图3为本发明实施例提供的一种逆变系统的结构示意图；
图4为本发明实施例提供的一种逆变器的结构示意图。
为了使本发明的目的、技术方案和优点更加清楚，下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整的描述。
为便于理解本发明实施例，下面先对本发明实施例中涉及的专业术语进行解释说明。
一、电势诱导衰减(potential induced degradation，PID)
PID效应指当光伏组件的电极与边框之间存在较高的偏置电压时，玻璃中的钠离子出现离子迁移，附着在电池片表面，从而造成光伏组件功率下降的现象。在实际中汇总，光伏组件处于负偏压情况下，光伏组件边框的电势为零，高于电池片电势。当玻璃表面有湿气、露水等时，会在组件表面形成一个带电的水膜，而这个带电水膜与电池片之间会因为电势差形成一个模拟电场，且钠离子本身带正电荷，因此在电场作用下，钠离子会通过封装材料向电池方向迁移，大量电荷积聚在电池片表面，使电池表面钝化。进一步，使得逆变器功率急剧衰减，降低了电站的输出功率，降低了发电量。
二、光伏组件对地阻抗
光伏组件对地阻抗是指光伏逆变系统中，光伏组件存在的漏电流对地的等效电阻。比如，光伏逆变器工作时，直流输入侧连接光伏组件。在理想工况下，光伏组件是浮地的，但是在雨雪大雾天气等特殊工况下，光伏组件对地的等效电阻可能会降低。
应理解，本发明实施例中的术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括一个或者更多个该特征。例如，“第一电压”、“第二电压”和“第三电压”，只是示例性地指出不同的电压，而并不意味着电压的重要程度或优先级不同。
另外，应理解，“至少一个”是指一个或者多个，“多个”是指两个或两个以上。“和/或”，描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B的情况，其中A，B可以是单数或者复数。字符“/”一般表示前后关联对象是一种“或”的关系。“以下至少一项(个)”或其类似表达，是指的这些项中的任意组合，包括单项(个)或复数项(个)的任意组合，例如，a，b，或c中的至少一项(个)，可以表示：a，b，c，a和b，a和c，b和c，或a和b和c。
目前，金属外壳的电气设备的机壳都需要接地，机壳漏接地、接地错误或者接地线端损坏等问题将会引发各种安全事故，另外，由于发电组件在潮湿的环境中容易发生PID效应，并在偏置电压的作用下出现功率衰减的现象，从而影响整个发电系统的功率输出，因此，往往通过使用PID修复电路在发电组件负极对地施加电压降低发电组件的PID效应对发电组件的影响。若机壳未接地，将会导致PID补偿功能失效。因此需要准确检测机壳是否接地，进而避免后续安全问题。
目前的检测方案，往往是通过隔离器件光耦原边在市电火线与机壳之间取电，光耦副边产生高低电平信号由控制电路进行检测。若检测光耦副边为低电平，则检测机壳接地；若检测光耦副边为高电平，则检测机壳未接地。在另一种方案中，可以使用非隔离器件三极管或MOS管代替光耦，检测机壳是否接地。但在传统逆变器结构基础上增加额外检测器件，会导致系统风险增加并且操作复杂。
基于上述问题，本发明实施例提供一种机壳接地检测方法及逆变器，用于在不额外增加检测器件的前提下，检测逆变器的机壳接地。
图1为一种逆变系统的结构示意图。如图1所示，该逆变系统包括逆变器101和发电组件102。其
中，逆变器101包括母线正极BUS+、母线负极BUS-、火线端L、中性线端N、地线端PE、PID修复电路1011、第一检测电阻R1、第二检测电阻R2和机壳1012。
第一检测电阻R1连接在母线正极BUS+和机壳1012之间，第二检测电阻R2连接在母线负极BUS-和机壳1012之间，PID修复电路1011连接在母线负极BUS-和机壳1012之间；逆变器101与发电组件102连接；其中，发电组件102的正极与母线正极BUS+连接，发电组件102的负极与母线负极BUS-连接。
另外，发电组件102存在的漏电流对地的等效电阻，如图1所示，该逆变系统还包括发电组件102的正极和接地端PE之间形成的第一等效电阻R3，以及发电组件102的负极和接地端PE形成的第二等效电阻R4。PID修复电路1011包括开关器件10111和补偿电源10112，开关器件10111和补偿电源10112串联连接。
下面结合上述描述的应用场景，参考附图来描述本发明示例性实施方式提供的机壳接地检测方法，需要注意的是，上述应用场景仅是为了便于理解本发明的精神和原理而示出，本发明的实施方式在此方面不受任何限制。
图2为本发明实施例提供的一种机壳接地检测方法的流程示意图。所述方法可以应用于如图1所示的逆变系统中的逆变器101，所述方法包括：
步骤201：逆变器控制PID修复电路的开关器件断开。
由于后续步骤中需要调整母线负极对地电压，进一步判断机壳对地电压变化量，因此需要控制开关器件10111使得PID修复电路1011的工作状态发生变化，即执行步骤202之前，使补偿电源10112不提供补偿，在需要调整母线负极BUS-对地电压时，使用补偿电源10112进行补偿。
需要说明的是，逆变器101控制开关器件10111断开可以是保持开关器件10111维持在断开状态，也可以是将闭合的开关器件10111断开。
在一种可能的实施例中，为不增加额外的器件，可以使用逆变系统中可以改变母线负极BUS-对地电压的补偿电路作为上述PID修复电路。比如，图3为本发明实施例提供的一种逆变系统的结构示意图，如图3所示，若上述逆变系统为光伏逆变系统，开关器件10111可以为继电器，补偿电源10112为电压源。
步骤202：逆变器采集第一电压。
需要说明的是，第一电压为机壳1012与地线端PE之间的电压，第一电压是通过采样和计算得到的。
在一种实施例中，逆变器可以通过如下步骤A1-A3采集第一电压：
A1：逆变器101采集火线电压和第一子电压；其中，第一子电压为机壳1012与中性线端N之间的电压。
A2：逆变器101根据火线电压计算第二子电压；其中，第二子电压为中性线端N与地线端PE之间的电压。火线电压即市电电压，计算方法可以根据电路实际情况进行应用，比如，在三相不平衡的情况下，可以通过向量合成方法根据火线电压计算第二子电压。
A3：逆变器101对第一子电压和第二子电压进行计算，得到第一电压。
另外，下文中的第三电压的采集方式与第一电压的采集方式近似，后续不再赘述。
步骤203：逆变器判断第一电压的绝对值是否大于电压阈值；若是，则执行步骤204；否则，执行步骤205。
可选的，电压阈值可以是根据机壳接地状态下，机壳1012与地线端PE之间的电压设定的；或者电压阈值可以是综合考虑到电压采样等误差因素设定的。比如，在理想的接地状态下，机壳1012与地线端PE之间的电压为零，可以设定电压阈值等于零；或者考虑到采样误差，设定电压阈值约等于零。
步骤204：逆变器检测到机壳未接地。
在一种可能的实施例中，在检测到机壳未接地后，逆变器可以通过显示或声音提示进行警示，下文中检测机壳接地后的警示过程同理，不再赘述。
步骤205：逆变器通过PID修复电路调整第二电压。
需要说明的是，第二电压为母线负极BUS-与地线端PE之间的电压。第二电压是采样得到的。
另外，由于存在第一等效电阻R3和第二等效电阻R4，当机壳1012未接地时，母线负极BUS-对地电压不受逆变器101内部阻抗的影响，逆变器101可以通过如下公式确定母线负极BUS-与地线端PE
之间的电压：
其中，U1为母线负极BUS-与地线端PE之间的电压，Upv为发电组件102的发电电压，r3为第一等效电阻R3的电阻值，r4为第二等效电阻R4的电阻值。
进一步的，当机壳1012未接地时，可以通过如下公式确定母线负极BUS-与机壳1012之间的电压：
其中，U2为母线负极BUS-与机壳1012之间的电压，UBUS为母线总电压，r1为第一检测电阻R1的电阻值，r2为第二检测电阻R2的电阻值。
通常Upv和母线负极BUS-的电压相等，r2与r1的比值不等于r3与r4的比值。在这种情况下，当第一电压小于或等于电压阈值时，可以检测机壳1012接地。但在特殊情况下，比如，工况影响下的发电组件102对地的等效电阻阻值变化，r2与r1的比值可能等于r3与r4的比值，因此，第一电压小于或等于电压阈值，无法证明机壳1012接地。
因此，需要调整母线负极BUS-对地电压(即第二电压)，进一步根据机壳1012对地电压的变化值检测机壳是否接地。
在一种可能的实施例中，逆变器可以通过控制开关器件10111闭合，控制补偿电源10112调整第二电压。
步骤206：逆变器采集第三电压。
需要说明的是，第三电压为第二电压调整后，机壳与地线端之间的电压。
步骤207：逆变器判断第三电压与第一电压之间的差值的绝对值是否大于电压差阈值；若是，则执行步骤204；否则，执行步骤208。
需要说明的是，在机壳未接地的情况下，调整母线负极BUS-与地线端PE之间的电压，机壳1012与地线端PE之间的电压会发生变化。在机壳1012接地的情况下，调整母线负极BUS-与地线端PE之间的电压，机壳1012与地线端PE之间的电压不会发生变化，或(在考虑误差的情况下)发生微小变化。
因此，电压差阈值可以根据机壳1012与地线端PE之间的电压的变化值设定。比如，在理想的接地状态下，机壳1012与地线端PE之间的电压变化值为零，可以设定电压差阈值等于零；或者考虑到采样误差，设定电压差阈值约等于零。
步骤208：逆变器检测到机壳接地。
综上，本发明提供的技术方案通过逆变器的已配置的器件调整母线负极与地线端之间的电压，根据负极母线的对地电压变化值可以准确判断逆变器的机壳的接地状态，因此，本发明公开的机壳接地检测方法可以保证检测精度，操作简单，且无需额外添加器件，成本较低。
基于相同的发明构思，本发明实施例还提供一种逆变器，该逆变器可以应用于上述图2所示的或者与图2实现方式类似的机壳接地检测方法。下面结合附图以及上述机壳接地检测方法，对本发明提供的一种逆变器作进一步说明：
图4为本发明实施例提供的一种逆变器的结构示意图。如图4所示，该逆变器101除图1中所示的电路结构，还包括采样电路401和控制器402；采样电路401，用于采集第一电压和第三电压；其中，第一电压为机壳与地线端之间的电压；其中，第三电压为第二电压调整后，机壳与地线端之间的电压。
在一种可能的实施例中，采样电路401通过下述方法采集第一电压：
采样电路401采集火线电压和第一子电压；其中，第一子电压为机壳与中性线端之间的电压。采样电路401根据火线电压计算第二子电压，并对第一子电压和第二子电压进行计算，得到第一电压；其中，第二子电压为中性线端与地线端之间的电压。
控制器402，用于在采集第一电压之前，控制开关器件断开；通过第一电压的绝对值大于电压阈值，以检测机壳是否接地；通过第一电压的绝对值小于或等于电压阈值，控制开关器件闭合，通过补偿电源调整第二电压；其中，第二电压为母线负极与地线端之间的电压。通过第三电压与第一电压之间的差值
的绝对值小于或等于设定的电压差阈值，以检测机壳是否接地。
通过以上实施方式的描述，所属领域的技术人员可以了解到，为描述的方便和简洁，仅以上述各功能模块的划分进行举例说明，实际应用中，可以根据需要而将上述功能分配由不同的功能模块完成，即将装置的内部结构划分成不同的功能模块，以完成以上描述的全部或者部分功能。
在本发明所提供的几个实施例中，应该理解到，所揭露的模块、单元和方法，可以通过其他的方式实现。例如，以上所描述的模块、单元实施例仅仅是示意性的，例如，模块或单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个装置，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互的耦合或直接耦合或通信连接可以是通过一些接口，模块或单元的间接耦合或通信连接，可以是电性，机械或其他的形式。
作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是一个物理单元或多个物理单元，即可以位于一个地方，或者也可以分布到多个不同地方。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本发明各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。上述集成的单元既可以采用硬件的形式实现，也可以采用软件功能单元的形式实现。
集成的单元如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个可读取存储介质中。基于这样的理解，本发明实施例的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的全部或部分可以以软件产品的形式体现出来，该软件产品存储在一个存储介质中，包括若干指令用以使得一个设备(可以是单片机，芯片等)或处理器(processor)执行本发明各个实施例方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(read only memory，ROM)、随机存取存储器(random access memory，RAM)、磁碟或者光盘等各种可以存储程序代码的介质。
为了使本发明的目的、技术方案和优点更加清楚，下面将结合附图对本发明作进一步地详细描述。方法实施例中的具体操作方法也可以应用于逆变器实施例或系统实施例中。其中，在本发明的描述中，除非另有说明，“多个”的含义是两个或两个以上。
可选的，本发明实施例中的计算机执行指令也可以称之为应用程序代码，本发明实施例对此不作具体限定。
在上述实施例中，可以全部或部分地通过软件、硬件、固件或者其任意组合来实现。当使用软件实现时，可以全部或部分地以计算机程序产品的形式实现。所述计算机程序产品包括一个或多个计算机指令。在计算机上加载和执行所述计算机程序指令时，全部或部分地产生按照本发明实施例所述的流程或功能。所述计算机可以是通用计算机、专用计算机、计算机网络、或者其他可编程装置。所述计算机指令可以存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个计算机可读存储介质传输。
本发明实施例中所描述的各种说明性的逻辑单元和电路可以通过通用处理器，数字信号处理器，专用集成电路(ASIC)，现场可编程门阵列(FPGA)或其它可编程逻辑装置，离散门或晶体管逻辑，离散硬件部件，或上述任何组合的设计来实现或操作所描述的功能。通用处理器可以为微处理器，可选地，该通用处理器也可以为任何传统的处理器、控制器、微控制器或状态机。处理器也可以通过计算装置的组合来实现，例如数字信号处理器和微处理器，多个微处理器，一个或多个微处理器联合一个数字信号处理器核，或任何其它类似的配置来实现。
本发明实施例中所描述的方法或算法的步骤可以直接嵌入硬件、处理器执行的软件单元、或者这两者的结合。软件单元可以存储于RAM存储器、闪存、ROM存储器、EPROM存储器、EEPROM存储器、寄存器、硬盘、可移动磁盘、CD-ROM或本领域中其它任意形式的存储媒介中。示例性地，存储媒介可以与处理器连接，以使得处理器可以从存储媒介中读取信息，并可以向存储媒介存写信息。可选地，存储媒介还可以集成到处理器中。处理器和存储媒介可以设置于ASIC中。
这些计算机程序指令也可装载到计算机或其他可编程数据处理设备上，使得在计算机或其他可编程设备上执行一系列操作步骤以产生计算机实现的处理，从而在计算机或其他可编程设备上执行的指令提供用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的步骤。
尽管结合具体特征及其实施例对本发明进行了描述，显而易见的，在不脱离本发明的精神和范围的情况下，可对其进行各种修改和组合。相应地，本说明书和附图仅仅是所附权利要求所界定的本发明的
示例性说明，且视为已覆盖本发明范围内的任意和所有修改、变化、组合或等同物。显然，本领域的技术人员可以对本发明进行各种改动和变型而不脱离本发明的范围。这样，倘若本发明的这些修改和变型属于本发明权利要求及其等同技术的范围之内，则本发明也意图包括这些改动和变型在内。
Claims (10)
- 一种机壳接地检测方法，其特征在于，应用于逆变器，所述逆变器包括母线正极、母线负极、地线端、PID电势诱导衰减修复电路、第一检测电阻、第二检测电阻和机壳；其中，所述第一检测电阻连接在所述母线正极和所述机壳之间，所述第二检测电阻连接在所述母线负极和所述机壳之间，所述PID修复电路连接在所述母线负极和所述机壳之间；所述逆变器与发电组件连接；所述方法包括：采集第一电压；其中，所述第一电压为所述机壳与所述地线端之间的电压；当所述第一电压的绝对值小于或等于设定的电压阈值时，通过所述PID修复电路调整第二电压；其中，所述第二电压为所述母线负极与所述地线端之间的电压；采集第三电压，所述第三电压为所述第二电压调整后所述机壳与所述地线端之间的电压，所述第三电压用于，所述第三电压与所述第一电压之间的差值的绝对值小于或等于设定的电压差阈值，以检测所述机壳是否接地。
- 如权利要求1所述的方法，其特征在于，所述第一电压用于，所述第一电压的绝对值大于所述电压差阈值，以检测所述机壳是否接地；所述第三电压还用于，所述第三电压与所述第一电压之间的差值的绝对值大于所述电压阈值，以检测所述机壳是否接地。
- 如权利要求1或2所述的方法，其特征在于，所述逆变器还包括火线端和中性线端，所述采集第一电压，包括：采集火线电压和第一子电压；其中，所述第一子电压为所述机壳与所述中性线端之间的电压；根据所述火线电压计算第二子电压，所述第二子电压为所述中性线端与所述地线端之间的电压；对所述第一子电压和所述第二子电压进行计算，得到所述第一电压。
- 如权利要求1-3任一所述的方法，其特征在于，所述PID修复电路包括开关器件和补偿电源；其中，所述开关器件和所述补偿电源串联，在所述采集第一电压之前，所述方法还包括：控制所述开关器件断开。
- 如权利要求4所述的方法，其特征在于，所述通过所述PID修复电路调整所述第二电压，包括：控制所述开关器件闭合，控制所述补偿电源调整所述第二电压。
- 一种逆变器，其特征在于，所述逆变器包括母线正极、母线负极、地线端、PID修复电路、第一检测电阻、第二检测电阻和机壳；其中，所述第一检测电阻连接在所述母线正极和所述机壳之间，所述第二检测电阻连接在所述母线负极和所述机壳之间，所述PID修复电路连接在所述母线负极和所述机壳之间；所述逆变器与发电组件连接；所述逆变器还包括：采样电路，用于采集第一电压；其中，所述第一电压为所述机壳与所述地线端之间的电压；控制器，用于当所述第一电压的绝对值小于或等于设定的电压阈值时，通过所述PID修复电路调整第二电压；其中，所述第二电压为所述母线负极与所述地线端之间的电压；所述采样电路，还用于采集第三电压，所述第三电压为所述第二电压调整后所述机壳与所述地线端之间的电压，所述第三电压用于，所述第三电压与所述第一电压之间的差值的绝对值小于或等于设定的电压差阈值，以检测所述机壳是否接地。
- 如权利要求6所述的逆变器，其特征在于，所述第一电压用于，所述第一电压的绝对值大于所述电压差阈值，以检测所述机壳是否接地；所述第三电压还用于，所述第三电压与所述第一电压之间的差值的绝对值大于电压阈值，以检测所述机壳是否接地。
- 如权利要求6或7所述的逆变器，其特征在于，所述逆变器还包括火线端和中性线端，所述采样电路通过下述方法采集所述第一电压：采集火线电压和第一子电压；其中，所述第一子电压为所述机壳与所述中性线端之间的电压；根据所述火线电压计算第二子电压，所述第二子电压为所述中性线端与所述地线端之间的电压；对所述第一子电压和所述第二子电压进行计算，得到所述第一电压。
- 如权利要求6-8任一所述的逆变器，其特征在于，所述PID修复电路包括开关器件和补偿电源；其中，所述开关器件和所述补偿电源串联，在所述采集第一电压之前，所述控制器还用于：控制所述开关器件断开。
- 如权利要求9所述的逆变器，其特征在于，所述控制器，具体用于：控制所述开关器件闭合，通过所述补偿电源调整所述第二电压。
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211243034.4 | 2022-10-11 | ||
| CN202211243034.4A CN115575852A (zh) | 2022-10-11 | 2022-10-11 | 一种机壳接地检测方法及逆变器 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2024078093A1 true WO2024078093A1 (zh) | 2024-04-18 |
Family
ID=84584589
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/CN2023/109357 WO2024078093A1 (zh) | 2022-10-11 | 2023-07-26 | 一种机壳接地检测方法及逆变器 |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN115575852A (zh) |
| WO (1) | WO2024078093A1 (zh) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115575852A (zh) * | 2022-10-11 | 2023-01-06 | 华为数字能源技术有限公司 | 一种机壳接地检测方法及逆变器 |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20160005613A (ko) * | 2014-07-07 | 2016-01-15 | 주식회사 케이디파워 | 태양광 발전 시스템 |
| CN105591609A (zh) * | 2015-12-31 | 2016-05-18 | 北京天诚同创电气有限公司 | 光伏系统的pid处理方法和系统 |
| CN106018967A (zh) * | 2016-05-12 | 2016-10-12 | 国网江苏省电力公司常州供电公司 | 分布式光伏系统在线对地绝缘安全监测装置 |
| CN107493057A (zh) * | 2017-09-22 | 2017-12-19 | 北京铂阳顶荣光伏科技有限公司 | 一种光伏发电的电势诱导衰减的电气调节系统及方法 |
| CN210323324U (zh) * | 2019-01-22 | 2020-04-14 | 艾伏新能源科技(上海)股份有限公司 | 一种光伏逆变器地线连接检测器 |
| CN111525887A (zh) * | 2020-05-12 | 2020-08-11 | 爱士惟新能源技术(江苏)有限公司 | 一种用于非隔离光伏逆变器的接地检测电路及方法 |
| CN111969646A (zh) * | 2020-07-24 | 2020-11-20 | 华为技术有限公司 | 一种电压补偿装置、逆变装置及光伏发电系统 |
| CN113872241A (zh) * | 2021-10-20 | 2021-12-31 | 固德威技术股份有限公司 | 防光伏组件电势诱导衰减的并网逆变系统 |
| CN115575852A (zh) * | 2022-10-11 | 2023-01-06 | 华为数字能源技术有限公司 | 一种机壳接地检测方法及逆变器 |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3517617B2 (ja) * | 1999-09-17 | 2004-04-12 | 株式会社東芝 | 電気機器の漏電検知方法 |
| CN204031071U (zh) * | 2014-09-02 | 2014-12-17 | 深圳茂硕电气有限公司 | 一种太阳能电池组的gfdi接地故障监测电路 |
| CN104467018B (zh) * | 2014-12-24 | 2017-10-31 | 北京格林科电技术有限公司 | 一种保护光伏组件抑制消除pid现象的方法及装置 |
| CN204330893U (zh) * | 2014-12-29 | 2015-05-13 | 常州佳讯光电产业发展有限公司 | 光伏逆变器用直流母线在线式对地阻抗检测装置 |
| CN110456154B (zh) * | 2019-07-26 | 2021-09-14 | 华为技术有限公司 | 绝缘阻抗检测电路和方法 |
| CN111474409A (zh) * | 2020-05-12 | 2020-07-31 | 爱士惟新能源技术(扬中)有限公司 | 用于非隔离光伏逆变器的绝缘阻抗检测电路及方法 |
| CN213275825U (zh) * | 2020-10-26 | 2021-05-25 | 哈尔滨科创继电设备有限公司 | 一种dc110v铝型材外壳接地检测装置 |
-
2022
- 2022-10-11 CN CN202211243034.4A patent/CN115575852A/zh active Pending
-
2023
- 2023-07-26 WO PCT/CN2023/109357 patent/WO2024078093A1/zh unknown
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20160005613A (ko) * | 2014-07-07 | 2016-01-15 | 주식회사 케이디파워 | 태양광 발전 시스템 |
| CN105591609A (zh) * | 2015-12-31 | 2016-05-18 | 北京天诚同创电气有限公司 | 光伏系统的pid处理方法和系统 |
| CN106018967A (zh) * | 2016-05-12 | 2016-10-12 | 国网江苏省电力公司常州供电公司 | 分布式光伏系统在线对地绝缘安全监测装置 |
| CN107493057A (zh) * | 2017-09-22 | 2017-12-19 | 北京铂阳顶荣光伏科技有限公司 | 一种光伏发电的电势诱导衰减的电气调节系统及方法 |
| CN210323324U (zh) * | 2019-01-22 | 2020-04-14 | 艾伏新能源科技(上海)股份有限公司 | 一种光伏逆变器地线连接检测器 |
| CN111525887A (zh) * | 2020-05-12 | 2020-08-11 | 爱士惟新能源技术(江苏)有限公司 | 一种用于非隔离光伏逆变器的接地检测电路及方法 |
| CN111969646A (zh) * | 2020-07-24 | 2020-11-20 | 华为技术有限公司 | 一种电压补偿装置、逆变装置及光伏发电系统 |
| CN113872241A (zh) * | 2021-10-20 | 2021-12-31 | 固德威技术股份有限公司 | 防光伏组件电势诱导衰减的并网逆变系统 |
| CN115575852A (zh) * | 2022-10-11 | 2023-01-06 | 华为数字能源技术有限公司 | 一种机壳接地检测方法及逆变器 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115575852A (zh) | 2023-01-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111060791B (zh) | 绝缘故障检测方法、装置、电动汽车、终端设备及介质 | |
| WO2024078093A1 (zh) | 一种机壳接地检测方法及逆变器 | |
| JP6478200B2 (ja) | 電源電圧検出装置 | |
| WO2017160035A1 (ko) | 전지모듈의 개방 회로 결함 상태를 결정하는 전지 시스템 및 방법 | |
| EP2741094A1 (en) | Ground fault detection device, ground fault detection method, solar energy system, and ground fault detection program | |
| CN105429226A (zh) | 大容量充放电电池管理系统 | |
| CN105071513A (zh) | 一种电动汽车车载式充电系统 | |
| CN105548712B (zh) | 逆变器及其方阵绝缘阻抗检测系统、方法和计算单元 | |
| CN112505419B (zh) | 车辆的绝缘电阻检测方法、装置、终端设备以及存储介质 | |
| WO2022227659A1 (zh) | 动力电池系统的高压接触器独立诊断装置及方法 | |
| WO2023131127A1 (zh) | 光伏逆变器直流侧绝缘阻抗检测方法及装置 | |
| CN113740749A (zh) | 电池组连线自动检测方法及系统 | |
| CN113472037A (zh) | 一种电池组均衡方法、电池组均衡装置及电池管理系统 | |
| CN103163419B (zh) | 电缆芯校对和变压器跳闸出口校对用指示器及校对方法 | |
| CN117214726B (zh) | 状态检测方法及装置、电子设备、计算机可读存储介质 | |
| CN103033763A (zh) | 一种控制移动终端充电时显示电池电量的方法及系统 | |
| CN115443412A (zh) | 用于检测电源与电气接地之间的电气绝缘故障的方法 | |
| CN112666399A (zh) | 光伏阵列对地绝缘阻抗检测方法和装置 | |
| JP2016099276A (ja) | 絶縁抵抗測定装置 | |
| CN109633357B (zh) | 三母线中多母线接地绝缘监测方法和监测装置 | |
| CN110843598A (zh) | 温度采集补偿方法及电路、电动设备电池管理系统 | |
| CN112557754B (zh) | 光伏逆变器的绝缘阻抗检测方法及装置 | |
| CN113687128B (zh) | 一种光伏pid抑制电路的电流检测方法、装置和设备 | |
| CN103117590B (zh) | 具精简化电压检知电路的不断电供电系统 | |
| CN116027207A (zh) | 电池电量检测电路、电子设备和电量计量方法 |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 23876299 Country of ref document: EP Kind code of ref document: A1 |