JPH0662375U - Power measurement system - Google Patents

Abstract

(57) [Summary] [Structure] The power measuring device 1 receives voltage, current, power, etc. by inputting the secondary side output signals of the transformers PT1 and PT2 for instruments and the current transformers CT1 and CT2 connected to the line. Obtain the measurement data and write it in the IC memory card 2. The data processing device reads the measurement data from the IC memory card 2, analyzes it, and outputs it to the printing unit 8. [Effect] The measurement condition data can be set on the data processing device side, and it is not necessary to print out the measurement results on the power measurement device side, so unattended measurement for a long period of time becomes possible,
It is possible to print out with high resolution by using the printing unit on the data processing device side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a power measuring system including a power measuring device that measures the power of a measured line and a data processing device that analyzes the measured data.

[0002]

[Prior art]

 Traditionally, portable power meters have been equipped with an input section for setting measurement conditions such as measurement time intervals, and measurement data is recorded by an attached printer.

[0003]

[Problems to be solved by the device]

 However, such a conventional portable power meter is easy to carry because it is compact in size and can be used by connecting it to various power measured parts. Since the printer is used to print the measurement results using roll paper as the recording medium, the paper length is limited, which is inconvenient for long-term measurement. Also, since the attached printer has a narrow paper width and a small number of dots per line, it is not possible to perform high-resolution graphics-related printouts such as so-called trend graphs that show trends in power demand. . Furthermore, it is necessary to set measurement condition data such as measurement start date and time, measurement end date and time, measurement time interval PT ratio, CT ratio, and recording interval at the measurement site.

An object of the present invention is to provide a power measuring system that uses a power measuring device that is small and can be, for example, portable and that solves the various problems described above.

[0005]

[Means for Solving the Problems]

 An electric power measuring system of the present invention comprises an IC memory card having a measuring condition data and a recording unit for the measuring data, a measuring condition data reading means for reading the measuring condition data written in the IC memory card, and the measuring condition data. Based on the input data extracting means for sampling the secondary side output signals of the instrument transformer and the current transformer connected to the line and converting them into digital data to obtain input data, and the line based on the input data. A power measuring device comprising: a measurement data calculating unit that obtains the power of the measurement data as measurement data; and a measurement data recording unit that writes the measurement data obtained by the measurement data calculating unit into the IC memory card based on the measurement condition data. A measurement data reading means for reading the measurement data from the IC memory card, and a solution of the measurement data. A data processing device comprising a measurement data analysis unit for performing analysis, a printing unit for printing out the measurement data or the analysis result, and a measurement condition data writing unit for writing the measurement condition data in the IC memory card, Consists of.

[0006]

[Action]

 The power measuring system of this invention comprises a power measuring device, a data processing device, and an IC memory card as a data recording medium. The IC memory card is provided with a measurement condition data and measurement data recording section. The measuring condition data reading means of the electric power measuring device reads the measuring condition data written in the IC memory card, and the input data extracting means changes current with the instrument transformer connected to the line based on the measuring condition data. The output signals of the secondary side of the converter are sampled and converted into digital data to obtain input data, and the measurement data calculation means obtains the power of the line as the measurement data based on the input data. The measurement data recording means writes the measurement data obtained by the measurement data calculating means in the IC memory card based on the measurement condition data. On the other hand, the measurement data reading means of the data processing device reads the measurement data from the IC memory card, and the measurement data analyzing means analyzes the measurement data to obtain, for example, statistics. The printing means prints out the measurement data or the analysis result, and the measurement condition data writing means writes the measurement condition data in the IC memory card.

By the above operation, if the IC memory card in which the measurement condition data is written is attached to the power measuring device, the measurement data according to the measurement condition can be sequentially stored in the IC memory card, and the predetermined value is set. By connecting the IC memory card storing the measurement data to the data processing device after performing the measurement for a certain period of time, the data processing device can read and analyze the measurement data and print out. It is possible to write the measurement condition data to the IC memory card using this data processing device. In this way, the power measurement device itself does not need to set measurement condition data, and the measurement data and its analysis results can be printed by the data processing device side without being restricted by the printer attached to the power measurement device. Therefore, trend graphs can be printed in high resolution.

Further, since the power measuring device itself does not need to print out the measurement data and a large amount of measurement data can be stored in the IC memory card, it is possible to support unmanned measurement for a long period of time. In addition, once the measurement condition data is written in the IC memory card, periodic measurement can be performed simply by exchanging the IC memory card between the measurement site where the power measuring device is installed and the office where the data processing device is installed. Will be easier to do.

[0009]

【Example】

 FIG. 1 is a block diagram showing the configuration of the power measuring system according to the embodiment of the present invention. In FIG. 1, the power measuring device 1 inputs a voltage value, a voltage phase, a current value, a current by inputting the secondary side output signals of the transformers PT1 and PT2 for meters and the current transformers CT1 and CT2 connected to the line, respectively. The phase and the power are measured, and the measurement data are sequentially written in the IC memory card 2 according to the recording interval. The data processing device 3 comprises a data processing unit 4, an IC memory card read / write unit 5, a display unit 6, a key input unit 7 and a printing unit 8. The IC memory card read / write unit 5 is provided for the mounted IC memory card 2. Read and write various data. (In FIG. 1, an IC memory card is shown on both the power measuring device side and the data processing device side, but this is an IC memory card as a common data medium. The data processing unit 4 is, for example, a personal computer. It is composed of a computer or the like, reads the input contents of the key input unit 7, displays the processing items to be selected on the display unit 6, and outputs the measurement data or the print data of the analysis result to the printing unit 8. The printing unit 8 includes a printer that prints graphics data at high resolution on a wide sheet.

FIG. 2 is a block diagram showing the configuration of the power measuring device 1 shown in FIG. In FIG. 2, analog filters 11, 12, 13, and 14 respectively input the secondary side output signals of PT1, PT2, CT1 and CT2, and pass only the frequency band component required for power measurement. The sample and hold circuits 15, 16, 17, and 18 sample and hold the outputs of the analog filters 11, 12, 13, and 14 in synchronization with a predetermined cycle, respectively. The multiplexer 19 selects the output of the sample hold circuits 15 to 18 and supplies it to the A / D converter 20. The A / D converter 20 converts the output signals of the sample hold circuits 15 to 18 into digital data via the multiplexer 19. The CTC 21 is a basic counter that determines the sampling period and the like. The CPU 22 executes the program previously written in the ROM 23. The RAM 24 is used as a temporary storage area for sampling data and various registers for power calculation when the program is executed. The IC memory card reader / writer 26 controls data writing and reading with respect to the attached IC memory card. The CPU 22 reads / writes data from / to the IC memory card via the interface 25. Normally, the CPU reads the measurement condition data from the IC memory card and writes the measurement data to the IC memory card, but this power measuring device itself also has a means for writing the measurement condition data to the IC memory card, and the measurement condition is set on site. It is possible to reconfigure or change.

Next, FIG. 3 shows a configuration example of data in the IC memory card. As shown in Fig. 3, there are areas for recording measurement start date and time, measurement end date and time, measurement interval, recording interval, PT ratio and CT ratio as the measurement condition data, where "measurement start date and time" and "measurement end date and time" are set. Is the year, month, day, hour, minute, and second data, and indicates the period of measurement. “Measurement interval” is data indicating at what time interval the measurement is performed, and “recording interval” is data indicating at what time interval the measurement data is written to the IC memory card. In addition, "PT ratio" is the transformer ratio of the instrument transformer, and "CT ratio" is the current transformer ratio of the current transformer. This ratio is referred to when calculating the power from the input data. These measurement condition data are usually written by the data processing device.

Further, as shown in FIG. 3, the measurement data is composed of a data string in which date and time data, voltage value, voltage phase, current value, current phase and power data are sequentially written. Here, the voltage value, voltage phase, current value, current phase, and power data are instantaneous values obtained by sampling one cycle of the power supply frequency. The “voltage phase” and the “current phase” are, for example, phases with reference to the PT1 input. "Electricity" consists of active power value and reactive power value. These measurement data are written by the power measuring device.

Next, a processing procedure of the power measuring device is shown as a flowchart in FIGS. 4 and 5.

FIG. 5 is a flowchart showing a main processing procedure of the power measuring apparatus. First, the power measuring apparatus reads the measurement condition data from the IC memory card (n21). After that, it is determined whether or not the current time is the timing to be measured, and if it is the measurement timing, various calculations to be described later are performed (n22 → n23). At the recording timing, the measurement data is written in the IC memory card (n24 → n25). Also, the abnormality of the power measuring device itself is monitored (n26).

FIG. 4 is a flowchart showing the processing procedure of step n23 in FIG.

First, each input signal of PT1, PT2, CT1 and CT2 shown in FIG. 2 is sampled, and its digital data is stored in a predetermined area in the RAM 24 (n1 → n2). At that time, each input signal is stored only for one cycle of the fundamental frequency, and is updated so as to always store the latest one cycle of data every time sampling is performed. Following this, the voltage value, voltage phase, current value, current phase, and power (active power, reactive power) are calculated based on the sampling data for one cycle (n3).

Next, a processing procedure on the data processing device side is shown in FIG. 6 as a flowchart. First, the item to be processed is displayed and the key input by the operator is read (n31).

When “Measurement condition setting” is selected as the processing item, the measurement conditions (measurement start date / time, measurement end date / time, measurement interval, recording interval, PT ratio and CT ratio) are read from the key, and these measurement condition data are read. Is written in the IC memory card (n32 → n33 → n34). If the selected processing item is "measurement data analysis", the measurement data is sequentially read from the IC memory card, analysis processing is performed to print out numerical data and trend graphs, and these print data are sent to the printing device. Output (n35 → n36 → n37 → n38).

In the embodiment, the example in which the instantaneous value of the voltage value, the voltage phase, the current value, the current phase, and the electric power is written to the IC memory card is shown. It is also possible to average the power up to recording and write the average power. It is also possible to integrate the instantaneous power and write the power amount.

[0020]

[Effect of device]

 According to the power measuring system of this invention, only the power measuring device is used at the measurement site, and the power measuring device only needs to measure the power and write the measured data to the IC memory card, and print out the measured data. Since it is not necessary to perform the measurement, long-term unmanned measurement is possible. On the other hand, in business sites that perform monitoring / management, only the data processing device is used, and the data processing device does not need to be portable. Therefore, a large printing device is used to collect measurement data or graphics data of the analysis result. You can print with high resolution. Furthermore, since the measurement condition data is recorded in the IC memory card by the data processing device, the setting of the measurement condition becomes easy, and it becomes possible to perform the regular power measurement by a simple operation in the field.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a power measuring system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a power measuring device.

FIG. 3 is a diagram showing a configuration example of data in an IC memory card.

FIG. 4 is a flowchart showing a processing procedure of the power measuring device.

FIG. 5 is a flowchart showing a processing procedure of the power measuring device.

FIG. 6 is a flowchart showing a processing procedure of the data processing device.

[Explanation of symbols]

 PT1, PT2-Meter transformer CT1, CT2-Current transformer

Claims (1)

[Scope of utility model registration request] 1. An IC memory card having measurement condition data and a recording unit for the measurement data, a measurement condition data reading unit for reading the measurement condition data written in the IC memory card, and a line based on the measurement condition data. Input data extracting means for sampling the secondary output signals of the connected instrument transformer and current transformer, converting them into digital data to obtain input data, and measuring power of the line based on the input data. And a measurement data recording unit that writes the measurement data obtained by the measurement data calculation unit into the IC memory card based on the measurement condition data, A measurement data reading means for reading the measurement data and a measurement data analyzer for analyzing the measurement data. When the measurement data or analysis results and printing means for printing out, the IC memory card writing the measurement condition data measurement condition data writing unit and a data processing apparatus having a power measurement system comprising a city.