A circuit status monitoring and load data recording device based on the RS485 interface of electric energy meter

Abstract

The present invention relates to a loop state monitoring and load data recording device based on the RS485 interface of an electric energy meter, and belongs to the technical field of data acquisition devices. The present invention includes an MCU processor, a data reading module, a data storage module, a small uninterruptible power supply, a human-computer interaction module, and an RS485 interface; the MCU processor is connected to the data reading module, the data storage module, the small uninterruptible power supply, the human-computer interaction module, and the RS485 interface, the RS485 interface of the electric energy meter is connected to the RS485 interface of the present invention through an RS485 bus, the RS485 interface of the present invention is connected to the data reading module, the auxiliary power interface and the terminal power auxiliary interface of the electric energy meter are connected to the small uninterruptible power supply, and the small uninterruptible power supply is also connected to an external power supply. The present invention can identify data anomalies and obtain high-precision discrete load data during faults.

Description

Technical Field

[0001] The present invention relates to a circuit state monitoring and load data recording device based on the RS485 interface of an electric energy meter, which reads the circuit current and voltage data collected in the electric energy meter through the RS485 interface, stores, analyzes and compares them, thereby realizing metering state monitoring and abnormality judgment functions, belonging to the technical field of data acquisition devices. Background Art

[0002] Abnormal voltage failure is a common fault in metering devices, and the reasons are complex. Direct lightning strikes, induced lightning, short circuit and ground faults on the low-voltage side, short circuit and ground faults on the high-voltage side, and overvoltage on the line caused by faults in the secondary circuit of the voltage transformer can cause damage to the voltage transformer or the high-voltage fuse to blow. In the actual operation and maintenance process, it is found that the voltage failure process is a complex process. During the voltage circuit failure, the voltage value may be a sudden change, uncertain value, and non-periodic process, which increases the difficulty of calculating the fault power. The metering operation and maintenance team of the power supply bureau often deals with voltage circuit undervoltage failures (excluding three-phase voltage loss), mainly due to the burning and damage of the transformer and the blowing of the fuse.

[0003] In the actual metering fault handling work, the data during the fault period is particularly important as the only basis for follow-up. However, due to the limitations of existing devices and automation systems, the data during the fault period that we can obtain cannot reflect the actual load situation well, including: 1) The conventional setting of the load curve sampling interval of the electric energy meter is 15 minutes, which is too large. For the load that changes all the time, such a description is too rough, and the memory design of the electric energy meter is too small, and the storage space is seriously insufficient; 2) The three-phase voltage circuit fault, undervoltage, and loss of pressure cause the equipment to lose power and stop working, and there is no data in this period. In this type of metering fault power follow-up work, the power of the phase with abnormal voltage value is followed up, especially in the case of three-phase voltage loss fault because of the lack of data during the fault period. At present, it mainly relies on the four-in-one master station system to verify the fault time, and the fault power is checked based on the fault time as the main basis, and the average load during normal operation is referred to for follow-up. This method has a large random uncertainty and a large error. Summary of the invention

[0004] The technical problem to be solved by the present invention is: the present invention provides a circuit state monitoring and load data recording device based on the RS485 interface of the electric energy meter, so as to identify data anomalies and obtain high-precision discrete load data during a fault period.

[0005] The technical solution of the present invention is: a circuit state monitoring and load data recording and storing device based on the rs485 interface of the electric energy meter, comprising an MCU processor, a data reading module, a data storage module, a small uninterruptible power supply, a human-computer interaction module, and an rs485 interface;

[0006] The MCU processor is connected to the data reading module, the data storage module, the small uninterruptible power supply, the human-computer interaction module, and the RS485 interface. The RS485 interface of the electric energy meter is connected to the RS485 interface of the loop status monitoring and load data recording and storage device based on the RS485 interface of the electric energy meter through the RS485 bus. The RS485 interface of the loop status monitoring and load data recording and storage device based on the RS485 interface of the electric energy meter is connected to the data reading module. The auxiliary power supply interface and the terminal power auxiliary interface of the electric energy meter are both connected to the small uninterruptible power supply, and the small uninterruptible power supply is also connected to an external power supply.

[0007] Furthermore, the MCU processor is used to control the data reading module to realize the reading of the internal data of the smart energy meter, and to determine whether the data is abnormal according to the set threshold value; at the same time, it controls the data storage module, the small uninterruptible power supply, and the human-computer interaction module;

[0008] The data storage module, which is composed of SD and control chip, is used to convert the data of MCU processor into txt format and store it in USB flash drive, and it has time stamp to facilitate the later data processing. It is like a data black box, which monitors and records the loop data collected by the electric energy meter at all times.

[0009] The small uninterruptible power supply is used to convert the 220V operating power supply or auxiliary power supply into a 12V regulated DC power supply, and automatically charge the battery. At the same time, it is inverted into an uninterruptible power supply for the electric energy meter. When a device or circuit failure occurs, it ensures that the electric energy meter does not lose power before the fault is handled and operates normally. The battery is composed of a polymer lithium battery, and the capacity ensures that the electric energy meter can continue to work for 96 hours in the case of power failure;

[0010] The human-computer interaction module includes a liquid crystal display screen and a key input. The liquid crystal display screen is used to display data content for easy browsing; the key input is used to perform parameter setting and equipment operation.

[0011] The steps of the MCU processor reading data and determining whether the data is abnormal according to the set threshold are as follows:

[0012] Step 1: The MCU processor controls the data reading module to read the current and voltage data in the current and voltage loops collected by the electric energy meter;

[0013] Step 2: Determine whether there is voltage in the three phases of the electric energy meter according to the voltage data in the voltage loop; if the voltage data in the voltage loop is not zero, it is determined that there is voltage in the voltage loop, and step 3 is executed; if the voltage data in the voltage loop is zero, it is determined that the voltage loop loses voltage, and step 4 is executed;

[0014] Step 3: If there is voltage in the voltage loop, then compare the voltage data in the voltage loop with the threshold. If the three-phase voltages are all greater than the threshold, it indicates that the loop is normal; if one or more phases of the three-phase voltages are lower than the set value, it indicates that the PT is abnormal.

[0015] Step 4: If the voltage circuit loses pressure, determine whether there is current based on the current data in the current circuit; if the current data in the current circuit is not zero, it is determined that there is current in the current circuit, indicating that there is no power outage and that the three-phase PTs are all damaged, causing the electric energy meter to lose pressure;

[0016] If the current data in the current loop is zero, it is judged that there is no current in the current loop, indicating that the status is normal and the line is regarded as power outage.

[0017] The beneficial effects of the present invention are:

[0018] 1. Use the data reading function of the rs485 port of the energy meter to read the current, voltage, and power factor data with a certain degree of accuracy collected by the energy meter itself at a high frequency, analyze and compare the collected data, and turn on the fast recording function when an abnormality is found, such as undervoltage, loss of pressure, and overvoltage. The read data is marked with a time stamp and saved in the form of text on the memory card to facilitate data extraction; this device does not need to add current and voltage data to the sensor acquisition circuit, and cleverly uses the high-precision load data collected by the energy meter itself.

[0019] 2. The equipment has an uninterruptible power supply function, which can serve as an auxiliary power supply for the operation of the electric energy meter in the event of three-phase voltage loss, undervoltage or power failure, ensuring the continuous normal operation of the electric energy meter. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the principle structure of the present invention;

[0021] Figure 2 is a flow chart of data anomaly determination of the present invention;

[0022] Figure 3 It is a schematic diagram of equipment connection when the present invention is applied. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0024] Example 1: Figure 1-3 As shown, a circuit state monitoring and load data recording device based on the RS485 interface of an electric energy meter includes an MCU processor, a data reading module, a data storage module, a small uninterruptible power supply, a human-computer interaction module, and an RS485 interface;

[0025] The MCU processor is connected to the data reading module, the data storage module, the small uninterruptible power supply, the human-computer interaction module, and the RS485 interface. The RS485 interface of the energy meter is connected to the RS485 interface of the circuit state monitoring and load data recording and storage device based on the RS485 interface of the energy meter through the RS485 bus. The RS485 interface of the circuit state monitoring and load data recording and storage device based on the RS485 interface of the energy meter is connected to the data reading module. The auxiliary power interface and the terminal power auxiliary interface of the energy meter are connected to the small uninterruptible power supply, and the small uninterruptible power supply is also connected to the external power supply. Figure 3 As shown, it is a schematic diagram of equipment connection when the present invention is applied. In the figure, the connection between the electric energy meter, the terminal and the junction box and the secondary circuit are all conventional connection methods used by technicians in this field.

[0026] Furthermore, the MCU processor is used to control the data reading module to realize the reading of the internal data of the smart energy meter, and to determine whether the data is abnormal according to the set threshold value; at the same time, it controls the data storage module, the small uninterruptible power supply, and the human-computer interaction module;

[0027] The data storage module, which is composed of SD and control chip, is used to convert the data of MCU processor into txt format and store it in USB flash drive, and it has time stamp to facilitate the later data processing. It is like a data black box, which monitors and records the loop data collected by the electric energy meter at all times.

[0028] The small uninterruptible power supply is used to convert the 220V operating power supply or auxiliary power supply into a 12V regulated DC power supply, and automatically charge the battery. At the same time, it is inverted into an uninterruptible power supply for the electric energy meter. When a device or circuit failure occurs, it ensures that the electric energy meter does not lose power before the fault is handled and operates normally. The battery is composed of a polymer lithium battery, and the capacity ensures that the electric energy meter can continue to work for 96 hours in the case of power failure;

[0029] The human-computer interaction module includes a liquid crystal display screen and a key input. The liquid crystal display screen is used to display data content for easy browsing; the key input is used to perform parameter setting and equipment operation.

[0030] Furthermore, the steps of the MCU processor reading data and determining whether the data is abnormal according to a set threshold value may be as follows:

[0031] Step 1: The MCU processor controls the data reading module to read the current and voltage data in the current and voltage loops collected by the electric energy meter;

[0032] Step 2: Determine whether there is voltage in the three phases of the electric energy meter according to the voltage data in the voltage loop; if the voltage data in the voltage loop is not zero, it is determined that there is voltage in the voltage loop, and step 3 is executed; if the voltage data in the voltage loop is zero, it is determined that the voltage loop loses voltage, and step 4 is executed;

[0033] Step 3: If there is voltage in the voltage loop, then compare the voltage data in the voltage loop with the threshold. If the three-phase voltages are all greater than the threshold, it indicates that the loop is normal; if one or more phases of the three-phase voltages are lower than the set value, it indicates that the PT is abnormal.

[0034] Step 4: If the voltage circuit loses pressure, determine whether there is current based on the current data in the current circuit; if the current data in the current circuit is not zero, it is determined that there is current in the current circuit, indicating that there is no power outage and that the three-phase PTs are all damaged, causing the electric energy meter to lose pressure;

[0035] If the current data in the current loop is zero, it is judged that there is no current in the current loop, indicating that the status is normal and the line is regarded as power outage.

[0036] The working principle of the present invention is: using the MCU processor to read the metadata of the three-phase multifunctional electric energy form through RS485, and perform data processing and storage, and indirectly judge whether the circuit is abnormal. In order to make the on-site use more convenient and the human-computer interaction more friendly, the LCD screen and buttons are used as data display and control, and the comprehensive information such as electric energy, voltage, and current can be read intuitively. The data is saved as a txt file that can be recognized by the computer, and the normal data and abnormal data are separately established for file storage, which is more convenient to read. The small uninterruptible power supply provides a stable and reliable power supply for the entire device. The device is equipped with a common interface and cooperates with a dedicated line to facilitate on-site installation and use.

[0037] Among them, in order to further illustrate the role of the MCU processor, the following explanation is made. The data processing method can be: read the data and determine whether the data is abnormal according to the set threshold value. As for how to determine, the conventional method in the field can be used to compare with the threshold value to determine whether it is abnormal, or the method of steps 1 to 4 specifically disclosed in the above application can be used to indirectly monitor whether the metering circuit is abnormal; such as the public line dedicated transformer user, the normal voltage circuit voltage value is 57.7V±3V. If the threshold value is set to 50V, when the voltage is lower than 50V, it is determined that the circuit is undervoltage and abnormal, and the fast data recording function should be turned on at this time. Among them, the data storage module, the small uninterruptible power supply, and the human-computer interaction module are controlled at the same time; for example, specifically control whether to perform data fast storage, read the load data once every 5 to 8 seconds through the rs485 port, if the data is within the threshold range, store a set of load data 20 times, if the data is abnormal, store the current data, and whether the small uninterruptible power supply supplies power to the energy meter and the terminal, and controls the human-computer interaction module to display data and receive the information input by the key to intuitively read the comprehensive information such as electric energy, voltage, and current.

[0038] The RS485 port of the loop state monitoring and load data recording device based on the RS485 interface of the electric energy meter is connected to the RS485 port of the electric energy meter, and the uninterruptible power supply is connected to the electric energy meter and the terminal power auxiliary interface to ensure the normal operation of the electric energy meter terminal in the event of a voltage loss fault.

[0039] The specific embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A circuit status monitoring and load data recording device based on the RS485 interface of an electric energy meter, characterized in that: Including MCU processor, data reading module, data storage module, small uninterruptible power supply, human-computer interaction module, RS485 interface; The MCU processor is connected to the data reading module, the data storage module, the small uninterruptible power supply, the human-computer interaction module, and the RS485 interface. The RS485 interface of the electric energy meter is connected to the RS485 interface of the loop state monitoring and load data recording and storage device based on the RS485 interface of the electric energy meter through the RS485 bus. The RS485 interface of the loop state monitoring and load data recording and storage device based on the RS485 interface of the electric energy meter is connected to the data reading module. The auxiliary power supply interface and the terminal power auxiliary interface of the electric energy meter are both connected to the small uninterruptible power supply, and the small uninterruptible power supply is also connected to the external power supply. The MCU processor is used to control the data reading module to realize the reading of the internal data of the smart energy meter, and to determine whether the data is abnormal according to the set threshold value; at the same time, it controls the data storage module, the small uninterruptible power supply, and the human-computer interaction module; The data storage module is composed of SD and control chip, and is used to convert the data of MCU processor into txt format and store it in U disk with time stamp; The small uninterruptible power supply is used to convert the 220V operating power supply or auxiliary power supply into a 12V regulated DC power supply, and automatically charge the battery, and at the same time invert it into an uninterruptible power supply for the electric energy meter. The battery is composed of a polymer lithium battery, and the capacity ensures that the electric energy meter can continue to work for 96 hours in the case of power failure; The human-computer interaction module includes a liquid crystal display screen and a key input, wherein the liquid crystal display screen is used to display data content; the key input is used to perform parameter setting and device operation; The steps of the MCU processor reading data and determining whether the data is abnormal according to the set threshold are as follows: Step 1: The MCU processor controls the data reading module to read the current and voltage data in the current and voltage loops collected by the electric energy meter; Step 2: Determine whether there is voltage in the three phases of the electric energy meter according to the voltage data in the voltage loop; if the voltage data in the voltage loop is not zero, it is determined that there is voltage in the voltage loop, and step 3 is executed; if the voltage data in the voltage loop is zero, it is determined that the voltage loop loses voltage, and step 4 is executed; Step 3: If there is voltage in the voltage loop, then compare the voltage data in the voltage loop with the threshold. If the three-phase voltages are all greater than the threshold, it indicates that the loop is normal; if one or more phases of the three-phase voltages are lower than the set value, it indicates that the PT is abnormal. Step 4: If the voltage circuit loses pressure, determine whether there is current based on the current data in the current circuit; if the current data in the current circuit is not zero, it is determined that there is current in the current circuit, indicating that there is no power outage and that the three-phase PTs are all damaged, causing the electric energy meter to lose pressure; If the current data in the current loop is zero, it is judged that there is no current in the current loop, indicating that the status is normal and the line is regarded as power outage.

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