Method and system for calibrating an electric energy meter

Abstract

The present application belongs to the technical field of wireless communication and electric energy meter, and particularly relates to an electric energy meter calibration method and system, comprising: establishing a Bluetooth connection between a calibration station and an electric energy meter to be calibrated, and then transmitting data through a first transmission channel or a second transmission channel; the first transmission channel is a broadcast synchronization channel; the second transmission channel is a CIS connection synchronization channel; the electric energy meter to be calibrated collects electric energy meter pulse signals according to a meter calibration command sent by the calibration station, and broadcasts the collected electric energy meter pulse signals through the broadcast synchronization channel, or sends the collected electric energy meter pulse signals to the calibration station through the CIS connection synchronization channel; the calibration station restores the pulse signals received from the corresponding channel, and calibrates the electric energy meter to be calibrated according to the restored pulse signals. Thus, the present application solves the problem of interruption of other Bluetooth channels caused by the use of private wireless communication to transmit calibration pulse data in order to improve calibration efficiency in the prior art.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of wireless communication and electric energy meter, and particularly relates to an electric energy meter calibration method and system. BACKGROUND

[0002] At present, when the smart electric energy meter is calibrated on the platform or the automatic line, the commonly used communication mode is Bluetooth. For example, a method for calibrating the electric energy meter by using low-power Bluetooth communication, that is, after the calibration platform and the electric energy meter to be calibrated establish Bluetooth connection, the calibration platform configures calibration parameters and issues a start calibration command to the electric energy meter to be calibrated by using an asynchronous connection-oriented link (ACL). However, when the Bluetooth ACL link transmits data, the communication time delay is not fixed, and the continuous transmission of the calibration pulse data by using the ACL link will greatly affect the calibration accuracy. In order to maintain the calibration accuracy, some schemes use a private wireless communication mode to transmit the calibration pulse data. For example, the Bluetooth wireless mode is used to avoid the wiring operation required by the previous calibration mode based on the pulse signal or infrared, thereby improving the calibration efficiency, and the method has been widely used at present.

[0003] However, the above method still has the following disadvantages. Specifically, because the communication mode is based on ACL, once the private wireless communication mode is used, other devices that have established connection with the electric energy meter by using Bluetooth will interrupt the Bluetooth connection, and the normal data service communication function with the electric energy meter needs to be disabled. In the field application of the electric energy meter, the Bluetooth channel needs to be connected and communicated with the circuit breaker, the field detection terminal, the fault analysis instrument and the sensor, and the start of the pulse calibration of the electric energy meter based on Bluetooth will inevitably interrupt the normal execution of these devices. SUMMARY

[0004] The purpose of the present application is to provide an electric energy meter calibration method and system to solve the problem that the private wireless communication mode is used to transmit the calibration pulse data in order to improve the calibration efficiency in the prior art, thereby interrupting other Bluetooth channels.

[0005] To solve the above technical problems, the technical solutions provided by the present application and the beneficial effects corresponding to the technical solutions are as follows:

[0006] The electric energy meter calibration method of the present application comprises the following steps:

[0007] 1) Establishing Bluetooth connection between the calibration platform and the electric energy meter to be calibrated; transmitting data between the calibration platform and the electric energy meter to be calibrated by using a first transmission channel or a second transmission channel; the first transmission channel is a broadcast synchronization channel; and the second transmission channel is a CIS connection synchronization channel established between the calibration platform and the electric energy meter to be calibrated after the Bluetooth connection is established;

[0008] 2) after the connection is established, the testing table sends a meter testing command to the meter to be tested;

[0009] 3) the meter to be tested collects the meter pulse signals according to the meter testing command, and broadcasts the collected meter pulse signals through a broadcast synchronization channel to be synchronously transmitted to the testing table, or sends the collected meter pulse signals to the testing table through the CIS connection synchronization channel; the testing table restores the pulse signals received from the corresponding channel, and tests the meter to be tested according to the restored pulse signals.

[0010] The beneficial effects of the above technical solutions are that the CIS connection synchronization channel or the broadcast synchronization channel is used to transmit the collected meter pulse signals, the testing table restores the pulse signals received from the corresponding channel, and tests the meter to be tested according to the restored pulse signals, so that the meter pulse testing requirements can be met, and the Bluetooth of the meter to be tested can continue to communicate with other external devices based on the ACL channel during the testing process, without affecting the normal operation of other services.

[0011] Further, in order to improve the transmission speed of the pulse data, the CIS connection synchronization channel established in step 1) has at least two channels, which are used to simultaneously test at least two pulse signals; or the testing table initiates at least two meter testing commands to the meter to be tested in step 2), and the meter to be tested broadcasts the collected at least two meter pulse signals through at least two corresponding broadcast synchronization channels in step 3), which are used to simultaneously test at least two pulse signals.

[0012] Further, in order to test multiple pulse signals, the meter to be tested samples and encodes the multiple pulse signals according to the meter testing command in step 3), wherein one bit in one encoding byte represents the high or low level state of one pulse signal at the current time, the sampling and encoding data in a set time period are sent to the testing table in the form of CIS data stream through the CIS connection synchronization channel, or the sampling and encoding data in a set time period are broadcasted in the form of BIS synchronization data stream through the broadcast synchronization channel; the testing table decodes the data stream after receiving the data stream to output each bit information, and restores the state of each pulse signal of the meter to be tested according to each bit information.

[0013] Further, in step 3), the energy meter to be tested outputs the corresponding pulse signal to the pulse signal output terminal of the energy meter according to the type information contained in the test command for sampling and encoding to obtain an encoded signal. During encoding, 8-bit binary data is used to represent the voltage amplitude of the signal. Then, the encoded signal within the set time period is sent to the testing station through the CIS connection synchronization channel as a CIS data stream, or the encoded signal within the set time period is broadcast through the broadcast synchronization channel as a BIS synchronization data stream. After receiving the data stream, the testing station performs decoding operations on the data stream, including fixed delay and digital-to-analog conversion, to restore the voltage waveform of the pulse output pin of the energy meter to be tested.

[0014] Furthermore, after the energy meter under test has been tested, the testing station sends a stop testing command to the energy meter. If the CIS synchronization channel exists, the testing station initiates the cancellation of the CIS synchronization channel. If the broadcast synchronization channel exists, the energy meter under test stops sending data streams on the broadcast synchronization channel after receiving the stop testing command, and the energy meter testing process ends.

[0015] Furthermore, in step 2), the testing station sends a test command to the energy meter to be tested via the ACL link.

[0016] Furthermore, when using CIS to connect the synchronous channel for pulse signal transmission, the CIS Event contains three sub_events arranged in equal time. For the energy meter end, each sub_event contains one transmit time slot for transmitting meter calibration data and one receive time slot for receiving acknowledgment messages.

[0017] When using a broadcast synchronization channel for pulse signal transmission, the AuxPtr field of the ADV_EXT_IND message of the broadcast synchronization channel leads to the auxiliary broadcast message AUX_ADV_IND on the second channel. The SyncInfo field of the auxiliary broadcast message AUX_ADV_IND describes the channel, time point, and time interval parameters of the auxiliary broadcast message AUX_SYNC_IND. The calibration station receives the auxiliary broadcast message AUX_SYNC_IND at the specified channel and time offset position, and then receives the BIS synchronization data stream on a specific Isochronous channel based on the AUX_SYNC_IND information.

[0018] To address the aforementioned problems, this invention provides an energy meter calibration system. The system includes a calibration platform, a first Bluetooth module, and a second Bluetooth module. The first Bluetooth module is located on the calibration platform. The second Bluetooth module is located on the energy meter to be calibrated, establishing a Bluetooth connection between the calibration platform and the energy meter. The system is characterized by a CIS (Content Information System) synchronization channel between the first and second Bluetooth modules. The second Bluetooth module transmits the collected pulse signal from the energy meter to be calibrated to the first Bluetooth module via the CIS synchronization channel or synchronously transmits it to the calibration platform via a broadcast synchronization channel. The first Bluetooth module receives the pulse signal from the corresponding channel. The calibration platform restores the pulse signal received by the first Bluetooth module and calibrates the energy meter based on the restored pulse signal.

[0019] Furthermore, in order to improve the efficiency of data transmission, there are at least two CIS connection synchronization channels established between the first Bluetooth module and the second Bluetooth module, or at least two broadcast synchronization channels initiated by the second Bluetooth module, for the simultaneous detection of multiple pulse signals.

[0020] Furthermore, the second Bluetooth module includes an encoder, which encodes the collected multi-channel pulse signals and then transmits them out as a data stream through the CIS connection synchronization channel or broadcast synchronization channel; during encoding, each bit in each encoded byte represents the high and low level state of each pulse signal at the current moment;

[0021] The first Bluetooth module includes a decoder, which decodes the received data stream and outputs each bit of information, and restores the state of each pulse signal of the energy meter to be tested based on each bit of information. Attached Figure Description

[0022] Figure 1 This is a flowchart of the energy meter verification method corresponding to the pulse signal transmitted via a broadcast synchronization channel in System Embodiment 1 of the present invention;

[0023] Figure 2 This is a flowchart of the energy meter verification method corresponding to the CIS connection synchronous channel transmission pulse signal in system embodiment 2 of the present invention;

[0024] Figure 3 This is a schematic diagram of the communication between the tested energy meter and the testing platform on the broadcast synchronization channel (BIG / BIS) in System Embodiment 1 of the present invention;

[0025] Figure 4 This is a schematic diagram of the communication between the tested energy meter and the testing platform on the connection synchronization channel CIS in system embodiment 2 of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0027] System Implementation Example 1:

[0028] The principle used in this invention is as follows:

[0029] This invention, based on the Bluetooth LE Audio Broadcast Synchronous Channel (BIG / BIS) feature released in Bluetooth 5.x, proposes a method and system for verifying energy meters by transmitting pulse signals from the energy meter under test via the broadcast synchronous channel. Bluetooth LE Audio defines a time-dependent data transmission channel and strategy. The LE Audio Broadcast Synchronous Channel (BIG / BIS) is based on Bluetooth Low Energy's Periodic Advertising technology, implementing audio transmission on the Broadcast Isochronous Channel (BIG / BIS). The broadcast synchronous channel is generally used to unidirectionally transmit digital audio streams at fixed time intervals on physical channels (a total of 37). A Broadcast Isochronous Group (BIG) can contain up to 31 Broadcast Isochronous Streams (BIS). Periodic Advertising was introduced in Bluetooth 5.0, which also introduced Extended Advertising; Periodic Advertising is an application of Extended Advertising. Extended Broadcast carries eight times more data than traditional Broadcast (Bluetooth 4.0), increasing the transmittable data size from 31 bytes to 255 bytes. Traditional Broadcast uses only three broadcast channels (37, 38, and 39), while Extended Broadcast uses two sets of broadcast channels: the primary advertising channel and the secondary advertising channel. The primary advertising channel also uses the three channels defined in Bluetooth 4.0 (37, 38, and 39), while the secondary advertising channel uses the remaining 37 data channels.

[0030] Periodic broadcasting allows connectionless broadcast data to be sent at fixed intervals, where the broadcast data can be varied between these intervals. One or more scanners can then listen for these broadcasts. It is a form of multicast. Compared to other broadcast modes, its advantages include a fixed transmission interval, the ability for scanners to sleep between broadcast events, and suitability for applications requiring isochronous propagation. The timing of periodic broadcasting is established as follows... Figure 3As shown, firstly, an ADV_EXT_IND message is sent on the main broadcast channels (channels 37, 38, and 39). The AuxPtr field of this message is used to generate a secondary broadcast message AUX_ADV_IND on the second channel. The SyncInfo field of this message describes the location (channel, time point) and time interval parameters of the AUX_SYNC_IND message. This AUX_SYNC_IND message is crucial for periodic broadcasting and carries data. At this point, it uses the data channel instead of the broadcast channel. The broadcast isochronous channel is based on periodic broadcasting. The ACAD field in the AUX_SYNC_IND message in the periodic broadcast is used to carry the BIGInfo of the BIG. If the synchronization receiver wants to receive the BIG isochronous synchronization data stream information, it needs to first obtain the BIGInfo, which contains all the parameter information of the BIG. Then, based on the BIGInfo, it listens for the BIS synchronization data stream in the BIG on a specific isochronous channel. For example... Figure 3 As shown, the LE Audio Broadcast Synchronization Channel (BIG / BIS) has the characteristics of one-way broadcasting and isochronous synchronization. Each BIG can contain up to 31 BIS synchronization data streams, which are used for LE Audio broadcast audio transmission. This invention is based on the inherent synchronization characteristics of the LE Audio Broadcast Synchronization Channel (BIG / BIS) to transmit the pulse signal of the energy meter to the testing platform.

[0031] Based on the above principles, this invention provides an energy meter calibration system, which includes a calibration platform (calibration platform body), a first Bluetooth module, and a second Bluetooth module. The first Bluetooth module is disposed at the calibration platform end; the second Bluetooth module is disposed at the energy meter to be calibrated end to establish a Bluetooth connection between the calibration platform and the energy meter to be calibrated. The second Bluetooth module is used to broadcast the collected pulse signal of the energy meter to be calibrated through a broadcast synchronization channel for synchronous transmission to the calibration platform; the first Bluetooth module is used to receive the pulse signal from the corresponding channel; the calibration platform restores the received pulse signal and calibrates the energy meter to be calibrated based on the restored pulse signal.

[0032] During specific testing, the accuracy of the electricity meter's energy metering and clocking functions is determined by comparing the pulse generation intervals. The metering accuracy is tested by measuring the electricity consumption over a period of time using standard equipment and calculating the cumulative number of pulses output by the meter. The pulses emitted by the electricity meter include: active energy pulses, reactive energy pulses, second pulse output, demand cycle pulses, time period switching pulses, positive harmonic energy pulses, and reverse harmonic energy pulses.

[0033] When acquiring the pulse signal from the energy meter under test, the pulse signal is sampled based on the LE Audio audio input. The energy meter outputs the corresponding pulse signal to its pulse signal output terminal according to the command type. In this embodiment, an 8kHz sampling frequency is used, with each sample represented by an 8-bit binary number, and each channel requires a data "width" of 64kbit per second. The 8kHz sampling rate generates one byte of data every 125µs. A single LEAudio Broadcast Synchronous Data Stream (BIS) message can carry a maximum of 251 bytes of data, with a fixed synchronous transmission interval of 20ms, transmitting 160 bytes of sampled data at a time. Therefore, pulse transmission has a delay. However, since energy meter pulse testing only detects the time interval between pulse edges, the delay does not affect the test results, and the accuracy of the 8kHz sampling frequency meets the pulse testing time interval error requirements for energy meters with an accuracy level not exceeding 0.2S. According to LEAudio's allowable parameters, a delay of 20ms introduces an error of ±16us. This error is an uncertain time caused by clock drift and jitter between the master and slave devices. This error is very small and does not affect the pulse verification time interval error requirement of energy meters with an accuracy of no more than 0.2S.

[0034] After sampling, the data is broadcast via the Bluetooth LE Audio Broadcast Synchronization Channel (BIG / BIS) as a BIS data stream. Upon receiving the data, the testing station decodes it at a frequency of 8kHz to restore the original pulse signal of the energy meter under test.

[0035] like Figure 1 As shown, when the pulse signal of the energy meter under test is transmitted using a broadcast synchronization channel, the system's operation process includes the following steps:

[0036] Step 1: The testing platform initiates and establishes a connection with the Bluetooth on the electricity meter based on the address of the electricity meter to be tested.

[0037] Step 2: After the Bluetooth connection is established, the testing platform sends a start test command (test command) to the energy meter under test via Bluetooth service. After receiving a response from the energy meter under test, the testing platform begins the test process.

[0038] Step 3: During the meter testing process, the pulse code data of the tested energy meter is transmitted to the testing platform as a BIS synchronous data stream through the broadcast synchronization channel and is restored to the original pulse.

[0039] like Figure 3As shown, after receiving the response, the testing station first searches for the ADV_EXT_IND message of the LE Audio Broadcast Synchronization Channel (BIG / BIS) on the broadcast channel. The AuxPtr field of the message is used to extract the auxiliary broadcast message AUX_ADV_IND on the second channel. The SyncInfo field of this message describes the channel, time point, and time interval parameters of the AUX_SYNC_IND message. Then, the testing station receives the AUX_SYNC_IND message at the specified channel and time offset position. The AUX_SYNC_IND message is a periodic broadcast message. The ACAD field in the AUX_SYNC_IND message carries the BIGInfo of the BIG. The BIGInfo contains all the parameter information of the BIG. The testing station then receives the BIS synchronization data stream from the BIG on a specific Isochronous channel based on the BIGInfo. In other embodiments, in step 2, the testing station sends a multi-channel testing command to the energy meter to be tested, and in step 3, the energy meter to be tested collects multiple energy meter pulse signals, and then broadcasts them through a one-to-one corresponding broadcast synchronization channel, thereby simultaneously testing multiple pulse signals.

[0040] Step 4: After the verification is completed, the verification platform sends a stop verification command to the tested energy meter via Bluetooth service. Upon receiving the command, the tested energy meter stops sending data through the LE Audio broadcast synchronization channel, and the energy meter verification process ends.

[0041] In other embodiments, the second Bluetooth module of the present invention uses a "digital" method for encoding and decoding pulse signals. Specifically, the Bluetooth at the energy meter sampling end samples several pulse signals from the energy meter at a sampling frequency of 8kHz, and a maximum of 8 signals can be encoded and transmitted. Each sampled data uses each bit to correspond to one pulse signal, with 0 corresponding to a low level and 1 corresponding to a high level. Thus, an audio transmission byte can encode and represent the state of 8 pulse signals at the current moment in this way. At a sampling frequency of 8kHz, 8 pulse signals are sampled every 125µs and combined and encoded into 1 byte. The above encoding process is completed by an encoder. The LE Audio Broadcast Synchronous Stream (BIS) can carry a maximum of 251 bytes of data per message, with a configurable 20ms synchronization interval. It transmits 160 bytes of sampled data at a time, sending the data as a BIS stream to the Bluetooth module on the testing platform. The Bluetooth module decodes the data at an 8kHz frequency, extracting one byte of data per decode, and outputting the corresponding 8 bits to the corresponding GPIO pins. This process reconstructs the pulse signals from the eight energy meters. The decoding process is performed by the decoder.

[0042] This invention uses an LE Audio broadcast synchronization channel (BIG / BIS) to transmit calibration pulse code information during the calibration process. Automatic synchronization between the Bluetooth master and slave devices and a fixed transmission delay meet the pulse calibration requirements for electricity meters. Simultaneously, during the calibration process, the electricity meter under calibration can still maintain communication with other external devices via the ACL channel, without affecting the normal operation of other services.

[0043] System Implementation Example 2:

[0044] This invention, based on the multi-stream audio feature of Bluetooth LE Audio released in Bluetooth version 5.x, proposes a method and system for verifying energy meters by transmitting pulse signals from the energy meter under test using a CIS synchronization channel. This technology enables the transmission of multiple independent, synchronized audio streams between audio source devices such as smartphones and one or more audio receiving devices such as in-ear headphones or regular headphones. To support multi-stream audio, LE Audio introduces Connected Isochronous Groups (CIGs) and Connected Isochronous Streams (CISs), collectively referred to as Connected Isochronous Channels (CISs). A CIG is created by the master (Link Layer) and contains one or more CIS synchronization channels; a single Bluetooth device can support up to 31 CIS synchronization channels simultaneously. A CIS is a special point-to-point data transmission stream between a master and a slave (Link Layer), featuring isochronous synchronization and automatic acknowledgment and retransmission. Furthermore, the transmission of CIS synchronization data streams can be divided into at least one or more subevents, which are periods in which the master and slave exchange data packets using a specific synchronization connection PDU. For example... Figure 4 As shown, within a CIG, the time interval ISO_Interval for each CIS event is the same, ranging from 5ms to 4s. The time interval Sub_Interval (ranging from SE_Length to ISO_Interval, where SE_Length is MPTM+T_IFS+MPTS+T_MSS, and T_IFS and T_MSS are both 150us) between multiple Subevents (i.e., CIS Data PDU message transmissions) within each CISevent is also the same; the start of each equal-time interval in a CIS is called its anchor point; for example... Figure 4 As shown, the anchor point begins at the first CIS data packet sent from the sender to the receiver. When the receiver receives data, it sends back an acknowledgment message, and this process repeats periodically at equal time intervals. Figure 4In the event of data loss, the sending end will retransmit. For example... Figure 4 As shown, the LE Audio connection synchronization channel CIS is based on Bluetooth connection. Its data transmission has the characteristics of isochronous synchronization and acknowledgment retransmission. Each CIG can contain up to 31 CIS synchronization data streams, which are used for unicast audio transmission of LE Audio. This invention is based on the inherent synchronization characteristics of the LE Audio connection synchronization channel CIS to transmit the pulse signal of the energy meter to the calibration platform.

[0045] Based on the above principles, this invention provides another electricity meter calibration system. The system includes a calibration platform (calibration platform body), a first Bluetooth module, and a second Bluetooth module. The first Bluetooth module is disposed on the calibration platform. The second Bluetooth module is disposed on the electricity meter to be calibrated, establishing a Bluetooth connection between the calibration platform and the electricity meter. A CIS connection synchronization channel is also established between the first and second Bluetooth modules. The second Bluetooth module transmits the collected pulse signal from the electricity meter to be calibrated to the first Bluetooth module through the CIS connection synchronization channel. The first Bluetooth module receives the pulse signal from the corresponding channel. The calibration platform reconstructs the received pulse signal and calibrates the electricity meter based on the reconstructed pulse signal.

[0046] During specific testing, the accuracy of the electricity meter's energy metering and clocking functions is determined by comparing the pulse generation intervals. The metering accuracy is tested by measuring the electricity consumption over a period of time using standard equipment and calculating the cumulative number of pulses output by the meter. The pulses emitted by the electricity meter include: active energy pulses, reactive energy pulses, second pulse output, demand cycle pulses, time period switching pulses, positive harmonic energy pulses, and reverse harmonic energy pulses.

[0047] When acquiring the pulse signal from the energy meter under test, the data sampling of the pulse signal output pin uses an 8kHz sampling frequency. Each sample is represented by an 8-bit binary number, and the required data "width" for each channel is 64kbit per second. Decoding is also performed at an 8kHz frequency to restore the original pulse signal waveform. Furthermore, the 8kHz sampling rate generates one byte of data every 125µs. The LE Audio connection synchronous data stream (CIS) can carry a maximum of 251 bytes of data per message, with a 20ms synchronous transmission interval, transmitting 160 bytes of sampled data at a time. Therefore, there is a delay in pulse transmission. However, since energy meter pulse testing only detects the time interval between pulse edges, the delay does not affect the test results. Moreover, the accuracy of the 8kHz sampling frequency meets the pulse testing time interval error requirements for energy meters with an accuracy level not exceeding 0.2S. Furthermore, according to the LE Audio allowable parameters, there is an error of ±16us for a 20ms delay. This error is an uncertain time caused by clock drift and jitter between the master and slave devices. This error is very small and does not affect the pulse verification time interval error requirement of the energy meter with an accuracy of no more than 0.2S.

[0048] After sampling, the data is transmitted via a CIS connection synchronization channel. The data is then simultaneously sent to the testing platform as a CIS data stream via the Bluetooth LE Audio CIS connection synchronization channel. Upon receiving the data, the testing platform converts it back to the original pulse signal of the energy meter under test using a digital-to-analog converter at the same rate.

[0049] like Figure 2 As shown, when using a CIS connection to transmit the pulse signal of the energy meter under test through a synchronous channel, the system's operation process includes the following steps:

[0050] Step 1: The testing platform initiates and establishes a connection with the Bluetooth on the electricity meter based on the address of the electricity meter to be tested.

[0051] Step 2: After establishing the connection, the testing station initiates the establishment of a CIS connection synchronization channel with the energy meter under test. First, the testing station sends a CIS establishment request (LL_CIS_REQ) to the energy meter under test through the ACL link. After receiving the request, the energy meter under test replies with an LL_CIS_RSP message. After receiving the LL_CIS_RSP reply, the testing station replies with an LL_CIS_IND message to the energy meter under test to create the CIS. During this interaction, the energy meter under test receives the synchronization parameters required for CIS synchronization transmission, and then begins to send and receive CIS synchronization messages.

[0052] In other embodiments, multiple CIS connection synchronization channels are established to simultaneously verify multiple pulse signals.

[0053] Step 3: After the CIS connection synchronization channel is established, the calibration platform sends a start test command to the energy meter under test via Bluetooth service. After receiving the response from the energy meter under test, the calibration platform begins the test process.

[0054] Step 4: During the meter testing process, the pulse code data of the tested energy meter is transmitted to the testing platform through the CIS synchronous data stream and restored to the original pulse.

[0055] like Figure 4 As shown in this example, taking a CIG containing two CISs, namely CIS0 and CIS1, CIS0 carries the calibration pulse code data of the energy meter under test. The CIS0 Event contains three sub_events, which are arranged at the same time according to the sub_interval. For the energy meter end, each sub_event contains one transmit time slot for sending calibration data and one receive time slot for receiving acknowledgment messages. The three sub_events are mainly used to perform retransmission processing when interference occurs. For example, if the first sub_event does not receive an acknowledgment, the second sub_event can be used to retransmit the message, and the third sub_event is used for data retransmission in the same way.

[0056] In this example, such as Figure 4 As shown, the time interval ISO_Interval of the CIS event (with a value range of 5ms-4s) is 20ms. For CIS0, it repeats periodically at 20ms based on the anchor point.

[0057] The energy meter outputs the corresponding pulse signal to its pulse signal output terminal according to the command type. In this example, using an 8kHz sampling frequency, each sample uses an 8-bit binary number to represent its amplitude. The required data "width" for each channel is 64kbit per second. After sampling, the data is then transmitted synchronously to the testing platform via Bluetooth LE Audio and the synchronization channel CIS as a CIS data stream. Upon receiving the data, the testing platform converts it back to the original pulse signal of the energy meter under test using a digital-to-analog converter at the same rate. Furthermore, the 8kHz sampling rate generates one byte of data every 125µs. The Audio Connection Synchronous Stream (CIS) can carry a maximum of 251 bytes of data per message. In this example, with a 20ms synchronization interval, 160 bytes of sampled data are transmitted at a time. Therefore, there is a delay in pulse transmission. However, since the pulse calibration of the energy meter only detects the time interval between the pulse transition edges, the delay does not affect the result of the pulse calibration. Furthermore, the accuracy of the 8kHz sampling frequency can meet the pulse calibration time interval error requirements of energy meters with an accuracy of no more than 0.2S.

[0058] Step 5: After the verification is completed, the verification platform sends a stop verification command to the tested energy meter via Bluetooth service. Upon receiving the command, the tested energy meter stops sending data through the LE Audio connection synchronization channel and replies with an acknowledgment to the verification platform. Upon receiving the acknowledgment, the verification platform cancels the CIS connection synchronization channel and then closes the Bluetooth connection, thus ending the energy meter verification process.

[0059] This invention uses LE Audio to connect to the synchronization channel CIS during the verification process to transmit verification pulse code information. The Bluetooth master and slave devices automatically synchronize, with fixed transmission delay, synchronous transmission, and support for retransmission confirmation, thus meeting the pulse verification requirements for electricity meters. Simultaneously, during the verification process, the electricity meter under verification can still maintain communication with other external devices via the ACL channel, without affecting the normal operation of other services.

[0060] In other embodiments, the second Bluetooth module of the present invention uses a "digital" method for encoding and decoding pulse signals. Specifically, the Bluetooth at the energy meter sampling end samples several pulse signals from the energy meter at a sampling frequency of 8kHz, and a maximum of 8 signals can be encoded and transmitted. Each sampled data uses each bit to correspond to one pulse signal, with 0 corresponding to a low level and 1 corresponding to a high level. Thus, an audio transmission byte can encode and represent the state of 8 pulse signals at the current moment in this way. At a sampling frequency of 8kHz, 8 pulse signals are sampled every 125µs and combined and encoded into 1 byte. The above encoding process is completed by an encoder. The LE Audio Broadcast Synchronous Stream (BIS) and the LEAudio Connection Synchronous Stream (CIS) can each carry a maximum of 251 bytes of data per message. A 20ms synchronization interval can be set, transmitting 160 bytes of sampled data at a time. The data is sent as a CIS data stream to the Bluetooth module on the testing platform. The Bluetooth module decodes the data at an 8kHz frequency, extracting one byte of data per decoder, and outputting the corresponding 8 bits to the corresponding GPIO. This process reconstructs the pulse signals from the eight energy meters. The decoding process is performed by the decoder.

[0061] Throughout the entire process, the voltage waveform on the GPIO pin of the energy meter's pulse output is encoded, transmitted, received, and decoded by the calibration platform. The delay is fixed at 20ms ± 16us, where ± 16us is the uncertain time caused by clock drift and jitter between the master and slave devices. This fixed delay does not affect the meter calibration. The 8kHz pulse resolution of the encoding and decoding meets the accuracy requirements of energy meter pulse calibration with an accuracy not exceeding 0.2S.

[0062] Method Example 1:

[0063] An embodiment of the energy meter calibration method of the present invention, wherein the method uses a broadcast synchronization channel to transmit the pulse signal of the energy meter under test, includes the following steps:

[0064] The calibration platform initiates and establishes a connection with the Bluetooth of the energy meter under test based on the meter's address. After establishing the connection, the calibration platform sends a start calibration command to the energy meter under test via Bluetooth service. Upon receiving a response from the energy meter under test, the calibration platform searches for ADV_EXT_IND messages for LE Audio broadcast synchronization data on the broadcast channel and begins the calibration process. During the calibration process, the energy meter's pulse data is encoded and broadcast through the LE Audio broadcast synchronization channel (BIG / BIS). After the calibration platform receives the encoded pulse data on the LE Audio broadcast synchronization channel, it is restored to the original pulse. After calibration, the calibration platform sends a stop calibration command to the energy meter under test via Bluetooth service. Upon receiving the command, the energy meter stops transmitting data on the LE Audio broadcast synchronization channel, and the energy meter calibration process ends. This method is consistent with the working process of the system in System Embodiment 1, achieving the same effect, and therefore will not be described in detail here. The method of this invention enables pulse-based calibration of energy meters without interrupting other Bluetooth data communications.

[0065] Method Example 2:

[0066] Another embodiment of the energy meter calibration method of the present invention, when the method uses a CIS connection synchronous channel to transmit the pulse signal of the energy meter under test, includes the following steps:

[0067] The calibration platform initiates and establishes a Bluetooth connection with the energy meter under test based on the meter's address. After establishing the Bluetooth connection, the calibration platform initiates a CIS (Continuous Indication System) synchronization channel connection with the energy meter under test. Once the CIS synchronization channel is established, the calibration platform sends a start calibration command to the energy meter under test via Bluetooth. Upon receiving a response from the energy meter under test, the calibration platform begins the calibration process. During the calibration process, the energy meter's pulse data is transmitted to the calibration platform via the CIS synchronization channel and restored to its original state. The CIS synchronization data has an acknowledgment and retransmission mechanism, ensuring high reliability. After calibration, the calibration platform sends a stop calibration command to the energy meter under test via Bluetooth. Upon receiving a response, the calibration platform initiates the cancellation of the CIS synchronization channel, ending the energy meter calibration process. This method operates identically to the system in System Embodiment 2, achieving the same effect, and therefore will not be elaborated further here.

[0068] The method of this invention enables the calibration of energy meters based on pulses without interrupting other Bluetooth data communications.

Claims

1. A method for calibrating an electricity meter, characterized in that, The verification method includes the following steps: 1) A Bluetooth connection is established between the calibration platform and the energy meter to be calibrated; data is transmitted between the calibration platform and the energy meter to be calibrated through a first transmission channel or a second transmission channel; the first transmission channel is a broadcast synchronization channel; the second transmission channel is a CIS connection synchronization channel established between the calibration platform and the energy meter to be calibrated after the Bluetooth connection is established. 2) After the connection is established, the verification station sends a verification command to the energy meter to be verified; 3) The energy meter to be tested collects the energy meter pulse signal according to the test command, and broadcasts the collected energy meter pulse signal through the broadcast synchronization channel to transmit it synchronously to the test station, or sends the collected energy meter pulse signal to the test station through the CIS connection synchronization channel; the test station restores the pulse signal received from the corresponding channel, and performs the test on the energy meter to be tested based on the restored pulse signal.

2. The method for verifying an electricity meter according to claim 1, characterized in that: In step 1), at least two CIS connection synchronization channels are established to simultaneously verify at least two pulse signals; or in step 2), the verification station sends at least two verification commands to the energy meter to be verified, and in step 3), the energy meter to be verified broadcasts the collected at least two energy meter pulse signals through the corresponding at least two broadcast synchronization channels to simultaneously verify at least two pulse signals.

3. The method for verifying an electricity meter according to claim 1, characterized in that: In step 3), the energy meter to be tested samples and encodes multiple pulse signals according to the test command. Each bit in the encoded byte represents the high or low level state of one pulse signal at the current moment. The sampled and encoded data within a set time period is sent to the testing station via the CIS connection synchronization channel as a CIS data stream, or the sampled and encoded data within a set time period is broadcast via the broadcast synchronization channel as a BIS synchronization data stream. After receiving the data stream, the testing station decodes the data stream and outputs the bit information. Based on the bit information, the state of each pulse signal of the energy meter to be tested is restored.

4. The method for verifying an electricity meter according to claim 1, characterized in that: In step 3), the energy meter to be tested outputs the corresponding pulse signal to the pulse signal output terminal of the energy meter according to the type information contained in the test command for sampling and encoding to obtain an encoded signal. During encoding, 8-bit binary data is used to represent the voltage amplitude of the signal. Then, the encoded signal within the set time period is sent to the testing station through the CIS connection synchronization channel as a CIS data stream, or the encoded signal within the set time period is broadcast through the broadcast synchronization channel as a BIS synchronization data stream. After receiving the data stream, the testing station performs decoding operations, including fixed delay and digital-to-analog conversion, to restore the voltage waveform of the pulse output pin of the energy meter to be tested.

5. The method for verifying an electricity meter according to claim 1, characterized in that: After the energy meter under test has been tested, the testing station sends a stop test command to the energy meter. If the CIS synchronization channel exists, the testing station initiates the cancellation of the CIS synchronization channel. If the broadcast synchronization channel exists, the energy meter under test stops sending data streams on the broadcast synchronization channel after receiving the stop test command, and the energy meter testing process ends.

6. The method for verifying an electricity meter according to claim 1, characterized in that: In step 2), the verification station sends a test command to the energy meter to be verified via the ACL link.

7. The method for verifying an electricity meter according to any one of claims 1-6, characterized in that: When using CIS to connect the synchronous channel for pulse signal transmission, the CIS Event contains three sub_events arranged in equal time. For the energy meter end, each sub_event contains one transmit time slot for transmitting meter calibration data and one receive time slot for receiving acknowledgment messages. When using a broadcast synchronization channel for pulse signal transmission, the AuxPtr field of the ADV_EXT_IND message of the broadcast synchronization channel leads to the auxiliary broadcast message AUX_ADV_IND on the second channel. The SyncInfo field of the auxiliary broadcast message AUX_ADV_IND describes the channel, time point, and time interval parameters of the auxiliary broadcast message AUX_SYNC_IND. The calibration station receives the auxiliary broadcast message AUX_SYNC_IND at the specified channel and time offset position. The calibration station then receives the BIS synchronization data stream on a specific Isochronous channel based on the BIGInfo information of BIG carried by the ACAD field in the auxiliary broadcast message AUX_SYNC_IND.

8. A power meter calibration system, comprising a calibration platform, a first Bluetooth module, and a second Bluetooth module; the first Bluetooth module is disposed on the calibration platform; the second Bluetooth module is disposed on the power meter to be calibrated, for establishing a Bluetooth connection between the calibration platform and the power meter, characterized in that, A CIS connection synchronization channel is also established between the first Bluetooth module and the second Bluetooth module. The second Bluetooth module is used to transmit the pulse signal of the energy meter to be tested to the first Bluetooth module through the CIS connection synchronization channel or to the testing station through the broadcast synchronization channel. The first Bluetooth module is used to receive the pulse signal from the corresponding channel. The testing station restores the pulse signal received by the first Bluetooth module and performs testing on the energy meter to be tested based on the restored pulse signal.

9. The electricity meter calibration system according to claim 8, characterized in that: There are at least two CIS connection synchronization channels established between the first Bluetooth module and the second Bluetooth module, or at least two broadcast synchronization channels initiated by the second Bluetooth module, for the simultaneous detection of multiple pulse signals.

10. The electricity meter calibration system according to claim 8, characterized in that: The second Bluetooth module includes an encoder, which encodes the collected multi-channel pulse signals and then transmits them out as a data stream through the CIS connection synchronization channel or broadcast synchronization channel; during encoding, each bit in each encoded byte represents the high and low level state of each pulse signal at the current moment. The first Bluetooth module includes a decoder, which decodes the received data stream and outputs each bit of information, and restores the state of each pulse signal of the energy meter to be tested based on each bit of information.

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