CN112688275B - Inverter protection method and device and terminal equipment - Google Patents
Inverter protection method and device and terminal equipment Download PDFInfo
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Abstract
The invention is applicable to the technical field of inverter protection, and provides an inverter protection method, an inverter protection device and terminal equipment, wherein the method comprises the following steps: acquiring an output voltage sampling value and an output current sampling value of an inverter; calculating an output voltage effective value of the inverter according to the output voltage sampling value; calculating the active power of the inverter according to the output voltage sampling value and the output current sampling value; triggering an under-voltage protection action when the effective value of the output voltage and the active power meet a first preset condition and the duration time of the first preset condition is longer than the output under-voltage protection time; the first preset condition is that the effective value of the output voltage is smaller than the undervoltage protection threshold value and the active power is larger than the power threshold value. According to the invention, the first preset condition and the condition that the duration time meeting the first preset condition is longer than the output under-voltage protection time are used as the condition that the inverter triggers the under-voltage protection action, so that whether the inverter needs to trigger the under-voltage protection action can be accurately judged, and the reliability of the inverter protection method is improved.
Description
Technical Field
The invention belongs to the technical field of inverter protection, and particularly relates to an inverter protection method, an inverter protection device and terminal equipment.
Background
The existing inverter protection mainly comprises: overcurrent protection, overvoltage protection, undervoltage protection, short-circuit protection on the output ac side, and the like. The existing undervoltage protection logic generally determines whether to trigger an undervoltage protection action by judging whether the voltage is lower than a threshold value in a certain time; the existing short-circuit protection logic on the output ac side generally determines whether to trigger a short-circuit protection action by determining whether the voltage is below a threshold value and the current is above the threshold value within a certain period of time.
In carrying out the present invention, the inventors have found that at least the following problems exist in the prior art: because the undervoltage protection and the short-circuit protection need to judge whether the voltage is lower than the threshold value or not in a certain time, whether the protection action is triggered or not is further determined, when the short-circuit protection logic judges, if the short-circuit protection time is kept short, namely the short-circuit protection is triggered, the short-circuit protection is possibly triggered, and then the short-circuit protection is switched to a bypass, and a silicon controlled rectifier (SiliconControlledRectifier, SCR) device in the bypass is damaged due to short-circuit current; if the short-circuit protection time is kept longer, the threshold value of the short-circuit protection logic and the threshold value of the under-voltage protection logic may overlap, so that the under-voltage protection action is triggered when the short-circuit protection should be triggered, and false alarm is generated, which is not beneficial to reliably protecting the inverter.
Disclosure of Invention
In view of the above, the embodiments of the present invention provide an inverter protection method, an inverter protection device, and a terminal device, so as to solve the problem in the prior art that the reliability of the inverter protection method is low.
A first aspect of an embodiment of the present invention provides an inverter protection method, including:
acquiring an output voltage sampling value and an output current sampling value of an inverter;
calculating an effective value of the output voltage of the inverter according to the sampling value of the output voltage; calculating the active power of the inverter according to the output voltage sampling value and the output current sampling value;
triggering an under-voltage protection action when the output voltage effective value and the active power meet a first preset condition and the duration time of the first preset condition is longer than the output under-voltage protection time; the first preset condition is that the effective value of the output voltage is smaller than an undervoltage protection threshold value and the active power is larger than a power threshold value.
Optionally, the inverter protection method is applied to a scenario in which an air switch is disposed between the inverter and a load, and further includes:
when the output voltage sampling value and the output current sampling value meet a second preset condition, and the duration time of the second preset condition is longer than the short-circuit protection time, triggering a short-circuit protection action to disconnect the air switch; the second preset condition is that the output voltage sampling value is smaller than a short-circuit protection threshold value and the output current sampling value is larger than a current threshold value;
wherein the short circuit protection time is greater than the output under-voltage protection time.
Optionally, the trip current of the air switch is less than or equal to the current threshold, and the air switch is turned off to protect the load when the output current sampling value is greater than the trip current;
the short-circuit protection time is greater than the time from closing to opening of the air switch.
Optionally, the calculating the effective value of the output voltage of the inverter according to the sampling value of the output voltage includes:
calculating the sum of squares of each output voltage sampling value according to a plurality of output voltage sampling values in one alternating current period to obtain the sum of squares of a plurality of output voltage sampling values;
and calculating the square root of the average value of the sum of squares of the sampling values of the plurality of output voltages to obtain the effective value of the output voltage of the inverter.
Optionally, the calculating the effective value of the output voltage of the inverter according to the sampling value of the output voltage includes:
acquiring a sampling interval of the output voltage sampling value;
determining an output voltage peak value of the inverter according to the maximum value of a plurality of output voltage sampling values in one alternating current period according to the sampling interval;
and calculating the effective value of the output voltage of the inverter according to the peak value of the output voltage.
Optionally, the calculating the effective value of the output voltage of the inverter according to the peak value of the output voltage includes:
according toCalculating an effective value of the output voltage of the inverter;
wherein V is rms For the effective value of the output voltage, V p Is the output voltage peak.
Optionally, the calculating the active power of the inverter according to the output voltage sampling value and the output current sampling value includes:
calculating the effective value of the output voltage of the inverter according to a plurality of sampling values of the output voltage in one alternating current period;
calculating an output current effective value of the inverter according to a plurality of output current sampling values in one alternating current period;
and calculating the active power of the inverter according to the effective value of the output voltage and the effective value of the output current.
A second aspect of an embodiment of the present invention provides an inverter protection device, including:
the sampling module is used for acquiring an output voltage sampling value and an output current sampling value of the inverter;
the calculating module is used for calculating the effective value of the output voltage of the inverter according to the sampling value of the output voltage; calculating the active power of the inverter according to the output voltage sampling value and the output current sampling value;
the protection module is used for triggering an under-voltage protection action when the output voltage effective value and the active power meet a first preset condition and the duration time of the first preset condition is longer than the output under-voltage protection time; the first preset condition is that the effective value of the output voltage is smaller than an undervoltage protection threshold value and the active power is larger than a power threshold value.
A third aspect of an embodiment of the present invention provides a terminal device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the inverter protection method as described in any one of the above when executing the computer program.
A fourth aspect of the embodiments of the present invention provides a computer-readable storage medium storing a computer program which, when executed by a processor, implements the steps of the inverter protection method as described in any one of the above.
Compared with the prior art, the embodiment of the invention has the beneficial effects that: according to the invention, the output voltage effective value can be calculated according to the output voltage sampling value by acquiring the output voltage sampling value of the inverter, and the active power can be calculated according to the output current sampling value and the output voltage sampling value by acquiring the output current sampling value of the inverter, and whether the undervoltage protection action is triggered or not can be accurately judged by judging whether the output voltage effective value and the active power meet the first preset condition and whether the duration time meeting the first preset condition is longer than the output undervoltage protection time or not, so that the reliability of the inverter protection method is improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic diagram of an implementation flow of an inverter protection method according to an embodiment of the present invention;
fig. 2 is a schematic diagram of an inverter protection device according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a terminal device according to an embodiment of the present invention.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.
In order to illustrate the technical scheme of the invention, the following description is made by specific examples.
Fig. 1 is a schematic implementation flow chart of an inverter protection method according to an embodiment of the present invention, which is described in detail below.
Step S101, an output voltage sampling value and an output current sampling value of the inverter are obtained.
When the inverter is usually protected, the output voltage and the output current of the inverter are continuously sampled according to the set sampling frequency, so as to obtain an output voltage sampling value and an output current sampling value.
In the prior art, in general, an output voltage sampling value of an inverter is detected in an output undervoltage protection time, and whether an output voltage effective value obtained according to a plurality of output voltage sampling values in an ac period is lower than an undervoltage protection threshold value is judged, so as to judge whether the inverter is in an impact undervoltage working condition. However, the inverter is usually also provided with a short-circuit protection, and the judgment logic of the short-circuit protection is to detect whether the sampling value of the output voltage of the inverter is lower than a short-circuit protection threshold value and whether the sampling value of the output current is higher than a current threshold value in the short-circuit protection time. When the output undervoltage protection time is equal to the short-circuit protection time, whether the inverter is in the impact undervoltage working condition or the short-circuit working condition can be accurately judged according to the output voltage sampling value and the output current sampling value of the inverter, so that the inverter is reliably protected. However, when the output undervoltage protection time is smaller than the short-circuit protection time, because the undervoltage protection threshold is generally larger than the short-circuit protection threshold, when the inverter is actually in the short-circuit working condition, if the inverter is judged whether to be in the impact undervoltage working condition only according to whether the output voltage sampling value or the output voltage effective value is lower than the undervoltage protection threshold in the output undervoltage time, the actual short-circuit working condition is misjudged as the impact undervoltage working condition, false alarm is generated, and the inverter cannot be accurately and reliably protected.
Step S102, calculating an effective value of the output voltage of the inverter according to the sampling value of the output voltage; and calculating the active power of the inverter according to the output voltage sampling value and the output current sampling value.
As an embodiment of the present invention, calculating the effective value of the output voltage of the inverter from the sampled value of the output voltage may include: calculating the sum of squares of each output voltage sampling value according to a plurality of output voltage sampling values in one alternating current period to obtain the sum of squares of a plurality of output voltage sampling values; and calculating the square root of the average value of the sum of squares of the plurality of output voltage sampling values to obtain the effective value of the output voltage of the inverter.
The effective voltage value is also called root mean square value, and is a measurement value of the sine voltage thermal effect. When the resistor is connected to an ac voltage source (sinusoidal waveform), the resistor consumes a portion of the energy in the form of heat. When the same resistor is connected to a dc voltage source, the resistor connected to the ac voltage source and the resistor connected to the dc voltage source generate equal heat, the voltage effective value of the ac voltage source is equal to the voltage value of the dc voltage source.
According to the definition of the effective voltage value, a plurality of output voltage sampling values V in an alternating current period are obtained according to a certain sampling frequency i Then, the effective value V of the corresponding output voltage in an alternating current period can be obtained according to the following formula rms ：
Wherein n is the number of output voltage sampling values obtained by sampling in one alternating current period.
As another embodiment of the present invention, calculating the effective value of the output voltage of the inverter from the sampled value of the output voltage may include: acquiring a sampling interval of an output voltage sampling value; determining an output voltage peak value of the inverter according to the maximum value of a plurality of output voltage sampling values in one alternating current period according to the sampling interval; and calculating the effective value of the output voltage of the inverter according to the peak value of the output voltage.
According to the definition of the effective value of the voltage, the sampling interval of the sampling value of the output voltage can be set, so that the sampling value of the output voltage obtained by sampling in one alternating current period comprises the peak value of the output voltage, and the effective value of the output voltage is calculated according to the peak value of the output voltage.
Optionally, calculating the effective value of the output voltage of the inverter according to the peak value of the output voltage may include: according toAnd calculating the effective value of the output voltage of the inverter.
Wherein V is rms To output the effective value of voltage V p Is the output voltage peak.
Optionally, calculating the active power of the inverter according to the output voltage sampling value and the output current sampling value may include: calculating an effective value of the output voltage of the inverter according to a plurality of sampling values of the output voltage in one alternating current period; calculating an effective value of the output current of the inverter according to a plurality of sampling values of the output current in one alternating current period; and calculating the active power of the inverter according to the effective value of the output voltage and the effective value of the output current.
The output voltage effective value can be obtained based on a plurality of output voltage sampling values in one alternating current period, or sampling intervals can be set, so that the plurality of output voltage sampling values in one alternating current period comprise output voltage peak values, and the output voltage effective value is obtained according to the output voltage peak values. Similarly, the sum of squares of each output current sampling value may be calculated according to a plurality of output current sampling values in one ac cycle, the sum of squares of the plurality of output current sampling values may be obtained, and the square root of the average value of the sum of squares of the plurality of output current sampling values may be calculated, thereby obtaining the output current effective value of the inverter.
Alternatively, the output current sampling value obtained by sampling in one ac cycle is made to include the peak value of the output current according to the sampling interval of the output current sampling value, and the output current effective value is calculated from the output current peak value.
According to the method for obtaining the effective value of the output current, the effective value of the output voltage and the effective value of the output current in the corresponding alternating current period can be obtained, and then the active power of the inverter in the corresponding alternating current period is obtained according to the product of the effective value of the output voltage and the effective value of the output current in the corresponding alternating current period.
Step S103, triggering the under-voltage protection action when the effective value of the output voltage and the active power meet a first preset condition and the duration time of the first preset condition is longer than the output under-voltage protection time.
The first preset condition is that the effective value of the output voltage is smaller than the undervoltage protection threshold value and the active power is larger than the power threshold value.
The triggered under-voltage protection action may be switched to a bypass, or other under-voltage protection actions may be set according to the working environment of the inverter, and the embodiment does not limit the specific under-voltage protection actions.
The output under-voltage protection time may be 10ms, or other time set according to the impact of the impact under-voltage working condition on the inverter, which is not limited in this embodiment.
In this embodiment, by using the condition that the effective value of the output voltage of the inverter is smaller than the undervoltage protection threshold and the active power of the inverter is larger than the power threshold, and the duration that the effective value of the output voltage of the inverter is smaller than the undervoltage protection threshold and the duration that the active power of the inverter is larger than the power threshold is larger than the output undervoltage protection time as the condition that the undervoltage protection action of the inverter is triggered, the judgment logic of the undervoltage protection of the inverter can be ensured not to conflict with the judgment logic of other protection, and then whether the undervoltage protection action of the inverter needs to be triggered can be accurately judged, and the reliability of the inverter protection method is improved.
Optionally, the inverter protection method is applied to a scenario in which an air switch is disposed between the inverter and the load, and the inverter protection method may further include: when the output voltage sampling value and the output current sampling value meet a second preset condition, and the duration time of the second preset condition is longer than the short-circuit protection time, triggering the short-circuit protection action to disconnect the air switch.
The second preset condition is that the output voltage sampling value is smaller than the short-circuit protection threshold value and the output current sampling value is larger than the current threshold value.
Wherein the short circuit protection time is greater than the output under-voltage protection time.
When the output voltage sampling value and the output current sampling value meet a second preset condition, and the duration time of the second preset condition is longer than the short-circuit protection time, the short-circuit protection action is triggered to disconnect the air switch, so that the phenomenon that other devices of a system where the inverter is located are damaged by short-circuit current after the short-circuit protection action is triggered when the inverter is protected can be avoided.
Optionally, the short-circuit protection action is triggered to turn off the air switch, and the air switch may be controlled to be turned off when the output voltage sampling value and the output current sampling value meet a second preset condition, and the duration of the second preset condition is greater than the short-circuit protection time.
Alternatively, the trip current of the air switch may be set to be less than or equal to the current threshold, and the short-circuit protection time is greater than the time from closing to opening of the air switch. So that the air switch is automatically turned off when the output voltage sampling value and the output current sampling value satisfy a second preset condition and the duration of the second preset condition is greater than the short-circuit protection time.
The air switch is provided with a tripping current for opening the air switch to protect a load when the sampling value of the output current is larger than the tripping current.
For example, the short-circuit protection time may be 100ms, 200ms, or other values, where the short-circuit protection time and the output under-voltage protection time may be in a multiple relationship, for example, 10 times, 20 times, etc., and a specific multiple relationship may be determined by combining the time from closing to opening with the air switch, and the specific value of the short-circuit protection time is not limited in this embodiment.
Optionally, after the short-circuit protection is triggered to turn off the air switch, the air switch may be switched to a bypass, or other protection actions may be set according to the working environment of the inverter.
In this embodiment, by setting the condition that the output voltage sampling value of the inverter is smaller than the short-circuit protection threshold value and the output current sampling value of the inverter is larger than the current threshold value, and the duration that the output voltage sampling value of the inverter is smaller than the short-circuit protection threshold value and the duration that the output current sampling value of the inverter is larger than the current threshold value is longer than the short-circuit protection time as the condition that the inverter triggers the short-circuit protection action, whether the inverter needs to trigger the short-circuit protection action can be accurately determined. An air switch is arranged between the inverter and the load; triggering the short-circuit protection action to disconnect the air switch can avoid damaging other devices of the system where the inverter is located by short-circuit current after triggering the short-circuit protection action. The tripping current of the air switch is smaller than or equal to the current threshold, the short-circuit protection time is longer than the time from closing to opening of the air switch, and meanwhile, the short-circuit protection time is longer than the output under-voltage protection time, so that the air switch can be automatically opened when the short-circuit working condition occurs, and the short-circuit working condition and the impact under-voltage working condition can be accurately distinguished.
According to the inverter protection method, the condition that the output voltage effective value of the inverter is smaller than the undervoltage protection threshold value, the active power of the inverter is larger than the power threshold value, the duration that the output voltage effective value of the inverter is smaller than the undervoltage protection threshold value and the duration that the active power of the inverter is larger than the power threshold value are larger than the output undervoltage protection time is used as the condition that the inverter triggers the undervoltage protection action can be ensured, the judgment logic of the undervoltage protection of the inverter cannot conflict with the judgment logic of other protection, whether the inverter needs to trigger the undervoltage protection action can be accurately judged, and the reliability of the inverter protection method is improved. The method comprises the steps that the output voltage sampling value of the inverter is smaller than a short-circuit protection threshold value, the output current sampling value of the inverter is larger than a current threshold value, the duration time that the output voltage sampling value of the inverter is smaller than the short-circuit protection threshold value and the duration time that the output current sampling value of the inverter is larger than the current threshold value are longer than the short-circuit protection time, the condition that the inverter triggers a short-circuit protection action is defined, the short-circuit protection time is longer than the output undervoltage protection time, whether the inverter needs to trigger the short-circuit protection action can be accurately judged, and the short-circuit current after triggering the short-circuit protection action can be prevented from damaging other devices of a system where the inverter is located by limiting the triggering the short-circuit protection action so that an air switch between the inverter and a load is disconnected.
It should be understood that the sequence number of each step in the foregoing embodiment does not mean that the execution sequence of each process should be determined by the function and the internal logic, and should not limit the implementation process of the embodiment of the present invention.
Fig. 2 shows an exemplary diagram of an inverter protection device according to an embodiment of the present invention, corresponding to the inverter protection method described in the above embodiments. As shown in fig. 2, the apparatus may include: a sampling module 21, a calculation module 22 and a protection module 23.
A sampling module 21, configured to obtain an output voltage sampling value and an output current sampling value of the inverter;
a calculating module 22, configured to calculate an effective value of the output voltage of the inverter according to the sampling value of the output voltage; calculating the active power of the inverter according to the output voltage sampling value and the output current sampling value;
the protection module 23 is configured to trigger an under-voltage protection action when the output voltage effective value and the active power meet a first preset condition, and a duration of the first preset condition is greater than an output under-voltage protection time; the first preset condition is that the effective value of the output voltage is smaller than an undervoltage protection threshold value and the active power is larger than a power threshold value.
Optionally, the protection module 23 is applied to a scenario in which an air switch is disposed between the inverter and the load, and may be further configured to trigger a short-circuit protection action to open the air switch when the output voltage sampling value and the output current sampling value satisfy a second preset condition, and a duration of the second preset condition is greater than a short-circuit protection time; the second preset condition is that the output voltage sampling value is smaller than a short-circuit protection threshold value and the output current sampling value is larger than a current threshold value; wherein the short circuit protection time is greater than the output under-voltage protection time.
Optionally, the trip current of the air switch is less than or equal to the current threshold, and the air switch is turned off to protect the load when the output current sampling value is greater than the trip current; the short-circuit protection time is greater than the time from closing to opening of the air switch.
Optionally, the calculating module 22 may be configured to calculate a sum of squares of each output voltage sampling value according to a plurality of output voltage sampling values in one ac period, to obtain a sum of squares of the plurality of output voltage sampling values; and calculating the square root of the average value of the sum of squares of the sampling values of the plurality of output voltages to obtain the effective value of the output voltage of the inverter.
Optionally, the calculating module 22 may be configured to obtain a sampling interval of the output voltage sampling value; determining an output voltage peak value of the inverter according to the maximum value of a plurality of output voltage sampling values in one alternating current period according to the sampling interval; and calculating the effective value of the output voltage of the inverter according to the peak value of the output voltage.
Optionally, the calculation module 22 may be configured to, based onCalculating an effective value of the output voltage of the inverter; wherein V is rms For the effective value of the output voltage, V p Is the output voltage peak.
Optionally, the calculating module 22 may be configured to calculate the effective output voltage value of the inverter according to a plurality of output voltage sampling values in one ac cycle; calculating an output current effective value of the inverter according to a plurality of output current sampling values in one alternating current period; and calculating the active power of the inverter according to the effective value of the output voltage and the effective value of the output current.
According to the inverter protection device, the condition that the output voltage effective value of the inverter is smaller than the undervoltage protection threshold value and the active power of the inverter is larger than the power threshold value, the duration that the output voltage effective value of the inverter is smaller than the undervoltage protection threshold value and the duration that the active power of the inverter is larger than the power threshold value are larger than the output undervoltage protection time is used as the condition that the inverter triggers the undervoltage protection action can be ensured, the judgment logic of the undervoltage protection of the inverter can not conflict with the judgment logic of other protection, whether the inverter needs to trigger the undervoltage protection action can be accurately judged, and the reliability of the inverter protection method is improved. The method comprises the steps that the output voltage sampling value of the inverter is smaller than a short-circuit protection threshold value, the output current sampling value of the inverter is larger than a current threshold value, the duration time that the output voltage sampling value of the inverter is smaller than the short-circuit protection threshold value and the duration time that the output current sampling value of the inverter is larger than the current threshold value are longer than the short-circuit protection time, the condition that the inverter triggers a short-circuit protection action is defined, the short-circuit protection time is longer than the output undervoltage protection time, whether the inverter needs to trigger the short-circuit protection action can be accurately judged, and the short-circuit current after triggering the short-circuit protection action can be prevented from damaging other devices of a system where the inverter is located by limiting the triggering the short-circuit protection action so that an air switch between the inverter and a load is disconnected.
Fig. 3 is a schematic diagram of a terminal device according to an embodiment of the present invention. As shown in fig. 3, the terminal device 300 of this embodiment includes: a processor 301, a memory 302 and a computer program 303, such as an inverter protection program, stored in the memory 302 and executable on the processor 301. The steps in the above-described embodiments of the inverter protection method are implemented by the processor 301 when the computer program 303 is executed, for example, steps S101 to S103 shown in fig. 1, and the functions of the modules in the above-described embodiments of the apparatus, for example, the functions of the modules 21 to 23 shown in fig. 2, are implemented by the processor 301 when the computer program 303 is executed.
By way of example, the computer program 303 may be split into one or more program modules that are stored in the memory 302 and executed by the processor 301 to carry out the present invention. The one or more program modules may be a series of computer program instruction segments capable of performing a specific function for describing the execution of the computer program 303 in the inverter protection device or terminal apparatus 300. For example, the computer program 303 may be divided into a sampling module 21, a calculating module 22 and a protecting module 23, where specific functions of each module are shown in fig. 2, and are not described in detail herein.
The terminal device 300 may be a computing device such as a desktop computer, a notebook computer, a palm computer, and a cloud server. The terminal device may include, but is not limited to, a processor 301, a memory 302. It will be appreciated by those skilled in the art that fig. 3 is merely an example of a terminal device 300 and is not limiting of the terminal device 300, and may include more or fewer components than shown, or may combine certain components, or different components, e.g., the terminal device may also include input and output devices, network access devices, buses, etc.
The processor 301 may be a central processing unit (Central Processing Unit, CPU), but may also be other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory 302 may be an internal storage unit of the terminal device 300, such as a hard disk or a memory of the terminal device 300. The memory 302 may also be an external storage device of the terminal device 300, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card) or the like, which are provided on the terminal device 300. Further, the memory 302 may also include both an internal storage unit and an external storage device of the terminal device 300. The memory 302 is used for storing the computer program and other programs and data required by the terminal device 300. The memory 302 may also be used to temporarily store data that has been output or is to be output.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional units and modules is illustrated, and in practical application, the above-described functional distribution may be performed by different functional units and modules according to needs, i.e. the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-described functions. The functional units and modules in the embodiment may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit, where the integrated units may be implemented in a form of hardware or a form of a software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working process of the units and modules in the above system may refer to the corresponding process in the foregoing method embodiment, which is not described herein again.
In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
In the embodiments provided in the present invention, it should be understood that the disclosed apparatus/terminal device and method may be implemented in other manners. For example, the apparatus/terminal device embodiments described above are merely illustrative, e.g., the division of the modules or units is merely a logical function division, and there may be additional divisions in actual implementation, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection via interfaces, devices or units, which may be in electrical, mechanical or other forms.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiments of the present invention may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated modules/units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the present invention may implement all or part of the flow of the method of the above embodiment, or may be implemented by a computer program to instruct related hardware, where the computer program may be stored in a computer readable storage medium, and when the computer program is executed by a processor, the computer program may implement the steps of each of the method embodiments described above. Wherein the computer program comprises computer program code which may be in source code form, object code form, executable file or some intermediate form etc. The computer readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a U disk, a removable hard disk, a magnetic disk, an optical disk, a computer Memory, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), an electrical carrier signal, a telecommunications signal, a software distribution medium, and so forth. It should be noted that the computer readable medium contains content that can be appropriately scaled according to the requirements of jurisdictions in which such content is subject to legislation and patent practice, such as in certain jurisdictions in which such content is subject to legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunication signals.
The above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention, and are intended to be included in the scope of the present invention.
Claims (10)
1. An inverter protection method is applied to a scene that the sampling value of the output voltage of an inverter is smaller than a short-circuit protection threshold value and the sampling value of the output current of the inverter is larger than a current threshold value and the short-circuit protection time is longer than the output undervoltage protection time, and is characterized by comprising the following steps:
acquiring an output voltage sampling value and an output current sampling value of an inverter;
calculating an effective value of the output voltage of the inverter according to the sampling value of the output voltage; calculating the active power of the inverter according to the output voltage sampling value and the output current sampling value;
triggering an under-voltage protection action when the output voltage effective value and the active power meet a first preset condition and the duration time of the first preset condition is longer than the output under-voltage protection time; the first preset condition is that the effective value of the output voltage is smaller than an undervoltage protection threshold value and the active power is larger than a power threshold value.
2. The inverter protection method of claim 1, applied to a scenario in which an air switch is provided between the inverter and a load, further comprising:
when the output voltage sampling value and the output current sampling value meet a second preset condition, and the duration time of the second preset condition is longer than the short-circuit protection time, triggering a short-circuit protection action to disconnect the air switch; the second preset condition is that the output voltage sampling value is smaller than a short-circuit protection threshold value and the output current sampling value is larger than a current threshold value;
wherein the short circuit protection time is greater than the output under-voltage protection time.
3. The inverter protection method of claim 2, wherein a trip current of the air switch is equal to or less than the current threshold for turning off the air switch to protect the load when the output current sampling value is greater than the trip current;
the short-circuit protection time is greater than the time from closing to opening of the air switch.
4. The inverter protection method according to any one of claims 1 to 3, wherein the calculating the output voltage effective value of the inverter from the output voltage sampling value includes:
calculating the sum of squares of each output voltage sampling value according to a plurality of output voltage sampling values in one alternating current period to obtain the sum of squares of a plurality of output voltage sampling values;
and calculating the square root of the average value of the sum of squares of the sampling values of the plurality of output voltages to obtain the effective value of the output voltage of the inverter.
5. The inverter protection method according to any one of claims 1 to 3, wherein the calculating the output voltage effective value of the inverter from the output voltage sampling value includes:
acquiring a sampling interval of the output voltage sampling value;
determining an output voltage peak value of the inverter according to the maximum value of a plurality of output voltage sampling values in one alternating current period according to the sampling interval;
and calculating the effective value of the output voltage of the inverter according to the peak value of the output voltage.
6. The inverter protection method of claim 5, wherein the calculating the output voltage effective value of the inverter from the output voltage peak value comprises:
according toCalculating an effective value of the output voltage of the inverter;
wherein V is rms For the effective value of the output voltage, V p Is the output voltage peak.
7. The inverter protection method of claim 4, wherein said calculating the active power of the inverter from the output voltage sample value and the output current sample value comprises:
calculating the effective value of the output voltage of the inverter according to a plurality of sampling values of the output voltage in one alternating current period;
calculating an output current effective value of the inverter according to a plurality of output current sampling values in one alternating current period;
and calculating the active power of the inverter according to the effective value of the output voltage and the effective value of the output current.
8. An inverter protection device, which is applied to the condition of short-circuit protection, is a scene that the sampling value of the output voltage of an inverter is smaller than a short-circuit protection threshold value and the sampling value of the output current of the inverter is larger than a current threshold value, and the short-circuit protection time is longer than the output undervoltage protection time, and is characterized by comprising:
the sampling module is used for acquiring an output voltage sampling value and an output current sampling value of the inverter;
the calculating module is used for calculating the effective value of the output voltage of the inverter according to the sampling value of the output voltage; calculating the active power of the inverter according to the output voltage sampling value and the output current sampling value;
the protection module is used for triggering an under-voltage protection action when the output voltage effective value and the active power meet a first preset condition and the duration time of the first preset condition is longer than the output under-voltage protection time; the first preset condition is that the effective value of the output voltage is smaller than an undervoltage protection threshold value and the active power is larger than a power threshold value.
9. A terminal device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the steps of the method according to any of claims 1 to 7 when the computer program is executed.
10. A computer readable storage medium storing a computer program, characterized in that the computer program when executed by a processor implements the steps of the method according to any one of claims 1 to 7.
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Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH027831A (en) * | 1988-06-27 | 1990-01-11 | Fuji Electric Co Ltd | Protective circuit for inverter |
| CN2250587Y (en) * | 1995-09-07 | 1997-03-26 | 薛小平 | Full automatic protective device for over voltage, under voltage, over current, delay and self protection |
| CN102005777A (en) * | 2010-11-04 | 2011-04-06 | 艾默生网络能源有限公司 | Control method and control system for photovoltaic grid-connected inverter |
| CN103683178A (en) * | 2012-09-26 | 2014-03-26 | 艾默生网络能源有限公司 | Data center equipment and over-current and under-voltage protection circuit thereof |
| CN104113047A (en) * | 2013-04-22 | 2014-10-22 | 上海市电力公司 | Electricity utilization protection method and electricity utilization protection device based on comprehensive integration of public transformers |
| EP2991209A1 (en) * | 2014-08-27 | 2016-03-02 | Sungrow Power Supply Co., Ltd. | Method for controlling shutdown of photovoltaic inverters, system thereof, and photovoltaic power generation system |
| WO2017126104A1 (en) * | 2016-01-22 | 2017-07-27 | 新電元工業株式会社 | Inverter device and method for controlling inverter device |
| WO2018006681A1 (en) * | 2016-07-07 | 2018-01-11 | 中兴通讯股份有限公司 | Reactive power compensation method and apparatus, photovoltaic grid-connected inverter, and computer storage medium |
| CN207967914U (en) * | 2018-01-11 | 2018-10-12 | 温州科宇电器有限公司 | A kind of voltage protection of photovoltaic parallel in system |
| CN109687399A (en) * | 2018-12-03 | 2019-04-26 | 漳州科华技术有限责任公司 | Inverter overcurrent protection control method, device and terminal device |
| CN110148948A (en) * | 2019-05-23 | 2019-08-20 | 四川科陆新能电气有限公司 | A kind of device and method improving power grid end photovoltaic DC-to-AC converter generated output |
| CN111474403A (en) * | 2020-04-21 | 2020-07-31 | 上能电气股份有限公司 | Leakage current detection method and device and photovoltaic inverter system |
| CN111983302A (en) * | 2020-08-07 | 2020-11-24 | 苏州浪潮智能科技有限公司 | Power correction circuit abnormality detection method, system and circuit |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7495875B2 (en) * | 2007-06-05 | 2009-02-24 | Fsp Technology Inc. | Power abnormal protection circuit |
| CN107612018B (en) * | 2017-08-15 | 2019-08-23 | 华为数字技术（苏州）有限公司 | The control method and device of inverter, inverter, computer readable storage medium |
| CN107302210A (en) * | 2017-08-21 | 2017-10-27 | 合肥翔望智能科技有限公司 | A kind of dynamic low-voltage protection method of photovoltaic DC-to-AC converter |
-
2020
- 2020-12-11 CN CN202011444958.1A patent/CN112688275B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH027831A (en) * | 1988-06-27 | 1990-01-11 | Fuji Electric Co Ltd | Protective circuit for inverter |
| CN2250587Y (en) * | 1995-09-07 | 1997-03-26 | 薛小平 | Full automatic protective device for over voltage, under voltage, over current, delay and self protection |
| CN102005777A (en) * | 2010-11-04 | 2011-04-06 | 艾默生网络能源有限公司 | Control method and control system for photovoltaic grid-connected inverter |
| CN103683178A (en) * | 2012-09-26 | 2014-03-26 | 艾默生网络能源有限公司 | Data center equipment and over-current and under-voltage protection circuit thereof |
| CN104113047A (en) * | 2013-04-22 | 2014-10-22 | 上海市电力公司 | Electricity utilization protection method and electricity utilization protection device based on comprehensive integration of public transformers |
| EP2991209A1 (en) * | 2014-08-27 | 2016-03-02 | Sungrow Power Supply Co., Ltd. | Method for controlling shutdown of photovoltaic inverters, system thereof, and photovoltaic power generation system |
| WO2017126104A1 (en) * | 2016-01-22 | 2017-07-27 | 新電元工業株式会社 | Inverter device and method for controlling inverter device |
| WO2018006681A1 (en) * | 2016-07-07 | 2018-01-11 | 中兴通讯股份有限公司 | Reactive power compensation method and apparatus, photovoltaic grid-connected inverter, and computer storage medium |
| CN207967914U (en) * | 2018-01-11 | 2018-10-12 | 温州科宇电器有限公司 | A kind of voltage protection of photovoltaic parallel in system |
| CN109687399A (en) * | 2018-12-03 | 2019-04-26 | 漳州科华技术有限责任公司 | Inverter overcurrent protection control method, device and terminal device |
| CN110148948A (en) * | 2019-05-23 | 2019-08-20 | 四川科陆新能电气有限公司 | A kind of device and method improving power grid end photovoltaic DC-to-AC converter generated output |
| CN111474403A (en) * | 2020-04-21 | 2020-07-31 | 上能电气股份有限公司 | Leakage current detection method and device and photovoltaic inverter system |
| CN111983302A (en) * | 2020-08-07 | 2020-11-24 | 苏州浪潮智能科技有限公司 | Power correction circuit abnormality detection method, system and circuit |
Non-Patent Citations (2)
| Title |
|---|
| （美）范瓦尔肯堡（Van Valkenburg）.《电学基础 修订版》.高等教育出版社,1990,198-199. * |
| 用于分布式发电的低压反孤岛保护策略;杨晨悦等;《电力电子技术》;第49卷(第12期);35-38 * |
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