TWI676805B - Data sampling method for power parameter measuring device - Google Patents

Abstract

The present invention is a data sampling method for a power parameter measurement device. The power parameter measurement device measures a power signal of a power system cable through a current ratior. First, a longer data transmission period and time are set. Short data acquisition cycle, the power parameter measurement device will periodically sample the power signal every interval of the data acquisition cycle to obtain a plurality of sampling data; and then transmit an external power parameter at each interval of the data transmission cycle Representative data; by increasing the sampling frequency, it can more accurately reflect the power signal, and because the power parameter representative data is sent to the data transmission cycle with a relatively long interval, it can also reduce the power consumption of the device.

Description

Data sampling method for power parameter measuring device

The invention relates to a power parameter measurement technology, in particular to a data sampling method capable of reducing the power consumption of a measurement device.

Electric power parameters are often used for power quality monitoring, electricity bill calculation, time electricity price contract capacity assessment, energy saving, predictive maintenance of power equipment, and power system safety maintenance. By measuring the voltage, current, power equipment temperature, ambient temperature, ambient humidity, environmental specific gas concentration and other power parameters obtained on the power system to meet the needs of power system monitoring.

The working power source of the power parameter measurement device usually adopts methods such as solar power or current converter, but this type of energy is not stable. In order to reduce the working energy consumption of the power parameter measurement device, the traditional method is to control the power parameter amount. The test device operates in a long duty cycle mode. Please refer to FIG. 5, the long duty cycle mode refers to the power parameter measuring device is usually in a sleep state, and the instant segment T is represented as the sleep period T. When the sleep period T ends, the power parameters are executed at the sampling time points a, b ... Sampling and measurement to obtain parameter data Xa, Xb,…. The parameter data Xa, Xb, ... will be displayed on the power parameter measurement device or transmitted to a host computer at the sampling time points a, b ..., and then the parameter measurement device will continue to sleep until the next sleep The parameter measurement is performed again at the end of the period T.

Although the above long duty cycle mode can achieve the purpose of saving power consumption, often because the time of the sleep cycle T is too long, the parameter data is not representative of the data and cannot represent the changing characteristics of the actual power parameters in the sleep cycle T. Affects the trend and accuracy of subsequent calculation results based on this parameter data Xa, Xb, ...

The main object of the present invention is to provide a "data sampling method for a power parameter measuring device" to reduce power consumption and increase the representativeness of the sampling data.

In order to achieve the above purpose, the power parameter measurement device measures a power signal of a power system cable through a current ratior. The data sampling method is performed by the power parameter measurement device and includes the following steps:

Set a data transmission cycle, each data transmission cycle includes a plurality of data acquisition cycles, the length of the data transmission cycle is greater than the length of each data acquisition cycle;

The power signal is sampled every interval of the data acquisition cycle to obtain a plurality of sampling data;

A power parameter representative data is transmitted to the outside every data transmission cycle, wherein the power parameter representative data is generated according to the plurality of sampling data.

According to the foregoing method, the present invention performs sampling at a higher frequency to obtain multiple pieces of sampling data and temporarily store them. The multiple pieces of sampling data can more specifically reflect the real power signal and make the power parameter representative data more representative; and The power parameter represents that the data is sent out at a relatively long data transmission cycle. It can also reduce the power consumption of the device when transmitting data, so that the stored power inside the device can maintain a longer working time.

Please refer to FIG. 1, the present invention is a data sampling method for a power parameter measurement device. First, the circuit structure of the power parameter measurement device is described, including: a signal switching unit 20, an energy collection unit 30, An energy storage unit 40, a power parameter conversion unit 50, and a wireless communication unit 60. The power parameter measuring device is applied together with a current ratior 10.

The converter 10 is mounted on a power system cable 100, and a power signal can be induced from the power system cable 100. The power signal can be a micro-voltage signal or a micro-current signal, where the ratio The current transformer 10 has a conversion ratio and can convert an actual voltage or actual current passing through the power system cable 100 into the power signal.

The signal switching unit 20 is connected to the current ratior 10 and is used to determine the transmission target of the power signal output by the current ratior 10, that is, to control the power signal to be output to the energy collection unit 30 or the power parameter unit 50.

The energy harvesting unit 30 has an input end and an output end, the input end is connected to the signal switching unit 20, and the output end is connected to the energy storage unit 40, wherein the energy harvesting unit 30 can be a charging circuit and the energy storage The unit 40 may be a rechargeable battery or a capacitor. When the power signal output from the current ratior 10 is transmitted to the energy collection unit 30 through the signal switching unit 20, the energy collection unit 30 converts the power signal into a reserve power and transfers it to the energy storage unit 40. The energy storage unit 40 stores the reserve power as a working power source of the power parameter measuring device.

The power parameter conversion unit 50 is connected to the signal switching unit 20. When the power signal output from the current converter 10 is transmitted to the power parameter conversion unit 50 through the signal switching unit 20, the power parameter conversion unit 50 can convert the power signal output from the current converter 10 into a digital signal and then output it. To the wireless communication unit 60, the wireless communication unit 60 can inversely calculate the actual voltage or current passing through the power system cable 100 according to the conversion ratio of the current converter 10 to obtain the required power parameters. In this embodiment, the power parameter conversion unit 50 includes a current signal measurement IC, which can convert the analog power signal output by the converter 10 into a digital signal, and then provide the digital signal to the wireless communication unit 60.

The wireless communication unit 60 is connected to the signal switching unit 20 and the power parameter conversion unit 50. The wireless communication unit 60 includes a processor (CPU) for performing calculations. The wireless communication unit 60 communicates with an external device according to a preset setting. A switching control signal is output to the signal switching unit 20 periodically, so that the signal switching unit 20 determines a power signal transmission object according to the switching control signal. In addition, the wireless communication unit 60 transmits power parameters to an external device in a periodic packet format for the external device to use as a basis for data calculation, analysis, display or control. The wireless communication unit 60 can transmit signals using a frequency band below 6 GHz, such as Bluetooth, Z-Wave, ZígBee, Wi-Fi, LoRa, Sigfox, NB-IoT and other protocols.

The power parameter measurement device operates in a measurement mode and an energy storage mode according to its circuit operation mode. The measurement mode and the energy storage mode can operate alternately. Generally speaking, most of the power parameter measurement devices operate in the energy storage mode. Only a few time periods are required to operate in the measurement mode to detect the power parameters. The energy storage unit 40 has sufficient power to provide the required working energy.

Energy storage mode: When the signal switching unit 20 is switched to be connected to the energy harvesting unit 30, the power signal induced by the current ratior 10 can be transmitted to the energy harvesting unit 30 through the switching unit 20. The energy collection unit 30 can collect power again and store it in the energy storage unit 40 to supplement the power required for the operation of the power parameter measurement device.

Measurement mode: When the signal switching unit 20 is connected to the power parameter conversion unit 50, the power signal induced by the current ratior 10 can be transmitted to the power parameter conversion unit 50 through the switching unit 20. At this time, the energy acquisition unit 30 is separated from the signal switching unit 20, and the power parameter conversion unit 50 can obtain an undisturbed power signal and convert a relatively accurate signal for the wireless communication unit 60 to calculate the actual power parameter. Because the energy acquisition unit 30 does not receive the power signal, the energy storage unit 40 will not store energy, but the power parameter measurement device can still maintain the power supply operation by the power stored in the energy storage unit 40.

Please refer to FIG. 2 and FIG. 3. In the measurement mode, the power parameter measurement device executes the data sampling method of the present invention. The data sampling method includes:

S201: Set a data transmission period Tr. As shown in FIG. 3, each data transmission period Tr includes a plurality of data acquisition periods Ts. The time length of the data transmission period Tr is greater than each data acquisition period Ts. Length of time.

S202: Sampling the power signal at every data acquisition cycle Ts to obtain a plurality of sampling data S1 ~ Sn; for example, at the time point t1 ~ tn when each data acquisition cycle Ts expires, the current sampling device 10 samples The output power signal is transmitted to the power parameter conversion unit 50 through the signal switching unit 20. The plurality of sampling data S1 ~ Sn may be temporarily stored in the power parameter conversion unit 50 or temporarily stored in the wireless communication unit 60.

S203: A power parameter representative data P is transmitted to the outside every data transmission period Tr. Among them, the power parameter representative data P may be the plurality of sampling data S1 ~ Sn, or the power parameter representative data P is based on the plurality of sampling data. Data obtained after the calculation of S1 ~ Sn, for example, the power parameter conversion unit 50 or the wireless communication unit 60 calculates the average value of the sampled data S1 ~ Sn as the power parameter representative data P, or obtains the power parameter through other calculation methods Representative data P. In this step, the power parameter representative data P is transmitted outward from the wireless communication unit 60.

According to the data sampling method of the foregoing first embodiment, the present invention can obtain multiple sampling data S1 to Sn in each data transmission cycle Tr, so that the power parameter representative data P is more representative and reflects the power signal more truly; And because the power parameter represents that the data P is sent out to the data transmission cycle Tr with a relatively long interval, the power consumption of the device can be reduced, and the device can maintain a longer working time.

Please refer to FIG. 4 again, which is a second embodiment of a data sampling method according to the present invention. The method further includes the following steps:

S401: Before executing step S202, it is determined in advance whether the remaining power of the power parameter measuring device is greater than a first preset value; that is, whether the power in the energy storage unit 40 is lower than a first preset value, such as the amount of power Whether it is below 10%, when the power is greater than the first preset value, enter the general mode, that is, continue to perform the foregoing steps S202 and S203;

S402: When it is determined that the remaining power is lower than the first preset value, it enters a power saving mode, that is, the power signal is sampled every interval data transmission period Tr and a single sample of data is transmitted to the outside. In other words, when the power in the energy storage unit 40 is lower than the first preset value, in order to further save power, the present invention samples the power signal only when each data transmission period Tr expires, and passes the sampled data through After the conversion, the wireless data communication unit 60 is used to transmit to the outside. In the original data acquisition cycle Ts, no sampling or conversion is performed to save the remaining energy in the energy storage unit 40.

S403: Determine whether the remaining power of the power parameter measuring device is greater than a second preset value, and if yes, return to the normal general mode; if not, continue to execute step S402.

According to the data sampling method of the aforementioned second embodiment, the present invention adjusts the sampling method of the power signal according to the power flexibility in the energy storage unit 40. When the power is still sufficient, data sampling is performed a plurality of times, and then the data transmission cycle is performed. Tr transmits data to the outside; on the contrary, when the power is insufficient, the number of data sampling is reduced, so that the device can maintain a longer working time. In the power-saving mode, if it is determined that the remaining power of the device is higher than a second preset value, for example, the power is higher than 20%, the normal multiple data sampling may be restored, and the second preset value may be high. At the first preset value or the second preset value is equal to the first preset value.

Regardless of the above first or second embodiment, at other times than data sampling, the power parameter measuring device works in the energy storage mode, and uses the current transformer 10 to capture the power signal and store the energy in the energy storage. Inside the unit 40.

10‧‧‧ Current Converter

20‧‧‧Signal Switching Unit

30‧‧‧ Energy Harvesting Unit

40‧‧‧ Energy Storage Unit

50‧‧‧Power parameter conversion unit

60‧‧‧Wireless communication unit

100‧‧‧Power System Cable

Tr‧‧‧Data transmission cycle

Ts‧‧‧Data acquisition cycle

S1 ~ Sn‧‧‧Sampling data

P‧‧‧Representative data of power parameters

Xa, Xb‧‧‧parameter data

Figure 1: Circuit block diagram of a power parameter measurement device.
FIG. 2 is a flowchart of a first embodiment of a data sampling method according to the present invention:
FIG. 3 is a schematic diagram of a data sampling method according to the present invention.
FIG. 4 is a flowchart of a second embodiment of a data sampling method according to the present invention:
Figure 5: Schematic diagram of a long duty cycle mode for a power parameter measurement device.

Claims (9)

A data sampling method for a power parameter measurement device. The power parameter measurement device measures a power signal of a power system cable through a current ratior. The data sampling method is performed by the power parameter measurement device and includes The following steps:
Set a data transmission cycle, each data transmission cycle includes a plurality of data acquisition cycles, the length of the data transmission cycle is greater than the length of each data acquisition cycle;
The power signal is sampled every interval of the data acquisition cycle to obtain a plurality of sampling data;
A power parameter representative data is transmitted to the outside every data transmission cycle, wherein the power parameter representative data is generated according to the plurality of sampling data. The data sampling method for a power parameter measurement device according to claim 1, wherein the power parameter representative data is the plurality of sampling data. The data sampling method for a power parameter measurement device as described in claim 1, wherein the power parameter representative data is generated after an arithmetic operation based on the plurality of sampling data. The data sampling method for a power parameter measuring device according to claim 3, wherein the power parameter representative data is an average value of the plurality of sampling data. A data sampling method for a power parameter measurement device. The power parameter measurement device measures a power signal of a power system cable through a current ratior. The data sampling method is performed by the power parameter measurement device and includes The following steps:
Set a data transmission cycle, each data transmission cycle includes a plurality of data acquisition cycles, the length of the data transmission cycle is greater than the length of each data acquisition cycle;
Determine whether the remaining power of the power parameter measuring device itself is higher than a first preset value. When the remaining power is higher than the first preset value, a general mode is executed. The general mode includes the following steps:
The power signal is sampled every interval of the data acquisition cycle to obtain a plurality of sampling data;
A power parameter representative data is transmitted to the outside every data transmission cycle, wherein the power parameter representative data is generated according to the plurality of sampling data. The data sampling method for a power parameter measuring device as described in claim 5, wherein when the remaining power is lower than the first preset value, a power saving mode is executed, and in the power saving mode:
The power signal is sampled every interval of data transmission cycle and a single sample of data is transmitted to the outside;
Determine whether the remaining power of the power parameter measurement device itself is higher than a second preset value, wherein if the remaining power is lower than the second preset value, the power saving mode is continuously maintained and executed; if the remaining power is higher than the second preset value Two preset values, the normal mode is executed. The data sampling method for a power parameter measuring device according to claim 5 or 6, wherein, in the general mode, the power parameter representative data is the plurality of sampling data. The data sampling method for a power parameter measuring device according to claim 5 or 6, wherein, in the general mode, the power parameter representative data is generated after an arithmetic operation based on the plurality of sampling data. The data sampling method for a power parameter measuring device according to claim 8, wherein the power parameter representative data is an average value obtained by calculating an average of the plurality of sampling data.