阅读说明：本技术 电流测量工具、电能测量系统、电能测量方法 (Current measuring tool, electric energy measuring system and electric energy measuring method ) 是由 侯慧娟 郅擎宇 赵睿 王雍 赵岩 田闽哲 赵洁 彭小平 丁涛 朱惠娣 李梦溪 于 2020-05-12 设计创作，主要内容包括：一种电能测量系统,包括控制器、用于输出与被测导线中的原始电流相关的衍生电流的非接触式电流感测器、用于输出衍生电流对应的第一信号的电流采样电路、用于识别衍生电流的理论截取区间的首标记点和尾标记点的标记点识别电路和用于电流测量指令及发送对应于原始电流或衍生电流的理论截取区间内的第二信号的工具侧无线通信模块。一种电能测量系统,包括无线通信连接的上位机和电流测量工具。一种电能测量方法,第n+1次采样衍生电流的瞬时电压与瞬时电流的相位差为<Image he="156" wi="680" file="DDA0002488473930000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>它可以兼顾电能计量的准确度、使用范围和使用便利性。(An electric energy measuring system comprises a controller, a non-contact type current sensor used for outputting derived current related to original current in a measured lead, a current sampling circuit used for outputting a first signal corresponding to the derived current, a mark point identification circuit used for identifying a header mark point and a tail mark point of a theoretical interception interval of the derived current, and a tool side wireless communication module used for measuring a command and sending a second signal corresponding to the original current or the derived current in the theoretical interception interval. An electric energy measuring system comprises an upper computer and a current measuring tool which are connected in a wireless communication mode. In the electric energy measuring method, the phase difference between the instantaneous voltage and the instantaneous current of the n +1 th sampling derived current is The electric energy metering device can give consideration to the accuracy, the application range and the convenience of use of electric energy metering.)

1. A current measuring tool comprises a non-contact current sensor, a current sampling circuit and a controller, and is characterized by also comprising a marking point identification circuit and a tool side wireless communication module; the non-contact current sensor is used for outputting derivative current related to original current in a tested lead; the current sampling circuit is used for outputting a first signal corresponding to the derived current; the mark point identification circuit is used for identifying a header mark point and a tail mark point of a theoretical interception interval of the derived current, wherein the theoretical interception interval corresponds to a first signal in 1 period of the derived current; the tool side wireless communication module is used for receiving a current measurement instruction and sending a second signal corresponding to the original current or the derived current in the theoretical interception interval.

2. The current measuring tool of claim 1, wherein the non-contact current sensor is an open-close type precision transformer.

3. The current measurement tool of claim 1, wherein the marker point identification circuit is a zero crossing detection circuit.

4. The current measurement tool of claim 1, further comprising a battery for powering the non-contact current sensor, the current sampling circuit, the marker identification circuit, the controller, and the tool-side wireless communication module, or further comprising a battery compartment for mounting a battery for powering the non-contact current sensor, the current sampling circuit, the marker identification circuit, the controller, and the tool-side wireless communication module.

5. An electric energy measuring system is used for measuring the power of M-phase electric equipment, wherein M is larger than or equal to 1, the electric energy measuring system comprises an upper computer and is characterized by further comprising a current measuring tool according to any one of claims 1 to 4, the current measuring tool is in wireless communication connection with the upper computer, at least M sets of current measuring tools are arranged, and the current measuring tools are in wireless communication connection with one set of the upper computer.

6. An electric energy measurement system as claimed in claim 5, wherein the upper computer is a site calibrator with an upper computer side wireless communication module.

7. An electric energy measuring method, characterized by comprising the steps of:

acquiring derivative current corresponding to original current in a tested wire;

identifying a header point, time t, of said derived current₁Time of day;

from t₂At the beginning of the moment, every time period t₃Sampling an instantaneous current of the derived current;

identifying the tail mark point of said derived current, time t₄Time of day; the duration between the leading and trailing marker points corresponds to 1 cycle of the derived current;

wherein at t₂Time to t₄In the time interval, the phase difference between the instantaneous voltage and the instantaneous current of the derivative current sampled for the (n + 1) th time is

8. An electric energy measuring method is used for measuring the power of M-phase electric equipment, wherein M is more than or equal to 1; the device comprises a current measuring tool and an upper computer which are in wireless communication connection, wherein the current measuring tool is provided with at least M sets of current measuring tools; the method comprises the following steps:

each phase of the tested conductor is provided with a corresponding set of the current measuring tools, wherein one set of the current measuring tools is configured as a first current measuring tool for intercepting a header mark point and a tail mark point of a theoretical interception interval of current, and the theoretical interception interval corresponds to a current wave band in 1 period of intercepted current;

the first current measuring means identifies a header point of the intercepted current and transmits a first trigger signal indicating when the first current measuring means identifies the header point of the intercepted currentIs carved as t₁Time of day; the upper computer receives the first trigger signal and sends a synchronous measurement starting signal;

all current measuring means receive and respond to the synchronous start measuring signal, and the time when the current measuring means respond to the synchronous measuring signal is recorded as t₂Time of day from t₂At the beginning of the moment, the current measuring means is at intervals of time t₃Sampling and measuring the instantaneous current of the matched tested wire, and sending a current measurement data signal; the upper computer receives the current measurement data signal;

the first current measuring tool identifies the tail mark point of the intercepted current and sends a second trigger signal, and the moment when the first current measuring tool identifies the tail mark point of the intercepted current is marked as t₄Time of day; the upper computer receives the second trigger signal at t₂Time to t₄In the time interval, the phase difference between the instantaneous voltage and the instantaneous current of the derived current sampled by the current measuring tool at the (n + 1) th time is

9. The method of claim 8, wherein M.gtoreq.2.

10. The electrical energy measurement method of claim 8, wherein the current measurement data signal encodes instantaneous current data of the derived current, identification code data of the current measurement tool corresponding thereto, and instantaneous current collection time data corresponding thereto.

Technical Field

The invention relates to the technical field of current measurement, in particular to a current measuring tool.

The invention relates to the technical field of electric energy measurement or power measurement, in particular to an electric energy measurement system and an electric energy measurement method, which can be applied to the scenes of alternating current measurement, electric energy meter verification and the like.

Background

The electric energy meter is a fixed electric energy measuring device. In order to correct the metering accuracy of the electric energy meter, the electric energy meter needs to be detached and moved into a standard test environment to detect the metering accuracy of the electric energy meter. During this period, the user end should not get electricity, and the electricity metering personnel are also greatly inconvenient.

At present, use current clamp and on-the-spot check gauge cooperation to use, can be under the condition of not tearing open the electric energy meter and proofread and correct the measurement accuracy of electric energy meter. In order to enhance the metering accuracy of the electric energy meter, a current clamp matched with the original current magnitude in the tested lead needs to be selected, so that the current clamp is not suitable for being integrally arranged with a field calibrator, and a proper current clamp can be selected according to the requirement. However, the current clamp and the on-site calibrator have more connecting wires, high wiring difficulty and high danger in use.

Disclosure of Invention

The invention aims to provide an electric energy measuring system and an electric energy measuring method, and aims to solve the technical problem that the existing non-fixed electric energy measuring equipment cannot give consideration to metering accuracy, use range and use convenience.

Taking the power supply frequency as 50Hz as an example, when a person skilled in the art uses a field calibrator to obtain the metering accuracy of the electric energy meter, the default measurement period is 0.02 s. The inventor imagines that the current clamp is in wireless communication connection with the field calibrator, so that the current clamp can be selected as required, and the convenience in use can be improved. However, wireless communication causes signal transmission delay, which is serious for devices that measure power at such a high frequency as to sample instantaneous current, instantaneous voltage, and involve the phase angle of the instantaneous current.

In order to realize the electric energy measuring system, the invention also provides a current measuring tool.

In order to solve the technical problems, the following technical scheme can be selected according to the needs:

a current measuring tool comprises a non-contact current sensor, a current sampling circuit, a marking point identification circuit, a controller and a tool side wireless communication module; the non-contact current sensor is used for outputting derivative current related to original current in a tested lead; the current sampling circuit is used for outputting a first signal corresponding to the derived current; the mark point identification circuit is used for identifying a header mark point and a tail mark point of a theoretical interception interval of the derived current, wherein the theoretical interception interval corresponds to a first signal in 1 period of the derived current; the tool side wireless communication module is used for receiving a current measurement instruction and sending a second signal corresponding to the original current or the derived current in the theoretical interception interval.

Preferably, the non-contact current sensor is an open-close type precision transformer.

Preferably, the mark point identification circuit is a zero-crossing detection circuit.

Preferably, the output end of the mark point identification circuit is electrically connected with an interrupt pin of the controller.

Preferably, the tool-side wireless communication module has an enable pin, and the controller is electrically connected to the enable pin.

Preferably, the power supply device further comprises a battery for supplying power to the non-contact current sensor, the current sampling circuit, the mark point identification circuit, the controller and the tool side wireless communication module, or further comprises a battery compartment for installing a battery for supplying power to the non-contact current sensor, the current sampling circuit, the mark point identification circuit, the controller and the tool side wireless communication module.

The utility model provides an electric energy measurement system, includes host computer and aforementioned current measurement instrument, current measurement instrument with host computer wireless communication connects.

Preferably, the electric energy measuring system is used for measuring the power of M-phase electric equipment, M is larger than or equal to 1, the current measuring tools are at least M sets, and the current measuring tools are in wireless communication connection with one set of the upper computer.

Preferably, the upper computer is a field calibrator with an upper computer side wireless communication module.

An electric energy measuring method comprising the steps of:

acquiring derivative current corresponding to original current in a tested wire;

identifying a header point, time t, of said derived current₁Setting the phase angle of the header mark point of the derived current as

From t₂At the beginning of the moment, every time period t₃Sampling an instantaneous current of the derived current;

identifying the tail mark point of said derived current, time t₄Time of day; the duration between the leading and trailing marker points corresponds to 1 cycle of the derived current;

wherein at t₂Time to t₄In the time interval, the phase difference between the instantaneous voltage and the instantaneous current of the derivative current sampled for the (n + 1) th time is

An electric energy measuring method is used for measuring the power of M-phase electric equipment, wherein M is more than or equal to 1; the device comprises a current measuring tool and an upper computer which are in wireless communication connection, wherein the current measuring tool is provided with at least M sets, and the current measuring tools are in wireless communication connection with one set of the upper computer; the method comprises the following steps:

each phase of the tested conductor is provided with a corresponding set of the current measuring tools, wherein one set of the current measuring tools is configured as a first current measuring tool for intercepting a header mark point and a tail mark point of a theoretical interception interval of current, and the theoretical interception interval corresponds to a current wave band in 1 period of intercepted current;

the first current measuring tool identifies the header mark point of the intercepted current and sends a first trigger signal, and the time when the first current measuring tool identifies the header mark point of the intercepted current is t₁Setting the phase angle of the header mark point of the derived current asThe upper computer receives the first trigger signal and sends a synchronous measurement starting signal;

all current measuring means receive and respond to the synchronous start measuring signal, and the time when the current measuring means respond to the synchronous measuring signal is recorded as t₂Time of day from t₂At the beginning of the moment, the current measuring means is at intervals of time t₃Sampling and measuring the instantaneous current of the matched tested wire, and sending a current measurement data signal; the upper computer receives the current measurement data signal;

the first current measuring tool identifies the tail mark point of the intercepted current and sends a second trigger signal, and the moment when the first current measuring tool identifies the tail mark point of the intercepted current is marked as t₄Time of day; the upper computer receives the second trigger signal at t₂Time to t₄In the time interval, the phase difference between the instantaneous voltage and the instantaneous current of the derived current sampled by the current measuring tool at the (n + 1) th time is

Preferably, M is greater than or equal to 2.

Preferably, the current measurement data signal encodes instantaneous current data of the derived current, identification code data of a current measurement tool corresponding to the current measurement data signal, and instantaneous current collection time data corresponding to the identification code data.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention uses a non-contact current sensor to sense the original current in a tested lead to obtain the derived current, and identifies the header mark point and the tail mark point of the derived current through the mark point identification circuit so as to determine the period duration of the derived current. The non-contact current sensor is convenient for measuring original current in a measured wire in a non-fixed mode, a wireless communication mode of the tool side wireless communication module can reduce signal cables, the accuracy, the application range and the use convenience of current measurement are considered, and instant current data related to derived current is sent by receiving a current measurement instruction, so that the non-contact current sensor is matched with an upper computer or other current measuring tools for use.

2. The output end of the mark point identification circuit is electrically connected with an interrupt pin of the controller, so that the measurement time difference of a current measurement tool can be reduced, more sampling data of derived current corresponding to the original current can be obtained, and the metering accuracy of electric energy can be improved.

3. The controller is connected with the full-function pin of the tool side wireless communication module, and data of derived current corresponding to the original current in a theoretical interception interval can be accurately sent.

4. Batteries are understood to be a broad range of batteries including rechargeable batteries, disposable batteries, and battery compartments refer to compartments into which the batteries may be mounted. In this way, the battery flow tool can be fully enabled for wireless connection with other devices.

5. The current measuring tool is matched with the upper computer through wireless communication connection to form a complete electric energy measuring system, wherein the wireless communication connection replaces the existing signal cable, so that the number of cables is reduced, and the electric energy measuring system can give consideration to the metering accuracy, the use range and the use convenience.

6. The command delay in the wireless communication process may cause the actual intercept interval of the power measurement not to be equal to the theoretical intercept interval, thereby causing an error. The method can reduce the error in the process of measuring the electric energy by measuring the instantaneous current of the nth sampling derived current and the corresponding phase angle thereof.

7. Generally, alternating current has a fraction of one phase of electricity and three phases of electricity. When measuring the current of three-phase electricity, the synchronization of three sets of current measuring tools is particularly important. The upper computer instructs the current measuring tool to start measuring the original current, and the current measuring tool obtains the instantaneous current and the phase angle of the original current or the derived current and then sends the instantaneous current and the phase angle to the upper computer. And processing the sampled instantaneous current and phase angle by the upper computer to obtain electric energy data.

8. When the current measurement data signal codes instantaneous current data of derived current, identification code data of a current measurement tool corresponding to the instantaneous current measurement data signal and instantaneous current acquisition time data corresponding to the instantaneous current measurement tool, a wireless communication data frame and specific equipment for acquiring the data can be determined. The inventor tests that the wireless communication channel is occupied by adding the heartbeat packet communication in the wireless communication, and data delay exists in wireless transmission of wireless communication interrupt signals and data.

Drawings

FIG. 1 is a circuit diagram of a charging circuit for a battery of the current measuring tool of the present invention.

Fig. 2 is a discharge circuit diagram of a battery of the current measuring tool of the present invention.

FIG. 3 is a circuit diagram of a controller of the current measurement tool of the present invention.

Fig. 4 is a circuit diagram of the current sampling circuit and the mark point identification circuit of the current measuring tool of the present invention.

Fig. 5 shows a time-dependent variation of the derived current, zero-crossing interrupt signal of the current measuring method of the invention.

Detailed Description

The present invention is described below in terms of embodiments in conjunction with the accompanying drawings to assist those skilled in the art in understanding and implementing the present invention. Unless otherwise indicated, the following embodiments and technical terms therein should not be understood to depart from the background of the technical knowledge in the technical field.

First part of the invention:

a current measurement tool, see fig. 1-4, includes a non-contact current sensor, a current sampling circuit, a marker identification circuit, a controller, and a tool-side wireless communication module. According to the requirement, the current measuring tool can further comprise a battery used for supplying power to the non-contact current sensor, the current sampling circuit, the marking point identification circuit, the controller and the tool side wireless communication module, or the current measuring tool can further comprise a battery cabin used for installing the battery, and the battery is used for supplying power to the non-contact current sensor, the current sampling circuit, the marking point identification circuit, the controller and the tool side wireless communication module.

The non-contact current sensor is used for outputting derivative current related to original current in a tested lead. The non-contact current sensor can be an open-close type precision transformer. The open-close type precision mutual inductor is a mutual inductor for an instrument which can be opened and closed, so that the non-contact current sensor is conveniently sleeved on a measured wire. Taking an open-close type precision transformer as an example, when the open-close type precision transformer is sleeved on a measured wire, the open-close type precision transformer can induce an original current passing through the measured wire and generate a derivative current, and the derivative current is a secondary current which is reduced by times generally, namely the derivative current is an analog signal. When the original current in the tested wire is an alternating current, the analog signal is also an alternating signal.

The current sampling circuit is used for outputting a first signal corresponding to the derived current. The current acquisition circuit comprises a signal amplification circuit and an analog-to-digital conversion circuit, and the first signal is a digital signal. In practical application, the current acquisition circuit can exist independently or be integrated in a non-contact current sensor; the signal amplification circuit can be integrated in the non-contact current sensor; the analog-to-digital conversion circuit may also be integrated in the controller. Referring to fig. 4, the output terminal pins 2 and 5 of the non-contact current sensor are electrically connected to the input terminal of the differential proportional circuit, and the resistor R111 of the differential proportional circuit is a standard resistor. Taking the original current in the open-close type precision mutual inductor and the tested lead as the alternating current as an example, the power supply ends of the differentiator are respectively connected with bipolar positive and negative voltages. The output end of the differential proportional circuit is electrically connected with the analog input end of the analog-to-digital conversion circuit, and the digital output end of the analog-to-digital conversion circuit is electrically connected with the GPIO pin of the controller.

The mark point identification circuit is used for identifying a header mark point and a tail mark point of a theoretical interception interval of the derived current, and the theoretical interception interval corresponds to a first signal in 1 period of the derived current. Also taking an open-close type precision transformer as an example, 1 cycle of the derived current identified by the marking point identification circuit also corresponds to one cycle of the original current in the tested lead. The mark point identification circuit may select a zero-cross detection circuit. Referring to fig. 4, the zero-crossing detection circuit includes a comparator, an inverting input terminal of the comparator is electrically connected to an output terminal of the differential proportional circuit, the inverting input terminal of the comparator is also connected in parallel with a grounded high-frequency filter capacitor C113, a non-inverting input terminal of the comparator is grounded, and an output terminal of the comparator is electrically connected to a GPIO pin of the controller.

The tool side wireless communication module is used for receiving a current measurement instruction and sending a second signal corresponding to the original current or the derived current in the theoretical interception interval. The controller can be selected from CC2540 type controller, which is provided with Bluetooth and infrared wireless communication module. Because the original current and the derived current have a corresponding relationship, the controller and the tool side wireless communication module can encode the first signal corresponding to the derived current within 1 cycle into the second signal, and the second signal can correspond to the original current data and the derived current data. The voltage of the GPIO pin of the CC2540 type controller is 3.3V, and if the output terminal of the analog-to-digital converter is at a high level of 5.0V, the voltage level can be converted by a digital isolator, for example, the ADUM5402 in fig. 4 is a four-channel digital isolator.

Fig. 1 shows a circuit diagram for charging a rechargeable battery, which should be understood broadly in terms of its function, and which may be a battery, a lithium battery, a nickel metal hydride battery, a 18650 battery, or the like. FIG. 2 shows a discharge circuit diagram of a battery, in which VDD _4.2V and VEE _4.2V form bipolar positive and negative voltages.

Non-rechargeable batteries are also to be understood in a broad sense of function and may be alkaline batteries, button cells.

Preferably, the output end of the mark point identification circuit is electrically connected with an interrupt pin of the controller. Referring to fig. 3, the controller selects CC2540, whose P2.0 and P2.1 can be used as interrupt pins.

Preferably, the tool-side wireless communication module has an enable pin, and the controller is electrically connected to the enable pin.

In fig. 4, a feedback circuit composed of a differential is connected to the pin 4, the pin 7, and the pin 8 of the open-close type precision transformer, and is used for correcting a phase angle offset between an output induced current and an original current caused by leakage flux of the open-close type precision transformer.

Second part of the invention

An electric energy measuring system comprises an upper computer and a current measuring tool of the first part of the invention, wherein the current measuring tool is in wireless communication connection with the upper computer.

It should be understood that when the power measuring system measures the consumed power of the load, it can also be understood as the power of the load.

Preferably, the electric energy measuring system is used for measuring the power of M-phase electric equipment, wherein M is greater than or equal to 1, taking the current national standard alternating current in China as an example, the electric energy measuring system has single-phase alternating current power supply, voltage is 220V, frequency is 50Hz, and namely M is 1; there is also a three-phase ac supply, 380V, at a frequency of 50Hz, i.e. M3. Of course, M may also be other non-zero natural numbers in non-standard electrical systems. At this time, the current measuring tools have at least M sets, and the current measuring tools are in wireless communication connection with one set of the upper computer. Optimally, M is more than or equal to 2, and at the moment, when the electric energy measuring system is used, the synchronous connection between the upper computer and the current measuring tools is particularly important.

Preferably, the upper computer is a field calibrator with an upper computer side wireless communication module. The upper computer side wireless communication module is to be matched with the tool side wireless communication module. The on-site calibrator belongs to a metering calibration tool, and in the prior art, the calibrator can comprise at least one function of on-site calibration of an electric energy meter, electricity utilization inspection, electric parameter test, vector analysis, harmonic test, CT (computed tomography) transformation ratio test and a portable oscilloscope according to requirements. When the device is used, the current measuring tool obtains the instantaneous current and the corresponding phase of the original current in the measured wire, the field calibrator obtains the voltage loaded in the measured wire, and the electric energy data is obtained through an active power calculation formula or a reactive power calculation formula.

Third part of the invention

An electric energy measuring method is used for measuring the power of M-phase electric equipment, wherein M is more than or equal to 1; taking the current national standard alternating current in China as an example, the alternating current is supplied by single-phase alternating current, the voltage is 220V, the frequency is 50Hz, and M is 1; there is also a three-phase ac supply, 380V, at a frequency of 50Hz, i.e. M3. Of course, M may also be other non-zero natural numbers in non-standard electrical systems.

The electric energy measuring method comprises a current measuring tool and an upper computer which are in wireless communication connection, wherein the current measuring tool is provided with at least M sets, and the current measuring tools are in wireless communication connection with one set of the upper computer; the method comprises the following steps:

each phase of the tested conductor is provided with a corresponding set of the current measuring tools, wherein one set of the current measuring tools is configured as a first current measuring tool for intercepting a header mark point and a tail mark point of a theoretical interception interval of the current, and the theoretical interception interval corresponds to a current wave band in 1 period of the intercepted current;

the first current measuring tool identifies the header mark point of the intercepted current and sends a first trigger signal, and the time when the first current measuring tool identifies the header mark point of the intercepted current is t₁Setting the phase angle of the header mark point of the derived current asThe upper computer receives the first trigger signal and sends a synchronous measurement starting signal;

all current measuring means receive and respond to the synchronous start measuring signal, and the time when the current measuring means respond to the synchronous measuring signal is recorded as t₂Time of day from t₂At the beginning of the moment, the current measuring means is at intervals of time t₃Sampling and measuring the instantaneous current of the matched tested wire, and sending a current measurement data signal; the upper computer receives the current measurement data signal;

the first current measuring tool identifies the tail mark point of the intercepted current and sends a second trigger signal, and the moment when the first current measuring tool identifies the tail mark point of the intercepted current is marked as t₄Time of day; the upper computer receives the second trigger signal at t₂Time to t₄In the time interval, the phase difference between the instantaneous voltage and the instantaneous current of the derived current sampled by the current measuring tool at the (n + 1) th time is

The following describes the method of measuring electric energy according to the present invention, taking the example that the electric energy measuring system described in the second part of the present invention measures the original current generated by the alternating current with the frequency of 50Hz passing through the measured wire. The non-contact current sensor selects a current transformer, the mark point identification circuit selects a zero-crossing detection circuit, the upper computer selects a field transformer with an upper computer side wireless communication module, and the upper computer side wireless communication module is in wireless communication connection with the tool side wireless communication module.

If the power supply voltage of the load is single-phase alternating current, sleeving a current transformer of the first current measuring tool on a live wire or a zero wire; if the power supply voltage of the load is three-phase alternating current, the current transformer of the first current measuring tool is sleeved on one live wire, and the current transformers of the other two sets of current measuring tools are sleeved on the other two live wires.

The theoretical interception interval of the current intercepted by the first current measuring tool is a first signal in 1 period of an analog signal output by the differential proportional circuit, theoretically, the analog signal output by the differential proportional circuit is equal to a waveform obtained by amplifying a waveform of a derivative current in an equal time in an amplitude direction, and the derivative current is equal to a waveform obtained by reducing a waveform of an original current passing through a measured wire in an equal time in an amplitude direction, that is, 1 period of the current intercepted by the first current measuring tool is equal to 1 period of the derivative current and 1 period of the original current.

The leading and trailing marking points detected by the zero-cross detection circuits shown in fig. 3 and 4 are both the time when the current passes through the 0 voltage point. When the zero-crossing detection circuit detects the head and tail marking points of the current, the t is recorded₁At the moment, the phase angle of the derived current header mark point isThe zero-crossing detection circuit abruptly changes the output voltage from a high level to a low level, the signal corresponding to an interrupt of the controllerAnd after the controller receives the interrupt signal, a first trigger signal is sent out through the tool side wireless communication module. Preferably, after the controller receives the interrupt signal, the controller controls the tool side wireless communication module to start wireless communication with an upper computer side wireless communication module of the upper computer;

and after receiving the first trigger signal, the upper computer sends a synchronous measurement starting signal.

All current measuring means receive and respond to the synchronous start measuring signal, noting that the current measuring means responds to the synchronous measuring signal at the time t₂Time of day from t₂At the beginning of the moment, the current measuring means is at intervals of time t₃Sampling and measuring the instantaneous current of the matched tested wire, and sending a current measurement data signal; the upper computer receives the current measurement data signal;

the first current measuring tool identifies the tail mark point of the intercepted current and sends a second trigger signal, and the moment when the first current measuring tool identifies the tail mark point of the intercepted current is marked as t₄Time of day; the second trigger signal may be a communication termination signal or a signal having a flag function.

The upper computer receives the second trigger signal at t₂Time to t₄In the time interval, the phase difference between the instantaneous voltage and the instantaneous current of the derived current sampled by the current measuring tool at the (n + 1) th time is

When M is more than or equal to 2, when the electric energy measuring system is used, the synchronous connection between the upper computer and the current measuring tools is particularly important.

Preferably, the current measurement data signal encodes instantaneous current data of the derived current, identification code data of a current measurement tool corresponding to the current measurement data signal, and instantaneous current collection time data corresponding to the identification code data. The identification code can be an address code or a hardware identification code. It should be understood that the time of the upper computer and each set of current measuring tool should be ensured to be in a synchronous state before use.

On the current measuring tool side, an electrical energy measuring method is represented by comprising the steps of:

acquiring derivative current corresponding to original current in a tested wire;

identifying a header point, time t, of said derived current₁Setting the phase angle of the header mark point of the derived current as

From t₂At the beginning of the moment, every time period t₃Sampling an instantaneous current of the derived current;

identifying the tail mark point of said derived current, time t₄Time of day; the duration between the leading and trailing marker points corresponds to 1 cycle of the derived current;

wherein at t₂Time to t₄In the time interval, the phase difference between the instantaneous voltage and the instantaneous current of the derivative current sampled for the (n + 1) th time isAt t₂The instant is the instantaneous current of the first sampled derived current.

The invention is described in detail above with reference to the figures and examples. It should be understood that in practice it is not intended to be exhaustive of all possible embodiments, and the inventive concepts of the present invention are presented herein by way of illustration. Without departing from the inventive concept of the present invention and without any creative work, a person skilled in the art should, in all of the embodiments, make optional combinations of technical features and experimental changes of specific parameters, or make a routine replacement of the disclosed technical means by using the prior art in the technical field to form specific embodiments, which belong to the content implicitly disclosed by the present invention.