KR100894228B1 - Electronic type watt hour meter using NAND flash memory and method for saving wave data thereof - Google Patents

Abstract

Industrial Applicability The present invention uses an NAND flash memory and a USB (Universal Serial Bus) or Ethernet (ETHERNET) communication method instead of an electronic power meter using an EPPROM. It relates to a power meter and a method for storing waveform data through the same.

 The electronic watt-hour meter of the present invention for achieving the above object, the data detector 20, the data measurement unit 30, the central processing unit 40 to measure the power data from the power element 10 and to store / display / transmit it In the electronic power meter including a power supply unit 50, a display unit 60, a memory unit 70, and a communication control unit 80, the memory unit 70 includes a NAND flash memory 71 and a NAND flash memory controller ( 72) to configure a mass storage medium, and the communication control unit 80 uses a USB or Ethernet communication method to configure a high-speed transmission medium, the central processing unit 40 for efficient data management to the NAND flash memory File system 44 and FTL (45) are built in, and the U.S. protocol for USB communication or TCP / IP file transfer protocol 46 for Ethernet communication is built in The.

Power meter, electronic, NAND flash memory, USB, Ethernet, waveform data

Description

Electronic type watt hour meter using NAND flash memory and method for saving wave data

The present invention relates to an electronic wattmeter using a NAND flash memory and a waveform data storage method using the same, and more particularly, a NAND flash memory and a USB (Universal Serial Bus) or Ethernet (ETHERNET) instead of an electronic wattmeter using an EPPROM. The present invention relates to an industrial electronic power meter developed to enable the storage and high-speed transmission of a large amount of waveform data by using a communication method.

Watt hour meter (WHM) is a device that measures the amount of electricity used, there are inductive (mechanical) meter and electronic meter. Induction wattmeters are mainly used in homes, and only the power consumption is measured using a rotating disc, while electronic wattmeters are mainly used in industrial sites, and not only power consumption but also three-phase current and voltage in power systems. All parameters can be measured.

1 is a block diagram showing the basic configuration of an industrial electronic electricity meter according to the present invention. The electronic electricity meter installed in various lines for supplying power in an industrial site measures the data of various power data transmitted from the power element 10 and stores the data detection unit 20 and the data measuring unit in order to store, display, and transmit the data. 30, the central control unit 40, the power supply unit 50, the display unit 60, the memory unit 70, and the communication control unit 80.

The data detector 20 is a device for detecting a variety of power data transmitted in real time from the power element 10. The voltage is detected by the voltage sensor 22 composed of a high impedance voltage separation circuit separated for each voltage of three phases. The current is detected by the current sensor 24 composed of current divider resistors separated by three currents.

The data measuring unit 30 is composed of six independent channels, the A / D converter 32 for converting an analog signal of the voltage and current of the three phases detected from the data detector 20 into a digital signal, and the current and voltage of each phase. Digital Signal Processor (DSP) 34 for high speed computation of RMS measurement, Harmonic extraction, and other parameters, which may be configured in the MPU 40.

The central processing unit 40 is controlled by an MPU (Micro Process Unit) and has a built-in RTC (Real Time Clock) 42, which is a timekeeping device, and is configured to enable data management for each time zone. The central processing unit 40 configured as described above uses the information transmitted from the data measuring unit 30, such as active power, reactive power, apparent power, power factor, and the like. It calculates various parameters necessary for control and performs various I / O and communication operations.

In addition, the power supply unit 50 supplies an operating voltage required for the watt-hour meter, and the display unit 60 displays the measured power data and the parameters calculated through the calculation of the power data through the LCD, and the memory unit 70. Is composed of non-volatile memory such as EEPROM to store and store power data, and the communication control unit 80 transmits power data to an external device through serial communication such as RS232 / RS485 of international standards (CCITT, ITU-T). .

FIG. 2 illustrates power data measured in an electronic wattmeter configured as in FIG. 1 and electrical parameters calculated therefrom. In general, the electronic electricity meter is managed on a weekly and monthly basis, and as an electrical parameter (1), the RMS current / RMS current maximum value and average value, RMS voltage / RMS voltage maximum value and average value, frequency, power / power maximum value and average value Information about power factor, cumulative power, and harmonics is generated and stored. Meanwhile, it is necessary to store the corresponding waveform data 2 together with the event data 3 so that the event of power fault and disturbance can be examined when an event occurs. The waveform data 2 includes a real-time voltage value or a current value of each phase, and the event data 3 includes an external digital input / output event, an external analog input / output event, an external communication event, a user operation event, and the like.

1 is not able to store a large amount of waveform data due to the limitation of the storage capacity of the EEPROM 70. Therefore, even if a failure occurs in the power system, there is no waveform data that can reveal the cause, and it takes a long time to restore the original condition.

In order to solve this problem, such as an oil refinery, many electronic electricity meters are installed, and in a device industry where stable power supply is required, a "Disturbance Recorder" that can store waveform data is separately installed and networked. We are building an integrated control system. However, not only is it expensive to build such a system, but because most "disaster burners" use hard disks as storage mediums, the products are large and heavy, and mechanical access methods allow slow data access and high power consumption. There are many problems in applying it to the embedded product line.

As such, the conventional electronic wattmeter using EEPROM could not store waveform data due to the limitation of storage capacity. In addition, since the serial communication method such as RS232 / RS485 is used, the data storage speed is very slow. In order to solve this problem, the "distortion recorder" is expensive to build a system, and due to the limitations of hard disk storage media, there are problems of low speed, high weight, high noise, and high power.

The present invention was developed to solve such a problem, a new concept of electronic energy meter and waveform data storage by solving the problem of large capacity, high speed at the same time by adopting NAND flash memory and USB or Ethernet communication method in the conventional electronic electricity meter The purpose is to provide a method.

In order to achieve the above object, an electronic wattmeter using a NAND flash memory according to the present invention includes a data detector, a data measuring unit, a central processing unit, a power supply unit, a display unit, for measuring and storing / displaying / transmitting power data from a power element. An electronic power meter comprising a memory unit and a communication control unit, wherein the memory unit comprises a NAND flash memory and a NAND flash memory controller to configure a mass storage medium, and the communication control unit uses a USB or Ethernet communication method to form a high-speed transmission medium. The central processing unit includes a file system and a FTF for efficient data management to the NAND flash memory, and a TCP / IP file transfer protocol for a UBSB communication or an Ethernet communication.

In addition, the central processing unit measures the power data including the waveform data from the power element at regular intervals and updates it to the RAM, and when the power failure signal is detected, the waveform data for a predetermined time before and after the basis of the time point through the file system The RAM is transferred to the memory unit and stored.

On the other hand, the method for storing the waveform data through the wattmeter configured as described above, (a) measuring the power data including the waveform data from the power element at regular intervals; (b) updating the measured power data to the RAM embedded in the central processing unit; (c) detecting a power failure signal through an electrical input or an external parameter calculated through calculation of measured power data; and (d) when the power failure signal is detected, transmitting and storing waveform data for a predetermined time before and after the time from the RAM to the memory through a file system.

According to the electronic wattmeter using the NAND flash memory and the waveform data storage method using the NAND flash memory according to the present invention configured as described above, a large amount of waveform data can be stored in the flash memory to easily check the waveform data associated with an event such as power failure. To respond more quickly, enabling a more stable power supply. In addition, by adopting the USB and Ethernet communication method, a large amount of waveform data stored in the NAND flash memory can be transmitted to the external inspection device at high speed for faster response.

Hereinafter, the configuration of an electronic wattmeter using a NAND flash memory according to the present invention will be described in more detail with reference to FIG. 3.

As shown in FIG. 3, the electronic wattmeter in accordance with the present invention is a data detector 20, a data measurer 30, and a central processor 40 to measure and store / display / transmit power data from the power element 10. ), The power supply unit 50, the display unit 60, the memory unit 70, the communication control unit 80 is the same as the conventional electronic power meter described with reference to FIG. Therefore, the basic description of each component will be omitted and only the characteristic components and functions according to the present invention will be described in detail.

According to the present invention, the memory unit 70 is composed of the NAND flash memory 71 and the NAND flash memory controller 72 to form a large capacity storage medium, the central processing unit 40 to the NAND flash memory File system 44 and FTEL 45 are embedded for effective data management. In addition, the communication control unit 80 employs a USB or Ethernet communication method to configure a high-speed and large-capacity transmission medium, for this purpose, the central processing unit 40, the USB protocol for the USB communication or IP / IP for Ethernet communication File transfer protocol 46 is built in.

First, the memory unit 70 will be described. NAND flash memory 71 is a nonvolatile memory that can change data electrically. It is similar to the existing EEPROM in that it can be electrically rewritten, but it is different in that it can rewrite high-capacity data compared to the EEPROM, and it is very inexpensive for capacity. It is also different from the conventional hard disk in that it is lightweight, fast data access speed and shock resistant to ensure high reliability. Due to these characteristics, recently, they are widely used in digital electronic products such as portable storage devices, cell phones, digital cameras. However, unlike EEPROM, since there is basically a BAD area, a high level of memory control technology is required to use NAND flash.

The present invention configures the memory unit 70 of the electricity meter together with the NAND flash memory controller 72 required for storing the large amount of data of the electricity meter such that the NAND flash memory 71 is relatively inexpensive than using a conventional EEPROM. Large capacity, high speed was achieved. This is the most characteristic technical configuration of the present invention. The NAND flash memory controller 72 includes logic capable of quickly and efficiently controlling a plurality of NAND flashes, and ECC (Error Code Collection Calculator) logic to detect and correct errors of the NAND flash.

On the other hand, the central processing unit 40 is embedded with a separate file system 44 for managing a large amount of data using the NAND flash memory (71). The file system 44 is basically adapted to the characteristics of the NAND flash memory in which reading and writing is performed in units of blocks, and further includes an algorithm for storing a large amount of waveform data in the form of a file.

In addition, the central processing unit 40 has a built-in Flash Translation Layer (FTL) 45 for efficient data management in the NAND flash memory. This software is a software algorithm to solve the problems caused by the embedded block of the NAND flash memory 71. The wear leveling wear as well as the recognition and management function of the embedded block are performed. It applies algorithms such as leveling to efficiently use NAND flash memory. In particular, the mapping technique for realizing this is currently devised, and is a key technique for determining NAND flash memory control performance.

The simplest method of storing a large amount of waveform data of the power data measured from the power element 10 in the memory unit 70 of the NAND flash memory is the three-phase measured by the MPU 41 of the central processing unit 40 at regular intervals. All waveform data of voltage and current are converted into a file form along with time zone information and stored in the NAND flash memory 71.

In this configuration, when an event such as a power fault or power disturbance occurs, the NAND flash memory may be searched based on the event occurrence time and the corresponding waveform data may be inspected. However, when storing a large amount of waveform data, there is a disadvantage in that the memory space is insufficient to shorten the storage cycle and frequent read / write operations. In addition, although the waveform data measured in the situation where power is normally supplied does not need to be stored, storing them is inefficient in terms of utilization of memory.

To solve this problem, temporarily store power data including waveform data of voltage and current measured at regular intervals in a separate storage space, and then store the relevant waveform data in NAND flash memory only when a power failure signal is detected. It is preferable to comprise so that.

According to the present invention, the temporary storage space uses the RAM 43 embedded in the central processing unit 40. That is, the MPU 41 of the central processing unit 40 temporarily stores the power data including the waveform data measured at regular intervals from the power element 10 in the RAM 43. The RAM 43 uses an S-RAM having a high access rate, and the power data is continuously updated every few seconds to several tens of seconds according to its capacity and sampling per cycle.

When a power failure signal is detected during this process, waveform data for a predetermined time period before and after the time point is detected from the RAM 43 as a flash memory through the file system 44 and the FTTEL 45. 70) to save. The file system 44 provides a management algorithm capable of storing a large amount of waveform data in a NAND flash memory. The time interval for storing the waveform data may be uniformly determined, such as "for 10 seconds before and after the detection of the fixed power signal", or may be determined differently according to the type of the event.

The power failure signal is detected by an electrical parameter calculated through calculation of power data stored in the RAM 43 or detected through an external input. The electrical parameter is calculated through calculation from power data (voltage, waveform data of current, phase value, etc.) measured from the power element 10, and includes RMS voltage value, RMS voltage maximum value and average value, RMS current value, RMS Current maximum value and average value, active power (Active power), reactive power (Reactive power), apparent power (Aparent power), Power Factor, Harmonics and the like. Among the calculated electrical parameters, for example, when the RMS current value is out of the normal range, it may be configured to detect it as a power failure signal.

On the other hand, the external input corresponds to a case where the power failure signal is detected by a digital or analog signal transmitted from an external device connected to the electricity meter. For example, when an error occurs in the integrated control device that controls the power supply system, this error signal (digital signal) is input to the electricity meter. The digital signal is detected as a power failure signal and the waveform measured for a certain time before and after the time point. Store data to NAND flash memory. This makes it easy to check the type of voltage and current supplied in the event of a corresponding error in the integrated control unit.

The central processing unit 40 transfers the electrical parameters calculated through the operation of the power data to the NAND flash memory 71 and the NAND flash memory controller 72 at regular intervals through the file system 44 and the FTTL 45. It is preferable to configure to store in the configured memory unit 70. This is because the electrical parameters can be usefully used to analyze the cause of power abnormality or power disturbance together with the waveform data.

On the other hand, another technical feature according to the present invention is that the communication control unit 80 employs the UESB or Ethernet communication method, the central processing unit 40 is a recipe for the UESB protocol or Ethernet communication method for the UESB communication / As described above, the IP file transfer protocol 46 is embedded.

USB (Universal Serial Bus) is one of the input and output standards for connecting computers and peripherals. The latest version of USB 2.0 has a transmission speed of up to 480 Mbps, which is much faster than 45 kbps of RS232 used in conventional electricity meters. To provide In order to implement such a USB communication method, the USB protocol (46) embedded in the central processing unit 40 is configured to support the USB communication standard and the Mass Storage Class (MSC) standard.

The communication control unit 80 employing the UESB communication method can transfer a large amount of waveform data stored in the NAND flash memory 71 to a notebook or the like in which a diagnostic program is installed. Therefore, by using the electronic watt-hour meter of the present invention, by connecting a notebook to a watt-hour meter in which a power failure signal is detected, a large amount of waveform data can be transmitted and analyzed at high speed to quickly check the cause of the failure.

Ethernet (ETHERNET) communication is a computer network communication developed for LAN and is a communication method standardized by IEEE 802.3 protocol. Ethernet communication speed is determined by media type and wiring method. In case of 10BASE-T, which is currently installed, 10Mbps is supported. This Ethernet communication and the TCP / IP file transfer protocol, which is a communication protocol for this, not only provide a much faster transfer rate than RS485 used in conventional electricity meters, but also provide a one-to-many communication method of RS485. It can support many-to-many communications that can overcome limitations.

In addition, if you install FTP (FILE TRANSFER PROTOCOL), one of the application layer protocols of TP / IP, it functions as a file server, allowing simultaneous access of data and user name and password when connecting to the server. The security part can be satisfied because the authentication process is needed to confirm the security. Therefore, if the electronic electricity meter of the present invention is used, a large amount of waveform data is accessed and analyzed through the network and analyzed quickly for the cause of failure without a large network system using a "disaster burner recorder" conventionally. can do.

Therefore, the electronic electricity meter applying the Ethernet communication method according to the present invention can be suitably used for small and medium-sized industrial plants that are difficult to build a network system using a costly disturbance recorder.

A method of storing waveform data in an electronic wattmeter using the NAND flash memory according to the present invention described above will be briefly described with reference to FIG.

First, power data including waveform data from the power element 10 is measured at regular intervals (S10). The predetermined period may vary depending on the storage capacity of the RAM 43 embedded in the central processing unit 40 to be described later, and is made at intervals of several seconds to several tens of seconds. As described above, the measurement of the power data is performed by the data detector 20 and the data measurer 30.

Next, the measured power data is updated to the RAM 43 embedded in the central processing unit 40 (S20). Since the power data measured in the state in which power is normally supplied in step S10 is not necessary to be stored separately in the memory unit 70, the data is continuously updated in the RAM 43, which is a temporary storage space.

During the process of updating the step S20, the central processing unit 40 detects the power failure signal through an electrical parameter or an external input calculated through the calculation of the measured power data (S30). The electrical parameter is an RMS value, frequency, power, power factor, etc. calculated from measured power data, and when a specific parameter is out of the normal range, it is detected as a power failure signal. The external input is a digital or analog signal input from an external device connected to the electricity meter and is a signal that can check whether the external device is abnormal.

When the power failure signal is detected in step S30, the central processing unit 40 transmits the waveform data from the RAM 43 through the file system 44 and the FTT-45 through the file system 44 and the FTF 45 based on the time point. The memory unit 70 transmits the data to the memory unit 70 that is a flash memory and stores it separately (S40). More specifically, the central processing unit 40 is a file system 44 adapted to store a large amount of waveform data and software for controlling NTL flash memory (FTL) for efficient data management to the NAND flash memory. Algorithm) to save the waveform data. The predetermined time before and after the power failure signal may be determined uniformly, or may be differently determined according to the type of event or parameter as described above.

Meanwhile, according to the present invention, the electrical parameters calculated through the operation of the power data in step S20 may be separately stored in the memory unit 70 at regular intervals through the file system 44 (S50). The electrical parameters may be stored by dividing the predetermined period by time, daily, weekly, and monthly, and the stored electrical parameters are usefully used to check the abnormality of power supply along with the stored waveform data in step S40.

According to the waveform data storage method according to the present invention configured as described above, since waveform data related to power abnormality is stored in a large-capacity NAND flash memory, it is possible not only to store the waveform data for a long time but also to quickly check and cope with it when necessary. have.

1 is a block diagram of a general electronic electricity meter.

2 is a diagram showing data measured by an electronic electricity meter;

3 is a block diagram of an electronic power meter according to the present invention;

Figure 4 is a flow chart showing a waveform data storage method of the electronic electricity meter according to the present invention.

※ Explanation of symbols about main part of drawing ※

10: power element 20: data detector

30: data measuring unit 40: central processing unit

41: Micro Process Unit (MPU) 42: Real Time Clock (RTC)

43: RAM 44: File System

45: Flash Translation Layer (FTL) 46: USB, TCP / IP Protocol

50: power supply unit 60: display unit

70: memory unit 80: communication control unit

71: NAND flash memory 72: NAND flash memory controller

Claims (7)

In order to measure and store / display / transmit power data from the power element 10, the data detector 20, the data measurer 30, the central processor 40, the power supply 50, the display 60, and memory In the electronic electricity meter composed of the unit 70, the communication control unit 80, The memory unit 70 includes a NAND flash memory 71 and a NAND flash memory controller 72 to form a mass storage medium. The communication control unit 80 uses a USB communication method to form a high speed transmission medium. The central processing unit 40 has a file system 44 and a FTF 45 for efficient data management to NAND flash memory, and a USB protocol 46 for USB communication; The central processing unit 40 measures power data including waveform data from the power element 10 at regular intervals, updates the RAM 43, and calculates electrical parameters calculated by calculating power data stored in the RAM 43. When a power failure signal is detected through an external input, the waveform data for a predetermined time period before and after the time is detected from the RAM 43 to the NAND flash memory through the file system 44 and the FTTEL 45. Electronic electricity meter using the NAND flash memory, characterized in that the transmission to the unit (70). In order to measure and store / display / transmit power data from the power element 10, the data detector 20, the data measurer 30, the central processor 40, the power supply 50, the display 60, and memory In the electronic electricity meter composed of the unit 70, the communication control unit 80, The memory unit 70 includes a NAND flash memory 71 and a NAND flash memory controller 72 to form a mass storage medium. The communication control unit 80 employs an Ethernet communication method to form a high speed transmission medium. The central processing unit 40 includes a file system 44 and a FTF 45 for efficient data management of the NAND flash memory, and a TCP / IP file transfer protocol 46 for Ethernet communication; The central processing unit 40 measures power data including waveform data from the power element 10 at regular intervals, updates the RAM 43, and calculates electrical parameters calculated by calculating power data stored in the RAM 43. When a power failure signal is detected through an external input, the waveform data for a predetermined time period before and after the time is detected from the RAM 43 to the NAND flash memory through the file system 44 and the FTTEL 45. Electronic electricity meter using the NAND flash memory, characterized in that the transmission to the unit (70). delete delete The NAND of claim 1 or 2, wherein the central processing unit 40 stores the electrical parameters calculated through the operation of the power data in the memory unit 70 at regular intervals through the file system 44. Electronic electricity meter using flash memory. A method of storing waveform data using the electricity meter of claim 1 or 2, (a) measuring power data including waveform data from the power element 10 at regular intervals; (b) updating the measured power data to the RAM 43 embedded in the central processing unit 40; (c) detecting a power failure signal through an electrical input or an external parameter calculated through calculation of measured power data; (d) When the power failure signal is detected, the memory unit including waveform data for a predetermined time before and after the time point from the RAM 43 to the NAND flash memory through the file system 44 and the FTT45. 70) waveform data storage method of the electricity meter using the NAND flash memory, characterized in that the step of transmitting and storing. The method according to claim 6, wherein step (d), (e) separately storing the electrical parameters calculated through the operation of the power data in the memory unit 70 at regular intervals through the file system 44 of the power meter using the NAND flash memory. How to save waveform data.

Images