Multi-parameter acquisition device based on transformer area intelligent fusion terminal

Abstract

The invention discloses a multi-parameter acquisition device based on a transformer area intelligent fusion terminal, and relates to the technical field of acquisition and metering. According to the multi-parameter acquisition device, an AC-DC switching power supply provides conventional power supply; the super capacitor module provides standby power supply; the protection circuit is used for protecting alternating current strong current voltage input from the outside and then transmitting the alternating current strong current voltage to the rectifier diode array; the rectifier diode array is used for carrying out rectification processing on the AC voltage after protection processing by using a diode and sending the AC voltage to the AC-DC switching power supply; the voltage transformer converts external power frequency strong current voltage into a weak current signal; the combined current transformer converts the external power frequency strong current into a weak current signal, injects a high-frequency signal into an external power frequency strong current loop and detects a return signal; the metering chip is used for metering weak current signals obtained after voltage and current conversion to obtain acquisition data; and the loop inspection algorithm module is connected with the combined current transformer, and analyzes the return signal to obtain state data of the current loop.

Description

Technical Field

[0001] The present invention relates to the field of data collection and metering technology, and in particular to a device for collecting and metering multiple electrical parameters of an intelligent fusion terminal in an area. Background Art

[0002] The low-voltage substation is the junction of the marketing and power distribution majors. The substation intelligent fusion terminal installed in the low-voltage substation provides functions such as collection, processing, remote signal sensing, and control output for the marketing and power distribution majors. With the development of the two majors, the functional requirements are becoming increasingly differentiated, and the performance requirements are increasing. On the one hand, the functional categories required by the two majors are becoming more and more inconsistent. For example, the loop inspection function is a new requirement for the marketing major; on the other hand, in the same functions required by both, the performance requirements are also becoming more and more different. For example, for the remote signal error time, the power distribution major requires that it should not be greater than 1ms, which is much higher than the marketing major.

[0003] The electric parameter acquisition and metering device is an important part of the intelligent fusion terminal of the substation area, and determines the functions and performance of the intelligent fusion terminal of the substation area at the basic acquisition and metering level. Therefore, a collection and metering device applied to the intelligent fusion terminal of the substation area, which has multiple functions required by the marketing and distribution professions, such as acquisition, metering, remote signaling, circuit inspection, topology identification, etc., and can also meet the performance requirements of the marketing and distribution professions, has become an urgent need. Summary of the invention

[0004] The purpose of the present invention is to propose a multi-parameter acquisition device applied to the intelligent fusion terminal of the substation area, aiming to solve the problems that the acquisition device in the intelligent fusion terminal of the substation area has insufficient types of collected parameters, incomplete collection functions, and insufficient collection performance.

[0005] The embodiment of the present application provides a multi-parameter acquisition device applied to the intelligent fusion terminal of the substation area, which has the functions of voltage acquisition, current acquisition, circuit status inspection, circuit topology identification, magnetic induction detection, remote signal identification and reporting, etc., and can communicate with the main control module in the intelligent fusion terminal of the substation area, and meet the needs of marketing and power distribution professionals in terms of function and performance. The multi-parameter acquisition device includes:

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

[0007] The supercapacitor module is used to store backup electric energy so as to supply power to the multi-parameter acquisition device and / or the main control module when the external power supply is cut off.

[0008] The protection circuit performs protection processing on the external input AC voltage and then transmits 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] The voltage transformer isolates the external industrial frequency strong voltage into a weak current signal and transmits it to the metering chip, eliminating the need for a specially added isolation chip between the strong current area and the weak current area in the traditional "resistance voltage division to collect strong current" method.

[0011] The combined current transformer is used to isolate and sense the external power frequency strong current into a weak current signal and transmit it to the metering chip. At the same time, it injects a high-frequency signal into the external power frequency strong 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 associated circuits can suppress the DC component and even harmonics input into the strong current loop. The high-frequency injection coil and the high-frequency detection coil are both enclosed in a copper shielding shell to prevent the high-frequency signal from radiating outward and to prevent the current detection accuracy of the combined current transformer from being disturbed.

[0012] The neutral line current transformer isolates the external neutral line strong current and senses it into a weak current signal and transmits it to the metering chip.

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

[0014] The main control chip is used to process and aggregate the received multiple data and report them to the main control module in the station area intelligent fusion terminal.

[0015] The loop inspection algorithm module is connected to the combined current transformer via an SPI bus and a synchronization signal line. The high-frequency signal data sent by the combined current transformer is received via the SPI bus, and analyzed and processed to obtain the external high-voltage current loop state data, and the external high-voltage current loop state data is reported to the main control chip. The loop inspection algorithm module is connected to the combined current transformer via a synchronization signal line, so that one loop inspection algorithm module cooperates with three combined current transformers to uniformly perform high-frequency signal injection and detection.

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

[0017] Magnetic induction chip: When an abnormal magnetic field appears in the outside world, the magnetic induction chip will sense it in time and report it to the main control chip via GPIO, so as to timely detect illegal behaviors such as using magnetic fields to disrupt electricity metering and steal electricity.

[0018] The memory chip comprises a ferroelectric memory chip and a FLASH memory chip. The ferroelectric memory chip and the FLASH memory chip can cross-back up data. When the data in the ferroelectric memory chip is abnormal, the data in the FLASH memory chip is read and the read data is written to the ferroelectric memory chip.

[0019] The shielded socket is metal-clad on the outside to prevent the transmitted signal from being interfered with. The multi-parameter acquisition device is connected to the power supply line and the communication line through the shielded socket to supply power to the main control module and report data to the main control module in a bus mode such as USB, SPI, GPIO, etc.

[0020] The circuit board layout of the multi-parameter acquisition device is divided into a strong current area and a weak current area. The protection circuit, the rectifier diode array, the AC-DC switching power supply, the voltage transformer, the combined current transformer, and the neutral line current transformer are arranged in the strong current area, and 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 shielding socket are arranged in the weak current area.

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

[0022] Exemplarily, the multi-parameter acquisition device includes a first surface and a second surface opposite to the first surface: the protection circuit, the AC-DC switching power supply, the voltage transformer, the combined current transformer, the neutral line current transformer, the supercapacitor module, and the shielded socket are arranged on the first surface; 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 arranged on the second surface.

[0023] Exemplarily, the protection circuit and the combined current transformer are arranged at a terminal block close to the casing of the multi-parameter acquisition device; the AC-DC switching power supply, the voltage transformer, and the neutral current transformer are away from the terminal block of the casing of the multi-parameter acquisition device and are 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 away from the protection circuit and the combined current transformer.

[0024] Exemplarily, 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 current of the load, wherein the load includes the main control module and / or a module connected to the main control module.

[0025] Exemplarily, the AC-DC switching power supply further 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] Exemplarily, the AC-DC switching power supply also has the following function: when the voltage of the external input is greater than a preset voltage value, the AC-DC switching power supply starts the overvoltage protection function and temporarily shuts down, and resumes starting after the voltage drops.

[0027] Exemplarily, 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, 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] Exemplarily, the AC-DC switching power supply also has the following functions: the DC voltage output by the AC-DC switching power supply is segmented according to the 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-insensitive 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] Exemplarily, the AC-DC switching power supply also has the following function: when the power of the load increases and causes the output power of the AC-DC switching power supply to be greater than a 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, and the output voltage returns to normal after a period of time. 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 is repeated until the output power of the AC-DC switching power supply is less than or equal to the preset power.

[0030] Exemplarily, 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 length is less than or equal to a preset time length.

[0031] Exemplarily, the supercapacitor module also has the following function: when the supercapacitor module outputs electrical energy causing the voltage inside the supercapacitor to drop, the supercapacitor module outputs electrical energy after stabilizing the voltage through a boost circuit.

[0032] Exemplarily, the main control chip also has the following functions: when the supercapacitor module starts to charge, the main control chip queries the voltage-electricity curve data and the time-electricity curve data based on the charging voltage to determine the current electric quantity of the supercapacitor module and the time during which the current electric quantity 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] Exemplarily, the main control chip also has the following functions: detecting a power-off signal of an external power supply, after detecting the power-off signal, storing current data before the energy of the supercapacitor module is exhausted, and reporting the power-off event to the main control module;

[0034] Exemplarily, the main control chip also has the following functions: the main control chip is connected to the test and debugging interface through the test point on the circuit board, so that the multi-parameter acquisition device communicates with the external tooling through the test and debugging interface, so as to facilitate the external tooling to communicate and test the multi-parameter acquisition device;

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

[0036] Exemplarily, the circuit board includes a four-layer structure, the bottom layer is adjacent to the casing of the multi-parameter acquisition device, the chip components are arranged on the bottom layer, the circuit lines susceptible to interference are led out from the chip components on the bottom layer, pass through the middle two layers, reach the top layer and routed on the top layer, and the middle two layers are GND layers.

[0037] Exemplarily, for the current line connected to the neutral line 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, and the copper on the four-layer structure is tightly connected through dense through holes to form the current line.

[0038] Exemplarily, 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 current; pins 25-26 are power supply pins, and pins 27-28 are GND pins, both using 2mm*4mm contact clips as plug-ins, capable of passing 25A current; among them, the D+ and D- of the USB are pins 2-3, and the two pins are adjacent; and the two are adjacent to the shielding shell and pins 1 and 4 as the GND pins; the CLK, DO, and CS of the unidirectional output SPI bus on the circuit board are pins 5-7, and the three are adjacent; and the three are adjacent to the shielding shell as the GND pin. The shielding shell and pins 4 and 8; the CLK, CS, MISO, and MOSI of the bidirectional input and output SPI bus on the circuit board are pins 9 to 11, and the four are adjacent to each other; and the four are together adjacent to pins 1, 4, 17, and 20 as GND pins; the unidirectional output active pulse CF1 and reactive pulse CF2 on the circuit board are pins 18 and 19, and the two are together adjacent to the shielding shell and pins 17 and 20 as GND pins; the unidirectional input remote signal YX1, YX3, YX2, and YX4 on the circuit board are pins 14, 15, 22, and 23 respectively, and the four are adjacent to each other; and the four are together adjacent to the shielding shell and pins 13, 16, 21, and 24 as GND pins.

[0039] Exemplarily, the USB line between the 2-3 pin and the main control module includes one 120Ω chip bead and two 33pF chip capacitors, forming a π-type filter circuit.

[0040] Exemplarily, the metering chip sends electrical parameter acquisition data to the main control chip through the SPI interface, the metering chip sends original waveform data to the topology identification module through the SPI interface, the topology identification module sends the topology connection relationship data to the main control chip through the UART interface, the topology identification module reports the original waveform data to the main control module through the SPI interface, and the main control chip reports data to the main control module through the SPI interface.

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

[0042] Exemplarily, the loop inspection algorithm module reads the weak current signal of the combined current transformer through an electric shock identification algorithm, wherein the weak current signal includes high-speed sampling data of the current waveform, synthesizes the three-phase residual current information based on the high-speed sampling number of the current waveform, separates the leakage current information in the three-phase residual current information, extracts the electric shock waveform features of the leakage current information, and compares the electric shock waveform features with the typical waveform features of electric shock faults in the model library to identify the type of electric shock fault.

[0043] Exemplarily, the multi-parameter acquisition device has the following functions: communicating with the main control module via an SPI interface so that the main control module can perform online upgrade of the firmware in the multi-parameter acquisition device;

[0044] Exemplarily, the multi-parameter acquisition device has the following functions: sampling the power frequency high-order harmonics, performing FFT transformation on the original sampled data to obtain the effective value of each harmonic, calculating the effective value based on the FFT transformed effective value to obtain the measurement value, and comparing the measurement value with the measurement value collected under the standard source for correction;

[0045] Exemplarily, the multi-parameter acquisition device has the following functions: calibrating electric energy measurement through multiple calibration methods, wherein the multiple calibration methods include a power calibration method and a pulse calibration method;

[0046] Exemplarily, the multi-parameter acquisition device has the following functions: filtering data by a variety of filtering algorithms, including: firstly screening and processing the original data by an empirical error determination method, then sorting the sampled data by a heap sort method and / or a quick sort method, deleting the front and rear parts of the data after sorting, and then averaging the middle part of the data;

[0047] Exemplarily, the multi-parameter acquisition device has the following functions: determining the temperature compensation coefficient corresponding to each temperature segment interval based on a 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] Exemplarily, for each type of data that needs to be recorded in the multi-parameter acquisition device, at least the first and last two valid flag bits are set.

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

[0050] The multi-parameter acquisition device disclosed in the present invention at least includes components such as 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 the components, it can effectively solve the problem that the acquisition device in the intelligent fusion terminal of the substation area has insufficient types of acquisition parameters, incomplete acquisition functions, and insufficient acquisition performance. Specifically, the AC-DC switching power supply is used to convert the external input AC voltage into a DC voltage and then power the multi-parameter acquisition device. The supercapacitor module is used to store backup power so as to power the multi-parameter acquisition device and / or the main control module when the external power supply is powered off. The protection circuit is used to perform protection processing on the external input AC strong voltage and transmit it to the rectifier diode array. The rectifier diode array is used to rectify the AC voltage after the protection processing through a diode and send it to the AC-DC switching power supply. The voltage transformer is used to convert the external input power frequency strong voltage into a weak current signal, and transmit the weak current signal to the metering chip through a filtering circuit. The metering chip is used to obtain electrical parameter acquisition data based on the received weak current signal. It can be seen that the present invention has the functions of voltage collection, current collection, loop status inspection, loop topology identification, magnetic induction detection, remote signal identification and reporting, etc. It can communicate with the main control module in the substation intelligent fusion terminal, and meet the needs of marketing and distribution professionals in terms of function and performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A schematic diagram of the composition architecture of a multi-parameter acquisition device provided in an embodiment of the present application is shown;

[0052] Figure 2 A front schematic diagram of a multi-parameter acquisition device provided in an embodiment of the present application is shown;

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

[0054] Figure 4 A functional schematic diagram of a multi-parameter acquisition device provided in an embodiment of the present application is shown;

[0055] Figure 5 A schematic diagram of the circuit board routing of the multi-parameter acquisition device provided in an embodiment of the present application is shown;

[0056] Figure 6A schematic diagram of a shielding socket provided in an embodiment of the present application is shown;

[0057] Figure 7 A schematic diagram of a filter circuit provided in an embodiment of the present application is shown;

[0058] Figure 8 A schematic diagram of data communication provided by an embodiment of the present application is shown.

[0059] Fig. 9 A schematic diagram of a combined current transformer provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

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

[0061] At present, the industry is developing and promoting intelligent integrated terminals in substations, trying to meet the new needs of integrating the above-mentioned marketing functions and distribution functions, collecting multiple electrical parameters, and multi-functional data information processing. Based on this situation, the present invention adopts multiple new technologies to meet the new needs.

[0062] At present, the data acquisition devices in the intelligent fusion terminals in the industry do not collect enough types of electrical parameters, resulting in a lack of commonality for the two professions of marketing and power distribution. Although there are some similar functions in the two professions of marketing and power distribution, there are still many functions that are different from each other. For example, the acquisition of industrial frequency AC voltage and current is required by both marketing and power distribution, but circuit inspection is only required by marketing. For another example, the current data acquisition devices used in the industry for marketing professionals only have 2-channel remote signal detection, which cannot meet the requirement of at least 4-channel for power distribution professionals.

[0063] The performance of current AC power parameter acquisition devices is not high enough. For example, many acquisition devices in the industry currently have too large telemetering errors, which can only meet the needs of marketing professionals, but cannot meet the needs of low errors in power distribution professionals.

[0064] Current AC power parameter acquisition devices lack extended functions. The lack of a loop inspection function is a typical example. Most acquisition devices only have voltage and current acquisition functions, and do not have the ability to monitor abnormal current conditions such as short circuits and open circuits on the strong power side. The loop inspection function can parse out relevant information about the operation of the strong power side by detecting the voltage induced by the current on the weak power side, thereby realizing functional operations such as measurement, monitoring, control, regulation, and protection of the equipment on the strong power side. For another example, there is a lack of topology recognition function. Topology recognition is to analyze characteristic current signals based on the waveform data of the metering chip through AC acquisition. Existing acquisition devices do not have the function of identifying the topological connection relationship of power equipment based on the original waveform data, which limits the functional expansion of the equipment.

[0065] The present invention realizes the functional integration of marketing and power distribution business in the same terminal, designs a collection device that is adapted to the intelligent fusion terminal of the substation and can collect multiple electrical parameters, and can simultaneously meet the collection functions required by the two professions of marketing and power distribution.

[0066] The present invention proposes a multi-parameter acquisition device suitable for intelligent fusion terminals in substations. In terms of hardware, the present invention has functional components that meet the needs of both marketing and power distribution. In terms of software, the present invention patent has real-time intelligent processing functions on components such as CPU chips and loop inspection algorithm modules. Through dedicated programs and algorithms, the corresponding hardware components are driven to work, realizing the functions required by the two professions.

[0067] Therefore, based on the basic AC power parameter collection function, the present invention can support marketing and power distribution business at the same time, meet the AC power parameter collection needs of the two professions, and can also expand some extended businesses suitable for marketing and power distribution, and meet the expansion needs of the two professions.

[0068] The present invention is a metering control device invented in accordance with the series of standards of "Technical Specifications for Intelligent Fusion Terminals in Substation Areas". The present invention adopts a high-performance Cortex M4 core processor as the main control chip, and integrates ferroelectric memory chips and FLASH memory chips on the periphery. It integrates functions such as power metering, power monitoring, harmonic analysis, state quantity collection, loop inspection, topology identification, power output, etc. It has excellent reliability, stability, and safety, and meets the application requirements of power distribution, marketing and other power services.

[0069] In view of the above-mentioned problems, this embodiment provides a multi-parameter acquisition device based on a substation intelligent fusion terminal.

[0070] Figure 1 A schematic diagram of the composition architecture of a multi-parameter acquisition device provided in an embodiment of the present application is shown.

[0071] Figure 1The composition structure of a multi-parameter acquisition device is shown, and the multi-parameter acquisition device can communicate 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] The AC-DC switching power supply is used to convert the external input AC voltage into a DC voltage and then supply power to the multi-parameter acquisition device.

[0073] 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 when the external power supply is cut off.

[0074] The protection circuit is used to protect the external input AC strong voltage and transmit it to the rectifier diode array.

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

[0076] The voltage transformer is used to convert the external input power frequency strong voltage into a weak current signal, and transmit the weak current signal to the metering chip through the filter circuit. The use of voltage transformers replaces the traditional method of resistor voltage division, isolates strong current from weak current, eliminates the "hot ground", and saves the use of isolation devices.

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

[0078] Figure 2 A front schematic diagram of a multi-parameter acquisition device provided in an embodiment of the present application is shown.

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

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

[0081] refer to Figures 1 to 3In another example, the multi-parameter acquisition device further 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. The protection circuit includes, for example, a varistor, a common mode inductor filter, and a thermistor. The shielded socket is, for example, a 24+4pin shielded socket, that is, a shielded socket including 28 pins.

[0082] The metering chip is also used to send the electrical parameter collection 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 and then report it to the main control module.

[0084] The storage chip includes a ferroelectric storage chip and a FLASH storage chip. The ferroelectric storage chip and the FLASH storage chip can cross-backup 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 in a single memory chip, the present invention stores data separately according to different data types. For example, a 16KB ferroelectric memory chip and a 16MB FLASH memory chip are used for separate storage. The multi-parameter acquisition device converts all the collected data into integer data and then into hexadecimal data. The currently used hexadecimal data is stored in the ferroelectric memory chip and is also stored in the FLASH memory chip as a backup. The ferroelectric memory chip is characterized by a long read and write life. Under normal circumstances, it can read and write 10 13 The FLASH memory chip is characterized by its large storage capacity, so it is suitable for storing data that is currently in use and changes frequently. The FLASH memory chip is characterized by its large storage capacity, so it is suitable for storing large amounts of data that are not frequently read or written. Therefore, the data currently in use is stored in the ferroelectric memory chip, making full use of the long read and write life of the ferroelectric memory chip; the backup data is stored in the FLASH memory chip, which can remain unchanged for a long time and can be backed up multiple times.

[0086] The present invention designs a special data protection mechanism to prevent loss and bad blocks of stored data. For important data in the software (such as the collected electrical parameter values), cross-backup is performed in the storage chip: normal data is written in a storage chip with good read and write durability such as a ferroelectric, and backup data is written in a storage chip with a large storage capacity such as a FLASH storage chip. When the main area data (data in the ferroelectric storage chip) is abnormal, the data in the backup area is immediately started for reading and writing, and the data in the backup area is written back to the main area (ferroelectric storage chip), thereby improving data security and system redundancy.

[0087] The shielded socket is coated with metal to prevent the transmitted power supply and signal from being interfered. The power output by the AC-DC switching power supply of the multi-parameter acquisition device is sent to the main control module through the shielded socket to provide power for the main control module. The main control chip of the multi-parameter acquisition device aggregates and processes the received multiple data and sends them to the main control module through the shielded socket in the form of USB, SPI, GPIO and other buses.

[0088] Magnetic induction chip: When an abnormal magnetic field appears in the outside world, the magnetic induction chip will sense it in time and report it to the main control chip via GPIO, so as to prevent illegal behaviors such as disrupting energy metering and stealing electricity by using magnetic fields.

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

[0090] The combined current transformer is used to convert the external input power frequency strong current into a weak current signal, and transmit the weak current signal to the metering chip through the filter circuit. Fig. 9 As shown, unlike traditional current transformers, 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 high-frequency signals into the external industrial frequency strong current loop and detects the return signal. After the return signal is detected, it is converted from an analog signal to data and sent from the SPI bus to the loop inspection algorithm module. The industrial frequency coil and its auxiliary circuits in the combined current transformer of the multi-parameter acquisition device can suppress DC components and even harmonics. In the combined current transformer of the multi-parameter acquisition device, the high-frequency injection coil and the high-frequency detection coil are enclosed with a copper shielding shell to prevent the high-frequency signal from radiating outward and to prevent the accuracy of the current detection of the combined current transformer from being disturbed.

[0091] The neutral current transformer realizes three-phase four-wire current measurement, and can also perform normal measurement when the external three-phase is unbalanced.

[0092] A loop inspection algorithm module is connected to three combined current transformers via an SPI bus. The loop inspection algorithm module analyzes the return 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 is connected to the combined current transformer with a synchronization signal, so that one loop inspection algorithm module can coordinate the high-frequency signal injection and detection of the three combined current transformers.

[0093] The topology recognition module is used to process the voltage and current waveform data output by the metering chip, obtain the topological connection relationship data of the external power-consuming equipment, and send the topological connection relationship data to the main control chip.

[0094] Among them, the multi-parameter acquisition device includes a circuit board, a combined current transformer is arranged on the circuit board, a high-voltage current line of the combined current transformer is located outside the circuit board, and other components can be arranged on the circuit board.

[0095] The present invention can be equipped with an external current transformer interface. In some special installation environments, the three-phase current transformer needs to be placed independently outside the whole machine, and the secondary side wire of the current transformer is connected to the metering chip. The present invention sets three sets of secondary side wire terminals of the current transformer, which are used to reserve the connection of the external current transformer. When the user uses the external current transformer, the wire of the current transformer can be plugged into the preset terminal of the present invention.

[0096] In addition, the present invention takes into account the requirements of adapting the main control module, adapting the relevant housing, and resisting electromagnetic interference, and makes a special layout of the components in the multi-parameter acquisition device.

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

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

[0099] The combined current transformer and the protection circuit are arranged at the terminal block close to the housing of the multi-parameter acquisition device. The AC-DC switching power supply, the voltage transformer, and the neutral current transformer are far away from the terminal block of the housing of the multi-parameter acquisition device and are adjacent to the protection circuit. The supercapacitor module, 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 far away from the combined current transformer and the protection circuit.

[0100] The present invention improves the layout of components of the multi-parameter acquisition device according to actual use requirements, combined with the housing form and the interface position of the main control module. According to the design principles of isolating strong and weak electricity, shortening signal routing as much as possible, and keeping analog chips away from interference sources, as well as production principles such as easy welding and easy assembly, the following improvements are made:

[0101] First reference Figure 2 The front schematic diagram shows that the first side (front) does not place SMD components, but only DIP components, which is convenient for simplifying the process during production welding and improving welding efficiency.

[0102] The present invention adopts the method of strong and weak electricity zoning for layout, in which the strong electricity area is Figure 2 The two areas within the red border are divided into high-current area (on the board) and high-current area (off the board). On the board means that the area is on the circuit board, and off the board means that the area is outside the circuit board. The rest of the area except the high-current area is the low-current area.

[0103] like Figure 2 As shown, the high-voltage area (not on the board) includes the high-voltage current line of the combined current transformer (A, B, C three-phase current line), the high-voltage current line of the neutral current transformer, and the voltage line (A, B, C, N three-phase four-wire voltage line). The high-voltage current is connected from the terminal block of the casing of the multi-parameter acquisition device to the plastic sheath wire of the combined current transformer, and then directly connected to the combined current transformer without passing through the circuit board. Therefore, the high-voltage in this area does not need to be protected on the board, and the protection and signal processing are completed by the combined current transformer. The combined current transformer is placed near the lower edge of the board, which also facilitates the installation of the plastic sheath wire to the terminal block of the casing.

[0104] Layout of the protection circuit in the high-voltage area (on the board): Since the three-phase voltage wires that input high-voltage 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 facilitate the connection of the high-voltage wires to the terminal block of the casing.

[0105] Layout of high-voltage application components in the high-voltage area (on the board): Place the AC-DC switching power supply, three voltage transformers, one neutral current transformer and other high-voltage application components on the right side of the front of the board, slightly above, adjacent to the protection circuit (varistor, common-mode inductor filter, thermistor) on the lower right side. This makes it easy to introduce high-voltage power that has been protected, and to convert AC signals into DC signals through three voltage transformers and current transformers, as well as convert high-voltage signals into low-voltage signals for post-stage sampling and processing. Three-phase four-wire AC power has voltages A, B, C, N, and currents A, B, C, N. When the three-phase voltage is unbalanced, the neutral current is not 0, and the current value needs to be detected. The low-voltage signal of the neutral current comes from the neutral current transformer.

[0106] Front layout of the weak current 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, there are only these two direct plug-in components in the weak current area. This design keeps the weak current area away from the strong current access area of ​​the combined current transformer on the lower side of the circuit board, and also away from the strong voltage access area on the lower right side of the circuit board, achieving isolation between the strong and weak current areas and reducing the impact of strong electromagnetic interference.

[0107] refer to Figure 3The back side of the diagram shows that the strong and weak current partitions overlap with the front side. The strong current area only has a rectifier diode array, and its position basically overlaps with the bottom of the AC-DC switching power supply on the front side, as shown in the figure below. Figure 3 The area within the red frame is the strong current area, and the rest is the weak current area. The layout plan is that the metering chip, loop inspection algorithm module and other devices are close to the left side of the circuit board (relative to the left side of the front of the circuit board), and close to the strong current conversion devices on the bottom (for example, including 3 voltage transformers, 3 combined current transformers, 1 zero line current transformer, and some conditioning circuits composed of resistors and capacitors, etc.), so as to facilitate the conversion of analog signals (such as 3 voltages, 3+1 currents, one of which is the converted zero line current) Connect to the analog device nearby. The digital devices such as CPU, FLASH memory chip, ferroelectric memory chip are above the circuit board, not only away from the strong current area, but also as far away from analog devices as possible to prevent interference to the analog devices, or to achieve the function of avoiding interference when there is external electromagnetic interference input.

[0108] Exemplarily, the AC-DC switching power supply is a gallium nitride switching power supply. The AC-DC switching power supply used on the circuit board of the present invention adopts a cascode gallium nitride power device (GaN FET) based on a silicon substrate, and has the following characteristics: high frequency, low loss, high reliability, etc.:

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

[0110] (2) At the same time, under the rated input and rated output test conditions, the temperature rise of GaN 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 life of the power supply.

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

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

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

[0114] This invention adopts a high-precision AC-DC switching power supply, which can supply power to the main control module through the AC-DC switching power supply on the circuit board. The output voltage of the switching power supply (for example, 5V) can be accurately and dynamically adjusted in real time within a certain range according to the load current size to ensure that the no-load voltage of the modules in the 1st and 2nd 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 meets the interface requirements of the "Technical Specifications for Intelligent Fusion Terminals in Substations". The load includes, for example, 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 when the computing task is heavy. There are 3 slots on the main control module. When small modules such as carrier and 4G are connected, the power consumption will increase, especially the 4G small module consumes a lot of power during wireless communication. The AC-DC switching power supply of the present invention can also ensure that the steady-state load voltage of the 1st, 2nd and 3rd 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, meeting the load capacity requirements of the "Technical Specifications for Intelligent Fusion Terminals in Substations".

[0115] (2) 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.

[0116] The AC-DC switching power supply used in the present invention has a wide voltage input range. Under the premise of ensuring accurate and stable output of DC voltage, the input AC voltage range is AC 154V~500V or DC 218V~700V, that is, the preset voltage range is AC 154V~500V or DC 218V~700V, and the preset voltage range is greater than the specific range threshold. The specific range threshold can be specifically set, such as AC 150V, DC 200V, etc. The wide input voltage range ensures that the multi-parameter acquisition device of the present invention has good adaptability to the external input voltage, and can adapt to the non-mains AC input voltage within the range, and can also adapt to the AC input voltage that fluctuates within the 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 and temporarily shuts down, and resumes starting after the voltage drops.

[0118] The AC-DC switching power supply used in the present invention has an input overvoltage protection function. When the input voltage is higher than AC760V or DC1077V, the preset voltage value is, for example, AC760V or DC1077V, and the AC-DC switching power supply starts the self-protection function, which can be temporarily shut down to ensure that the power supply is not damaged. After the overvoltage is released, it can return to normal.

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

[0120] The input of the patent of this invention is a three-phase 220 / 380V AC voltage. Through the on-board AC-DC switching power supply, a 7A steady-state power supply current can be provided to the main control module used in conjunction with the patent of this invention. When the short-term power consumption is large, such as greater than the preset power consumption, a maximum peak current of 9A can be provided, and the duration is ≥200ms. The strong load capacity ensures that the steady-state load capacity and transient load capacity of the three module slots of the main control module meet the load capacity requirements of the "Technical Specifications for Intelligent Fusion Terminals in Substations".

[0121] (5) The DC voltage output by the AC-DC switching power supply is segmented according to the frequency to obtain multiple frequency bands, the discrete noise value in the communication-sensitive frequency band is less than a first preset noise threshold (for example, 1 mV), the discrete noise value in the communication-insensitive frequency band is less than a second preset noise threshold (for example, 2 mV, 3 mV or 3 mV), and 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 is segmented according to frequency, and the discrete noise satisfies the following:

[0123] 3.0kHz~150kHz,≤5mV;

[0124] 150kHz~200kHz,≤3mV;

[0125] 200kHz~500kHz,≤2mV;

[0126] 0.5MHz~30MHz,≤1mV.

[0127] Achieve lower discrete noise in the communication sensitive frequency band. Generally speaking, 0.7M~3M, 2M~5M, and 2M~12MHz are all carrier communication frequency bands, which are more sensitive to interference. Therefore, these frequency bands are used as communication sensitive frequency bands, and 0.5M~30MHz requires the lowest noise because these three frequency bands are covered. Appropriately relax the discrete noise in the frequency band that is not particularly sensitive to communication, which ensures that the power carrier communication module used in conjunction with the multi-parameter acquisition device of the present invention is not easily interfered during carrier communication, and does not need to invest too many components to reduce ripple in the full frequency band, thus achieving a balance between performance and cost.

[0128] (6) When the load power increases and causes the output power of the AC-DC switching power supply to be greater than the preset power (for example, 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, the AC-DC switching power supply has a hiccup protection function under overpower. When the external load is too heavy (such as an external circuit short circuit, partial damage causing excessive power consumption, and other unexpected situations), causing the output current to be greater than the rated value and the output power to be greater than 35W, the AC-DC switching power supply starts the hiccup self-protection function, the output current remains unchanged, but the output voltage is reduced, and the output power is reduced. After a period of time, the AC-DC switching power supply automatically tries to restore the output voltage to normal levels. After the output voltage returns to normal levels, if it is found that the load has not been reduced and the output power is not less than 35W, the voltage will be reduced again and a new round of hiccup protection will be started until the output power is reduced to meet the rated power index of the power supply.

[0130] In the present invention, the supercapacitor module is composed of two supercapacitors connected in series, and the capacity of the supercapacitor module is greater than or equal to the preset capacity value, and the preset capacity value is, for example, 165F. For example, a 165F high-capacity supercapacitor module is selected as a backup power supply, and the stored electricity is 165F*5V=825C. When discharged at a power of 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, after the external AC power is cut off (after the external AC power is cut off, the AC-DC switching power supply loses the power supply source and cannot continue to supply power to the outside), it continues to work for not less than 3 minutes under the support of the supercapacitor module, and continues to output 5V power to the main control module, supporting the main control module to continue to work for not less than 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 (for example, 1.5 A), and the charging time is less than or equal to a preset time length (for example, 25 minutes).

[0133] For example, the charging current and charging time of the supercapacitor module can be strictly set. The supercapacitor module is designed to have a charging current of 1.5A. This current is developed after comprehensive design in many aspects. Through ADC monitoring, feedback, and current limiting mechanisms of the charging current, the patent of the present invention effectively limits the charging current to 1.5A, ensuring that the mainboard does not consume too much current due to charging, thereby avoiding the impact of charging on the normal operation of the multi-parameter acquisition device of the present invention. When the current is limited to 1.5A, the charging time can also be accurately controlled to ≤25 minutes, achieving charging within a limited time range, and avoiding the impact of long charging time on the use of the entire machine.

[0134] (2) When the supercapacitor module outputs electrical energy and causes the voltage inside the supercapacitor to drop, the supercapacitor module stabilizes the voltage through a boost circuit and then outputs the electrical energy.

[0135] For example, the energy storage, boost, and voltage stabilization 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 the present invention can withstand is appropriately greater than the working voltage (5V) on the board, which not only meets the demand but also leaves a certain margin.

[0136] The voltage output of the supercapacitor module adopts a "boost-stabilization" architecture. As the supercapacitor module continuously outputs electrical energy, the voltage of the supercapacitor body also continues to drop. The present invention adopts a boost circuit to increase the reduced voltage of the supercapacitor body to 5V, and then outputs it after voltage stabilization. The output voltage is 5V±2%, and the output ripple is 30mV, which meets the specific needs of related use.

[0137] In addition, the main control chip of the present invention is a main control chip with variable frequency. According to actual use needs, a high-performance Cortex M4 core processor is used as the main control chip. The main control chip realizes that the operating frequency is configurable within a certain range, up to 150MHz. Built-in 256KB SRAM, 1MB Flash, 32K Cache RAM, support system startup from Flash (Flash saves data for not less than 10 years). Thus, the present invention can be implemented according to different actual use needs, for different versions of products, different CPU frequencies are configured, and different programs are loaded. It is achieved that the lowest operating frequency is selected under the premise of meeting the use requirements, 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 to charge, the main control chip queries the voltage-capacity curve data and the time-capacity curve data based on the charging voltage to determine the current capacity of the supercapacitor module and the time that the current capacity can maintain the normal operation of the multi-parameter acquisition device and the main control module, so as to make decisions based on the time.

[0140] For example, the supercapacitor module supports the internal power detection function. The capacitor module has the function of monitoring its internal voltage. The pin function definition of the supercapacitor module is as follows:

[0141] Pin number 1 2 3 4 Pin Function Definition Vin (voltage input) Vout (voltage output) Vdet (voltage detection) GND (ground)

[0142] Among them, the third pin is connected from the positive pole of the series-connected supercapacitor in the supercapacitor module, and is connected to the high-precision ADC pin of the CPU chip (main control chip) on the board through this pin. The CPU chip on the board stores a data table of the various data points that make up the "voltage-electricity" curve of the supercapacitor. The high-precision ADC pin of the CPU collects the voltage of the supercapacitor and calculates it into data, and then consults the data table for conversion or matching operations to obtain the value of the current amount of electricity stored in the supercapacitor. For example, a voltage of 2.7V corresponds to 150F of electricity, 2.6V corresponds to 140F of electricity, 2.5V corresponds to 120F of electricity, and so on. This correspondence may not be linear. Substituting the voltage into the curve, you can convert or match to find out how much electricity is currently available.

[0143] Supercapacitor storage electricity metering algorithm: The voltage of the supercapacitor is not completely linear with the amount of electricity stored. In the middle of charging (i.e., constant current charging period), the amount of electricity is linearly related to the voltage. In the early stage of charging (i.e., trickle charging period) and after charging to a certain amount of electricity (i.e., constant voltage charging period), the amount of electricity increases normally but the voltage increases slightly. The CPU chip of the present invention has a built-in specially designed supercapacitor electricity metering algorithm, as well as a "time-electricity" curve data table prepared for a preliminary test of this type of supercapacitor. When the supercapacitor starts to charge, the CPU collects voltage on the one hand and performs timing on the other hand. According to the stored "voltage-electricity" curve data table and "time-electricity" curve data table, combined with the currently collected voltage, the measurement of the stored electricity is calculated and calibrated, and then the percentage of the current stored electricity in the total storage is accurately calculated, and the time that the current electricity supply multi-parameter acquisition device and the main control module can maintain normal operation is calculated, thereby providing a basis for the CPU chip to perform various decision-making operations.

[0144] (2) Detecting a power-off signal of an external power supply, after detecting the power-off signal, storing current data before the energy of the supercapacitor module is exhausted, and reporting the power-off event to the main control module.

[0145] The present invention can timely monitor the power failure event of the external alternating current. At the output end of the AC-DC switching power supply on the board, the output 5V is used as a control signal to control the base circuit of the transistor, thereby controlling the on and off state of the transistor. If the 5V voltage output by the AC-DC switching power supply is disconnected, the on and off state of the transistor cannot be controlled any more. The base of the transistor is pulled up to the 5V output voltage of the supercapacitor, and the 5V output by the AC-DC switching power supply pulls the base down through the inverter circuit; when the 5V output by the AC-DC switching power supply is disconnected, the base of the transistor is pulled up again and is turned on instead. The on and off signal of the transistor is connected to the main control chip on the board to realize the function of the external power failure monitoring circuit. When the external alternating current fails, the monitoring circuit on the circuit board of the present invention is triggered, and a notification signal is generated and transmitted to the main control chip on the board. After receiving the power failure signal, the main control chip saves the data currently in use before the energy storage of the backup power supply is exhausted. After the power-off signal is generated, information is also sent 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-off event, so that the main control module can also save 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, thereby facilitating the external tooling to test the multi-parameter acquisition device.

[0147] The main control chip supports connecting the JTAG (Joint Test Action Group) test interface and the SW debugging interface. The SW interface usually refers to the serial wire debug interface (SWD for short). The SW interface is a serial interface standard for debugging and programming. The JTAG test interface and the SW debugging interface are connected to a special test point on the PCB board (circuit board) by routing. After the main control chip is welded to the whole board, when the multi-parameter acquisition device of the present invention is mass-produced in the factory, the factory's tooling uses a probe to contact the reserved test points on the PCB board (including the JTAG test interface and the SW debugging interface, and other contact points that require test signals) to download the program, so that the download device and the test device are implemented with the same tooling, which is convenient for debugging and maintenance. The tooling outputs the program, and the multi-parameter acquisition device receives the program. The tooling has a special circuit board to initiate the output program. The tooling has a special circuit board. After downloading, the interface functions and signals of the multi-parameter acquisition device are tested through the test points of the multi-parameter acquisition device. During the test, the multi-parameter acquisition device is taken as a whole. When the multi-parameter acquisition device is tested, the program just downloaded is run, and the program controls the multi-parameter acquisition device to be tested.

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

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

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

[0151] The boot program is initialized and executed or dominated by the main control chip on the multi-parameter acquisition device board to initialize the clock and peripherals. After the settings are completed, it communicates with the main control module, and detects in turn whether the main control module has sent it an online upgrade file, whether the online upgrade file is valid, and whether the online upgrade file has been verified. If the detection passes, it communicates with the main control module, transfers 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 jump to the application running area.

[0152] Application initialization. Since the application and boot program run in different address areas, it is necessary to initialize and configure the peripherals after jumping to the application area. The peripherals include watchdog (timer circuit or chip), SPI bus, IIC bus, Uart, etc. After that, the parameters are initialized and configured. The calibration parameters, remote signal parameters, 698 communication default parameters, and freeze parameters are loaded and configured respectively. During the loading process, if there is configuration data in the Flash storage chip, it is loaded according to the stored data, otherwise it is configured according to the default set of parameters (default values).

[0153] Application function, after the above initialization is completed, the software enters the application function loop processing process (this process is led by the main control chip): data reception and transmission of each communication channel, including exchange sampling (AC sampling) channel, loop inspection channel, topology identification channel, remote signal pulse channel, debugging serial port channel, etc. The received data is first placed in the RAM area of ​​the main control chip for data verification. After the verification is successful, the data is classified and processed: for setting data, the parameters sent are parsed and saved in the storage chip; for reading data, the data is parsed from the variable (read data) and returned to the upper application (the high-level program running in the main control module). Setting data such as sampling frequency, sampling mode, etc. are used to configure and control the parameters of this board. Reading data such as the read three-phase voltage and current values ​​are the results of the collection and need to be reported to the main control module.

[0154] The acquisition of AC power parameter data can be carried out regularly, and three-phase voltage, current, power and other parameters are collected in real time during the acquisition process. The collected raw data is converted into high-precision data after temperature compensation and coefficient calibration. In this process, harmonic data is also analyzed and calculated, and up to 21 harmonics can be achieved. Then, zero-sequence voltage, zero-sequence current, voltage / current pass rate statistics and other functions are calculated and analyzed based on high-precision data.

[0155] After data collection is completed, some tiny current signals will be zeroed out, and then the accumulated electric energy data such as forward active power and reverse active power will be stored in the storage chip. At the same time, the active demand is calculated. For example, the calculation of active demand 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 at regular intervals, such as minute freezing, daily freezing, monthly freezing, etc. Taking minute freezing as an example, the software will configure the freezing cycle and freezing parameters. When the timing time is up, some current data and the current time will be saved in the storage chip. When the stored data reaches the set maximum value, it will be cyclically overwritten.

[0157] The present invention can realize the function of abnormal reporting of electric energy meter events. When a specific event occurs, the event validity flag will be determined first. If the event is valid, when the set delay time is reached, the event data and related data will be stored in the chip. At the same time, the event status is continuously determined. If the event is determined to be restored, the data when the event occurs will also be stored in the storage chip.

[0158] The multi-parameter acquisition device can realize 4-way remote signaling function, refer to Figure 4 The software timer periodically scans the telesignaling interface to read the telesignaling status. When it is determined that the telesignaling status has changed, the new read status is de-shaked. After the set time is reached, when it is determined that a telesignaling event has occurred, the current 4-way telesignaling status and the occurrence time of the telesignaling event (the event of telesignaling changing) are reported to the upper-level application. The upper-level application can be, for example, 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 the present application is shown.

[0160] like Figure 5 As shown, the circuit board includes a four-layer structure. The bottom layer is adjacent to the housing of the multi-parameter acquisition device. The chip components are arranged on the bottom layer. The circuit lines susceptible to interference are led out from the chip components on the bottom layer and pass through the middle two layers to the top layer and are routed on the top layer. The middle two layers are GND layers. The circuit line routing is as shown in FIG. Figure 5 Black part.

[0161] In order to provide protection in an electromagnetic interference environment, the circuit board stack of the present invention adopts a special enhanced shielding design, and the wiring on the board is also designed in a special way. The bottom layer (i.e., the BOTTOM layer) is adjacent to the housing of the multi-parameter acquisition device and is relatively close to the electromagnetic interference source. Chips and other patch components are all on the bottom layer, so the wiring led out of the patch components on the board is susceptible to electromagnetic interference. For local areas on the circuit board that are susceptible to electromagnetic interference, special designs are used for wiring and copper plating. For example, for sensitive signal wiring, after being led out from the patch components on the bottom layer, holes are punched nearby, passing through the two middle layers, and passing to the top layer, and wiring is done on the top layer. The second and third layers in the middle are both GND layers, each of which is a complete ground plane. In this way, the sensitive signal is doubly protected by two layers of GND planes, so that the electromagnetic interference source outside the housing of the adjacent bottom layer cannot interfere with the sensitive signal, so that the present invention can pass the electromagnetic compatibility test, ensuring that the present invention can be used normally 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 (such as 1 cm), and the copper on the four-layer structure is tightly connected through dense through holes to form a current line.

[0163] For example, a current neutral line (i.e., the primary input line of a neutral current transformer) can withstand a short-term excessive current of 100A (lasting 1 second) after a thickened design, which can meet the relevant test requirements of users and can be used in situations where the neutral current is unstable. The thickening method is to replace the conventional routing with copper on all four layers of the circuit board, and change the conventional 40mil single-layer routing to a square copper with a width of 1cm on each layer, and the copper area of ​​each layer is the same. Dense through holes are then used to tightly connect the copper on the four layers, thereby significantly increasing the overcurrent capacity and allowing the current to be evenly distributed between the four layers of copper, thereby improving the heat dissipation capacity of the copper when a large current passes through. Therefore, for some areas where there is a problem of three-phase imbalance in electricity consumption, the multi-parameter acquisition device of the present invention can be used in the area to prevent damage to the current phase line and the current neutral line caused by abnormal conditions such as single-phase overcurrent damage.

[0164] Figure 6 A schematic diagram of a shielding socket provided in an embodiment of the present application is shown.

[0165] like Figure 6 As shown, the shell of the multi-parameter acquisition device is made of stainless steel with a coating, which is connected to the GND on the circuit board and the outer shielding layer of the matching shielded patch cord, ensuring the shielding of GND against electromagnetic interference. The shielded socket includes 28 (24+4) pins. The specific definition of each pin can be found in the following table:

[0166]

[0167]

[0168] Pins 1 to 24 are digital signal interfaces, using 0.5mm*0.5mm square pins, and can pass a maximum current of 2.5A. Pins 25 to 26 are 5V power supply pins (5V is the output voltage after the AC-DC switching power supply and the supercapacitor module are combined), and pins 27 to 28 are GND pins, all of which use 2mm*4mm contact clips as plug-ins, and can pass a maximum current of 25A. Sufficient current passing capacity ensures that the multi-parameter acquisition device is sufficiently powered for the corresponding main control module, and also ensures that the output signal line impedance of the multi-parameter acquisition device of the present invention is low enough and will not affect the quality of the signal. The power supply voltage 5V is supplied to the external main control module through the socket and is not controlled by the main control chip. The collected data (cross-collection data) and other signals are output to the external main control module through the socket. Most of these signals are sent by the main control chip, but unidirectional SPI, active power, reactive power, power-off detection, etc. are sent 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 current;

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

[0171] Among them, the D+ and D- of the USB are pins 2-3, and the two pins are adjacent to each other; and the two are adjacent to the shielding shell and pins 1 and 4 which serve as the GND pins.

[0172] The 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 the three are also adjacent to the shielding shell and pins 4 and 8 that serve as the GND pins.

[0173] The CLK, CS, MISO, and MOSI of the bidirectional input and output SPI bus on the circuit board are pins 9 to 11, and the four are adjacent to each other; and the four are also adjacent to pins 1, 4, 17, and 20 which are GND pins.

[0174] The unidirectional active pulse CF1 and reactive pulse CF2 on the circuit board are pins 18 and 19, and the two are close to the shielding shell and pins 17 and 20 as the GND pins.

[0175] The YX1, YX3, YX2, and YX4 of the unidirectional input remote signal on the circuit board are pins 14, 15, 22, and 23 respectively, and the four are adjacent to each other; and the four are adjacent to the shielding shell and pins 13, 16, 21, and 24 which serve as the GND pin.

[0176] Figure 7 A schematic diagram of a filter circuit provided in an embodiment of the present application is shown.

[0177] like Figure 7 As shown, the USB line between the 2-3 pin in the shielded socket and the main control module includes a 120Ω chip bead and two 33pF chip capacitors to form a π-type filter circuit.

[0178] Since the electromagnetic environment of the place where the power terminal products are used is usually relatively bad, the present invention needs a special protection design for the anti-electromagnetic interference of the USB line connected to the main control module. The present invention adopts special anti-interference filtering measures for the USB 2.0 communication line (the routing circuit of the 2-3 pins of the D+ and D- of the USB in the shielded socket on the board), such as using a 120Ω chip bead and two 33pF chip capacitors to form a π-type filter circuit. The filter circuit can effectively filter out interference when electromagnetic interference such as pulse groups, static electricity, surges, etc. is applied externally, ensuring the normal operation of USB data communication.

[0179] Figure 8 A schematic diagram of data communication provided by an embodiment of the present 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 original waveform data to the topology recognition module through the SPI interface, the topology recognition module sends topology connection relationship data to the main control chip through the UART interface, the topology recognition module reports the original waveform data to the main control module through the SPI interface, and the main control chip reports data to the main control module through the SPI interface.

[0181] Specifically, the multi-parameter acquisition device of the present invention is provided with a high-speed SPI bus interface, and the metering chip sends the real-time voltage and real-time current sampling waveform data to the main control module based on the SPI bus interface through the topology recognition module. The SPI bus interface works in the main mode, adopts a 3-wire mode, and is composed of CS, SCL, and SDA (for example, corresponding to pins 5 to 7 in the shielded socket), with a maximum speed of 10MHz, and data transmission adopts a 32-bit data frame format and is sent cyclically. This function provides real-time data for the main control module, effectively supporting the main control module's business functions such as power load identification and topology identification.

[0182] Specifically, the three-phase AC voltage outside the patent of the present invention is rectified and conditioned, and connected to the AC-DC switching power supply on the board to be converted into a DC 5V voltage for powering the circuit on the board; at the same time, the three-phase AC voltage is also provided to the three voltage transformers on the board to sense the secondary side signal of the three-phase voltage. The three-phase current and the neutral current outside the multi-parameter acquisition device of the present 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 the neutral current.

[0183] The voltage and current signals on the secondary side are connected to the metering chip, which samples and processes these signals and sends the processed data (such as data collected and processed by filtering) to the main control chip through the SPI bus. The main control chip stores the data in the storage chip and reports the processed 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 and can analyze the normal working, open circuit, short circuit and other states of the current loop according to the current.

[0185] The circuit board of the multi-parameter acquisition device of the present invention is provided with a topology recognition module, which is connected to the metering chip. The topology recognition module can analyze the topological connection relationship data of the relevant metering equipment (such as the number of downstream concentrators of the multi-parameter acquisition device, the number of downstream collectors of each concentrator, the number of downstream electric meters of each collector or the number of other metering equipment, etc.) on the strong electric circuit connected to the multi-parameter acquisition device according to the data collected and processed by the metering chip (such as the original voltage waveform data without processing after collection), and report it to the main control chip on the board. That is, the topology recognition module is connected to the metering chip and the main control chip, and the topology recognition module receives the original waveform data from the metering chip, and after analyzing the topological connection relationship, reports it 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 is used as an SPI Slave to receive the recorded data (original waveform data) input from the metering chip. The other one synchronously forwards the input recorded data (original waveform data) to the main control module according to a certain protocol format. This SPI works in the Master.

[0187] The multi-parameter acquisition device of the present invention has the function of extending the topology recognition module, and the topology recognition module can be installed on the circuit board of the multi-parameter acquisition device of the present invention. Topology recognition technology is the core basic application of the construction of the power distribution Internet of Things, and is also the basis for the lean operation and maintenance management of the distribution network and the application of energy Internet business under the cloud-edge-end collaboration. The functions realized by the topology recognition module are as follows:

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

[0189] (2) The topology identification module has two SPI ports with a communication rate of no less than 8Mbps. One of them is used as an SPI Slave to receive the recorded data input from the metering chip, and the other one synchronously forwards the input recorded data to the main control module according to a certain protocol format. This SPI works in 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 (Master) controls the entire communication process, and the slave device (Slave) responds to the master device's request.

[0190] (3) Automatically identify the recorded 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 recorded data.

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

[0192] (5) The number of topology identification records to be kept shall not be less than 5,000.

[0193] (6) Supports both DL / T645-2007 and DL / T645-698.45 protocols and reads topology recognition results.

[0194] (7) The topology identification module supports remote upgrade and breakpoint resumption.

[0195] (8) The topology identification module has an RTC function and supports module time calibration.

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

[0197] Exemplarily, the external terminal is used as the remote signal input interface (4-way remote signal input line) through the 4-way switch input interface in the shielded socket of the multi-parameter acquisition device (for example, the 14, 15, 22, and 23 pins in the shielded socket). The interface adopts a passive node mode. When the level of the input remote signal terminal (the 4+1 plugs for remote signal input) is low (when the external contact is closed), it indicates that the remote signal level is valid. When the level of the input remote signal terminal is high (when the external contact is disconnected), it indicates that the remote signal level is invalid. The external contact is a user-provided contactable connector external to the remote signal plug, which can realize the open / close function. The access status information (the open / closed state of the user-provided contactable connector) can be collected in real time through the remote signal interface. When the remote signal changes position, when the remote signal pin changes position, the main control chip records the remote signal change data and reports the remote signal change data to the main control module through the USB interface in the shielded socket. The 4 remote signal input pin interface circuits can perform hardware filtering on the jump waveform in the collected remote signal information. The main control chip has a built-in trigger interrupt mechanism and digital filtering algorithm to implement anti-shake function for the remote signal input signal, so that the remote signal resolution is no more than 5ms and the remote signal error is no more than 1ms. The anti-shake time is 200ms by default, and the user can set it according to actual needs (10ms~6000ms). After the remote signal is recognized, it will communicate and report to the main control module through the USB interface.

[0198] Exemplarily, 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, synthesizes the three-phase residual current information based on the high-speed sampling data of the current waveform, and separates the leakage current information in the three-phase residual current information, extracts the electric shock waveform features of the leakage current information, and compares the electric shock waveform features with the typical waveform features of electric shock faults in the model library to identify the type of electric shock fault.

[0199] The multi-parameter acquisition device of the present invention has the function of identifying electric shock in a low-voltage distribution network. For example, an electric shock identification algorithm is built into the loop inspection algorithm module, and the three-phase residual current information is synthesized in real time by reading the high-speed sampling data of the current waveform of the three-phase combined current transformer, and the leakage current information in the low-voltage distribution network is separated. By using algorithms such as wavelet transform and Hilbert transform, the accurate detection of the abnormal point at the time of the electric shock fault is achieved based on the mutation characteristics of the instantaneous phase and amplitude at the time of the electric shock fault, and the characteristics of the electric shock waveform generated by the low-voltage distribution network are extracted in real time. The characteristic values ​​of the typical waveforms of electric shock faults are made into a model library, and the characteristic quantity results received in real time are compared with the established electric shock fault model library to realize the identification of the type of electric shock fault.

[0200] The loop inspection algorithm module also has a loop status inspection function. 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 have a loop status inspection function. The loop inspection algorithm module reads the loop impedance modulus, impedance angle, instantaneous effective value of the power frequency current, ambient temperature value and other information of the three combined current transformers at each frequency in turn through the SPI high-speed data interface, and combines the transformer ratio, accuracy grade, model, core cross-sectional area, transformer magnetic circuit length and other information to call the loop status inspection special algorithm, calculate and determine the normal, open circuit, short circuit and other states of the current loop, and report this information 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] Exemplarily, 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] The online firmware upgrade includes online upgrade using IAP. For example, after the multi-parameter acquisition device is installed at the user's site, it can be upgraded on the spot without removing it or returning it to the manufacturer. Especially for installations in mountainous areas, farmlands and other places where manual maintenance is not convenient, this online upgrade method enables the multi-parameter acquisition device to easily upgrade the firmware program remotely. The main control module used in conjunction with the multi-parameter acquisition device performs online upgrades of the firmware in the multi-parameter acquisition device through the SPI port in accordance with the DL / T 698.45-2017 protocol. During the upgrade, the maximum transmission amount of communication data per frame is 2K bytes. During the upgrade process, each frame of data is individually verified to prevent abnormal data transmission.

[0204] (2) Sampling the high-order harmonics of the power frequency is performed, and the original sampled data is subjected to FFT transformation to obtain the effective value of each harmonic. The measured value is calculated based on the effective value after FFT transformation, and the measured value is compared with the measured value collected under the standard source for correction.

[0205] The present invention supports a multi-parameter acquisition device to collect power frequency high-order harmonic samples in real time, up to 21 times. By performing FFT transformation on the original sampling points, the effective value of each harmonic is obtained. The multi-parameter acquisition device completes the acquisition through voltage and current transformers, conditioning circuits, metering chips, etc., among which the metering chip plays a major role. The original point is a series of voltage values, such as 220V, 219V, 221V,..., which actually also contains many values ​​that are too high, too low, and 0 values ​​that are measured due to interference. In order to solve the harmonic value error caused by the fluctuation of the sampling value, the present invention adopts a comparative method to correct the effective value after FFT transformation and the metering value collected under the standard source, which effectively improves the calculation accuracy.

[0206] (3) The electric energy meter is calibrated by multiple calibration methods, wherein the multiple calibration methods include a power calibration method and a pulse calibration method.

[0207] The multi-parameter acquisition device of the present invention supports the electric energy metering function. In order to solve the problem of metering accuracy, the multi-parameter acquisition device of the present invention supports multiple calibration methods to calibrate the metering. The calibration process may involve a main control chip, a metering chip, a storage chip, etc. Usually, the power method is used for calibration, and the three-phase voltage, three-phase current, power and angle are calibrated respectively. The calibrated data will be stored in the storage chip for preservation to prevent power loss. When an abnormality occurs in the power calibration, it will be transferred to the pulse calibration, and the pulse constant of the meter will be used for calibration. The two schemes back up each other to enhance the stability of the system.

[0208] (4) Filtering the data through a variety of filtering algorithms, including: first, filtering the original data through an empirical error judgment method, then sorting the sampled data through a heap sort method and / or a quick sort method, deleting the front and back parts of the data after sorting, and then averaging the middle part of the data.

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

[0210] The multi-parameter acquisition device of the present invention adopts a variety of filtering algorithms to optimize the data. Due to the power equipment and external environment, the power transmission signal contains various noises and interferences, which come from the signal source itself or from the sensor, as well as from external interference. In order to accurately measure, the interference and noise in the signal must be eliminated. For this purpose, the multi-parameter acquisition device uses a dedicated software method to filter the signal.

[0211] For the sampled raw data, firstly, the data is screened and processed by the empirical error judgment method: according to the existing empirical data and judgment criteria, the maximum error allowed for each sampling data is formulated. After that, a judgment is made every time a new sampling data value is detected. If it is less than the maximum empirical error, the data is judged to be valid and the sampling value is accepted; if it is greater than the maximum empirical error, the data is judged to be invalid and the sampling value is abandoned. After that, the heap sort / quick sort method is used to sort the sampled data. After sorting, the first 5% of the data and the last 5% of the data are deleted, and then the middle data is averaged. Thus, the final sampling result is obtained by calculation, which effectively filters out the values ​​that are too large or too small, and can effectively overcome the 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 calibration curve is fitted using the Lagrange interpolation method, and the data is calibrated for temperature compensation based on the calibration curve.

[0213] The multi-parameter acquisition devices in the industry are generally calibrated at a standard temperature of 25°C, but their working environment temperature may rise from -40°C to 85°C. The sampling circuit is composed of multiple components, and the characteristics of the sensitive elements are closely related to the temperature, and often have inconsistent characteristics in different temperature ranges.

[0214] In order to reduce the influence of ambient temperature, the multi-parameter acquisition device of the present invention realizes accurate calibration of temperature influence based on the special calibration algorithm of segmented calibration + Lagrangian curve fitting. For example, the minimum unit of temperature interval is defined as 2°C, and a separate temperature compensation coefficient is calculated for each interval; at the same time, combined with the common characteristics of the modules, a calibration curve is fitted using the Lagrangian interpolation method to achieve overall gain correction. Two complementary measurement calibration methods.

[0215] The multi-parameter acquisition device of the present invention is specially designed with an electric energy metering data communication software interface, so that the reported data effectively complies with the "Object-oriented Electricity Information Data Exchange Protocol".

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

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

[0218] The multi-parameter acquisition device of the present invention can collect the electrical parameter data of the substation in real time, and conduct comprehensive power quality analysis and monitoring based on the data, including voltage sag and short-term interruption, voltage fluctuation, voltage harmonics, voltage qualification rate, frequency deviation, three-phase imbalance, etc. The multi-parameter acquisition device of the present invention can store and manage the collected and analyzed data for subsequent analysis and decision-making. Accurate power quality monitoring is the basis for implementing power quality improvement, which helps to understand the status, causes and impacts of power quality problems.

[0219] The multi-parameter acquisition device of the present invention records various abnormal events occurring in the substation, such as electric energy metering, operation, fault, etc. It records in detail the overvoltage, undervoltage, power limit, programming, zeroing, etc. of the substation. At the same time, it stores the active electric energy, power and other parameters at the time of occurrence and recovery. These event records help power companies or users understand the working status and power consumption of electric energy meters.

[0220] In view of the characteristics of many types of events and large amount of event storage data, the multi-parameter acquisition device of the present invention classifies and stores the data content: for parameter variables, according to their characteristics of large amount of data 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, the large storage capacity of the FLASH storage chip is utilized to store the associated data when the event occurs in the second half of the storage area of ​​the Flash, without standardized sorting, but with a retrieval function in the program to facilitate timely retrieval.

[0221] In the multi-parameter acquisition device of the present invention, since the backup data is stored in the FLASH storage chip, the data volume is large and the types are many. Based on this situation, a unique algorithm is designed to realize fast data reading, writing and erasing. For each type of data, more than two valid flag bits are set at the beginning and the end. The data includes data that need to be recorded, such as electrical parameter data collected in real time, electrical parameter data that need to be recorded every minute / day / month, and event data that occurs. Based on the way of storing data format in C language, these data are composed of signed 8 / 32 / 64-bit integer data; at the same time, a time verification function is added to the data of each hour and each custom time period (generally five minutes). When data reading and writing is required, a valid bit verification is performed first, and then a time verification is performed. When the verification passes, data reading and writing can be performed, which improves the accuracy of data search, eliminates unnecessary data retrieval, speeds up reading and writing, and improves program processing efficiency.

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

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

[0224] (2) Complete functions. It has acquisition functions such as cross acquisition, telemetry, and remote signaling, as well as communication functions such as USB and SPI. Cross acquisition is for the acquisition of three-phase voltage and four-wire current, and remote signaling is for 4-way acquisition. 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 signal acquisition error can be achieved within 1ms, meeting the needs of both marketing and power distribution.

[0226] (4) Strong scalability. For example, it has a circuit inspection function. It realizes the monitoring of abnormal current conditions such as short circuit and open circuit of the primary side circuit, and realizes the measurement, monitoring, control, adjustment, protection and other functional operations of the primary side equipment. For another example, it has a topology recognition function. Through AC acquisition, according to the recorded data of the metering chip, the characteristic current signal of the primary side is analyzed.

[0227] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0228] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

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

[0230] In this application, unless otherwise clearly specified or limited in the embodiments, the terms "installed", "connected", "connected" and "fixed" etc. appearing in the embodiments should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integrated connection. It can be understood that 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 connection of two elements, or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific implementation situation.

[0231] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0232] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A multi-parameter acquisition device based on a station area intelligent fusion terminal, characterized in that: The substation intelligent fusion terminal includes a main control module, and 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 super capacitor module, a protection circuit, a rectifier diode array, a voltage transformer and a metering chip: The AC-DC switching power supply is used to convert the external input AC voltage into a DC voltage and then supply power to the multi-parameter acquisition device; The supercapacitor module is used to store backup electric energy so as to supply power to the multi-parameter acquisition device and / or the main control module when the external power supply is cut off; The protection circuit is used to perform protection processing on the external input AC strong voltage and transmit it to the rectifier diode array; The rectifier diode array is used to rectify the AC voltage after protection treatment through a diode and send it to the AC-DC switching power supply; The voltage transformer is used to convert the external input power frequency strong voltage into a weak current signal, and transmit the weak current 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 electric signal.

2. The multi-parameter acquisition device according to claim 1, characterized in that: The multi-parameter acquisition device also includes a main control chip, a storage chip and a shielding 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 report the data to the main control module after summarizing and processing the data; The memory chip includes a ferroelectric memory chip and a FLASH memory chip, and the ferroelectric memory chip and the FLASH memory chip can perform cross-backup of data. When the data in the ferroelectric memory chip is abnormal, the data in the FLASH memory chip is read and the read data is written to the ferroelectric memory chip; The shielded socket is coated with metal to prevent the transmitted power supply signal and data signal from being interfered with. The electric energy output by the AC-DC switching power supply is sent to the main control module through a shielded socket to provide power for the main control module. The main control chip aggregates and processes the received multiple data and sends them to the main control module through a shielded socket in the form of at least one of a USB bus, an SPI bus, and a 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 appears in the outside world, the magnetic induction chip senses it in time and reports 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 also includes: a combined current transformer, which is used to convert the external input power frequency strong current into a weak current signal, and transmit the weak current signal to the metering chip through a filtering circuit, wherein the combined current transformer has a signal processing circuit board, a high-frequency injection coil, and a high-frequency detection coil inside. During operation, a high-frequency signal is injected into the external power frequency strong current loop, and a return signal is detected. After the return signal is detected, the return signal is converted from an analog signal to data, and sent 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, and the high-frequency injection coil and the high-frequency detection coil are both enclosed with a copper shielding shell.

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 normal measurement can be performed even when the external three-phase is unbalanced.

6. The multi-parameter acquisition device according to claim 4, characterized in that: The multi-parameter acquisition device also includes: a loop inspection algorithm module, one loop inspection algorithm module is connected to the three combined current transformers via an SPI bus, the loop inspection algorithm module analyzes the return signal to obtain status data of the current loop, and reports the status data to the main control chip, the loop inspection algorithm module and the combined current transformer are connected with a synchronization signal, so that one loop inspection algorithm module can coordinate the high-frequency signal injection and detection of the three combined current transformers.

7. The multi-parameter acquisition device according to claim 2, characterized in that: The multi-parameter acquisition device also includes: a topology identification module, which is used to process the voltage and current waveform data output by the metering chip, obtain topological connection relationship data of external electrical equipment, and send the topological connection relationship data to the main control chip.

8. 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 arranged in the high-voltage area, and the metering chip, main control chip, topology identification module, loop inspection algorithm module, storage chip, magnetic induction chip, and shielded socket are arranged in the low-voltage area.

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

10. The multi-parameter acquisition device according to any one of claims 1 to 9, characterized in that: The multi-parameter acquisition device comprises a first surface and a second surface opposite to the first surface: 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 arranged on the first surface; The rectifier diode array, the metering chip, the main control chip, the loop inspection algorithm module, the topology identification module, the storage chip, and the magnetic induction chip are arranged on the second surface.

11. The multi-parameter acquisition device according to claim 4, characterized in that: The combined current transformer and the protection circuit are arranged at a terminal block close to the housing of the multi-parameter acquisition device; The AC-DC switching power supply, the voltage transformer, and the neutral current transformer are away from the terminal block of the housing of the multi-parameter acquisition device and are adjacent to the protection circuit; The supercapacitor module, 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 shielding socket are far away from the combined current transformer and the protection circuit.

12. 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 fine-tuned within a preset range according to the current of the load, wherein the load includes the main control module and / or a module connected to the main control module.

13. The multi-parameter acquisition device according to claim 1, characterized in that: The AC-DC switching power supply also has the following functions: 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.

14. 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 voltage of the external input is greater than the preset voltage value, the AC-DC switching power supply starts the overvoltage protection function and temporarily shuts down, and resumes starting after the voltage drops.

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 AC-DC switching power supply is capable of outputting 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, outputting 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.

16. 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 segmented according to the 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-insensitive frequency band is less than a second preset noise threshold, and the first preset noise threshold is less than the second preset noise threshold.

17. 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 power of the load increases and causes 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.

18. The multi-parameter acquisition device according to claim 1, characterized in that: 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 length is less than or equal to a preset time length.

19. The multi-parameter acquisition device according to claim 1, characterized in that: The supercapacitor module also has the following functions: In the case that the super capacitor module outputs electric energy causing the voltage in the super capacitor to drop, the super capacitor module outputs electric energy after stabilizing the voltage through a boost circuit.

20. 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 to charge, the main control chip queries the voltage-charge curve data and the time-charge curve data based on the charging voltage to determine the current charge of the supercapacitor module and the time the current charge 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.

21. The multi-parameter acquisition device according to claim 2, characterized in that: The main control chip also has the following functions: Detecting a power-off signal of an external power source, after detecting the power-off signal, storing current data before the energy of the supercapacitor module is exhausted, and reporting the power-off event to the main control module.

22. 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 the external tooling through the test and debugging interface, which facilitates the external tooling to communicate and test the acquisition device.

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

24. The multi-parameter acquisition device according to claim 9, characterized in that: The circuit board includes a four-layer structure. The bottom layer is adjacent to the casing of the multi-parameter acquisition device. The chip components are arranged on the bottom layer. The circuit lines susceptible to interference are led out from the chip components on the bottom layer and pass through the middle two layers to the top layer and are routed on the top layer. The middle two layers are GND layers.

25. The multi-parameter acquisition device according to claim 5, characterized in that: 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, and the copper on the four-layer structure is tightly connected through dense through holes to form the current line.

26. 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 current; Pins 25-26 are power supply pins, and pins 27-28 are GND pins. Both use 2mm*4mm contact clips as plug-ins and can pass 25A current. The USB D+ and D- are pins 2-3, and the two pins are adjacent to each other. They are also adjacent to the shielding shell and pins 1 and 4 which are the GND pins. The 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 the three are also adjacent to the shielding shell and pins 4 and 8 that serve as the GND pins; The CLK, CS, MISO, and MOSI of the bidirectional input and output SPI bus on the circuit board are pins 9 to 11, and the four are adjacent to each other; and the four are also adjacent to pins 1, 4, 17, and 20 which are GND pins; The unidirectional output active pulse CF1 and reactive pulse CF2 on the circuit board are pins 18 and 19, and the two are close to the shielding shell and pins 17 and 20 as the GND pins; The YX1, YX3, YX2, and YX4 of the unidirectional input remote signal on the circuit board are pins 14, 15, 22, and 23 respectively, and the four are adjacent to each other; and the four are adjacent to the shielding shell and pins 13, 16, 21, and 24 which serve as the GND pin.

27. The multi-parameter acquisition device according to claim 26, characterized in that: The USB line between the 2-3 pin and the main control module includes a 120Ω chip bead and two 33pF chip capacitors to form a π-type filter circuit.

28. The multi-parameter acquisition device according to claim 7, characterized in that: The metering chip sends electrical parameter acquisition data to the main control chip through the SPI interface, the metering chip sends original waveform data to the topology identification module through the SPI interface, the topology identification module sends the topology connection relationship data to the main control chip through the UART interface, the topology identification module reports the original waveform data to the main control module through the SPI interface, and the main control chip reports data to the main control module through the SPI interface.

29. The multi-parameter acquisition device according to claim 2, characterized in that: The external terminal collects the telesignal information through the four telesignal input GPIO pin interfaces in the shielded socket of the multi-parameter acquisition device. When the telesignal pin changes position, the main control chip records the telesignal change data and reports the telesignal change data to the main control module through the USB interface in the shielded socket. The four telesignal input pin interfaces can filter the jump waveforms in the collected telesignal information. The main control chip has a built-in trigger interrupt mechanism and a digital filtering algorithm to de-shake the telesignal input signal, and the de-shake time can be configured. After the telesignal is recognized, a communication report is sent to the main control module through the USB interface.

30. The multi-parameter acquisition device according to claim 6, characterized in that: The loop 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, synthesizes the three-phase residual current information based on the high-speed sampling number of the current waveform, separates the leakage current information in the three-phase residual current information, extracts the electric shock waveform features of the leakage current information, and compares the electric shock waveform features with the typical waveform features of electric shock faults in the model library to identify the type of electric shock fault.

31. The multi-parameter acquisition device according to claim 2, characterized in that: The multi-parameter acquisition device has the following functions: The SPI interface is used to communicate with the main control module so that the main control module can perform online upgrade of the firmware in the multi-parameter acquisition device.

32. The multi-parameter acquisition device according to claim 2, characterized in that: The multi-parameter acquisition device has the following functions: Sampling of high-order harmonics of the power frequency is performed, and the original sampling 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.

33. The multi-parameter acquisition device according to claim 2, characterized in that: The multi-parameter acquisition device has the following functions: The electric energy metering is calibrated through a variety of calibration methods, wherein the multiple calibration methods include a power calibration method and a pulse calibration method.

34. 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 through a variety of filtering algorithms, including: first, the original data is screened and processed by an empirical error determination method, and then the sampled data is sorted by a heap sort method and / or a quick sort method, and after sorting, the front and back parts of the data are deleted, and then the middle part of the data is averaged.

35. 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.

36. The multi-parameter acquisition device according to claim 2, characterized in that: For each type of data that needs to be recorded in the multi-parameter acquisition device, at least the first and last two valid flag bits are set.

37. The multi-parameter acquisition device according to claim 36, characterized in that: When reading and writing data to the FLASH storage chip, firstly perform a valid bit check on the data, and then perform a time check.

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