JP7706836B2 - Measurement and monitoring system - Google Patents

Description

The present invention relates to a measurement and monitoring system.

As described in Patent Document 1, in measuring and monitoring environmental information, measurement data is collected by sending measurement data from multiple sub-modules to a base module (monitoring module). Such measurements are performed at regular intervals, but in recent years, the increasing volume and speed of data communication has created a demand to shorten the measurement intervals and collect more measurement data. The reason for this is that by collecting large amounts of data at short measurement intervals, a more accurate monitoring system can be constructed, for example by grasping the instantaneous increase in current value during a lightning strike, making it possible to grasp the situation at the measurement location more accurately.

JP 2020-20619 A

However, measurement data cannot be sent from multiple submodules to the base module simultaneously. For this reason, conventionally, the base module sends transmission commands to specific submodules in sequence, and the base module and submodules communicate one-to-one. In this case, however, there is a possibility that the time of the measurement data may differ significantly between multiple submodules. When there are many submodules, the measurement time difference of the measurement data becomes noticeable. In other words, when the base module sends transmission commands to specific submodules in sequence, and the base module and submodules communicate one-to-one, it is difficult to synchronize the time between the measurement data, and it may be difficult to compare measurement data at the same time.

The inventors of this invention have thoroughly investigated this issue and attempted to solve it. The problem that this invention aims to solve is to suppress the time lag between each piece of acquired data.

To solve the above problem, a measurement and monitoring system is provided that includes a base module and multiple sub-modules, in which the base module can transmit a communication start signal to the multiple sub-modules all at once, and the multiple sub-modules that receive the communication start signal from the base module can each transmit measurement data to the base module at different timings, and the time from the timing of the base module transmitting the communication start signal to the corresponding transmission of measurement data by each sub-module is within the power supply cycle.

The submodule also includes a judgment unit that judges whether there is an abnormality in the measurement data, and in response to a communication start signal sent by the base module, the submodule is capable of sending to the base module both measurement data measured within the power supply cycle and long-period measurement data that is longer than the power supply cycle, and it is preferable that the base module is configured not to output the measurement data during the power supply cycle to an external device under normal circumstances, but to output the measurement data during the power supply cycle to an external device under abnormal circumstances.

When measuring the period of three-phase AC, the submodule transmits, for the R phase, measurement data measured over the power supply period up to the 0 point of the R phase immediately prior to the received communication start signal, and for the T phase, measurement data measured over the power supply period up to a position 60° delayed from the 0 point of the R phase immediately prior to the received communication start signal, and it is preferable to configure the configuration so that the time from the timing of the transmission of the communication start signal by the base module to the corresponding transmission of the measurement data for both phases by each submodule is within the power supply period.

The base module is preferably configured to output to the outside the measurement data, time information in seconds when the measurement data was measured, and periodic information indicating at what point in time in seconds the measurement data was measured, all in association with the measurement data.

The base module is preferably configured to output to the outside the measurement data relating to the power source and the measurement data relating to something other than the power source, time information in seconds at which each of the measurement data was measured, and periodic information indicating at what point in time in seconds the measurement data was measured, all in association with each other.

It is also preferable to configure the determination unit so that it can determine that an abnormality has occurred when measurement data related to the power supply exceeds a threshold value and measurement data related to something other than the power supply also exceeds a threshold value.

The present invention can reduce the time lag between the acquired data.

4 is a diagram showing the relationship between a base module, a sub-module, a sensor, and an external contact output module in the embodiment. FIG. FIG. 2 is a diagram showing signal exchange during a power supply period of a power supply waveform. This is a table showing data such as voltage, current, acceleration, and contact on/off for each period of one second at a specific time, which is imported into the base module. Note that the commercial frequency is 50 Hz. This is a diagram showing a comparison between changes in current over time and changes in sound over time. This figure shows that a communication start signal is issued immediately after a notification indicating that the zero point of the R phase has been confirmed, and for the R phase, measurement data measured in the power supply cycle up to the zero point of the R phase immediately before the received communication start signal is transmitted, and for the T phase, measurement data measured in the power supply cycle up to a position 60° delayed from the zero point of the R phase immediately before the received communication start signal is transmitted, and that the transmission of the measurement data for the R phase and T phase is performed within the power supply cycle (20 ms in this example) from the notification indicating that the zero point has been confirmed.

The following describes an embodiment of the invention. As can be seen from FIGS. 1 and 2, the measurement and monitoring system 1 of this embodiment includes a base module 2 and multiple sub-modules 5. The base module 2 of this measurement and monitoring system 1 can transmit a communication start signal to the multiple sub-modules 5 all at once. Furthermore, the multiple sub-modules 5 that receive a communication start signal from the base module 2 can each transmit measurement data to the base module 2 at different timings. Furthermore, the time from the timing of the transmission of the communication start signal by the base module 2 to the corresponding transmission of measurement data by each sub-module 5 is within the power supply cycle. This makes it possible to suppress time lags in the data acquired.

The base module 2 and submodule 5 communicate with each other to exchange information, but the submodule 5 mainly sends data acquired by the sensor 7 connected to the submodule 5 to the base module 2. Some of the sensors 7 may be connected to the base module 2, but it is preferable to connect most of the sensors 7 to the submodule 5. In the example shown in FIG. 1, the base module 2 and the sensor 7 module are connected by a communication line 41.

Each sensor 7 performs measurements. Examples of items that can be measured using the measurement and monitoring system 1 include current, voltage, power, vibration, sound, temperature, humidity, and images, but other items may also be measured. However, it is preferable that one of the sensors 7 measures at least the AC commercial power supply. In particular, it is preferable that the measurement items include any of the current, voltage, and power of the AC commercial power supply.

Here we will explain the power supply cycle. The AC power supplied by the power company has a specific commercial frequency (50 Hz or 60 Hz). With AC power, the positive and negative charges of electricity alternate dozens of times per second; the number of times this alternates is called the frequency, and one cycle of alternation is called a power supply cycle. The power supply cycle is the smallest unit of AC power, and the state of the AC power supply can be read for each power supply cycle.

In the embodiment, in order to exchange signals between the base module 2 and the submodule 5, a communication start signal is sent from the base module 2 to the submodule 5, and the timing of sending this communication start signal is based on the zero point notification sent from the submodule 5. Of course, it is not essential to use the zero point notification from the submodule 5 to determine the timing of sending the communication start signal. For example, the zero point may be detected by directly applying an AC power voltage to the base module 2, and the communication start signal may be sent. The zero point notification is a signal that notifies that a zero point has been confirmed in the AC power source (see FIG. 2).

In this embodiment, when the base module 2 receives a zero point notification from the sub-modules 5, it uses the command unit 21 to send a communication start signal to all sub-modules 5 at once.

In addition, in the embodiment, the base module 2 is given selection setting information for the power supply frequency value (50 or 60), and the communication start signal is transmitted to the submodule 5 at each cycle. Therefore, when 50 Hz is used, the communication start signal is transmitted to the submodule 5 50 times per second, and when 60 Hz is used, the communication start signal is transmitted to the submodule 5 60 times per second.

Incidentally, while measurement data relating to current, voltage, and power is often measured at power supply cycles, the measurement data handled by each module does not have to be measured only at power supply cycles. In other words, rather than measuring 50 or 60 times per second, the measurement data may be measured at cycles longer than the power supply cycle, such as once per second. The measurement data relating to current, voltage, and power is filtered. Filtering involves using a low-pass filter to remove certain high-frequency noise.

When handling measurement data other than current, voltage, or power, the settings can be switched so that the processing unit 22 processes only measurement data with a long period longer than the power supply period. In this way, it is possible to handle measurement data with the power supply period, but when there is no need to handle measurement data with the power supply period, the burden of signal exchange can be reduced.

In the example shown in FIG. 2, both power supply cycle measurement data and long cycle measurement data are handled, but the base module 2 stores the long cycle measurement data in the memory unit 23. In this way, the long cycle measurement data stored in the memory unit 23 can be used for comparison with the power supply cycle measurement data, etc.

The power cycle measurement data does not need to be stored in the base module 2, but it is preferable to store it. Even in this case, it is sufficient that the power cycle measurement data is stored in the temporary storage unit 24 for a certain period of time (at least one power cycle), and that new measurement data is sent and then overwritten in order.

The base module 2 of the embodiment also includes a judgment unit 11 capable of judging whether there is an abnormality in the measurement data of the power supply cycle. Of course, the judgment unit 11 may be provided separately from the base module 2. For example, the judgment unit 11 may be provided in the sub-module 5. In this way, only long-cycle measurement data is sent to the base module 2 under normal circumstances, and if it is determined that there is an abnormality in the measurement data of the power supply cycle, the measurement data of the power supply cycle is sent to the base module 2, so that the volume of communication between the base module 2 and the sub-module 5 under normal circumstances can be reduced.

Furthermore, regardless of the location of the determination unit 11, if the submodule 5 can transmit both "measurement data measured within the power supply cycle to the base module 2" and "long-period measurement data with a cycle longer than the power supply cycle" in response to a communication start signal transmitted by the base module 2, it is preferable that the base module 2 is configured not to output the power supply cycle measurement data to an external device under normal circumstances, but to output the power supply cycle measurement data to an external device under abnormal circumstances. In this way, it is possible to reduce communication capacity under normal circumstances. It is also preferable to configure the long-period measurement data to be output to an external device during this time as well. To make this possible, the base module 2 is provided with an external output unit 25. Note that the external device is a different device from the submodule 5.

In the example shown in FIG. 1, the base module 2 is provided with a contact signal transmission unit 26, and is configured to transmit a contact signal to an external contact output module 8 (DOT: digital output terminal) connected via a communication line 43 in the event of an abnormality, instructing the opening and closing of the contacts of the device.

In addition, in this example, the contact signal is transmitted as a contact output signal within the power supply cycle after the base module 2 transmits the communication start signal and before the sub-module 5 transmits the measurement data to the base module 2. In this way, the contact signal can be sent between the time the sub-module 5 receives the communication start signal and the time it transmits the measurement data. This makes it possible to efficiently transmit and receive a large number of signals within the power supply cycle.

The base module 2 of the embodiment also includes an external output unit 25 that can output to an external server, PC, etc. In the embodiment, this external output unit 25 is used to output long-period measurement data to an external server, PC, etc. under both normal and abnormal conditions. On the other hand, data related to the measurement data of the power supply cycle is not output using the external output unit 25 under normal conditions, but when the measurement data of the power supply cycle exceeds a threshold value, it is used to create and output a report of the measurement data measured during the power supply cycle.

As can be seen from these examples, in this embodiment, the measurement data of the power supply cycle is used to determine whether or not there is an abnormality. It is also used to determine whether or not to send a contact signal to the external contact output module 8 that can shut off each breaker.

The contact signal transmission pattern can be any, but can be, for example, "When the measurement data during a power cycle exceeds a threshold, a contact signal is sent to turn the device's contacts OFF," or "A contact signal is sent every power cycle, but under normal circumstances a signal is sent to keep the contacts ON, and when an abnormality occurs a signal is sent to turn the contacts OFF." The contact signal to turn the contacts OFF can be sent when it is determined that there is an abnormality in the measurement data before the power cycle.

In the embodiment, when transmitting data to the outside, the measurement data of the power supply cycle, time information, and cycle information can be transmitted to the outside all together. In this case, it is preferable for the base module 2 to output to the outside a report that is created by associating the measurement data, the time information in seconds when the measurement data was measured, and cycle information that indicates at what point in time in seconds indicated by the time information the measurement data was measured.

To make this possible, the base module 2 of the embodiment consolidates the measurement data and creates a report as shown in Figure 3. In this case, since the commercial frequency is 50 Hz, measurement data is managed every 1/50th of a second, but in the case of 60 Hz, measurement data only needs to be managed every 1/60th of a second. The base module 2 is designed to create reports in this way only when necessary, such as when an abnormality occurs. This reduces the load on the processing unit 22, allowing the processing unit 22 to be configured more inexpensively.

Next, the submodule 5 will be described. In the embodiment, the submodule 5 can be connected to multiple sensors 7, and measurement data measured by each sensor 7 is input. In the embodiment, the submodule 5 has an internal calculation unit, and can perform calculations to derive power and power factor from current and voltage information input from the sensors 7. In the example shown in Figure 1, three sensors 7 are connected to one submodule 5, but two, four or more sensors 7, or just one sensor 7 may be connected.

In this example, the waveform information of the power supply cycle is grasped by the submodule 5. Therefore, the moment the submodule 5 detects a zero point, it notifies the base module 2 of the zero point. In addition, when the base module 2 receives the zero point notification from the submodule 5, it sends a communication start signal to each submodule 5 at the same time.

When the submodule 5 receives a communication start signal from the base module 2, it transmits a set of power supply cycle and long cycle measurement data to the base module 2 within the power supply cycle. However, to prevent each submodule 5 from transmitting to the base module 2 at the same time, the submodules 5 transmit to the base module 2 in a predetermined order.

The order may be determined in any manner, but for example, the order may be determined by assigning an address to each submodule 5 so that the order is determined in accordance with the communication order. Also, the communication order may be set based on the order in which setting buttons provided on the submodules 5 are pressed during installation, etc.

Here, we will provide a specific example of the flow of information exchange that takes place in this embodiment. First, when a specific submodule 5 detects a zero point, it sends a zero point notification to the base module 2. When the base module 2 receives the zero point notification, it sends a communication start signal to the submodule 5.

If an abnormality was detected in the previous cycle, the base module 2 sends a contact signal to the external contact output module 8, and the external contact output module 8 sends a signal to the contact device to open the contacts. Note that if no abnormality was detected, the base module 2 does not send a contact signal to the external contact output module 8.

The submodule 5 transmits the power cycle and long cycle measurement data to the base module 2. The base module 2 receives this measurement data and outputs the long cycle measurement data together to the outside. If an abnormality is determined for the power cycle measurement data or if a preset condition is satisfied, the base module 2 outputs the power cycle measurement data together to the outside. The power cycle measurement data may be data of effective values within the power cycle, or may be data that includes both effective values and instantaneous maximum values within the power cycle. By including instantaneous maximum value measurement data, it is possible to grasp instantaneous fluctuations in the measurement data within the power cycle, such as during a lightning strike. The instantaneous maximum value is the peak value of an electrical signal that changes from moment to moment, and noise has been removed by filtering. The measurement data is processed by AD conversion.

If no abnormality is detected during the next power cycle or if the preset conditions are not met, the base module 2 stops processing the measurement data during the power cycle. In other words, it returns to normal operation. It is not essential to handle the measurement data in the above-described manner, and other processes may be used.

For example, measurement data related to the power supply and measurement data related to something other than the power supply may be output so as to be compared, or comparison and determination may be performed. More specifically, measurement data related to current and measurement data related to something other than current may be made comparable. Examples of measurement data related to something other than current include measurement data for sound and vibration, and in the example shown in Figure 4, measurement data related to current and measurement data related to sound are made comparable. In this example, it can be estimated whether the occurrence of an abnormal sound is caused by the power supply.

To make this possible, it is preferable that the base module 2 be able to externally output measurement data relating to the power source and measurement data relating to something other than the power source, time information in seconds at which each of the measurement data was measured, and periodic information indicating at what point in time in seconds indicated by each of the time information the measurement data was measured.

The determination unit 11 may be configured to determine that an abnormality has occurred when measurement data related to the power supply exceeds a threshold value and measurement data related to something other than the power supply also exceeds a threshold value. In this way, it is possible to avoid determining that an abnormality has occurred even if the power supply operates unstably at startup, etc.

Here, we will explain the case of measuring the power supply of a three-phase AC power supply as an example. A three-phase AC power supply transmits three AC currents (R phase, S phase, T phase) shifted by 120° each. In the case of three-phase AC, it is possible to measure the R phase and T phase, which have a phase difference, but the T phase is 240° (=120°+120°) behind the R phase, and it is difficult to transmit measurement data of the R phase and T phase of the same power supply cycle within the power supply cycle (360°) from the 0 point of the R phase.

Therefore, the reference AC voltage is set to R phase, and when the 0 point of R phase is detected, processing is performed so that measurement data for the power supply cycle up to the 0 point is transmitted for R phase. Also, for T phase, since the timing when the 0 point occurred in R phase and the immediately preceding 0 point are located 60° behind the 0 point of R phase, processing is performed so that measurement data for the power supply cycle up to the 0 point of T phase is transmitted. By performing these processing steps, the reference for starting measurement of T phase can be kept 60° behind the reference for starting measurement of R phase (see Figure 5).

In this way, it becomes easier to transmit the T-phase measurement data within the power cycle from the detected R-phase zero point. Furthermore, by positioning the T-phase zero point and the R-phase zero point closer in time, it is possible to improve the consistency of the measurement data between the R-phase and T-phase.

For this reason, when measuring the period of three-phase AC, it is preferable for the submodule 5 to transmit, for the R phase, measurement data measured over the power supply period up to the 0 point of the R phase immediately prior to the received communication start signal, and for the T phase, measurement data measured over the power supply period up to a position 60° delayed from the 0 point of the R phase immediately prior to the received communication start signal. In this way, it becomes easier to fit the time from the timing of the transmission of the communication start signal by the base module 2 to the corresponding transmission of the measurement data of both phases by each submodule 5 within the power supply period.

In the example shown in Figure 5, the zero point of the R phase is based on the zero point going from the negative polarity side to the positive polarity side, but it may also be based on the zero point going from the positive polarity side to the negative polarity side. In this case, the zero point at a position shifted by 180° from Figure 5 is the reference.

The present invention has been described above using an embodiment as an example, but the present invention is not limited to the above embodiment and can be implemented in various forms. For example, an abnormality may be determined when the measurement data of the power supply cycle exceeds a threshold value for a certain period of time.

1 Measurement monitoring system 2 Base module 5 Submodule 11 Determination unit

Claims (6)

A measurement and monitoring system comprising a base module and a plurality of sub-modules,
The base module can transmit a communication start signal to multiple sub-modules at once,
The sub-modules each receive a communication start signal from the base module and are capable of transmitting measurement data to the base module at different times.
A measurement and monitoring system in which the time from the timing of transmission of a communication start signal by a base module to the corresponding transmission of measurement data by each sub-module is within one cycle of a commercial power supply . When measuring the period of three-phase AC,
The submodules are
For the R phase, transmit the measurement data measured during the power cycle up to the 0 point of the R phase immediately before the received communication start signal,
For the T phase, transmit the measurement data measured in the power supply cycle from the 0 point of the R phase immediately before the received communication start signal to a position 60° behind,
2. The measurement and monitoring system according to claim 1 , wherein the time from the timing of transmission of the communication start signal by the base module to the timing of transmission of the measurement data of both phases by each sub-module in response thereto is within a power supply cycle. The measurement monitoring system of claim 1, wherein the base module outputs to an external device the measurement data, time information in seconds when the measurement data was measured, and periodic information indicating at what point in time in seconds indicated by the time information the measurement data was measured, in association with each other. A determination unit is provided for determining whether or not there is an abnormality in the measurement data,
the submodule is capable of transmitting to the base module, in response to a communication start signal transmitted by the base module, both measurement data measured within a power supply cycle and measurement data having a cycle longer than the power supply cycle;
2. The measurement and monitoring system according to claim 1, wherein the base module does not output the measurement data of the power supply cycle to the external device under normal conditions, but outputs the measurement data of the power supply cycle to the external device under abnormal conditions. The measurement and monitoring system of claim 3, wherein the base module outputs to the outside measurement data relating to the power source and measurement data relating to something other than the power source, time information in seconds at which each of the measurement data was measured, and periodic information indicating at what point in time in seconds indicated by each of the time information the measurement data was measured, in association with each other. When the measurement data related to the power supply exceeds the threshold and the measurement data related to something other than the power supply exceeds the threshold,
6. The measurement and monitoring system according to claim 5, wherein the determining unit is capable of determining that an abnormality has occurred.

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