A signal phase difference measurement system and method for an electric energy metering device

Abstract

The application discloses a signal phase difference measurement system and method for an electric energy metering device, comprising: a signal conversion module, which is used for respectively converting voltage detection signals and current detection signals output by the electric energy metering device to obtain first voltage signals and second voltage signals; a zero-crossing comparison module, which is used for respectively generating first trigger signals and second trigger signals when the first voltage signals and the second voltage signals are at zero-crossing points; a pulse trigger module, which is used for generating rectangular waves based on the first trigger signals and the second trigger signals, and controlling an AND gate to be open based on the rectangular waves to output standard pulses; a pulse counting module, which is used for counting the output standard pulses to determine the number of the standard pulses; and a phase difference measurement module, which is used for determining the signal phase difference based on the signal period of the voltage signals, the frequency of the standard pulses and the number of the standard pulses. The application can reduce the influence of harmonics and other noise, has fast response speed and high precision.

Description

Technical Field

[0001] This invention relates to the field of small-signal phase measurement technology for electricity metering devices, and more specifically, to a signal phase difference measurement system and method for electricity metering devices. Background Technology

[0002] Currently, phase measurement technology has wide applications in power systems, industrial automation, intelligent control, communications, and electronics. In power systems, it is necessary to determine the power factor (cosθ), active power (P), reactive power (Q), and electricity consumption, all of which are directly related to the phase angle between the voltage and current of alternating current. Phase is one of the three characteristics of alternating signals (the other two being frequency and amplitude). Consistent phase ensures power quality. By measuring the phase θ between current and voltage, and using the calculated power factor (cosθ), active power can be determined, enabling the billing function for electricity.

[0003] Traditional phase measurement instrument systems are complex in structure and cannot be widely applied to problems such as testing laboratory power metering devices. Therefore, a signal phase difference measurement system for power metering devices is needed. Summary of the Invention

[0004] This invention proposes a signal phase difference measurement system and method for electricity metering devices to solve the problem of how to determine the phase difference between the current signal and the voltage signal output by the electricity metering device.

[0005] To address the aforementioned problems, according to one aspect of the present invention, a signal phase difference measurement system for an electricity metering device is provided, the system comprising:

[0006] The signal conversion module is used to convert the voltage detection signal and the current detection signal output by the power metering device into a first voltage signal and a second voltage signal, respectively.

[0007] The zero-crossing comparison module is used to generate a first trigger signal and a second trigger signal respectively when the first voltage signal and the second voltage signal are at the zero-crossing point;

[0008] A pulse triggering module is used to generate a rectangular wave based on the first trigger signal and the second trigger signal, and to control the opening of a NAND gate based on the rectangular wave to output a standard pulse;

[0009] The pulse counting module is used to count the output standard pulses and determine the number of standard pulses.

[0010] The phase difference measurement module is used to determine the signal phase difference based on the signal period of the voltage signal, the frequency of the standard pulse, and the number of standard pulses.

[0011] Preferably, the pulse triggering module is a binary information storage device with memory function, including logic units of various timing circuits and a standard pulse output submodule. When generating a rectangular wave, the first received trigger signal is used as an enable signal (high-level signal), and the second received trigger signal is used as an disable signal (low-level signal). The triggering module generates a rectangular wave with a width equal to the phase difference between the two voltage signals based on the high-level and low-level signals, and controls the opening of the NAND gate based on the rectangular wave to control the output of the standard pulse.

[0012] Preferably, the pulse counting module is a counter.

[0013] Preferably, the phase difference measurement module determines the signal phase difference based on the signal period of the voltage signal, the frequency of the standard pulse, and the number of standard pulses, including:

[0014]

[0015] Where Φ is the signal phase difference; m is the number of standard pulses; f0 is the frequency of the standard pulses; T θ The signal period is the voltage signal.

[0016] Preferably, the system further includes:

[0017] The display module is used to display the phase difference of the signal.

[0018] According to another aspect of the present invention, a method for measuring signal phase difference based on the signal phase difference measurement system for an electricity metering device as described above is provided, the method comprising:

[0019] Using a voltage conversion module, the voltage detection signal and current detection signal output by the power metering device are converted into a first voltage signal and a second voltage signal, respectively.

[0020] Using a zero-crossing comparison module, a first trigger signal and a second trigger signal are generated respectively when the first voltage signal and the second voltage signal cross zero.

[0021] Using a pulse triggering module, a rectangular wave is generated based on the first trigger signal and the second trigger signal, and the opening of the NAND gate is controlled based on the rectangular wave to output a standard pulse;

[0022] The number of standard pulses is determined by counting the output standard pulses using a pulse counting module.

[0023] The phase difference is determined using a phase difference measurement module based on the signal period of the voltage signal, the frequency of the standard pulse, and the number of standard pulses.

[0024] Preferably, the pulse triggering module is a binary information storage device with memory function, including logic units of various timing circuits and a standard pulse output submodule. When generating a rectangular wave, the first received trigger signal is used as an enable signal (high-level signal), and the second received trigger signal is used as an disable signal (low-level signal). The triggering module generates a rectangular wave with a width equal to the phase difference between the two voltage signals based on the high-level and low-level signals. The rectangular wave is used to control the opening of the NAND gate and control the output of the standard pulse.

[0025] Preferably, the pulse counting module is a counter.

[0026] Preferably, the determination of the signal phase difference using the phase difference measurement module based on the signal period of the voltage signal, the frequency of the standard pulse, and the number of standard pulses includes:

[0027]

[0028] Where Φ is the signal phase difference; m is the number of standard pulses; f0 is the frequency of the standard pulses; T θ The signal period is the voltage signal.

[0029] Preferably, the method further includes:

[0030] The display module is used to display the phase difference of the signal.

[0031] This invention provides a signal phase difference measurement system and method for an energy metering device, comprising: a signal conversion module for converting voltage detection signals and current detection signals output by the energy metering device to obtain a first voltage signal and a second voltage signal; a zero-crossing comparison module for generating a first trigger signal and a second trigger signal respectively when the first voltage signal and the second voltage signal cross zero; a pulse triggering module for generating a rectangular wave based on the first trigger signal and the second trigger signal, and controlling the opening of a NAND gate based on the rectangular wave to output a standard pulse; a pulse counting module for counting the output standard pulses to determine the number of standard pulses; and a phase difference measurement module for determining the signal phase difference based on the signal period of the voltage signal, the frequency of the standard pulses, and the number of standard pulses. This invention utilizes the independently output voltage and current signals of the energy metering device and measures the signal phase difference based on the zero-crossing comparison method. This reduces the influence of harmonics and other noise, provides fast response speed and high accuracy, and provides technical support for accurately realizing energy metering in energy metering devices. Attached Figure Description

[0032] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0033] Figure 1 This is a schematic diagram of the structure of a signal phase difference measurement system 100 for an electricity metering device according to an embodiment of the present invention;

[0034] Figure 2 This is an example diagram of a signal phase difference measurement system for an electricity metering device according to an embodiment of the present invention;

[0035] Figure 3 This is a flowchart of a signal phase difference measurement method 300 for an electricity metering device according to an embodiment of the present invention. Detailed Implementation

[0036] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0037] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0038] Figure 1 This is a schematic diagram of the structure of a signal phase difference measurement system 100 for an electricity metering device according to an embodiment of the present invention. Figure 1 As shown, the signal phase difference measurement system for an energy metering device provided by this embodiment of the invention utilizes the voltage and current signals that the energy metering device can independently output. Based on the zero-crossing comparison method, it measures the signal phase difference, reducing the influence of harmonics and other noise. It features fast response speed and high accuracy, providing technical support for accurately measuring energy consumption. The signal phase difference measurement system 100 for an energy metering device provided by this embodiment of the invention includes: a signal conversion module 101, a zero-crossing comparison module 102, a pulse triggering module 103, a pulse counting module 104, and a phase difference measurement module 105.

[0039] Preferably, the signal conversion module 101 is used to convert the voltage detection signal and the current detection signal output by the power metering device into a first voltage signal and a second voltage signal, respectively.

[0040] In this invention, the signal conversion module includes two parts: voltage conversion and current conversion. It can convert both the voltage signal and the current signal output by the metering device into two small voltage signals, thereby obtaining a first voltage signal and a second voltage signal. Specifically, during voltage conversion, a voltage divider can be used to obtain one small voltage signal; during current conversion, a shunt can be used to obtain the other small voltage signal.

[0041] In addition, in this invention, the signal conversion module has an overload protection function. Once the range exceeds the limit, it can automatically cut off the range and issue an alarm.

[0042] Preferably, the zero-crossing comparison module 102 is used to generate a first trigger signal and a second trigger signal respectively when the first voltage signal and the second voltage signal are at the zero-crossing point.

[0043] Preferably, the pulse triggering module 103 is used to generate a rectangular wave based on the first trigger signal and the second trigger signal, and to control the opening of the NAND gate based on the rectangular wave to output a standard pulse.

[0044] Preferably, the pulse trigger module 103 is a binary information storage device with memory function, including logic units of various timing circuits and a standard pulse output submodule. When generating a rectangular wave, the first received trigger signal is used as an on signal, which is a high-level signal, and the second received trigger signal is used as an off signal, which is a low-level signal. The trigger module generates a rectangular wave with a width equal to the phase difference between the two voltage signals based on the high-level signal and the low-level signal, so as to control the opening of the NAND gate based on the rectangular wave and control the output of the standard pulse.

[0045] In this invention, the two small voltage signals being measured are two sinusoidal voltage signals of the same frequency, wherein the period of the sinusoidal signal is T. θ Two voltage signals pass through a zero-comparison module, each generating a trigger signal at its zero-crossing point. These two trigger signals are input to a pulse trigger module, serving as the on and off signals respectively. This causes the pulse trigger module to output a rectangular wave (time width T) with a width equal to the phase difference between the two small voltage signals, while simultaneously emitting a standard pulse. The rectangular wave controls the opening of a NAND gate, thereby controlling the number of standard pulses that pass through.

[0046] In this invention, the zero-crossing comparison module can be a zero-crossing comparator. The zero-crossing comparison module generates a trigger signal. When two small voltage signals change from negative to positive and cross zero, or change from positive to negative, a trigger signal is generated and input to the pulse trigger module. The zero-crossing comparison module has a filtering function, which can reduce the influence of harmonics and other noise.

[0047] In this invention, the pulse trigger module is a binary information storage device with memory function, composed of logic units of various timing circuits and a standard pulse output submodule. It receives the trigger signal from the zero-crossing comparison module. If the small voltage signal 1 leads signal 2, then signal 1 acts as the enable signal, which is high, and the trigger module is set to "1". Signal 2 acts as the disable signal, which is low, and the trigger module is set to "0". At this time, the trigger module outputs a rectangular wave with a width equal to the phase difference between the two small voltage signals. This rectangular wave is used to control the opening of the NAND gate, thereby controlling the number of standard pulses.

[0048] Preferably, the pulse counting module 104 is used to count the output standard pulses and determine the number of standard pulses.

[0049] Preferably, the pulse counting module 104 is a counter.

[0050] Preferably, the phase difference measurement module 105 is used to determine the signal phase difference based on the signal period of the voltage signal, the frequency of the standard pulse, and the number of standard pulses.

[0051] Preferably, the phase difference measurement module determines the signal phase difference based on the signal period of the voltage signal, the frequency of the standard pulse, and the number of standard pulses, including:

[0052]

[0053] Where Φ is the signal phase difference; m is the number of standard pulses; f0 is the frequency of the standard pulses; T θ The signal period is the voltage signal.

[0054] Preferably, the system further includes:

[0055] The display module is used to display the phase difference of the signal.

[0056] In this invention, a pulse counting module is used to record the number m of standard pulses passing through an AND gate. The pulse counting module is typically composed of a general-purpose counter, featuring multi-channel operation, fast level signal capture, high resolution, and high precision; its function is to determine the number of standard pulses. Given that the frequency of the pulse counting module is f0, the time interval T can be calculated. Then the signal phase difference is calculated. The signal phase difference value can also be displayed via the display module.

[0057] like Figure 2The diagram shows an example of a signal phase difference measurement system for an electricity metering device, including: a voltage divider, a current shunt, a zero-crossing comparator, a time difference meter, and a digital display. The electricity metering device outputs voltage and current signals. The voltage signal is connected to the voltage divider, and the current signal is connected to the current shunt. Small voltage signals are output from the voltage divider and current shunt, respectively. These small voltage signals are then input to the time difference meter, which processes and calculates the voltage signals. Finally, the digital display shows the numerical value of the signal phase difference. The time difference meter consists of a pulse triggering module and a pulse counting module.

[0058] This invention utilizes the independently output voltage and current signals of an energy metering device. Based on the zero-crossing comparison method, it achieves the measurement of the phase difference between the voltage and current signals of the energy metering device, featuring fast response, high accuracy, and simple operation. Furthermore, the signal phase measurement system can be connected to a CPU via a serial port, enabling the calculation, storage, and display of experimental data. It also possesses secondary development capabilities, is compatible with various software and hardware systems, and can easily share data with other information systems, facilitating user access, operation, and maintenance by technical personnel.

[0059] Figure 3 This is a flowchart of a signal phase difference measurement method 300 for an electricity metering device according to an embodiment of the present invention. Figure 3 As shown, the signal phase measurement method 300 based on the signal phase difference measurement system for an electricity metering device as described above, provided by an embodiment of the present invention, includes:

[0060] Step 301: Using a voltage conversion module, the voltage detection signal and current detection signal output by the power metering device are converted into a first voltage signal and a second voltage signal, respectively.

[0061] Step 302: Using the zero-crossing comparison module, a first trigger signal and a second trigger signal are generated respectively when the first voltage signal and the second voltage signal cross the zero point.

[0062] Step 303: Using the pulse triggering module, a rectangular wave is generated based on the first trigger signal and the second trigger signal, and the opening of the NAND gate is controlled based on the rectangular wave to output a standard pulse.

[0063] Preferably, the pulse triggering module is a binary information storage device with memory function, including logic units of various timing circuits and a standard pulse output submodule. When generating a rectangular wave, the first received trigger signal is used as an enable signal (high-level signal), and the second received trigger signal is used as an disable signal (low-level signal). The triggering module generates a rectangular wave with a width equal to the phase difference between the two voltage signals based on the high-level and low-level signals. The rectangular wave is used to control the opening of the NAND gate and control the output of the standard pulse.

[0064] Step 304: Use the pulse counting module to count the output standard pulses and determine the number of standard pulses.

[0065] Preferably, the pulse counting module is a counter.

[0066] Step 305: Using the phase difference measurement module, determine the signal phase difference based on the signal period of the voltage signal, the frequency of the standard pulse, and the number of standard pulses.

[0067] Preferably, the determination of the signal phase difference using the phase difference measurement module based on the signal period of the voltage signal, the frequency of the standard pulse, and the number of standard pulses includes:

[0068]

[0069] Where Φ is the signal phase difference; m is the number of standard pulses; f0 is the frequency of the standard pulses; T θ The signal period is the voltage signal.

[0070] Preferably, the method further includes:

[0071] The display module is used to display the phase difference of the signal.

[0072] The signal phase difference measurement method 300 for an energy metering device according to an embodiment of the present invention corresponds to the signal phase difference measurement system 100 for an energy metering device according to another embodiment of the present invention, and will not be described again here.

[0073] The invention has been described with reference to a few embodiments. However, as will be known to those skilled in the art, and as defined in the appended claims, other embodiments besides those disclosed above fall equivalently within the scope of the invention.

[0074] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the art, unless otherwise expressly defined herein. All references to “a / the / the [device, component, etc.]” ​​are openly interpreted as at least one instance of said device, component, etc., unless otherwise expressly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed unless explicitly stated otherwise.

[0075] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0076] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0077] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0078] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A signal phase difference measurement system for an electricity metering device, characterized in that, The system includes: The signal conversion module is used to convert the voltage detection signal and the current detection signal output by the power metering device into a first voltage signal and a second voltage signal, respectively. The zero-crossing comparison module is used to generate a first trigger signal and a second trigger signal respectively when the first voltage signal and the second voltage signal cross zero. A pulse triggering module is used to generate a rectangular wave based on the first trigger signal and the second trigger signal, and to control the opening of a NAND gate based on the rectangular wave to output a standard pulse; The pulse counting module is used to count the output standard pulses and determine the number of standard pulses. The phase difference measurement module is used to determine the signal phase difference based on the signal period of the voltage signal, the frequency of the standard pulse, and the number of standard pulses. The pulse triggering module is a binary information storage device with memory function, including logic units of various timing circuits and a standard pulse output submodule. When generating a rectangular wave, the first received trigger signal is used as the turn-on signal (high-level signal), and the second received trigger signal is used as the turn-off signal (low-level signal). The triggering module generates a rectangular wave with a width equal to the phase difference between the two voltage signals based on the high-level and low-level signals. The rectangular wave is used to control the opening of the NAND gate and control the output of the standard pulse. The phase difference measurement module determines the signal phase difference based on the signal period of the voltage signal, the frequency of the standard pulse, and the number of standard pulses, including: = ， in, is the signal phase difference; m is the number of standard pulses; The frequency of the standard pulse; The signal period is the voltage signal.

2. The system according to claim 1, characterized in that, The pulse counting module is a counter.

3. The system according to claim 1, characterized in that, The system also includes: The display module is used to display the phase difference of the signal.

4. A method for measuring the signal phase difference of a signal phase difference measurement system for an electricity metering device as described in any one of claims 1-3, characterized in that, The method includes: Using a voltage conversion module, the voltage detection signal and current detection signal output by the power metering device are converted into a first voltage signal and a second voltage signal, respectively. Using a zero-crossing comparison module, a first trigger signal and a second trigger signal are generated respectively when the first voltage signal and the second voltage signal cross zero. Using a pulse triggering module, a rectangular wave is generated based on the first trigger signal and the second trigger signal, and the opening of the NAND gate is controlled based on the rectangular wave to output a standard pulse; The number of standard pulses is determined by counting the output standard pulses using a pulse counting module. The phase difference is determined using a phase difference measurement module based on the signal period of the voltage signal, the frequency of the standard pulse, and the number of standard pulses. The pulse triggering module is a binary information storage device with memory function, including logic units of various timing circuits and a standard pulse output submodule. When generating a rectangular wave, the first received trigger signal is used as the turn-on signal, which is a high-level signal, and the second received trigger signal is used as the turn-off signal, which is a low-level signal. The triggering module generates a rectangular wave with a width equal to the phase difference between the two voltage signals based on the high-level signal and the low-level signal. The rectangular wave is used to control the opening of the NAND gate and control the output of the standard pulse. The step of using a phase difference measurement module to determine the signal phase difference based on the signal period of the voltage signal, the frequency of the standard pulse, and the number of standard pulses includes: = ， in, is the signal phase difference; m is the number of standard pulses; The frequency of the standard pulse; The signal period is the voltage signal.

5. The method according to claim 4, characterized in that, The pulse counting module is a counter.

6. The method according to claim 4, characterized in that, The method further includes: The display module is used to display the phase difference of the signal.

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