A multi-parameter acquisition device based on a smart fusion terminal in a transformer substation

Abstract

This invention discloses a multi-parameter acquisition device based on a smart converged terminal for a distribution area, relating to the field of data acquisition and metering technology. The multi-parameter acquisition device includes: an AC-DC switching power supply providing conventional power; a supercapacitor module providing backup power; a protection circuit that protects externally input AC high-voltage signals before transmitting them to a rectifier diode array; a rectifier diode array that uses diodes to rectify the protected AC voltage before sending it to the AC-DC switching power supply; a voltage transformer that converts external power frequency high-voltage signals into low-voltage signals; a combined current transformer that converts external power frequency high-current signals into low-voltage signals, simultaneously injecting high-frequency signals into the external power frequency high-current loop and detecting the return signal; a metering chip that measures the low-voltage signals obtained after voltage and current conversion to obtain acquired data; and a loop inspection algorithm module connected to the combined current transformer that analyzes the return signal to obtain the current loop status data.

Description

Technical Field

[0001] This invention relates to the field of data acquisition and metering technology, and in particular to a multi-parameter data acquisition and metering device for a smart fusion terminal for transformer substations. Background Technology

[0002] Low-voltage distribution areas serve as a convergence point for marketing and power distribution specialties. The intelligent integrated terminals installed in these areas provide both specialties with functions such as data acquisition, processing, remote signaling sensing, and control output. With the development of these two specialties, functional requirements are becoming increasingly differentiated, and performance demands are rising. On the one hand, the functional categories required by the two specialties are becoming more inconsistent; for example, circuit inspection is a new requirement for the marketing specialty. On the other hand, even for functions required by both specialties, the performance requirements are becoming increasingly different. For instance, the power distribution specialty requires a remote signaling error time of no more than 1ms, far exceeding that of the marketing specialty.

[0003] Electrical parameter acquisition and metering devices are a crucial component of smart distribution transformer terminals, determining the terminal's functionality and performance at the basic acquisition and metering levels. Therefore, a device applicable to smart distribution transformer terminals that simultaneously possesses multiple functions required by both marketing and power distribution professionals, including acquisition, metering, remote signaling, circuit inspection, and topology identification, while also meeting the performance requirements of both fields, has become an urgent need. Summary of the Invention

[0004] The purpose of this invention is to propose a multi-parameter acquisition device for use in intelligent converged terminals in distribution areas, aiming to solve the problems of insufficient types of acquisition parameters, incomplete acquisition functions, and insufficient acquisition performance in the acquisition devices of intelligent converged terminals in distribution areas.

[0005] This application provides a multi-parameter acquisition device for use in a smart integrated terminal of a distribution transformer area. The multi-parameter acquisition device has functions such as voltage acquisition, current acquisition, loop status inspection, loop topology identification, magnetic induction detection, and remote signaling identification and reporting. It can communicate with the main control module within the smart integrated terminal of the distribution transformer area, meeting the functional and performance requirements of marketing and power distribution professionals. The multi-parameter acquisition device includes:

[0006] An AC-DC switching power supply is used to convert AC power into DC power to supply power to the multi-parameter acquisition device and / or the main control module, and has functions such as overvoltage input protection and overcurrent output protection.

[0007] A supercapacitor module is used to store backup power so as to supply power to the multi-parameter acquisition device and / or the main control module in the event of an external power outage.

[0008] The protection circuit protects the externally input AC voltage before transmitting it to the rectifier diode array and / or the voltage transformer.

[0009] The rectifier diode array rectifies the protected AC voltage through diodes and then sends it to the AC-DC switching power supply.

[0010] Voltage transformers isolate and induce external high-voltage power into low-voltage signals and transmit them to metering chips, eliminating the need for a dedicated isolation chip between the high-voltage and low-voltage areas in the traditional "resistive voltage divider for high-voltage acquisition" method.

[0011] The combined current transformer is used to isolate and induce a weak signal from the external high-frequency power current and transmit it to the metering chip. Simultaneously, it injects a high-frequency signal into the external high-frequency power current, detects the returned high-frequency signal, converts the returned high-frequency signal into data, and sends the data to the loop inspection algorithm module via the SPI bus. The combined current transformer contains a power frequency coil, a high-frequency injection coil, and a high-frequency detection coil. The power frequency coil and its auxiliary circuitry suppress the DC component and even harmonics of the high-frequency current input loop. Both the high-frequency injection coil and the high-frequency detection coil are enclosed in copper shielding shells to prevent high-frequency signal radiation and avoid interference with the accuracy of the combined current transformer's current detection.

[0012] The neutral current transformer isolates the strong external neutral current and converts it into a weak signal, which is then transmitted to the metering chip.

[0013] The metering chip is used to perform analog-to-digital conversion, digital filtering, and metering statistics on the weak electrical signals obtained from external power frequency voltage and power frequency current conversion to obtain collected metering data, and then send the collected metering data to the main control chip and topology identification module.

[0014] The main control chip is used to process and summarize the received data and report it to the main control module in the intelligent converged terminal of the distribution area.

[0015] The loop inspection algorithm module is connected to the combined current transformer via an SPI bus and a synchronization signal line. It receives high-frequency signal data sent by the combined current transformer via the SPI bus, analyzes and processes it to obtain external high-voltage current loop status data, and reports this data to the main control chip. The loop inspection algorithm module and the combined current transformer are connected via a synchronization signal line, enabling one loop inspection algorithm module to coordinate with three combined current transformers to perform unified high-frequency signal injection and detection.

[0016] The topology identification module is used to analyze and process the electrical parameter acquisition data obtained by the metering chip to obtain the topology connection relationship data of external electrical equipment, and send the topology connection relationship data to the main control chip.

[0017] When an abnormal magnetic field appears in the external environment, the magnetic induction chip can detect it in time and report it to the main control chip via GPIO. This makes it easier to detect illegal activities such as using the magnetic field to disrupt the electricity meter and steal electricity.

[0018] The storage chip includes a ferroelectric storage chip and a FLASH storage chip. The ferroelectric storage chip and the FLASH storage chip can perform cross-backup of data. When the data in the ferroelectric storage chip is abnormal, the data in the FLASH storage chip is read and the read data is written to the ferroelectric storage chip.

[0019] The shielded socket is externally covered with metal to prevent interference to the transmitted signals. The multi-parameter acquisition device connects to the power supply line and communication line through the shielded socket to supply power to the main control module and reports data to the main control module via buses such as USB, SPI, and GPIO.

[0020] The circuit board layout of the multi-parameter acquisition device is divided into a high-voltage area and a low-voltage area. The protection circuit, the rectifier diode array, the AC-DC switching power supply, the voltage transformer, the combined current transformer, and the neutral current transformer are located in the high-voltage area. The metering chip, the main control chip, the loop inspection algorithm module, the topology identification module, the storage chip, the magnetic induction chip, and the shielded socket are located in the low-voltage area.

[0021] For example, the multi-parameter acquisition device includes a circuit board, the combined current transformer is disposed on the circuit board, and the high-voltage current line of the combined current transformer is located outside the circuit board.

[0022] For example, the multi-parameter acquisition device includes a first side and a second side opposite to the first side: the protection circuit, the AC-DC switching power supply, the voltage transformer, the combined current transformer, the neutral current transformer, the supercapacitor module, and the shielded socket are disposed on the first side; the rectifier diode array, the metering chip, the main control chip, the topology identification module, the loop inspection algorithm module, the storage chip, and the magnetic induction chip are disposed on the second side.

[0023] For example, the protection circuit and the combined current transformer are located near the terminal block of the housing of the multi-parameter acquisition device; the AC-DC switching power supply, the voltage transformer, and the neutral current transformer are located away from the terminal block of the housing of the multi-parameter acquisition device and adjacent to the protection circuit; the supercapacitor module, the main control chip, the metering chip, the loop inspection algorithm module, the topology identification module, the storage chip, the magnetic induction chip, and the shielded socket are located away from the protection circuit and the combined current transformer.

[0024] For example, the AC-DC switching power supply is a gallium nitride switching power supply; the AC-DC switching power supply also has the following function: dynamically fine-tuning the output voltage of the AC-DC switching power supply within a preset range according to the load current, wherein the load includes the main control module and / or a module connected to the main control module.

[0025] For example, the AC-DC switching power supply also has the following function: the external input voltage that the AC-DC switching power supply can receive is within a preset voltage range, and the preset voltage range is greater than a specific range threshold.

[0026] For example, the AC-DC switching power supply also has the following function: when the external input voltage is greater than a preset voltage value, the AC-DC switching power supply activates the overvoltage protection function to temporarily shut down, and resumes startup after the voltage drops.

[0027] For example, the AC-DC switching power supply also has the following functions: the AC-DC switching power supply can output a steady-state power supply current greater than a first current threshold to the main control module, and when the short-term power consumption of the main control module is greater than a preset power consumption, it can output a peak current greater than a second current threshold to the main control module within a preset time period, wherein the second current threshold is greater than the first current threshold.

[0028] For example, the AC-DC switching power supply also has the following function: the DC voltage output by the AC-DC switching power supply is segmented according to frequency to obtain multiple frequency bands, the discrete noise value in the communication sensitive frequency band is less than a first preset noise threshold, the discrete noise value in the communication non-sensitive frequency band is less than a second preset noise threshold, and the first preset noise threshold is less than the second preset noise threshold.

[0029] For example, the AC-DC switching power supply also has the following function: when the power of the load increases, causing the output power of the AC-DC switching power supply to be greater than the preset power, the output current of the AC-DC switching power supply remains unchanged and the output voltage is reduced, so that the output power is reduced. After a period of time, the output voltage returns to normal. If the output power of the AC-DC switching power supply is still greater than the preset power, the output voltage is reduced again, and the cycle continues until the output power of the AC-DC switching power supply is less than or equal to the preset power.

[0030] For example, the supercapacitor module is composed of two supercapacitors connected in series, and the capacity of the supercapacitor module is greater than or equal to a preset capacity value; the supercapacitor module also has the following functions: the received charging current is less than or equal to a specific current value, and the charging time is less than or equal to a preset time length.

[0031] For example, the supercapacitor module also has the following function: when the voltage inside the supercapacitor drops due to the output of electrical energy by the supercapacitor module, the supercapacitor module outputs electrical energy after stabilizing the voltage through a boost circuit.

[0032] For example, the main control chip also has the following function: when the supercapacitor module starts charging, the main control chip queries the voltage-power curve data and time-power curve data based on the charging voltage to determine the current power of the supercapacitor module and the time that the current power can maintain the normal operation of the multi-parameter acquisition device and the main control module, so as to make a decision based on the time.

[0033] For example, the main control chip also has the following functions: detecting the power failure signal of the external power supply, storing the current data before the supercapacitor module runs out of energy after detecting the power failure signal, and reporting the power failure event to the main control module;

[0034] For example, the main control chip also has the following function: the main control chip is connected to the test and debugging interface through the test points on the circuit board, so that the multi-parameter acquisition device can communicate with the external tooling through the test and debugging interface, so that the external tooling can test the multi-parameter acquisition device.

[0035] For example, the main control chip also has the following functions: executing boot program initialization and application program initialization.

[0036] For example, the circuit board includes a four-layer structure. The bottom layer is adjacent to the housing of the multi-parameter acquisition device. Surface mount components are disposed on the bottom layer. Interference-prone circuit lines are led out from the surface mount components on the bottom layer, pass through the middle two layers, and reach the top layer for routing. The middle two layers are GND layers.

[0037] For example, for the current line connected to the neutral current transformer: each layer of the four-layer structure is covered with copper with a width greater than or equal to a preset width threshold, and the copper on the four-layer structure is tightly connected by dense vias to form the current line.

[0038] For example, the shielded socket includes 28 pins: pins 1-24 are digital signal interfaces, using 0.5mm*0.5mm square pins, capable of carrying 2.5A current; pins 25-26 are power supply pins, and pins 27-28 are GND pins, both using 2mm*4mm contact clips as plugs, capable of carrying 25A current; among them, USB D+ and D- are pins 2-3, which are adjacent to each other; and both are adjacent to the shielding shell serving as the GND pin and pins 1 and 4; CLK, DO, and CS of the unidirectional output SPI bus on the circuit board are pins 5-7, which are adjacent to each other; and all three are adjacent to the shielding shell serving as the GND pin. The shield and pins 4 and 8; the CLK, CS, MISO, and MOSI of the bidirectional input / output SPI bus on the circuit board are pins 9 to 11, which are adjacent to each other; and the four of them are also adjacent to pins 1, 4, 17, and 20, which serve as GND pins; the active pulse CF1 and reactive pulse CF2 of the unidirectional output on the circuit board are pins 18 and 19, which are adjacent to the shield and pins 17 and 20, which serve as GND pins; the YX1, YX3, YX2, and YX4 of the unidirectional input remote signaling on the circuit board are pins 14, 15, 22, and 23, which are adjacent to each other; and the four of them are also adjacent to the shield and pins 13, 16, 21, and 24, which serve as GND pins.

[0039] For example, the USB line between pins 2-3 and the main control module includes a 120Ω surface mount ferrite bead and two 33pF surface mount capacitors, forming a π-type filter circuit.

[0040] For example, the metering chip sends electrical parameter acquisition data to the main control chip via the SPI interface, the metering chip sends raw waveform data to the topology identification module via the SPI interface, the topology identification module sends the topology connection relationship data to the main control chip via the UART interface, the topology identification module reports the raw waveform data to the main control module via the SPI interface, and the main control chip reports data to the main control module via the SPI interface.

[0041] For example, the external terminal acquires remote signaling information through the four remote signaling input GPIO pin interfaces in the shielded socket of the multi-parameter acquisition device. When the remote signaling pin changes position, the main control chip records the remote signaling change data and reports the remote signaling change data to the main control module through the USB interface in the shielded socket. The four remote signaling input pin interfaces can filter the jump waveforms in the acquired remote signaling information. The main control chip has a built-in trigger interrupt mechanism and digital filtering algorithm to debouncing the remote signaling input signal. The debouncing time can be configured. After remote signaling is identified, a communication report is sent to the main control module through the USB interface.

[0042] For example, the circuit inspection algorithm module reads the weak current signal of the combined current transformer through the electric shock identification algorithm. The weak current signal includes high-speed sampling data of the current waveform. Based on the high-speed sampling data of the current waveform, three-phase residual current information is synthesized, and leakage current information in the three-phase residual current information is separated. Electric shock waveform features are extracted from the leakage current information, and the electric shock waveform features are compared with typical electric shock fault waveform features in the model library to identify the type of electric shock fault.

[0043] For example, the multi-parameter acquisition device has the following function: communicating with the main control module through the SPI interface so that the main control module can perform online upgrades on the firmware of the multi-parameter acquisition device;

[0044] For example, the multi-parameter acquisition device has the following functions: sampling high-order harmonics at power frequency, performing FFT transformation on the original sampled data to obtain the effective values ​​of each harmonic, calculating the measurement value based on the effective values ​​after FFT transformation, and comparing the measurement value with the measurement value acquired under a standard source for correction.

[0045] For example, the multi-parameter acquisition device has the following function: calibrating the power meter through multiple calibration methods, wherein the multiple calibration methods include power calibration method and pulse calibration method;

[0046] For example, the multi-parameter acquisition device has the following functions: filtering data through a variety of filtering algorithms, including: firstly filtering the original data through an empirical error judgment method, then sorting the sampled data through heap sort and / or quick sort, deleting the data before and after sorting, and then averaging the data in the middle.

[0047] For example, the multi-parameter acquisition device has the following functions: determining the temperature compensation coefficient corresponding to each temperature segment interval based on the segmented calibration algorithm, fitting the calibration curve using the Lagrange interpolation method, and performing temperature compensation calibration on the data based on the calibration curve.

[0048] For example, for each type of data that needs to be recorded in a multi-parameter acquisition device, at least two valid flag bits are set at the beginning and end.

[0049] For example, when reading and writing data to the FLASH storage chip, the data is first checked for valid bits, and then the time is checked.

[0050] The multi-parameter acquisition device disclosed in this invention includes at least an AC-DC switching power supply, a supercapacitor module, a protection circuit, a rectifier diode array, a voltage transformer, and a metering chip. Through the functional and information interaction between these components, it effectively solves the problems of insufficient parameter types, incomplete acquisition functions, and low acquisition performance in intelligent converged terminals for distribution areas. Specifically, the AC-DC switching power supply converts the externally input AC voltage into DC voltage to power the multi-parameter acquisition device. The supercapacitor module stores backup energy to power the multi-parameter acquisition device and / or the main control module in the event of an external power outage. The protection circuit protects the externally input high-voltage AC signal before transmitting it to the rectifier diode array. The rectifier diode array rectifies the protected AC voltage using diodes and sends it to the AC-DC switching power supply. The voltage transformer converts the externally input high-voltage power frequency signal into a low-voltage signal and transmits the low-voltage signal through a filter circuit to the metering chip. The metering chip obtains electrical parameter acquisition data based on the received low-voltage signal. Therefore, this invention has functions such as voltage acquisition, current acquisition, loop status inspection, loop topology identification, magnetic induction detection, and remote signaling identification and reporting. It can communicate with the main control module in the intelligent integrated terminal of the distribution area, and meets the needs of marketing and power distribution professionals in terms of function and performance. Attached Figure Description

[0051] Figure 1 This paper shows a schematic diagram of the composition architecture of the multi-parameter acquisition device provided in an embodiment of this application;

[0052] Figure 2 A front view of the multi-parameter acquisition device provided in an embodiment of this application is shown;

[0053] Figure 3 A schematic diagram of the back of the multi-parameter acquisition device provided in an embodiment of this application is shown;

[0054] Figure 4 This paper shows a functional schematic diagram of the multi-parameter acquisition device provided in an embodiment of this application;

[0055] Figure 5 This paper shows a schematic diagram of the circuit board wiring of the multi-parameter acquisition device provided in an embodiment of this application;

[0056] Figure 6A schematic diagram of a shielded socket provided in an embodiment of this application is shown;

[0057] Figure 7 A schematic diagram of the filtering circuit provided in an embodiment of this application is shown;

[0058] Figure 8 A schematic diagram of data communication provided in an embodiment of this application is shown.

[0059] Figure 9 A schematic diagram of a combined current transformer provided in an embodiment of this application is shown. Detailed Implementation

[0060] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0061] Currently, the industry is developing and promoting intelligent integrated terminals for distribution areas, striving to meet the new demands for the integration of marketing and power distribution functions, the collection of multiple electrical parameters, and the processing of multifunctional data information. This invention, starting from this situation, employs a variety of new technologies to meet these new needs.

[0062] Currently, the data acquisition devices within intelligent integrated terminals in the industry don't collect a wide variety of electrical parameters, resulting in a lack of versatility for both marketing and power distribution. While marketing and power distribution share some similar functions, many others differ. For example, both marketing and power distribution require the acquisition of power frequency AC voltage and current, but circuit inspection is only needed by marketing. Furthermore, current data acquisition devices used in marketing only have two channels for remote signaling detection, which cannot meet the power distribution requirement of at least four channels.

[0063] Current AC power parameter acquisition devices are not performing well enough. For example, many acquisition devices in the industry have excessively large remote signaling errors, which can only meet the needs of marketing professionals but cannot meet the low-error requirements of power distribution professionals.

[0064] Current AC parameter acquisition devices lack extended functionality. A typical example is the lack of loop inspection capabilities. Most AC acquisition devices only have voltage and current acquisition functions, lacking the ability to monitor abnormal current conditions such as short circuits and open circuits on the high-voltage side. Loop inspection, however, detects the voltage induced by current on the low-voltage side, allowing for the analysis of relevant information about the high-voltage side's operation, thus enabling measurement, monitoring, control, regulation, and protection of high-voltage equipment. Another example is the lack of topology identification functionality. Topology identification is achieved through AC acquisition, analyzing characteristic current signals based on waveform data recorded by the metering chip. Existing AC acquisition devices lack the ability to identify the topological connections of power equipment based on raw waveform data, limiting the device's functional expansion.

[0065] This invention integrates marketing and power distribution functions within a single terminal, and designs a data acquisition device that is compatible with intelligent integrated terminals in distribution areas and can collect various electrical parameters, thus simultaneously meeting the data acquisition needs of both marketing and power distribution professionals.

[0066] This invention proposes a multi-parameter data acquisition device suitable for intelligent converged terminals in distribution transformer areas. In terms of hardware, this invention simultaneously possesses functional components that meet the needs of both marketing and power distribution specialties. In terms of software, this invention patent features real-time intelligent processing capabilities in components such as the CPU chip and circuit inspection algorithm module. Through dedicated programs and algorithms, it drives the corresponding hardware components to operate, realizing the functions required by both specialties.

[0067] Therefore, in addition to the basic AC power parameter acquisition function, this invention can simultaneously support marketing and power distribution businesses, meeting the AC power parameter acquisition needs of both professions. It can also be extended to include some extended businesses applicable to marketing and power distribution, thus meeting the expansion needs of both professions.

[0068] This invention is a metering and control device invented in accordance with the "Technical Specifications for Intelligent Converged Terminals in Distribution Areas" series of standards. This invention uses a high-performance Cortex M4 core processor as the main control chip, and integrates ferroelectric memory chips and FLASH memory chips. It integrates functions such as power metering, power monitoring, harmonic analysis, status quantity acquisition, circuit inspection, topology identification, and power output, and has excellent reliability, stability, and security, meeting the application needs of power distribution, marketing, and other power businesses.

[0069] In view of the problems mentioned above, this embodiment provides a multi-parameter acquisition device based on a smart converged terminal for distribution areas.

[0070] Figure 1 A schematic diagram of the composition architecture of the multi-parameter acquisition device provided in the embodiments of this application is shown.

[0071] Figure 1The structure of a multi-parameter acquisition device is shown, which is capable of communicating with an external main control module. In one example, the multi-parameter acquisition device includes at least an AC-DC switching power supply, a supercapacitor module, a protection circuit, a rectifier diode array, a voltage transformer, and a metering chip.

[0072] AC-DC switching power supplies are used to convert externally input AC voltage into DC voltage to power multi-parameter acquisition devices.

[0073] The supercapacitor module is used to store backup power to supply power to the multi-parameter acquisition device and / or the main control module in the event of an external power outage.

[0074] The protection circuit is used to protect against externally input high-voltage AC power before transmitting it to the rectifier diode array.

[0075] The rectifier diode array is used to rectify the protected AC voltage through diodes and send it to the AC-DC switching power supply.

[0076] Voltage transformers are used to convert externally input high-frequency power voltage into a low-voltage signal, and then transmit the low-voltage signal to the metering chip after passing through a filter circuit. Using voltage transformers replaces the traditional method of resistive voltage division, isolating high-voltage and low-voltage circuits, eliminating "hot ground," and saving the need for isolation devices.

[0077] The metering chip is used to obtain electrical parameter acquisition data based on the received weak electrical signals.

[0078] Figure 2 A front view of the multi-parameter acquisition device provided in the embodiments of this application is shown.

[0079] Figure 3 A schematic diagram of the back of the multi-parameter acquisition device provided in an embodiment of this application is shown.

[0080] like Figure 2 and Figure 3 As shown, the multi-parameter acquisition device is divided into a high-voltage area and a low-voltage area. The protection circuit, rectifier diode array, AC-DC switching power supply, voltage transformer, combined current transformer, and neutral current transformer are located in the high-voltage area, while the metering chip, main control chip, topology identification module, loop inspection algorithm module, storage chip, magnetic induction chip, and shielded socket are located in the low-voltage area, achieving strong and weak electrical isolation.

[0081] refer to Figures 1 to 3In another example, the multi-parameter acquisition device also includes: a main control chip, a storage chip, a magnetic induction chip, a combined current transformer, a neutral current transformer, a loop inspection algorithm module, a topology identification module, and a shielded socket. Protection circuitry includes, for example, varistors, common-mode inductor filters, and thermistors. The shielded socket is, for example, a 24+4 pin shielded socket, i.e., a shielded socket with 28 pins.

[0082] The metering chip is also used to send electrical parameter acquisition data to the main control chip and the topology identification module.

[0083] The main control chip is used to report the received data to the main control module or to summarize and process the data before reporting it to the main control module.

[0084] The storage chips include ferroelectric storage chips and FLASH storage chips. The ferroelectric storage chips and FLASH storage chips can perform cross-backup of data. When the data in the ferroelectric storage chip is abnormal, the data in the FLASH storage chip is read and the read data is written to the ferroelectric storage chip.

[0085] Compared to storing data on a single memory chip, this invention stores data separately according to its type. For example, it uses a 16KB ferroelectric memory chip and a 16MB FLASH memory chip for separate storage. The multi-parameter acquisition device converts all acquired data into integer data, and then into hexadecimal data. The currently used hexadecimal data is stored in the ferroelectric memory chip, and also stored as backup in the FLASH memory chip. The ferroelectric memory chip is characterized by its long read / write lifespan, typically capable of 10 read / write cycles. 13 Therefore, it is suitable for storing currently used, frequently changing data. FLASH memory chips are characterized by their large storage capacity, making them suitable for storing large amounts of data that are not frequently read or written. Thus, currently used data is stored in ferroelectric memory chips, fully utilizing their long read / write lifespan; backup data is stored in FLASH memory chips, allowing for longer periods without modification and enabling multiple backups.

[0086] This invention addresses the need to prevent data loss and bad blocks in stored data by designing a special data protection mechanism. For critical data in the software (such as collected electrical parameter values), cross-backup is performed on the storage chips: normal data is written to storage chips with high read / write durability, such as ferroelectric chips, while backup data is written to storage chips with larger storage capacity, such as FLASH memory chips. When an anomaly occurs in the primary area data (data in the ferroelectric storage chip), the backup area data is immediately read and written, while simultaneously being written back to the primary area (ferroelectric storage chip), thereby improving data security and system redundancy.

[0087] The shielded socket is externally encased in metal to prevent interference with the transmitted power supply and signals. The AC-DC switching power supply output from the multi-parameter acquisition device passes through the shielded socket and is sent to the main control module, providing power to the module. The main control chip of the multi-parameter acquisition device aggregates and processes the received data, then sends it to the main control module via USB, SPI, GPIO, and other bus formats through the shielded socket.

[0088] When an abnormal magnetic field appears in the external environment, the magnetic induction chip can detect it in time and report it to the main control chip via GPIO, so as to prevent illegal acts such as using magnetic fields to disrupt power metering and steal electricity.

[0089] Figure 9 A schematic diagram of a combined current transformer provided in an embodiment of this application is shown.

[0090] Combined current transformers are used to convert externally input high-frequency power current into a low-voltage signal, and then transmit this low-voltage signal to the metering chip via a filter circuit. For example... Figure 9 As shown, unlike traditional current transformers, the combined current transformer internally includes a signal processing circuit board, a high-frequency injection coil, and a high-frequency detection coil. During operation, it injects a high-frequency signal into the external power frequency current loop and detects the return signal. After detecting the return signal, it converts it from an analog signal to data and sends it to the loop inspection algorithm module via the SPI bus. The power frequency coil and its associated circuitry within the combined current transformer of the multi-parameter acquisition device can suppress DC components and even harmonics. Inside the combined current transformer of the multi-parameter acquisition device, both the high-frequency injection coil and the high-frequency detection coil are enclosed in copper shielding shells to prevent high-frequency signal radiation and avoid interference with the accuracy of the combined current transformer's current detection.

[0091] The neutral current transformer enables three-phase four-wire current metering, and can perform metering normally even when the external three-phase is unbalanced.

[0092] One loop inspection algorithm module is connected to three combined current transformers via an SPI bus. The loop inspection algorithm module analyzes the returned signal data to obtain the status data of the current loop and reports the status data to the main control chip. In the multi-parameter acquisition device, the loop inspection algorithm module and the combined current transformers are connected by a synchronization signal, enabling the unified coordination of high-frequency signal injection and detection of the three combined current transformers by one loop inspection algorithm module.

[0093] The topology identification module is used to process the voltage and current waveform data output by the metering chip to obtain the topology connection data of external electrical equipment, and then send the topology connection data to the main control chip.

[0094] The multi-parameter acquisition device includes a circuit board, a combined current transformer is mounted on the circuit board, the high-voltage current lines of the combined current transformer are located outside the circuit board, and other components can be mounted on the circuit board.

[0095] This invention allows for an external current transformer interface. In some special installation environments, it is necessary to place the three-phase current transformer independently outside the main unit, with the secondary side wires of the current transformer connected to the metering chip. This invention provides three sets of terminals for the secondary side wires of the current transformer, reserved for connecting an external current transformer. When using an external current transformer, the user simply connects the current transformer's wires to the pre-set terminals of this invention.

[0096] In addition, considering the need to adapt to the main control module, the relevant housing, and the need to resist electromagnetic interference, the present invention has made a special layout for the components in the multi-parameter acquisition device.

[0097] refer to Figure 2 and Figure 3 The multi-parameter acquisition device includes a first side (front) and a second side (back) opposite to the first side. An AC-DC switching power supply, a supercapacitor module, a protection circuit, a voltage transformer, a combined current transformer, a neutral current transformer, and a shielded socket are located on the first side.

[0098] The rectifier diode array, metering chip, main control chip, loop inspection algorithm module, topology identification module, storage chip, and magnetic induction chip are located on the second side.

[0099] The combined current transformer and protection circuit are located on the terminal block near the chassis of the multi-parameter acquisition device. The AC-DC switching power supply, voltage transformer, and neutral current transformer are located away from the terminal block of the multi-parameter acquisition device and adjacent to the protection circuit. The supercapacitor module, metering chip, main control chip, loop inspection algorithm module, topology identification module, storage chip, magnetic induction chip, and shielded socket are located away from the combined current transformer and protection circuit.

[0100] Based on actual usage requirements, and considering the chassis shape and interface location of the main control module, this invention improves the component layout of the multi-parameter acquisition device. Following design principles such as strong and weak current isolation, minimizing signal traces, and keeping analog chips away from interference sources, as well as manufacturing principles such as ease of soldering and assembly, the following improvements were made:

[0101] First refer to Figure 2 The front view shows that no surface-mount components are placed on the first side (front), only through-hole components are placed, which simplifies the process and improves welding efficiency during production and soldering.

[0102] This invention employs a strong and weak current zoned layout, wherein the strong current zone is shown below. Figure 2 The two areas within the red border are divided into a high-voltage area (on the board) and a high-voltage area (off the board). On the board indicates that the area is located on the circuit board, and off the board indicates that the area is located outside the circuit board. The remaining areas, excluding the high-voltage areas, are low-voltage areas.

[0103] like Figure 2 As shown, the high-voltage area (non-board) includes the high-voltage current lines (A, B, C three-phase current lines) of the combined current transformer, the high-voltage current lines of the neutral current transformer, and the voltage lines (A, B, C, N three-phase four-wire voltage lines). The high-voltage current is connected from the terminal blocks of the multi-parameter acquisition device's housing to the plastic-sheathed conductors of the combined current transformer, and then directly to the combined current transformer without passing through the circuit board. Therefore, the high-voltage area does not require on-board protection; the combined current transformer handles the protection and signal processing. Placing the combined current transformer near the lower edge of the panel also facilitates the easy installation of the plastic-sheathed conductors onto the terminal blocks of the housing.

[0104] Layout of protection circuit in high voltage area (board): Since the three-phase voltage wires that input high voltage to the board are first connected to the varistor, the varistor, common mode inductor filter, thermistor and other components in the protection circuit are placed near the lower right side to facilitate the installation of the high voltage wires nearby, and also to facilitate the connection of the high voltage wires to the terminal block of the chassis.

[0105] Layout of high-voltage components on the high-voltage area (board): The AC-DC switching power supply, three voltage transformers, and one neutral current transformer are placed on the upper right side of the front of the board, adjacent to the protection circuit (varistor, common-mode inductor filter, thermistor) on the lower right. This facilitates the introduction of protected high-voltage power, enabling the conversion of AC signals to DC signals via the three voltage transformers and the current transformer, and the conversion of high-voltage signals to low-voltage signals for subsequent sampling and processing. The three-phase four-wire AC power system has voltages A, B, C, and N, and currents A, B, C, and N. When the three-phase voltages are unbalanced, the neutral current is not zero, requiring current detection. The low-voltage neutral current signal comes from the neutral current transformer.

[0106] The front layout of the low-voltage area: The supercapacitor module and the shielded socket for connecting the main control module are placed on the left. On the front of the circuit board, the low-voltage area contains only these two through-hole components. This design keeps the low-voltage area away from the high-current input area of ​​the combined current transformer on the lower side of the circuit board, and also away from the high-voltage input area on the lower right side of the circuit board, achieving isolation between the high and low voltage areas and reducing the impact of electromagnetic interference from high voltage sources.

[0107] refer to Figure 3The diagram shows the back panel, where the strong and weak current zones overlap with the front panel. The strong current area contains only the rectifier diode array, whose position roughly coincides with the area below the AC-DC switching power supply on the front panel, as shown below. Figure 3 The area within the red border is the high-voltage area, and the rest is the low-voltage area. The layout places metering chips, loop inspection algorithm modules, and other components close to the left side of the circuit board (relative to the front of the board) and near the lower high-voltage conversion devices (such as three voltage transformers, three combined current transformers, one neutral current transformer, and conditioning circuits consisting of resistors, capacitors, and diodes). This facilitates the connection of the converted analog signals (e.g., three voltages and three + one current, with one current being the converted neutral current) to the analog devices. Digital devices such as the CPU, FLASH memory chips, and ferroelectric memory chips are positioned above the circuit board, away from both the high-voltage area and the analog devices to prevent interference or to avoid external electromagnetic interference.

[0108] For example, the AC-DC switching power supply is a gallium nitride (GaN) switching power supply. The AC-DC switching power supply used on the circuit board of this invention employs a silicon substrate-based cascaded gallium nitride power device (GaN FET), possessing the following characteristics: high frequency, low loss, and high reliability.

[0109] (1) At rated power, the energy efficiency of gallium nitride switching power supply is 1-3% higher than that of silicon-based power supply solution, which can provide an overall energy saving solution for terminal.

[0110] (2) At the same time, under rated input and rated output test conditions, the temperature rise of gallium nitride power devices is about 5°C lower than that of silicon power devices. Under the same conditions, the device degradation rate is slower, thus having the advantage of extending the power supply life.

[0111] (3) It has high frequency characteristics, which realizes the switching frequency to about 100kHz, thereby reducing the volume of the back-end magnetic components by 5%. Among them, after the frequency is increased, the volume of the back-end inductor can be appropriately reduced.

[0112] In addition, AC-DC switching power supplies also have the following functions:

[0113] (1) The output voltage of the AC-DC switching power supply is dynamically adjusted within a preset range according to the load current, wherein the load includes the main control module and / or the module connected to the main control module.

[0114] This device uses a high-precision AC-DC switching power supply. The AC-DC switching power supply on the circuit board can supply power to the main control module. The output voltage of the switching power supply (e.g., 5V) can be precisely and dynamically adjusted in real time within a certain range according to the load current, ensuring that the open-circuit voltage of the modules in the first and second module slots of the main control module is between 4.80V and 5.20V. The preset range can be, for example, 4.80V to 5.20V, which complies with the interface requirements of the "Technical Specification for Intelligent Converged Terminals in Distribution Areas". The load includes the main control module and the modules plugged into the main control module. The power consumption of the main control module is not fixed. Sometimes, the power consumption is high due to heavy computing tasks. The main control module has three slots. When small modules such as carrier and 4G are plugged in, the power consumption will increase, especially the 4G small module, which consumes a lot of power when conducting wireless communication. The AC-DC switching power supply of this invention can also ensure that the steady-state load voltage of the first, second, and third module slots of the main control module is not higher than 5.20V, and the transient load voltage is not lower than 4.5V / 4.5V / 3.8V, which meets the load capacity requirements of the "Technical Specification for Intelligent Converged Terminals in Distribution Areas".

[0115] (2) The AC-DC switching power supply can receive external input voltages within a preset voltage range, and the preset voltage range is greater than a specific range threshold.

[0116] The AC-DC switching power supply used in this invention has a wide voltage input range. While ensuring accurate and stable DC voltage output, the input AC voltage range is AC 154V~500V or DC 218V~700V, i.e., the preset voltage range is AC 154V~500V or DC 218V~700V. This preset voltage range is greater than a specific threshold, which can be specifically set, such as AC 150V, DC 200V, etc. This wide input voltage range ensures that the multi-parameter acquisition device of this invention has good adaptability to external input voltages, adapting to non-mains AC input voltages within the specified range, as well as AC input voltages fluctuating within the specified range.

[0117] (3) When the external input voltage is greater than the preset voltage value, the AC-DC switching power supply starts the overvoltage protection function temporarily and resumes startup after the voltage drops.

[0118] The AC-DC switching power supply used in this invention has an input overvoltage protection function. When the input voltage exceeds AC 760V or DC 1077V (the preset voltage value is, for example, AC 760V or DC 1077V), the AC-DC switching power supply activates its self-protection function, which can temporarily shut down the power supply to prevent damage. Normal operation resumes after the overvoltage is released.

[0119] (4) The AC-DC switching power supply can output a steady-state power supply current greater than the first current threshold (e.g., 7A) to the main control module, and when the short-term power consumption of the main control module is greater than the preset power consumption, it can output a peak current greater than the second current threshold (e.g., 9A) to the main control module within a preset time period (e.g., ≥200ms), wherein the second current threshold is greater than the first current threshold.

[0120] This invention patent accepts a three-phase 220 / 380V AC input and, through an on-board AC-DC switching power supply, can provide a steady-state power supply current of 7A to the main control module used in conjunction with this invention patent. During short-term periods of high power consumption, such as exceeding the preset power consumption, it can provide a peak current of up to 9A for a duration of ≥200ms. Strong load-carrying capacity ensures that the steady-state and transient load-carrying capacities of the three module slots of the main control module meet the load-carrying capacity requirements of the "Technical Specification for Intelligent Converged Terminals in Distribution Areas".

[0121] (5) The DC voltage output by the AC-DC switching power supply is divided into multiple frequency bands according to the frequency. The discrete noise value in the communication sensitive frequency band is less than the first preset noise threshold (e.g., 1mV), and the discrete noise value in the communication non-sensitive frequency band is less than the second preset noise threshold (e.g., 2mV, 3mV or 3mV). The first preset noise threshold is less than the second preset noise threshold.

[0122] For example, the output DC voltage of an AC-DC switching power supply, segmented by frequency, exhibits discrete noise as follows:

[0123] 3.0kHz~150kHz, ≤5mV;

[0124] 150kHz~200kHz, ≤3mV;

[0125] 200kHz~500kHz, ≤2mV;

[0126] 0.5MHz~30MHz, ≤1mV.

[0127] To achieve low discrete noise in communication-sensitive frequency bands, generally 0.7MHz–3MHz, 2MHz–5MHz, and 2MHz–12MHz are carrier communication frequency bands, which are more sensitive to interference. Therefore, these frequency bands are considered communication-sensitive bands. The 0.5MHz–30MHz band requires the lowest noise level because it covers these three frequency bands. In less communication-sensitive frequency bands, the discrete noise level is appropriately relaxed. This ensures that the power line carrier communication module used with the multi-parameter acquisition device of this invention is not easily interfered with during carrier communication, while also eliminating the need for excessive components to reduce ripple across the entire frequency band, thus achieving a balance between performance and cost.

[0128] (6) When the power of the load increases, causing the output power of the AC-DC switching power supply to be greater than the preset power (e.g., 35W), the output current of the AC-DC switching power supply remains unchanged and the output voltage is reduced, so that the output power is reduced. After a period of time, the output voltage returns to normal. If the output power of the AC-DC switching power supply is still greater than the preset power, the output voltage is reduced again, and the cycle continues until the output power of the AC-DC switching power supply is less than or equal to the preset power.

[0129] For example, AC-DC switching power supplies have a hiccup protection function under overpower conditions. When the external load is too heavy (such as due to a short circuit or partial damage in the external circuit causing excessive power consumption), resulting in the output current exceeding the rated value and the output power exceeding 35W, the AC-DC switching power supply activates its hiccup self-protection function. The output current remains unchanged, but the output voltage decreases, thereby reducing the output power. After a period of time, the AC-DC switching power supply automatically attempts to restore the output voltage to a normal level. If, after the output voltage returns to a normal level, the load has not decreased and the output power is not less than 35W, the voltage is reduced again, triggering a new round of hiccup protection until the output power is reduced to meet the power supply's rated power specifications.

[0130] In this invention, the supercapacitor module consists of two supercapacitors connected in series. The capacity of the supercapacitor module is greater than or equal to a preset capacity value, such as 165F. For example, if a 165F high-capacity supercapacitor module is selected as a backup power supply, the stored charge is 165F * 5V = 825C. When discharging at 10W, since the output voltage is 5V, the output current is 10 / 5 = 2 (A), and the discharge time is 825 / 2 = 412.5 (s) ≈ 6.8 (minutes). Therefore, even after the external AC power is lost (when the external AC power fails, the AC-DC switching power supply loses its power source and cannot continue to supply power), the supercapacitor module can continue to operate for at least 3 minutes and continuously output 5V power to the main control module, supporting the main control module to continue operating for at least 3 minutes.

[0131] In addition, the supercapacitor module also has at least one of the following functions:

[0132] (1) The received charging current is less than or equal to a specific current value (e.g., 1.5A) and the charging time is less than or equal to a preset time (e.g., 25 minutes).

[0133] For example, the charging current and charging time of the supercapacitor module can be precisely set. The supercapacitor module is designed with a charging current of 1.5A, a value determined through comprehensive design. By using ADC monitoring, feedback, and current limiting mechanisms to monitor the charging current, this invention effectively limits the charging current to 1.5A, ensuring that charging does not consume excessive current from the motherboard and preventing any impact on the normal operation of the multi-parameter acquisition device. With the current limited to 1.5A, the charging time can also be precisely controlled to ≤25 minutes, enabling charging to be completed within a limited time frame and preventing excessively long charging times from affecting the overall functionality of the device.

[0134] (2) When the voltage inside the supercapacitor drops due to the output power of the supercapacitor module, the supercapacitor module outputs power after stabilizing the voltage through the boost circuit.

[0135] For example, the energy storage, boost, and voltage regulation architecture of the supercapacitor module is optimized. The supercapacitor module is composed of two supercapacitors with a rated voltage of 2.7V connected in series, so that the maximum voltage of the supercapacitor module is 2.7*2=5.4 (V). Since the output voltage of the AC-DC switching power supply on the board is 5V, the maximum voltage (5.4) that the supercapacitor of this invention can withstand is appropriately greater than the operating voltage (5V) on the board, which satisfies the requirements and leaves a certain margin.

[0136] The voltage output of the supercapacitor module adopts a "boost-regulate" architecture. As the supercapacitor module continuously outputs electrical energy, the voltage of the supercapacitor itself continuously decreases. This invention uses a boost circuit to raise the reduced voltage of the supercapacitor to 5V, and then regulates it before outputting. The output voltage is 5V ± 2%, with an output ripple of 30mV, meeting the specific requirements of relevant applications.

[0137] Furthermore, the main control chip of this invention is a variable-frequency main control chip. A high-performance Cortex M4 core processor is used as the main control chip according to actual usage needs. This main control chip allows for configurable operation within a certain range, up to a maximum of 150MHz. It has built-in 256KB SRAM, 1MB Flash, and 32K Cache RAM, supporting system boot from Flash (Flash data storage is no less than 10 years). Therefore, this invention can configure different CPU frequencies and load different programs for different product versions according to different actual usage requirements. It achieves the selection of the lowest operating frequency while meeting usage needs, thus saving hardware resources.

[0138] The main control chip of the present invention also has at least one of the following functions:

[0139] (1) When the supercapacitor module starts charging, the main control chip queries the voltage-power curve data and time-power curve data based on the charging voltage to determine the current power of the supercapacitor module and the time that the current power can maintain the multi-parameter acquisition device and the main control module to work normally, so as to make a decision based on the time.

[0140] For example, supercapacitor modules support internal charge detection, and the modules have the ability to monitor their internal voltage. The pin functions of supercapacitor modules are defined in the following table:

[0141] Pin number 1 2 3 4 Pin function definition Vin (voltage input) Vout (voltage output) Vdet (voltage detection) GND (Ground)

[0142] Pin 3 is led out from the positive terminal of the supercapacitor connected in series within the supercapacitor module. This pin connects to the high-precision ADC pin of the on-board CPU chip (main control chip). The CPU chip stores a data table of various data points on the "voltage-charge" curve of the supercapacitor. The CPU's high-precision ADC pin acquires the voltage of the supercapacitor, calculates and converts it into data, and then consults the data table for conversion or matching to obtain the current amount of charge stored in the supercapacitor. For example, 2.7V corresponds to 150F of charge, 2.6V corresponds to 140F, 2.5V corresponds to 120F, and so on. This correspondence may not be linear; by substituting the voltage into the curve, the remaining charge can be calculated or matched to determine the current amount of charge.

[0143] Supercapacitor Storage Capacity Metering Algorithm: The voltage and stored capacity of a supercapacitor are not entirely linearly related. During the middle of charging (constant current charging period), the capacity and voltage are linearly related. In the initial charging phase (trickle charging period) and after reaching a certain capacity (constant voltage charging period), the capacity increases normally, but the voltage increase is relatively weak. The CPU chip of this invention incorporates a specially designed supercapacitor capacity metering algorithm and a "time-capacity" curve data table prepared for this type of supercapacitor based on preliminary testing. When the supercapacitor begins charging, the CPU simultaneously collects voltage data and performs timing. Based on the stored "voltage-capacity" and "time-capacity" curve data tables, combined with the currently collected voltage, the CPU calculates and calibrates the stored capacity, accurately calculating the percentage of the total stored capacity and the time the current capacity can sustain normal operation for the multi-parameter acquisition device and main control module. This provides a basis for various decision-making operations by the CPU chip.

[0144] (2) Detect the power failure signal of the external power supply. After detecting the power failure signal, store the current data before the supercapacitor module runs out of energy and report the power failure event to the main control module.

[0145] This invention can promptly detect power outages caused by external AC power. At the output of the AC-DC switching power supply on the board, the 5V output is used as a control signal to control the base circuit of a transistor, thereby controlling the transistor's on / off state. If the 5V output voltage of the AC-DC switching power supply is interrupted, the transistor's on / off state cannot be controlled. The transistor's base is pulled high to the 5V output voltage of the supercapacitor, while the 5V output from the AC-DC switching power supply pulls the base low through an inverting circuit. When the 5V output voltage of the AC-DC switching power supply is interrupted, the transistor's base returns to high, and it is turned on. The transistor's on / off signal is connected to the main control chip on the board, realizing the function of the external power outage monitoring circuit. When the external AC power fails, the monitoring circuit on the circuit board is triggered, generating a notification signal, which is transmitted to the main control chip on the board. Upon receiving this power outage signal, the main control chip saves the currently used data before the backup power supply runs out of energy. After generating a power failure signal, it also sends information to the main control module (the hardware circuit in the multi-parameter acquisition device notifies the main control module through the change of an independent pin) to report the power failure event, so that the main control module can also save the data before the backup power supply is exhausted.

[0146] (3) The main control chip is connected to the test and debugging interface through the test points on the circuit board so that the multi-parameter acquisition device can communicate with the external tooling through the test and debugging interface, which facilitates the external tooling to test the multi-parameter acquisition device.

[0147] The main control chip supports connection to the JTAG (Joint Test Action Group) test interface and the SW debug interface. The SW interface typically refers to the Serial Wire Debug (SWD) interface, a serial interface standard used for debugging and programming. On the PCB board (circuit board) of this invention, traces connect the JTAG test interface and the SW debug interface to dedicated test points on the PCB board. After the main control chip is soldered onto the board, during mass production of the multi-parameter acquisition device of this invention in the factory, the factory's tooling uses probes to contact the pre-reserved test points on the PCB board (including the JTAG test interface, the SW debug interface, and other contact points requiring test signals) to download the program. This allows the downloading and testing equipment to be implemented using the same tooling, facilitating debugging and maintenance. The tooling outputs the program, and the multi-parameter acquisition device receives the program. The tooling has a dedicated circuit board that initiates the output program. After downloading, the tooling, with its dedicated circuit board, tests the functions and signals of each interface of the multi-parameter acquisition device through the test points. During testing, the multi-parameter acquisition device is treated as a whole. When the multi-parameter acquisition device is being tested, the program that was just downloaded is run, and the program controls the testing of the multi-parameter acquisition device.

[0148] (4) Execute the boot program initialization and application initialization.

[0149] Figure 4 A functional schematic diagram of the multi-parameter acquisition device provided in an embodiment of this application is shown.

[0150] like Figure 4 As shown, the functions of the multi-parameter acquisition device can be executed by the main control chip or be executed by it, and the execution process involves other components.

[0151] The boot program initialization is executed or primarily performed by the main control chip on the multi-parameter acquisition device board, initializing the clock and peripherals. After setup, it communicates with the main control module, sequentially checking whether the main control module has sent it the online upgrade file, whether the online upgrade file is valid, and whether the online upgrade file has been verified. If the checks pass, it communicates with the main control module to write the new upgrade file to Flash and reads the existing old upgrade file from Flash and uploads it to the main control module as a backup. Then it jumps to the application runtime area.

[0152] Application initialization: Because the application and boot program run in different address areas, peripherals need to be initialized and configured again after jumping to the application area. Peripherals include watchdog timer (timer circuit or chip), SPI bus, IIC bus, UART, etc. Then, parameters are initialized and configured, including calibration parameters, remote signaling parameters, 698 communication default parameters, and frozen parameters. During loading, if configuration data exists in the Flash memory chip, it is loaded according to the stored data; otherwise, the default set of parameters (default values) is used.

[0153] After the initialization is complete, the software enters the application function loop processing process (this process is mainly executed by the main control chip): data reception and transmission of various communication channels, including the AC sampling channel, loop inspection channel, topology identification channel, remote signaling pulse channel, and debugging serial port channel. The received data is first placed in the RAM area of ​​the main control chip for data verification. After successful verification, the data is classified and processed: for setting data, the issued parameters are parsed and stored in the memory chip; for read data, the data is parsed from the variables (read data) and returned to the upper-layer application (a high-level program running in the main control module). Setting data, such as sampling frequency and sampling method, is used to configure and control the parameters of this board. Read data, such as the read three-phase voltage and current values, is the collected result and needs to be reported to the main control module.

[0154] The acquisition of AC parameter data can be performed periodically, during which parameters such as three-phase voltage, current, and power are collected in real time. The raw data is then converted into high-precision data after temperature compensation and coefficient calibration. Harmonic data is also analyzed and calculated during this process, up to the 21st harmonic. Subsequently, based on the high-precision data, calculations and analyses are performed on zero-sequence voltage, zero-sequence current, and voltage / current pass rate statistics.

[0155] After data acquisition, some minute current signals are zeroed out, and the accumulated electrical energy data, such as forward active power and reverse active power, are stored in the memory chip. At the same time, active power demand is calculated, which refers to the maximum value of active power measured within a specific time period (such as 15 minutes). The demand is calculated and stored according to the set parameter period.

[0156] The AC power parameters will freeze some data periodically, such as minute freeze, day freeze, and month freeze. Taking minute freeze as an example, the software will configure the freeze period and freeze parameters. When the timer expires, it will save some current data and the current time in the storage chip. When the stored data reaches the set maximum value, it will be overwritten in a loop.

[0157] This invention enables the reporting of abnormal events from electricity meters. When a specific event occurs, it first determines the event's validity. If the event is valid, after a set delay, the event data and associated data are stored in the chip. Simultaneously, the event status is continuously monitored. If the event is determined to have resolved, the data from when the event occurred is similarly stored in the memory chip.

[0158] The multi-parameter acquisition device can realize 4-channel remote signaling function, reference Figure 4 The software timer periodically scans the remote signaling interface to read the remote signaling status. When a change in the remote signaling status is detected, debouncing is performed on the newly read status. After a set time is reached, if a remote signaling event is detected, the current status of the four remote signaling channels and the occurrence time of the remote signaling event (the event in which the remote signaling status changed) are reported to the upper-layer application. The upper-layer application may be the main control module or a high-level program running in the main control module.

[0159] Figure 5 A schematic diagram of the circuit board routing of the multi-parameter acquisition device provided in an embodiment of this application is shown.

[0160] like Figure 5 As shown, the circuit board has a four-layer structure. The bottom layer is adjacent to the housing of the multi-parameter acquisition device. Surface mount components are located on the bottom layer. Interference-prone circuit lines are led out from the surface mount components on the bottom layer, pass through the middle two layers, and reach the top layer where they are routed. The middle two layers are GND layers. The circuit routing is as follows: Figure 5 The black part.

[0161] To protect against electromagnetic interference, the circuit board of this invention employs a special reinforced shielding design, and the traces on the board also utilize a unique design. The bottom layer (BOTTOM layer) is adjacent to the chassis of the multi-parameter acquisition device, making it close to electromagnetic interference sources. Since surface-mount components such as chips are located on the bottom layer, their traces are susceptible to electromagnetic interference. For vulnerable areas on the circuit board, the traces and copper pours are specially designed. For example, sensitive signal traces are routed from the surface-mount components on the bottom layer, drilled near the nearest via, pass through the two middle layers, and reach the top layer, where the traces are routed. The second and third middle layers are both GND layers, each a complete ground plane. This provides double protection for sensitive signals with two GND planes, preventing electromagnetic interference sources outside the chassis of the adjacent bottom layer from interfering with them. This allows the invention to pass electromagnetic compatibility testing and ensures normal operation in harsh environments with severe electromagnetic interference.

[0162] For the current line connected to the neutral current transformer: each layer in the four-layer structure is laid with copper with a width greater than or equal to a preset width threshold (e.g., 1cm). The copper on the four-layer structure is tightly connected by dense vias to form the current line.

[0163] For example, the thickened design of the single-channel neutral wire (i.e., the primary input line of a single neutral current transformer) allows it to withstand a short-term overcurrent of 100A (lasting 1 second), meeting relevant user testing requirements and adapting to applications with unstable neutral current. The thickening method involves replacing conventional traces with copper plating on all four layers of the circuit board. The conventional 40mil single-layer trace is replaced with 1cm wide square copper plating on each layer, with the same plating area across all layers. Dense vias are then used to tightly connect the copper plating on the four layers, significantly increasing the current carrying capacity and ensuring even current distribution across the four copper layers, thus improving heat dissipation when high currents pass through. Therefore, in areas with three-phase power imbalance, the multi-parameter acquisition device of this invention can be used in these areas, preventing damage to the phase and neutral wires caused by single-phase overcurrent or other abnormal conditions.

[0164] Figure 6 A schematic diagram of a shielded socket provided in an embodiment of this application is shown.

[0165] like Figure 6 As shown, the housing of the multi-parameter acquisition device is made of plated stainless steel and is connected to GND on the circuit board. It is also connected to the outer shielding layer of the matching shielded connector, ensuring that GND is shielded against electromagnetic interference. The shielded connector has 28 (24+4) pins; the specific pin definitions are shown in the table below.

[0166]

[0167]

[0168] Pins 1-24 are digital signal interfaces, using 0.5mm*0.5mm square pins, and can handle a maximum current of 2.5A. Pins 25-26 are 5V power supply pins (5V is the output voltage after combining the AC-DC switching power supply and the supercapacitor module), and pins 27-28 are GND pins, both using 2mm*4mm contact clips as plug-ins, and can handle a maximum current of 25A. This ample current carrying capacity ensures sufficient power supply to the corresponding main control module by the multi-parameter acquisition device, and also ensures that the output signal line impedance of the multi-parameter acquisition device is sufficiently low, without affecting signal quality. The 5V power supply voltage powers the external main control module through this socket, and is not controlled by the main control chip. Acquired data (cross-acquisition data) and other signals are output to the external main control module through this socket. Most of these signals are issued by the main control chip, but unidirectional SPI, active power, reactive power, and power failure detection are issued by other circuits outside the main control chip.

[0169] Pins 1-24 are digital signal interfaces, using 0.5mm*0.5mm square pins, capable of passing 2.5A of current;

[0170] Pins 25-26 are power supply pins, and pins 27-28 are GND pins. Both use 2mm*4mm contact clips as plugs and can carry 25A of current.

[0171] Among them, USB's D+ and D- are pins 2 and 3, which are adjacent to each other; and they are also adjacent to the shielding shell that serves as the GND pin and pins 1 and 4.

[0172] On the circuit board, the CLK, DO, and CS pins of the unidirectional output SPI bus are pins 5-7, which are adjacent to each other; and all three are adjacent to the shielding shell that serves as the GND pin and pins 4 and 8.

[0173] On the circuit board, the bidirectional input / output SPI bus CLK, CS, MISO, and MOSI are pins 9 to 11, which are adjacent to each other; and all four are adjacent to pins 1, 4, 17, and 20, which serve as GND pins.

[0174] The active pulse CF1 and reactive pulse CF2, which are output in one direction on the circuit board, are pins 18 and 19, respectively. They are located next to the shielding shell that serves as the GND pin and pins 17 and 20.

[0175] On the circuit board, YX1, YX3, YX2, and YX4, which are unidirectional input remote signals, are pins 14, 15, 22, and 23, respectively, and are adjacent to each other; and together they are adjacent to the shielding shell that serves as the GND pin and pins 13, 16, 21, and 24.

[0176] Figure 7 A schematic diagram of the filtering circuit provided in an embodiment of this application is shown.

[0177] like Figure 7 As shown, the USB line between pins 2-3 of the shielded socket and the main control module includes a 120Ω surface mount ferrite bead and two 33pF surface mount capacitors, forming a π-type filter circuit.

[0178] Because power terminal products are typically used in environments with relatively harsh electromagnetic conditions, this invention requires special protection against electromagnetic interference for the USB lines connected to the main control module. This invention employs special anti-interference filtering measures for the USB 2.0 communication lines (the onboard traces of pins 2-3 of the USB D+ and D- connectors in the shielded socket), for example, using a 120Ω surface-mount ferrite bead and two 33pF surface-mount capacitors to form a π-type filter circuit. This filter circuit can effectively filter out interference from external electromagnetic interference such as pulse groups, static electricity, and surges, ensuring normal USB data communication.

[0179] Figure 8 A schematic diagram of data communication provided in an embodiment of this application is shown.

[0180] like Figure 8 As shown, the metering chip sends electrical parameter acquisition data (such as conventional three-phase AC electrical parameter acquisition data) to the main control chip through the SPI interface. The metering chip sends raw waveform data to the topology identification module through the SPI interface. The topology identification module sends topology connection relationship data to the main control chip through the UART interface. The topology identification module reports raw waveform data to the main control module through the SPI interface. The main control chip reports data to the main control module through the SPI interface.

[0181] Specifically, the multi-parameter acquisition device of this invention is equipped with a high-speed SPI bus interface. The metering chip sends real-time voltage and current sampling waveform data to the main control module via the topology identification module through the SPI bus interface. The SPI bus interface operates in master mode, using a 3-wire mode, consisting of CS, SCL, and SDA (e.g., corresponding to pins 5-7 in a shielded socket), with a maximum speed of 10MHz. Data transmission uses a 32-bit data frame format and is sent cyclically. This function provides real-time data to the main control module, effectively supporting the main control module's power load identification, topology identification, and other business functions.

[0182] Specifically, the external three-phase AC voltage of this invention is rectified and conditioned, then connected to the on-board AC-DC switching power supply to convert it into a 5V DC voltage for powering the circuitry on the board. Simultaneously, the three-phase AC voltage is also supplied to three voltage transformers on the board to sense the secondary side signals of the three-phase voltage. The external three-phase current and neutral current of the multi-parameter acquisition device of this invention are connected to three combined current transformers and one neutral current transformer on the board to sense the secondary side signals of the three-phase current and neutral current.

[0183] The voltage and current signals on the secondary side are connected to the metering chip. The metering chip samples and processes these signals, and sends the processed data (such as data that has been filtered after acquisition) to the main control chip via the SPI bus. The main control chip stores the data in the memory chip and, after further processing, reports the data to the main control module.

[0184] The circuit board of the multi-parameter acquisition device of the present invention has a loop inspection algorithm module, which is connected to the combined current transformer. It can analyze the normal operation, open circuit, short circuit and other states of the current loop based on the current.

[0185] The multi-parameter acquisition device of this invention has a topology identification module on its circuit board. This module is connected to a metering chip and can analyze the topology connections of related metering devices (such as the number of downstream concentrators, the number of downstream collectors for each concentrator, the number of downstream meters for each collector, or the number of other metering devices) on the high-voltage circuit connected to the multi-parameter acquisition device based on the data acquired and processed by the metering chip (e.g., raw voltage waveform data after acquisition but without processing). This data is then reported to the main control chip on the board. In other words, the topology identification module is connected to both the metering chip and the main control chip. It receives raw waveform data from the metering chip, analyzes the topology connections, and then reports them to the main control chip.

[0186] The topology identification module has two SPI interfaces with a communication rate of no less than 8Mbps. One of them acts as an SPISlave, used to receive waveform data (raw waveform data) input from the metering chip. The other SPI interface synchronously forwards the input waveform data (raw waveform data) to the master control module according to a certain protocol format. This SPI interface operates as the Master.

[0187] This invention's multi-parameter acquisition device features an extended topology identification module function, allowing a topology identification module to be added to the circuit board of the multi-parameter acquisition device. Topology identification technology is a core foundational application for the construction of the distribution network Internet of Things (IoT), and also the basis for carrying out lean operation and maintenance management of the distribution network under cloud-edge-device collaboration and energy internet business applications. The topology identification module implements the following functions:

[0188] (1) The MCU core is Cortex-M4 with a main frequency of 192MHz, 128Kbytes of memory, and 256K bytes of on-chip Flash.

[0189] (2) The topology identification module has two SPI ports with a communication rate of no less than 8Mbps. One port acts as an SPISlave, receiving waveform data input from the metering chip. The other port synchronously forwards the input waveform data to the master control module according to a certain protocol format. This SPI port operates as the Master. SPI Slave is a role in the SPI communication protocol. SPI is a high-speed, full-duplex, synchronous communication bus. In SPI communication, the master device controls the entire communication process, while the slave device responds to the master device's requests.

[0190] (3) Automatically identify the waveform recording data of common metering chips, and use filtering-buffering-restoration and other technologies to achieve distortion-free reception of signal waveforms, thereby avoiding the loss of waveform recording data.

[0191] (4) Adaptive analysis of characteristic current signals, frequency range 500Hz-1.5kHz.

[0192] (5) No less than 5,000 topology identification records shall be stored.

[0193] (6) Simultaneously supports DL / T645-2007 and DL / T645-698.45 protocols to read topology recognition results.

[0194] (7) The topology identification module supports remote upgrades and resume interrupted transmission.

[0195] (8) The topology identification module has RTC function and supports time synchronization of the module.

[0196] (9) The topology identification module communicates with the main control chip via UART. The default communication length is 9600bps, with even parity, 1 stop bit, and 8 data bits.

[0197] For example, the external terminals use the four-channel switch input interface (e.g., pins 14, 15, 22, and 23 in the shielded socket of the multi-parameter acquisition device) as remote signaling input interfaces (four remote signaling input lines). The interface uses a passive node method. When the level of the input remote signaling terminal (the 4+1 plugs used for remote signaling input) is low (when the external contact is closed), the remote signaling level is valid; when the level of the input remote signaling terminal is high (when the external contact is open), the remote signaling level is invalid. The external contacts are user-supplied accessible connectors connected to the remote signaling plug, enabling open / close functionality. The remote signaling interface can collect access status information (the open / closed status of the user-supplied accessible connectors) in real time. When a remote signaling change occurs, when the remote signaling pin changes position, the main control chip records the remote signaling change data and reports it to the main control module via the USB interface in the shielded socket. The four remote signaling input pin interface circuits can perform hardware filtering on the transient waveforms in the collected remote signaling information. The main control chip incorporates a built-in interrupt triggering mechanism and digital filtering algorithm to achieve anti-jitter functionality for remote signaling input signals, ensuring a remote signaling resolution of no more than 5ms and a remote signaling error of no more than 1ms. The default anti-jitter time is 200ms, which can be set by the user according to actual needs (10ms~6000ms). After remote signaling recognition, a communication report is sent to the main control module via the USB interface.

[0198] For example, the loop inspection algorithm module reads the weak current signal of the three-phase combined current transformer through the electric shock identification algorithm. The weak current signal includes high-speed sampling data of the current waveform. Based on the high-speed sampling data of the current waveform, the module synthesizes the three-phase residual current information, separates the leakage current information in the three-phase residual current information, extracts the electric shock waveform features from the leakage current information, and compares the electric shock waveform features with the typical electric shock fault waveform features in the model library to identify the type of electric shock fault.

[0199] This invention's multi-parameter acquisition device has a low-voltage distribution network electric shock identification function. For example, it incorporates an electric shock identification algorithm within the loop inspection algorithm module. By reading high-speed sampling data of the current waveforms from three-phase combined current transformers, it synthesizes three-phase residual current information in real time and separates leakage current information within the low-voltage distribution network. Utilizing algorithms such as wavelet transform and Hilbert transform, it accurately detects the abnormal point at the moment of the electric shock fault based on the instantaneous phase and amplitude abrupt change characteristics acquired at the time of the fault, and extracts the electric shock waveform features generated by the low-voltage distribution network in real time. A model library of typical electric shock fault waveform feature values ​​is created, and the real-time received feature results are compared with the established electric shock fault model library to achieve electric shock fault type identification.

[0200] The loop inspection algorithm module also features loop status inspection functionality. Specifically, each current phase line is equipped with a combined current transformer, and the entire board is equipped with a loop inspection algorithm module to provide loop status inspection capabilities. The loop inspection algorithm module uses an SPI high-speed data interface to sequentially read information from the three combined current transformers at various frequencies, including loop impedance magnitude, impedance angle, instantaneous effective value of power frequency current, and ambient temperature. Combined with information such as transformer ratio, accuracy class, model, core cross-sectional area, and magnetic circuit length, it calls a dedicated loop status inspection algorithm to calculate and determine various states of the current loop, such as normal, open circuit, and short circuit. This information is then reported to the main control module; for example, the loop inspection algorithm module first reports to the main control chip on the board, and then the main control chip reports to the main control module.

[0201] For example, the multi-parameter acquisition device also has at least one of the following functions:

[0202] (1) Communicate with the main control module through the SPI interface so that the main control module can upgrade the firmware in the multi-parameter acquisition device online.

[0203] Firmware online upgrades include those using In-Application (IAP). For example, after installing the multi-parameter acquisition device at the user's site, upgrades can be performed on-site without removal or return to the manufacturer. This is particularly useful for installations in mountainous areas, farmland, or other locations where manual maintenance is difficult, allowing for convenient remote firmware upgrades. The main control module used in conjunction with the multi-parameter acquisition device performs online firmware upgrades via the SPI port according to the DL / T 698.45-2017 protocol. During the upgrade, the maximum data transmission per frame is 2KB, and each frame is individually verified to prevent data transmission anomalies.

[0204] (2) Perform power frequency high harmonic sampling, perform FFT transformation on the original sampling data to obtain the effective value of each harmonic, calculate the measurement value based on the effective value after FFT transformation, and compare the measurement value with the measurement value collected under the standard source for correction.

[0205] This invention supports real-time acquisition of high-order harmonics at the power frequency using a multi-parameter acquisition device, up to the 21st order. The effective values ​​of each harmonic are obtained by performing an FFT transform on the original sampling points. The multi-parameter acquisition device completes the acquisition through voltage and current transformers, conditioning circuits, and metering chips, with the metering chip playing a key role. The original points are a series of voltage values, such as 220V, 219V, 221V, etc., but actually include many values ​​measured due to interference, such as excessively high values, excessively low values, and 0 values. To address harmonic value errors caused by sampling value fluctuations, this invention uses a comparative method to correct the effective values ​​after the FFT transformation with the metering values ​​acquired under a standard source, effectively improving calculation accuracy.

[0206] (3) The power meter is calibrated through multiple calibration methods, including power calibration and pulse calibration.

[0207] This invention's multi-parameter data acquisition device supports electricity metering. Addressing the issue of metering accuracy, the device supports multiple calibration methods, involving the main control chip, metering chip, and storage chip. Typically, the power method is used for calibration, calibrating the three-phase voltage, three-phase current, power, and angle separately. The calibration data is stored in the storage chip to prevent data loss in case of power failure. When an anomaly occurs during power calibration, pulse calibration is used, utilizing the meter's pulse constant. These two methods serve as backups for each other, enhancing system stability.

[0208] (4) Filter the data using a variety of filtering algorithms, including: first, filtering the original data by using the empirical error judgment method, then sorting the sampled data by heap sort and / or quick sort, deleting the data before and after sorting, and then averaging the data in the middle.

[0209] Data optimization processing based on multiple filtering algorithms can be handled by the main control chip, which can work in conjunction with other components.

[0210] This invention's multi-parameter acquisition device employs various filtering algorithms to optimize data processing. Due to factors such as power equipment and the external environment, power transmission signals contain various noises and interferences. These interferences originate from the signal source itself, from the sensor, or from external sources. To achieve accurate measurement, interference and noise in the signal must be eliminated. Therefore, the multi-parameter acquisition device uses dedicated software to filter the signal.

[0211] For the original sampled data, data filtering is first performed using an empirical error judgment method: based on existing empirical data and judgment criteria, a maximum allowable error for each sample is determined. Each newly detected sampled data value is then judged. If the error is less than the empirical maximum, the data is considered valid and accepted; if it is greater than the empirical maximum, the data is considered invalid and discarded. Next, the sampled data is sorted using heap sort / quick sort. After sorting, the first 5% and last 5% of the data are deleted, and the average of the remaining data is calculated. Thus, the final sampling result is obtained through calculation, effectively filtering out excessively large or small values ​​and effectively overcoming sampling interference caused by electromagnetic factors.

[0212] (5) Based on the segmented calibration algorithm, the temperature compensation coefficient corresponding to each temperature segment interval is determined, the Lagrange interpolation method is used to fit the calibration curve, and the data is calibrated for temperature compensation based on the calibration curve.

[0213] Industry experts typically calibrate multi-parameter acquisition devices at a standard temperature of 25°C, but their operating environment temperature can range from -40°C to 85°C. The sampling circuit consists of multiple components, among which the sensitive elements have characteristics closely related to temperature, often exhibiting inconsistent characteristics across different temperature ranges.

[0214] To minimize the impact of ambient temperature, the multi-parameter acquisition device of this invention employs a dedicated calibration algorithm based on segmented calibration and Lagrange curve fitting to achieve precise calibration of temperature effects. For example, the smallest unit of temperature range is defined as 2°C, and a separate temperature compensation coefficient is calculated for each range. Simultaneously, considering the common characteristics of the modules, a calibration curve is fitted using Lagrange interpolation to achieve overall gain correction. These two complementary metrological calibration methods are employed.

[0215] The multi-parameter acquisition device of this invention has a specially designed power metering data communication software interface, which enables the reported data to effectively comply with the "Object-Oriented Power Information Data Exchange Protocol".

[0216] The multi-parameter acquisition device of this invention adopts the above-mentioned sampling and filtering algorithms to effectively ensure that the accuracy of power metering meets the industry standard requirements: active power 0.5S, reactive power level 2.

[0217] The multi-parameter acquisition device of this invention meets the requirements of remote signaling status acquisition function, with SOE resolution <5ms and error ±1ms.

[0218] This invention's multi-parameter acquisition device can collect electrical parameter data of a transformer substation in real time and perform comprehensive power quality analysis and monitoring based on this data, including voltage sags and short-term interruptions, voltage fluctuations, voltage harmonics, voltage compliance rate, frequency deviation, and three-phase imbalance. This multi-parameter acquisition device can store and manage the collected and analyzed data for subsequent analysis and decision-making. Accurate power quality monitoring is the foundation for implementing power quality improvement and helps to understand the current status, causes, and impacts of power quality problems.

[0219] This invention provides a multi-parameter data acquisition device that records various abnormal events occurring in a power distribution area, such as energy metering, operation, and faults. It records in detail events such as overvoltage, undervoltage, power exceeding limits, and its own programming and zeroing. Simultaneously, it stores parameters such as active energy and power at the time of occurrence and recovery. These event records help power companies or users understand the working status of the energy meter and electricity consumption.

[0220] Given the diverse types of events and the large volume of event data, the multi-parameter acquisition device of this invention classifies and stores the data content: For parameter variables, based on their large quantity and complex types, they are centrally stored in a fixed area of ​​the FLASH storage chip (generally the header area of ​​the Flash) to ensure data stability; for event data, taking advantage of the large storage capacity of the FLASH storage chip, the associated data at the time of the event is stored in the latter half of the Flash storage area without standardized sorting, but with retrieval functionality in the program for easy and timely retrieval.

[0221] In this multi-parameter acquisition device, backup data is stored in a FLASH memory chip, resulting in a large volume and diverse types of data. To address this, a unique algorithm is designed to enable rapid data reading, writing, and erasure. For each data type, at least two valid flag bits are set at the beginning and end. This data includes data to be recorded, such as real-time acquired electrical parameters, electrical parameters to be recorded every minute / day / month, and event data. Based on a C language data storage format, this data consists of signed 8 / 32 / 64-bit integers. A time verification function is added for each hour and each custom time period (typically five minutes). When data reading or writing is required, valid flag bit verification is performed first, followed by time verification. Only after successful verification can data reading or writing proceed. This improves the accuracy of data retrieval, eliminates unnecessary data searches, accelerates read / write speeds, and enhances program processing efficiency.

[0222] The multi-parameter acquisition device of the present invention has the following advantages:

[0223] (1) Compatible with both marketing and power distribution professions, with strong versatility. The multi-parameter acquisition device of this invention, with a unified design architecture, unified form and unified interface, can simultaneously meet the functional requirements of both marketing and power distribution professions. It has AC power parameter acquisition function and auxiliary functions such as remote signaling and control. It can realize data sharing and functional integration of AC power parameters, which makes it easier for users to reduce costs, simplify management and reduce workload.

[0224] (2) Fully functional. It has data acquisition functions such as cross-data acquisition, telemetry, and remote signaling, and communication functions such as USB and SPI. Among them, cross-data acquisition is used to acquire three-phase voltage and four-wire current, and remote signaling is used to acquire four channels. USB and main SPI are used to communicate with the main control module, and high-speed SPI is used to output real-time waveform data to the main control module.

[0225] (3) High performance. For example, the acquisition accuracy is high, and the remote signaling acquisition error can be reduced to 1ms, which meets the needs of both marketing and power distribution.

[0226] (4) High scalability. For example, it has a loop inspection function. It realizes the monitoring of abnormal current states such as short circuits and open circuits in the primary side loop, and realizes the measurement, monitoring, control, adjustment and protection functions of the primary side equipment. Another example is that it has a topology recognition function. Through AC acquisition, the characteristic current signal of the primary side is analyzed according to the waveform data recorded by the metering chip.

[0227] In the description of this application, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0228] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0229] Furthermore, the terms "first," "second," etc., used in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying relative importance, or implicitly specifying the number of technical features indicated in this embodiment. Therefore, features defined with terms such as "first" and "second" in the embodiments of this application can explicitly or implicitly indicate that the embodiment includes at least one of those features. In the description of this application, the word "multiple" means at least two or more, such as two, three, four, etc., unless otherwise explicitly and specifically defined in the embodiments.

[0230] In this application, unless otherwise explicitly specified or limited in the embodiments, the terms "installation," "connection," "joining," and "fixing" appearing in the embodiments should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral part; it can also be a mechanical connection, an electrical connection, etc. Of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication between two components, or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific implementation.

[0231] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0232] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A multi-parameter acquisition device based on a smart fusion terminal for distribution areas, characterized in that, The intelligent fusion terminal for the distribution area includes a main control module. The multi-parameter acquisition device can communicate with the main control module. The multi-parameter acquisition device includes an AC-DC switching power supply, a supercapacitor module, a protection circuit, a rectifier diode array, a voltage transformer, a metering chip, a storage chip, a combined current transformer, and a loop inspection algorithm module. The AC-DC switching power supply is used to convert the externally input AC voltage into DC voltage to power the multi-parameter acquisition device. The supercapacitor module is used to store backup power so as to supply power to the multi-parameter acquisition device and / or the main control module in the event of an external power failure. The protection circuit is used to protect against externally input AC high voltage before transmitting it to the rectifier diode array. The rectifier diode array is used to rectify the protected AC voltage through diodes and then send it to the AC-DC switching power supply. The voltage transformer is used to convert the externally input power frequency high voltage into a low voltage signal, and transmit the low voltage signal to the metering chip through a filter circuit. The metering chip is used to obtain electrical parameter acquisition data based on the received weak electrical signal; The storage chip includes a ferroelectric storage chip and a FLASH storage chip. The ferroelectric storage chip is used to store currently used and frequently changing data, while the FLASH storage chip is used to store large amounts of data with low read / write frequency. The ferroelectric storage chip and the FLASH storage chip can perform cross-backup of data. When the data in the ferroelectric storage chip is abnormal, the data in the FLASH storage chip is read and written back to the ferroelectric storage chip. For each type of data that needs to be stored, at least two valid flag bits are set at the beginning and end. When reading and writing data to the FLASH storage chip, the valid flag bits of the data are checked, and then the time of the data is checked. One loop inspection algorithm module is connected to three combined current transformers via a synchronization signal. The synchronization signal enables the one loop inspection algorithm module to coordinate the high-frequency signal injection and signal detection of the three combined current transformers. The one loop inspection algorithm module communicates with the three combined current transformers via an SPI bus. The loop inspection algorithm module analyzes the return signals detected by the combined current transformers to obtain the status data of the current loop and reports the status data to the main control chip. The circuit inspection algorithm module reads the weak current signal of the combined current transformer through the electric shock identification algorithm. The weak current signal includes high-speed sampling data of the current waveform. Based on the high-speed sampling data of the current waveform, three-phase residual current information is synthesized, and leakage current information in the three-phase residual current information is separated. Electric shock waveform features are extracted from the leakage current information, and the electric shock waveform features are compared with typical electric shock fault waveform features in the model library to identify the type of electric shock fault.

2. The multi-parameter acquisition device according to claim 1, characterized in that, The multi-parameter acquisition device also includes a main control chip and a shielded socket: The metering chip is also used to send the electrical parameter acquisition data to the main control chip; The main control chip is used to report the received data to the main control module or to summarize and process the data before reporting it to the main control module. The shielded socket is externally covered with metal to prevent interference with the transmitted power and data signals. The AC-DC switching power supply outputs electrical energy through a shielded socket and sends it to the main control module to provide power to the main control module. The main control chip aggregates and processes the various data received and sends them to the main control module through the shielded socket in the form of at least one of USB bus, SPI bus, and GPIO bus.

3. The multi-parameter acquisition device according to claim 1, characterized in that, The multi-parameter acquisition device also includes a magnetic induction chip. When an abnormal magnetic field occurs in the external environment, the magnetic induction chip can detect it in time and report it to the main control chip through the GPIO bus.

4. The multi-parameter acquisition device according to claim 1, characterized in that, The multi-parameter acquisition device further includes a combined current transformer, used to convert externally input power frequency high-voltage current into a low-voltage signal, and transmit the low-voltage signal to the metering chip through a filtering circuit. The combined current transformer has a signal processing circuit board, a high-frequency injection coil, and a high-frequency detection coil. During operation, it injects a high-frequency signal into the external power frequency high-voltage current loop and detects the return signal. After detecting the return signal, it converts the return signal from an analog signal into data and sends it to the loop inspection algorithm module from the SPI bus. The power frequency coil and its auxiliary circuits in the combined current transformer can suppress DC components and even harmonics. The high-frequency injection coil and the high-frequency detection coil are both enclosed with copper shielding shells.

5. The multi-parameter acquisition device according to claim 1, characterized in that, The multi-parameter acquisition device also includes a neutral current transformer, which is used to realize three-phase four-wire current measurement so that it can be measured normally even when the external three-phase is unbalanced.

6. The multi-parameter acquisition device according to claim 2, characterized in that, The multi-parameter acquisition device further includes a topology identification module, which processes the voltage and current waveform data output by the metering chip to obtain the topology connection data of the external electrical equipment, and sends the topology connection data to the main control chip.

7. The multi-parameter acquisition device according to claim 1, characterized in that, The multi-parameter acquisition device is divided into a high-voltage area and a low-voltage area. The protection circuit, rectifier diode array, AC-DC switching power supply, voltage transformer, combined current transformer, and neutral current transformer are located in the high-voltage area. The metering chip, main control chip, topology identification module, loop inspection algorithm module, storage chip, magnetic induction chip, and shielded socket are located in the low-voltage area.

8. The multi-parameter acquisition device according to claim 4, characterized in that, The multi-parameter acquisition device includes a circuit board, the combined current transformer is disposed on the circuit board, and the high-voltage current line of the combined current transformer is located outside the circuit board.

9. The multi-parameter acquisition device according to any one of claims 1 to 8, characterized in that, The multi-parameter acquisition device includes a first surface and a second surface opposite to the first surface: The AC-DC switching power supply, supercapacitor module, protection circuit, voltage transformer, combined current transformer, neutral current transformer, and shielded socket are arranged on the first side. The rectifier diode array, metering chip, main control chip, loop inspection algorithm module, topology identification module, storage chip, and magnetic induction chip are disposed on the second side.

10. The multi-parameter acquisition device according to claim 4, characterized in that, The combined current transformer and the protection circuit are located on the terminal block near the housing of the multi-parameter acquisition device; The AC-DC switching power supply, voltage transformer, and neutral current transformer are located away from the terminal blocks of the multi-parameter acquisition device's housing and adjacent to the protection circuit. The supercapacitor module, metering chip, main control chip, loop inspection algorithm module, topology identification module, storage chip, magnetic induction chip, and shielded socket are located away from the combined current transformer and the protection circuit.

11. The multi-parameter acquisition device according to claim 1, characterized in that, The AC-DC switching power supply is a gallium nitride switching power supply; the AC-DC switching power supply also has the following functions: The output voltage of the AC-DC switching power supply is dynamically and finely adjusted within a preset range according to the load current, wherein the load includes the main control module and / or a module connected to the main control module.

12. The multi-parameter acquisition device according to claim 1, characterized in that, The AC-DC switching power supply also has the following functions: The AC-DC switching power supply can receive external input voltages within a preset voltage range, which is greater than a specific range threshold.

13. The multi-parameter acquisition device according to claim 1, characterized in that, The AC-DC switching power supply also has the following functions: When the external input voltage exceeds the preset voltage value, the AC-DC switching power supply will temporarily shut down its overvoltage protection function and resume operation once the voltage drops.

14. The multi-parameter acquisition device according to claim 1, characterized in that, The AC-DC switching power supply also has the following functions: The AC-DC switching power supply can output a steady-state power supply current greater than a first current threshold to the main control module, and when the short-term power consumption of the main control module is greater than a preset power consumption, it can output a peak current greater than a second current threshold to the main control module within a preset time period, wherein the second current threshold is greater than the first current threshold.

15. The multi-parameter acquisition device according to claim 1, characterized in that, The AC-DC switching power supply also has the following functions: The DC voltage output by the AC-DC switching power supply is divided into multiple frequency bands according to the frequency. The discrete noise value in the communication-sensitive frequency band is less than the first preset noise threshold, and the discrete noise value in the communication-insensitive frequency band is less than the second preset noise threshold. The first preset noise threshold is less than the second preset noise threshold.

16. The multi-parameter acquisition device according to claim 1, characterized in that, The AC-DC switching power supply also has the following functions: When the load power increases, causing the output power of the AC-DC switching power supply to exceed the preset power, the output current of the AC-DC switching power supply remains unchanged while the output voltage is reduced, resulting in a decrease in output power. After a period of time, the output voltage returns to normal. If the output power of the AC-DC switching power supply is still greater than the preset power, the output voltage is reduced again, and the cycle continues until the output power of the AC-DC switching power supply is less than or equal to the preset power.

17. The multi-parameter acquisition device according to claim 1, characterized in that, The supercapacitor module consists of two supercapacitors connected in series, and the capacitance of the supercapacitor module is greater than or equal to a preset capacitance value; the supercapacitor module also has the following functions: The received charging current is less than or equal to a specific current value, and the charging time is less than or equal to a preset time.

18. The multi-parameter acquisition device according to claim 1, characterized in that, The supercapacitor module also has the following functions: When the voltage inside the supercapacitor drops due to the output power of the supercapacitor module, the supercapacitor module outputs power after stabilizing the voltage through a boost circuit.

19. The multi-parameter acquisition device according to claim 2, characterized in that, The main control chip also has the following functions: When the supercapacitor module starts charging, the main control chip queries the voltage-power curve data and time-power curve data based on the charging voltage to determine the current power of the supercapacitor module and the time that the current power can sustain the multi-parameter acquisition device and the main control module to work normally, so as to make a decision based on the time.

20. The multi-parameter acquisition device according to claim 2, characterized in that, The main control chip also has the following functions: The system detects power failure signals from the external power supply. Upon detection of a power failure signal, it stores the current data before the supercapacitor module runs out of energy and reports the power failure event to the main control module.

21. The multi-parameter acquisition device according to claim 2, characterized in that, The main control chip also has the following functions: the main control chip is connected to the test and debugging interface through the test points on the circuit board, so that the multi-parameter acquisition device can communicate with external tooling through the test and debugging interface, which facilitates the external tooling to test the acquisition device.

22. The multi-parameter acquisition device according to claim 2, characterized in that, The main control chip also has the following functions: Execute the boot program initialization and application initialization.

23. The multi-parameter acquisition device according to claim 8, characterized in that: The circuit board has a four-layer structure. The bottom layer is adjacent to the housing of the multi-parameter acquisition device. Surface mount components are placed on the bottom layer. Circuit lines that are susceptible to interference are led out from the surface mount components on the bottom layer, pass through the two middle layers, and run on the top layer. The two middle layers are GND layers.

24. The multi-parameter acquisition device according to claim 5, characterized in that: For the current line connected to the neutral current transformer: each layer of the four-layer structure is covered with copper with a width greater than or equal to a preset width threshold, and the copper on the four-layer structure is tightly connected by dense vias to form the current line.

25. The multi-parameter acquisition device according to claim 2, characterized in that, The shielded socket includes 28 pins: Pins 1-24 are digital signal interfaces, using 0.5mm*0.5mm square pins, capable of passing 2.5A of current; Pins 25-26 are power supply pins, and pins 27-28 are GND pins. Both use 2mm*4mm contact clips as plug-in connectors and can carry 25A of current. Among them, USB's D+ and D- are pins 2 and 3, which are adjacent to each other; and they are also adjacent to the shielding shell of the GND pin and pins 1 and 4. On the circuit board, the CLK, DO, and CS pins of the unidirectional output SPI bus are pins 5-7, which are adjacent to each other; and all three are adjacent to the shielding shell that serves as the GND pin and pins 4 and 8. On the circuit board, the bidirectional input / output SPI bus CLK, CS, MISO, and MOSI are pins 9 to 11, which are adjacent to each other; and all four are adjacent to pins 1, 4, 17, and 20, which serve as GND pins. The active pulse CF1 and reactive pulse CF2, which are unidirectional outputs on the circuit board, are pins 18 and 19, respectively. They are adjacent to the shielding shell that serves as the GND pin and pins 17 and 20. On the circuit board, YX1, YX3, YX2, and YX4, which are unidirectional input remote signals, are pins 14, 15, 22, and 23, respectively, and are adjacent to each other; and together they are adjacent to the shielding shell that serves as the GND pin and pins 13, 16, 21, and 24.

26. The multi-parameter acquisition device according to claim 25, characterized in that, The USB line between pins 2-3 and the main control module includes a 120Ω surface-mount ferrite bead and two 33pF surface-mount capacitors, forming a π-type filter circuit.

27. The multi-parameter acquisition device according to claim 6, characterized in that, The metering chip sends electrical parameter acquisition data to the main control chip via the SPI interface. The metering chip sends raw waveform data to the topology identification module via the SPI interface. The topology identification module sends the topology connection relationship data to the main control chip via the UART interface. The topology identification module reports the raw waveform data to the main control module via the SPI interface. The main control chip reports data to the main control module via the SPI interface.

28. The multi-parameter acquisition device according to claim 2, characterized in that, External terminals acquire remote signaling information through four remote signaling input GPIO interface pins in the shielded socket of the multi-parameter acquisition device. When the four remote signaling input GPIO interface pins change position, the main control chip records the remote signaling change data and reports the remote signaling change data to the main control module through the USB interface in the shielded socket. The four remote signaling input GPIO interface pins can filter the jump waveforms in the acquired remote signaling information. The main control chip has a built-in trigger interrupt mechanism and digital filtering algorithm to de-jitter the remote signaling input signal. The de-jitter time can be configured. After remote signaling is identified, a communication report is sent to the main control module through the USB interface.

29. The multi-parameter acquisition device according to claim 2, characterized in that, The multi-parameter acquisition device has the following functions: The device communicates with the main control module via the SPI interface, enabling the main control module to perform online firmware upgrades in the multi-parameter acquisition device.

30. The multi-parameter acquisition device according to claim 2, characterized in that, The multi-parameter acquisition device has the following functions: Power frequency high-order harmonics are sampled, and the original sampled data is subjected to FFT transformation to obtain the effective value of each harmonic. The measurement value is calculated based on the effective value after FFT transformation, and the measurement value is compared with the measurement value collected under the standard source for correction.

31. The multi-parameter acquisition device according to claim 2, characterized in that, The multi-parameter acquisition device has the following functions: Electricity metering is calibrated using multiple calibration methods, including power calibration and pulse calibration.

32. The multi-parameter acquisition device according to claim 2, characterized in that, The multi-parameter acquisition device has the following functions: The data is filtered using a variety of filtering algorithms, including: first, the original data is filtered by using an empirical error judgment method; then, the sampled data is sorted by heap sort and / or quick sort; after sorting, the data at the beginning and end is deleted; and then the data in the middle is averaged.

33. The multi-parameter acquisition device according to claim 2, characterized in that, The multi-parameter acquisition device has the following functions: The temperature compensation coefficient corresponding to each temperature segment interval is determined based on the segmented calibration algorithm. The calibration curve is fitted using the Lagrange interpolation method, and the data is calibrated for temperature compensation based on the calibration curve.

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