Method for realizing three-phase voltage protection through single-channel ADC sampling, medium and terminal

Abstract

The invention is suitable for the technical field of equipment protection, and relates to a method for realizing three-phase voltage protection by single-channel ADC sampling, a medium and a terminal.The method comprises the steps that S10, the output end of each phase of voltage is connected to a diode through a hardware circuit, and the three-phase voltage outputs three steamed bun waves with different peak values; s20, sampling the points of the four steamed bun waves to ensure that three complete steamed bun waves are found in the cache; s30, finding out continuous crest values of the first three steamed bun waves and recording the position of each crest value; s40, obtaining a voltage effective value according to the peak value searched in the cache and the voltage calibration coefficient; and S50, immediately judging a power failure condition after sampling of each cycle is completed, and executing overvoltage and undervoltage protection in a second task. The method is simple in process and convenient to operate, hardware overhead is saved on the premise that hardware functions are not added, components of the structure with small space can be reduced, the function of the Internet of Things can be achieved more easily, and cost is low.

Description

Technical Field

[0001] The present invention belongs to the technical field of equipment protection, and in particular relates to a method, a medium and a terminal for implementing three-phase voltage protection by single-channel ADC sampling. Background Art

[0002] The three-phase voltage protection function exists in all aspects of embedded products. Whether the voltage value can be sampled and detected correctly is an important indicator for product promotion and application. The traditional miniature circuit breaker is the most widely used terminal protection device in the building electrical terminal distribution device. It is used for single-phase and three-phase short circuit, overload, overvoltage and other protection below 125A, including single-pole 1P, two-pole 2P, three-pole 3P, four-pole 4P and other four types. With the development of smart distribution networks in recent years, traditional distribution networks and their supporting equipment have begun to establish physical links with various industries through the relationship between power supply and demand. This requires traditional miniature circuit breaker products to integrate information and communication technologies. The traditional miniature circuit breaker has a small structural space and limited hardware circuit board space, and cannot realize the three-phase voltage protection function. If the Internet of Things function is added, it means adding more components and the cost is also higher.

[0003] The patent application with publication number CN105548885A provides a motor control and protection switch with a three-phase voltage protection function, including a motor and a three-phase switch, and its characteristic point is that it also includes a three-phase voltage detection module, a first to a third voltage transformer, the input ends of the first to the third voltage transformer are respectively connected to the A phase line, the B phase line, and the C phase line of the three-phase power supply, the output ends of the first voltage transformer, the second voltage transformer, and the third voltage transformer are respectively connected to the A phase terminal, the B phase terminal, and the C phase terminal of the motor through the three-phase switch, the control ends of the first voltage transformer, the second voltage transformer, and the third voltage transformer are respectively connected to the corresponding input ends of the three-phase voltage detection module, and the output end of the three-phase voltage detection module is connected to the three-phase switch by means of a wire. Although this patent application realizes the three-phase voltage protection function, the device provided by it has a complex structure and high cost, and has the same disadvantages as the prior art.

[0004] Therefore, how to provide a method for realizing three-phase voltage protection at a relatively low cost is an urgent problem to be solved by personnel in this technical field. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a method for implementing three-phase voltage protection using a single-channel ADC, so as to solve the problem in the prior art that the miniature circuit breaker cannot implement the three-phase voltage protection function at low cost due to the small structural space and limited hardware circuit board space; in addition, the present invention also provides a medium and terminal for implementing three-phase voltage protection using a single-channel ADC.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for implementing three-phase voltage protection using a single-channel ADC, comprising the following steps:

[0008] S10, the hardware circuit connects the output end of each phase voltage to a diode, and the three-phase voltage outputs three steamed bun waves with different peak values;

[0009] S20, sampling the points of four steamed bun waves to ensure that three complete steamed bun waves are found in the cache;

[0010] S30, finding out the peak values ​​of the first three consecutive waves and recording the position of each peak value;

[0011] S40, obtaining a voltage effective value according to the peak value and voltage calibration coefficient found in the cache;

[0012] S50: After each cycle sampling is completed, the power-off condition is immediately determined, and over-voltage and under-voltage protection is performed in the second task.

[0013] Furthermore, in the step S10, when a phase is missing, a steamed bun wave is correspondingly reduced, and the waveform of the single-channel ADC sampling point is related to the amplitude, frequency and angle of the three-phase voltage.

[0014] Furthermore, the specific steps of step S30 are as follows:

[0015] S301, searching for a maximum value starting from cache index 2;

[0016] S302, calculating the left and right differences of the maximum value dat1 and dat2, and the left and right differences are both less than the maximum allowable change value;

[0017] S303. If the above conditions a and b are met at the same time, and two consecutive points on the left side of the extreme value rise and two points on the right side fall, then record the maximum value and coordinates, and continue with steps S301 and S302 until three peaks or cache points are found, then the search ends.

[0018] Further, when the condition of step S301 is satisfied but the condition of step S302 is not satisfied, the value is a burr, and the extreme value is replaced by the average value of the left and right values, and the condition of step S301 and step S302 is continued.

[0019] Furthermore, if there is a complete initial wave in the cache, it is directly filtered out and the subsequent three complete steamed bun waves are collected.

[0020] Furthermore, when there are glitches in the environmental interference problem, the glitches are filtered out by taking the average value and filling the gap.

[0021] Furthermore, in step S50, the power-off conditions include phase failure, sampling amplitude less than the power-off threshold, and waveform sampling point deviation. The above three conditions are independent of each other, and power-off protection occurs when any one of the conditions is met.

[0022] Furthermore, if the ADC channel output is less than three peaks, it is called phase failure and power-off protection will occur; the supply voltage threshold range under normal voltage conditions is [0.75Un, 1.25Un], where Un is 220V. When the effective value calculated by the peak amplitude of a certain phase is less than the minimum power-off threshold, power-off protection will occur; when power is off, each cycle sampling point will jump, and the subscript of each peak obtained from steps S20 to S40 will determine the change size of each cycle sampling point. If the change threshold is exceeded, power-off protection will occur.

[0023] In a second aspect, the present invention further provides a computer-readable storage medium, wherein the storage medium stores a computer program, and the computer program implements the above method when executed by a processor.

[0024] In a third aspect, the present invention further provides an electronic terminal, comprising: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal executes the method as described above.

[0025] Compared with the prior art, the method, medium and terminal for implementing three-phase voltage protection by single-channel ADC sampling provided by the present invention have at least the following beneficial effects:

[0026] The traditional miniature circuit breaker has a small structure space and limited hardware circuit board space, and cannot realize the three-phase voltage protection function. If the Internet of Things function is added, it means adding more components and the cost is also high. The present invention has a simple process and convenient operation. It saves ADC sampling channels in hardware resources. Under the premise of not increasing hardware functions, it saves hardware expenses, and can reduce components in the structure with small space, which is low in cost. The three-phase voltage protection Bluetooth micro-circuit breaker is realized through single-channel ADC sampling, making it easier to add the Internet of Things function to the circuit breaker without changing the structure, improving the competitiveness of the product, and making the application safer, more economical and safer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the scheme of the present invention, a brief introduction is given below to the figures required for use in the description of the embodiments. Obviously, the figures described below are some embodiments of the present invention. For ordinary technicians in this field, other figures can be obtained based on these figures without paying any creative work.

[0028] Figure 1A flow chart of a method for implementing three-phase voltage protection by single-channel ADC sampling provided by an embodiment of the present invention;

[0029] Figure 2 This is a typical single-channel three-phase sampling waveform;

[0030] Figure 3 A logic diagram of voltage protection tasks in a method for implementing three-phase voltage protection by single-channel ADC sampling provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0033] The present invention provides a method for implementing three-phase voltage protection by single-channel ADC sampling, which is applied to the process of sampling and detecting voltage values ​​in embedded products. The method for implementing three-phase voltage protection by single-channel ADC sampling includes the following steps:

[0034] S10, the hardware circuit connects the output end of each phase voltage to a diode, and the three-phase voltage outputs three steamed bun waves with different peak values;

[0035] S20, sampling the points of four steamed bun waves to ensure that three complete steamed bun waves are found in the cache;

[0036] S30, finding out the peak values ​​of the first three consecutive waves and calculating the position of each peak value;

[0037] S40, obtaining a voltage effective value according to the peak value and voltage calibration coefficient found in the cache;

[0038] S50: After each cycle sampling is completed, the power-off condition is immediately determined, and over-voltage and under-voltage protection is performed in the second task.

[0039] The present invention has a simple process and is easy to operate. It saves hardware expenses without increasing hardware functions, can reduce components in a structure with a small space, and can more easily realize Internet of Things functions at a lower cost.

[0040] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0041] The present invention provides a method for implementing three-phase voltage protection by single-channel ADC sampling, which is applied to the process of sampling and detecting voltage values ​​in embedded products. Figures 1 to 3 In this embodiment, the single-channel ADC sampling method for implementing three-phase voltage protection includes the following steps:

[0042] S10, firstly, the hardware circuit connects the output end of each phase voltage to the diode, and the three-phase voltage outputs three steamed bun waves with different peak values. When a phase is missing, one steamed bun wave is reduced accordingly. The waveform of the single-channel ADC sampling point is related to the amplitude, frequency and phase angle of the three-phase voltage;

[0043] In this embodiment, under the condition of 50Hz, one cycle is 20ms, and the typical waveform is as follows Figure 2 When the three-phase voltage is input, there will be three steamed waves, which are Figure 2 It can be seen that the waveform under normal working conditions is a periodic fixed waveform, and each cycle of 20ms output waveform contains 3 consecutive peaks (i.e. 3 consecutive steamed bun waves), where the different peak values ​​indicate different three-phase effective values, and the positions of the 3 cycle peaks in each cycle are related to the three-phase voltage.

[0044] S20, to ensure that three complete steamed bun waves are sampled in the sampling cache, the number of points of four steamed bun waves is sampled to ensure that three complete steamed bun waves are found in the cache;

[0045] In this embodiment, if 60 points are sampled in 20 ms, then storing 80 points in the ADC sampling buffer can ensure that 3 steamed bun waves can be found in the buffer.

[0046] S30, finding out the peak values ​​of the first three consecutive waves and recording the position of each peak value;

[0047] Specifically, in this embodiment, step S30 includes the following steps:

[0048] S301, start searching for the maximum value from cache index 2, the maximum value must be greater than the sampling value corresponding to 30V, filter the interference wave, that is, greater than the left value and the right value;

[0049] S302, calculating the left and right differences of the maximum value dat1 and dat2, and the left and right differences are both less than the maximum allowable change value (maximum sampling amplitude*{sin(π / 2)-sin(π / 2-π / 20)});

[0050] S303, if the above conditions a and b are met at the same time, and two points on the left side of the extreme value rise continuously, and two points on the right side fall continuously, then record the maximum value and coordinates, and continue the steps S301 and S302 until three peaks or cache points are found, then the search ends;

[0051] Further, in this embodiment, when the condition of step S301 is met but the condition of step S302 is not met, the value is a burr, and the extreme value is replaced by the average value of the left and right values; and step S301 and step S302 are continued.

[0052] S40, obtaining a voltage effective value according to the peak value and voltage calibration coefficient found in the cache;

[0053] Specifically, in this embodiment, the problem of Figure 2 The coordinates of the waveform in the ADC sampling buffer may move left and right. If there is a complete wave at the beginning in the buffer, it can be directly filtered out and the subsequent three complete steamed bun waves can be obtained. The glitches that may exist due to environmental interference are also filtered out by taking the average value and filling the gaps, thereby improving the sampling effectiveness.

[0054] S50, after ADC sampling and completing the calculation of the three-phase voltage effective value, enter the voltage protection task, such as Figure 3 As shown, the implementation of power-off protection must respond immediately and have the highest priority. Therefore, the power-off condition is judged immediately after each cycle sampling is completed, and the over-voltage and under-voltage protection can be executed in the second task.

[0055] Specifically, combined Figures 1 to 3 It can be seen that under normal voltage conditions of 50Hz, the ADC channel will output 3 consecutive peaks of different sizes per cycle. The judgment conditions for power failure include:

[0056] Phase loss: If the ADC channel output is less than 3 peaks, it is considered as phase loss, which can cause power-off protection.

[0057] The sampling amplitude is less than the power-off threshold: the supply voltage threshold range under normal voltage conditions is [0.75Un, 1.25Un], where Un is usually 220V. When the effective value of a phase peak amplitude is calculated to be less than the minimum power-off threshold, such as 0.5Un, it is considered a power-off, and power-off protection can be generated at this time;

[0058] Waveform sampling point deviation: Figure 2 It can be seen that when the three-phase 50Hz voltage output is stable, the continuous cycle is a periodic three-steamed bun waveform. When the power is off, each cycle sampling point will jump. The change can be seen from each peak subscript obtained by ADC sampling and effective value algorithm, so as to judge the change size of each cycle sampling point. If the change threshold is exceeded, it means power off. At this time, the frequency deviation generates power-off protection;

[0059] The above three conditions are independent of each other, and power-off protection will occur if any one of the conditions is met.

[0060] In this embodiment, Figure 3 As shown, when the power-off judgment times Cnt>=2, it indicates that the voltage is lower than the power-off threshold. If the power-off condition is met, power-off protection is performed. If the power-off condition is not met, the second timing detection is entered. The over- and under-voltage protection judgment scenarios are generally satisfied for several seconds, that is, the over- and under-voltage anti-shake time is at least greater than 2s. If the judgment threshold is not met once, the times are reset to zero. If the overvoltage times are greater than the overvoltage delay time, the overvoltage protection is met. If it is not met, the overvoltage times are reset to zero. The undervoltage times are judged in the same way. The method provided in the embodiment of the present invention is based on a one-channel ADC sampling output of a three-phase voltage waveform (mantou wave) with a voltage angle difference. The three-phase voltage values ​​are extracted by software filtering and extracting the peak value (i.e., voltage amplitude). On the one hand, this method saves a sampling interface, and on the other hand, power-off detection within 60ms can be achieved without adding a power-off detection circuit inside the chip. It is economical, safe, efficient, and easy to implement.

[0061] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, any one of the methods in the present embodiment is implemented.

[0062] An embodiment of the present invention further provides an electronic terminal, comprising: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal executes any one of the methods in this embodiment.

[0063] The computer-readable storage medium in this embodiment can be understood by ordinary technicians in this field: all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to the computer program. The aforementioned computer program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other media that can store program codes.

[0064] The electronic terminal provided in this embodiment includes a processor, a memory, a transceiver and a communication interface. The memory and the communication interface are connected to the processor and the transceiver and complete communication with each other. The memory is used to store computer programs, the communication interface is used to communicate, and the processor and the transceiver are used to run computer programs so that the electronic terminal executes each step of the above method.

[0065] The method, medium and terminal for realizing three-phase voltage protection by single-channel ADC sampling described in the above embodiments, compared with the prior art, the traditional miniature circuit breaker has a small structure space and limited hardware circuit board space, and cannot realize the three-phase voltage protection function. If the Internet of Things function is added, it means adding more components and the cost is also high. The present invention has a simple process and convenient operation. It saves ADC sampling channels in hardware resources. Under the premise of not increasing hardware functions, it saves hardware expenses, and can reduce components in the structure with small space, and the cost is low. The three-phase voltage protection Bluetooth micro-breaker is realized by single-channel ADC sampling, making it easier to add the Internet of Things function to the circuit breaker without changing the structure, improving the competitiveness of the product, and making the application safer, more economical and safer.

[0066] Obviously, the embodiments described above are only preferred embodiments of the present invention, rather than all embodiments. The preferred embodiments of the present invention are shown in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific embodiments, or to perform equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of the present invention, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present invention.

Claims

1. A method for implementing three-phase voltage protection by single-channel ADC sampling, characterized in that: include: S10, the hardware circuit connects the output end of each phase voltage to a diode, and the three-phase voltage outputs three steamed bun waves with different peak values; S20, sampling the points of four steamed bun waves to ensure that three complete steamed bun waves are found in the cache; S30, finding out the peak values ​​of the first three consecutive waves and recording the position of each peak value; S40, obtaining a voltage effective value according to the peak value and voltage calibration coefficient found in the cache; S50: After each cycle sampling is completed, the power-off condition is immediately determined, and over-voltage and under-voltage protection is performed in the second task.

2. The method for implementing three-phase voltage protection by single-channel ADC sampling according to claim 1, characterized in that: In the step S10, when a phase is missing, a steamed bun wave is reduced accordingly, and the waveform of the single-channel ADC sampling point is related to the amplitude, frequency and angle of the three-phase voltage.

3. The method for implementing three-phase voltage protection by single-channel ADC sampling according to claim 1, characterized in that: The specific steps of step S30 are as follows: S301, searching for a maximum value starting from cache index 2; S302, calculating the left and right differences of the maximum value dat1 and dat2, and the left and right differences are both less than the maximum allowable change value; S303. If the above conditions a and b are met at the same time, and two consecutive points on the left side of the extreme value rise and two points on the right side fall, then record the maximum value and coordinates, and continue with steps S301 and S302 until three peaks or cache points are found, then the search ends.

4. The method for implementing three-phase voltage protection by single-channel ADC sampling according to claim 3, characterized in that: When step S301 is satisfied but step S302 is not satisfied, the value is a burr, the extreme value is replaced by the average of the left and right values, and step S301 and step S302 are continued.

5. The method for implementing three-phase voltage protection by single-channel ADC sampling according to claim 4, characterized in that: If there is a complete initial wave in the cache, it will be directly filtered out and the subsequent three complete steamed bun waves will be collected.

6. The method for implementing three-phase voltage protection by single-channel ADC sampling according to claim 4, characterized in that: When there are glitches due to environmental interference, the glitches are filtered out by taking the average value and filling the gap.

7. The method for implementing three-phase voltage protection by single-channel ADC sampling according to claim 1, characterized in that: In step S50, the power-off conditions include phase failure, sampling amplitude less than the power-off threshold, and waveform sampling point deviation. The above three conditions are independent of each other, and power-off protection occurs when any one of the conditions is met.

8. The method for implementing three-phase voltage protection by single-channel ADC sampling according to claim 7, characterized in that: If the ADC channel output is less than three peaks, it is called phase failure and power-off protection will occur; the supply voltage threshold range under normal voltage conditions is [0.75Un, 1.25Un], where Un is 220V. When the effective value calculated by the peak amplitude of a phase is less than the minimum power-off threshold, power-off protection will occur; when power is off, each cycle sampling point will jump, and the subscript of each peak obtained from steps S20 to S40 will determine the change size of each cycle sampling point. If the change threshold is exceeded, power-off protection will occur.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

10. An electronic terminal, characterized in that: include: Processor and memory; The memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal executes the method according to any one of claims 1 to 8.

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