KR101027816B1 - Electronic electricity meter for distribution with overcurrent observing unit for detecting overcurrent in distribution system - Google Patents

Abstract

The present invention provides a power distribution unit having an overcurrent observation unit for detecting an overcurrent of a distribution system that can detect an overcurrent of a distribution system quickly and efficiently by a simple operation in order to prevent a safety accident due to the occurrence of an overcurrent in a distribution system. An electronic power meter, comprising: an electrical power meter for distribution comprising an overcurrent observing unit for measuring power consumption of a load electrically connected to a power supply of a distribution system and detecting overcurrent of the distribution system, wherein the load is proportional to the consumption current consumed by the load. An instrument current transformer for detecting a current output signal; An instrument transformer for detecting a voltage output signal proportional to the load voltage of the wiring; A temperature sensor attached to a primary side of the current transformer for detecting the voltage, the temperature sensor detecting a voltage proportional to a temperature of an electronic electricity meter for a power distribution; A first surge protector composed of a capacitor connected in parallel with an inductor connected in series with the secondary line of the instrument current transformer to block a surge to an A / D converter and remove noise; A second surge protector composed of a resistor and a capacitor connected in parallel with an inductor connected in series with the secondary line of the instrument transformer to block the surge to the A / D converter and to remove the noise; An amplifier amplifying the voltage detected by the temperature sensor to generate a temperature output signal; A current output signal detected by the instrument current transformer and input through the first surge protector, a voltage output signal detected by the instrument transformer and input through the second surge protector, and a temperature output signal generated by the amplifier An A / D converter for converting the digital signals into digital signals; A power amount calculating unit for calculating a power amount from the current output signal and the voltage output signal which is converted into a digital signal through an A / D converter, and calculates an average estimated value of the current temperature output signal, A micro-controller unit (MCU) including an overcurrent observing unit configured to generate an overcurrent sensing signal in comparison with an average estimated value of a temperature output signal, and a memory unit storing the amount of power and an average estimated value of a current temperature output signal; And an overcurrent observing unit configured to detect an overcurrent of a distribution system including an output unit configured to output the amount of power generated by the MCU and an overcurrent sensing signal.

Description

DISTRIBUTION WATT-HOUR METER HAVING OVER-CURRENT OBSERVER}

The present invention relates to an electronic electricity meter for power distribution, and more particularly, a power distribution system capable of quickly and efficiently detecting overcurrent of a power distribution system by a simple operation in order to prevent safety accidents due to the occurrence of overcurrent in the power distribution system. An electronic power meter for a power distribution unit having an overcurrent observing unit for detecting an overcurrent of the present invention.

Conventionally, the method of metering power in a power distribution system has been widely used by manpower, that is, a method in which a meter visitor visits a customer to check the value of a meter and record the confirmed data. However, since such a metering method is very inefficient, a device for automatically metering a remote power has been developed. As such equipment, an electric power meter for power distribution capable of performing remote meter reading has been proposed. However, such a conventional electric power meter for power distribution is often not implemented to detect this when an overcurrent occurs in the distribution system, and the customer has been operating separately from the power meter by installing a separate overcurrent detection device.

On the other hand, there are some conventionally proposed power distribution meters with overcurrent sensing, but these are disadvantageous in that the circuit configuration is complicated and the manufacturing cost is high because most of them perform a complicated operation internally. In addition, the prior art has a problem of increasing the manufacturing cost and the cumbersome management of the accumulated overcurrent information data because the data necessary for the detection of overcurrent is continuously stored and stored in the memory to use a large-capacity memory means. In addition, there is a problem in that the complex operation must be performed and the presence of overcurrent is determined based on a fixed reference value, so that it is not robust to changes in the surrounding environment and disturbance.

Disclosure of Invention The present invention has been made to solve the above problems, and an object of the present invention is to provide an electronic electricity meter for a distribution having an overcurrent observation unit that can quickly and efficiently determine the overcurrent generated in the distribution system by a simple operation. do.

In addition, the present invention does not accumulate and store data necessary for overcurrent observation in a distribution system in a memory, and thus is low in manufacturing and maintenance costs, and an electronic electricity meter for distribution having an overcurrent observer that can be easily applied to an existing installation. To provide another purpose.

In addition, the present invention is to observe the over-current in the power distribution system based on the variable reference value, it is another object to provide an electric power meter for a distribution having an over-current monitoring unit that is robust to environmental changes and disturbances, such that, the overall power distribution system To increase the efficiency of.

The present invention for solving the above problems, the electronic power meter for power distribution including an overcurrent observation unit for measuring the power consumption of the load electrically connected to the power supply of the distribution system, and detects the overcurrent of the distribution system, the load A current transformer for detecting a current output signal proportional to the current consumed by the consumer; An instrument transformer for detecting a voltage output signal proportional to the load voltage of the wiring; A temperature sensor attached to a primary side of the current transformer for detecting the voltage, the temperature sensor detecting a voltage proportional to a temperature of an electronic electricity meter for a power distribution; A first surge protector composed of a capacitor connected in parallel with an inductor connected in series with the secondary line of the instrument current transformer to block a surge to an A / D converter and remove noise; A second surge protector composed of a resistor and a capacitor connected in parallel with an inductor connected in series with the secondary line of the instrument transformer to block the surge to the A / D converter and to remove the noise; An amplifier amplifying the voltage detected by the temperature sensor to generate a temperature output signal; A current output signal detected by the instrument current transformer and input through the first surge protector, a voltage output signal detected by the instrument transformer and input through the second surge protector, and a temperature output signal generated by the amplifier An A / D converter for converting the digital signals into digital signals; A power amount calculating unit for calculating a power amount from the current output signal and the voltage output signal which is converted into a digital signal through an A / D converter, and calculates an average estimated value of the current temperature output signal, A micro-controller unit (MCU) including an overcurrent observing unit configured to generate an overcurrent sensing signal in comparison with an average estimated value of a temperature output signal, and a memory unit storing the amount of power and an average estimated value of a current temperature output signal; And an overcurrent observing unit configured to detect an overcurrent of a distribution system including an output unit configured to output the amount of power generated by the MCU and an overcurrent sensing signal.

In an exemplary embodiment, the overcurrent observing unit of the MCU calculates an average estimated value of the current temperature output signal and compares the average estimated value of the immediately stored temperature output signal with a reference value for a predetermined error. It may also be configured to generate an overcurrent sensing signal.

(여기서,

는

번째 온도 출력 신호에 대한 평균 추정값이고,

는

번째 온도 출력 신호값임)의 수식에 의하여 계산할 수 있다.In addition, the overcurrent observation unit of the MCU, the average estimated value for the current temperature output signal

(here,

Is

Is an average estimate of the first temperature output signal,

Is

Second temperature output signal value).

In addition, the output unit, a display unit for displaying the amount of power generated by the power amount calculation unit of the MCU, and when the over-current detection signal is generated in the over-current monitoring unit of the MCU, the alarm signal so that the user can recognize visually or auditoryly It may include an alarm for outputting, and an overcurrent blocking switch which operates when an overcurrent detection signal is generated in the overcurrent observing unit of the MCU to block the overcurrent.

According to the present invention, it is possible to provide an electric power meter for a distribution having an overcurrent observing unit capable of quickly and efficiently determining an overcurrent generated in a distribution system by a simple calculation.

In addition, according to the present invention, since the data necessary for the observation of overcurrent in the distribution system is not accumulated and stored in the memory, the boat is equipped with an overcurrent observing unit which is inexpensive to manufacture and maintain and can be easily applied to existing installations. A dedicated electronic wattmeter can be provided.

In addition, since the present invention observes the overcurrent in the distribution system on the basis of the variable reference value, it is possible to provide an electric power meter for a distribution having an overcurrent observation unit that is robust to environmental changes and disturbances, etc. As a result, to improve the efficiency of the overall distribution system It can be effective.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of an electric power meter for a distribution having an overcurrent observation unit for detecting the overcurrent of the distribution system according to the present invention.

1 is a block diagram showing an embodiment of an internal configuration of an electronic power meter for distribution (hereinafter, simply referred to as an electronic electricity meter for distribution) including an overcurrent observing unit for detecting an overcurrent of a distribution system according to the present invention.

Referring to FIG. 1, the electric power meter 100 for power distribution of the present embodiment is connected between a power supply 10 and a load 20 of a power distribution system to measure power consumption of the load 20 connected to the power supply 10. As to perform the function of detecting the over-current of the distribution system, the instrument current transformer 110, instrument transformer 120, temperature sensor 130, the first and second surge protector (140, 150), amplifier (160), A / D converter 170, MCU 180 and the output unit 190 is provided. Here, the MCU 180 includes a power amount calculator 181, an overcurrent observing unit 182, and a memory unit 183, and the output unit 190 includes a display unit 191, an alarm unit 192, and an overcurrent blocking unit. Switch 193.

The instrument current transformer 110 detects a current output signal proportional to the current consumed by the load 20 side, and the instrument transformer 120 detects a voltage output signal proportional to the load voltage of the wiring. To perform.

The temperature sensor 130 is attached to the primary side of the current transformer 110 for the instrument to detect a voltage proportional to the temperature of the electronic wattmeter.

The first surge protector 140 is composed of a capacitor connected in parallel with the inductor connected in series with the secondary line of the current transformer 110 for the instrument to block the surge and remove the noise by removing the A / D converter 170 Function to protect and improve measurement accuracy. In addition, the second surge protector 150 is composed of a resistor and a capacitor connected in parallel with the inductor connected in series with the secondary line of the instrument transformer 120 to block the surge and remove the noise by the A / D converter To protect the 170 and to improve the measurement accuracy. The first and second surge protectors 140 and 150 are for blocking surge and removing noise, and are not directly related to the present invention.

The amplifier 160 generates a temperature output signal by amplifying the low output voltage detected by the temperature sensor 130 so as to be easily processed, and transmits it to the A / D converter 170.

The A / D converter 170 is detected by the current transformer 110 for the instrument and the current output signal input through the first surge protector 140, and the second surge protector 150 is detected by the instrument transformer 120 And converts the voltage output signal input through the temperature sensor 130 and the temperature output signal detected by the temperature sensor 130 and amplified by the amplifier 160 into digital signals that can be processed by the MCU 180 and then converts the signal into the MCU 180. To send).

The MCU (Micro-Controller Unit) 180 includes a power amount calculating unit 181, an overcurrent observing unit 182, and a memory unit 183.

The overcurrent observing unit 182 calculates an average estimated value for the current temperature output signal detected by the temperature sensor 130 and amplified by the amplifier 160 and input through the A / D converter 170. The overcurrent sensing signal is generated by comparing the average estimated value of the temperature output signal of the previous stage stored in the memory unit 183.

번째 측정되는 온도 센서(130)로부터의 온도 출력 신호를 아래의 수학식 1로 나타낼 수 있다.For example, the overcurrent observing unit 172 may calculate an average estimated value for the current temperature output signal in the following manner. first,

The temperature output signal from the temperature sensor 130 to be measured first may be represented by Equation 1 below.

(는 실제 온도, 는 측정 오차)

(The actual temperature, the measurement error)

번째 온도 출력 신호에 대한 평균 추정값을 아래의 수학식 2 에서와 같이

이라고 하면,

번째 온도 출력 신호에 대한 평균 추정값

은 아래의 수학식 3의 순환형으로 나타낼 수 있다.And,

The average estimate of the first temperature output signal is obtained as shown in Equation 2 below.

Speaking of

Average estimate for the first temperature output signal

May be represented by a cyclic form of Equation 3 below.

)이 계산되면, 계산된 평균 추정값(

)과 메모리부(183)에 저장되어 있는 직전 단계의 온도 출력 신호에 대한 평균 추정값(

)을 비교하여, 예컨대

이 기설정된 오차에 대한 기준값 이상인 경우 배전 계통에서 과전류가 존재하는 것으로 판단하고 과전류 감지 신호를 발생하여 출력부(190)로 전달하게 된다.By this equation, the average estimated value for the current temperature output signal (

) Is calculated, the calculated average estimate (

) And an average estimated value for the temperature output signal of the previous stage stored in the memory unit 183 (

), For example

When the reference value for the preset error is greater than or equal to the current, it is determined that the overcurrent exists in the distribution system, and generates an overcurrent detection signal and transmits it to the output unit 190.

)을 현재의 온도 출력 신호에 대한 평균 추정값(

) 으로 대치하여 메모리부(183)에 저장한다. 따라서, 메모리부(183)에는 항상 현재 단계에서의 온도 출력 신호에 대한 평균 추정값(

)만이 저장되므로 대용량의 데이터를 누적하여 관리할 필요가 없다. 따라서, 제조 및 유지 비용이 저렴하고 기존에 설치된 설비에 용이하게 적용할 수 있다. 또한, 이와 같이 직전 단계의 온도 출력 신호에 대한 평균 추정값과 현재의 온도 출력 신호에 대한 평균 추정값만을 이용하여 과전류의 존재 여부를 판단하므로, 연산 과정이 간단하여 회로 구현이 용이하고 연산 속도도 매우 빠르게 유지할 수 있다. 또한, 기준값이 가변될 수 있으므로 주변 환경의 변화 및 외란 등에 강인한 특성을 얻을 수 있다. When this process is finished, the average estimate of the temperature output signal from the previous stage (

) Is the average estimate of the current temperature output signal (

) Is stored in the memory unit 183. Therefore, the memory unit 183 always includes an average estimated value for the temperature output signal at the present stage.

) Is stored so there is no need to accumulate and manage large amounts of data. Therefore, the manufacturing and maintenance cost is low and can be easily applied to existing installations. In addition, since the presence of overcurrent is determined using only the average estimation value of the temperature output signal of the previous stage and the average estimation value of the current temperature output signal, the calculation process is simple and the circuit implementation is easy and the operation speed is very fast. I can keep it. In addition, since the reference value can be varied, it is possible to obtain characteristics that are robust against changes in the surrounding environment and disturbances.

2 is a flowchart illustrating an overcurrent signal generation process performed by the overcurrent observing unit 182 as described above.

를 획득한다(S200). 여기서,

는

번째 측정되는 온도 출력 신호로서, 전술한 수학식 1(

)에 의하여 획득할 수 있다. Referring to Figure 2, first

Obtain (S200). here,

Is

As the first measured temperature output signal, the above-described equation (1)

Can be obtained by

번째 측정되는 온도 출력 신호)에 대한 평균 추정값(

)를 계산한다(S210). 이는 메모리부(183)에 저장되어 있는 직전 단계의 온도 출력 신호에 대한 평균 추정 값(

)에 기초하여, 전술한 바와 같은 수학식 3(

)에 의하여 계산할 수 있다. Next, the overcurrent observation unit 182 is a current temperature output signal (that is,

Average estimate (for the first measured temperature output signal)

) Is calculated (S210). This is an average estimated value for the temperature output signal of the previous stage stored in the memory unit 183 (

Based on Equation 3 as described above

Can be calculated by

)과 메모리부(183)에 저장되어 있는 직전 단계의 온도 출력 신호에 대한 평균 추정값(

)을 비교하여,

을 계산하여 계산 결과가 기설정된 오차에 대한 기준값 이상인지를 판단한다(S220). 기준값 미만인 경우에는, 과전류가 없는 것으로 판단하고 기존에 저장되어 있는 직전 단계의 온도 출력 신호에 대한 평균 추정값(

)을 현재의 온도 출력 신호에 대한 평균 추정값(

)으로 대치하여 메모리부(183)에 저장한다(S230). 단계(S220)에서의 계산 결과, 기준값 이상인 경우에는 과전류가 존재하는 것으로 판단하고 과전류 감지 신호를 발생하여 출력부(190)로 전달하게 된다(S240). 다음으로, 단계(S230)을 수행하게 된다.Next, the overcurrent observing unit 171 calculates the average estimated value (

) And an average estimated value for the temperature output signal of the previous stage stored in the memory unit 183 (

),

It is determined whether the calculation result is more than the reference value for the predetermined error (S220). If it is less than the reference value, it is judged that there is no overcurrent, and the average estimated value of the temperature output signal of the previous stage (previously stored) (

) Is the average estimate of the current temperature output signal (

) And store in the memory unit 183 (S230). As a result of the calculation in step S220, when the reference value is equal to or greater than the reference value, it is determined that an overcurrent exists and an overcurrent detection signal is generated and transmitted to the output unit 190 (S240). Next, step S230 is performed.

) 및 전력량 산출부(181)에서 산출된 전력량을 저장한다. Referring back to FIG. 1, the power amount calculator 181 of the MCU 180 calculates a power amount from a current output signal and a voltage output signal converted into a digital signal by the A / D converter 170, and the memory unit 183. ) Is the average estimate of the current temperature output signal (

) And the power amount calculated by the power amount calculator 181.

The output unit 190 may be a means for outputting the amount of power and the overcurrent detection signal generated by the MCU 180, and may include a display unit 191, an alarm unit 192, and an overcurrent cutoff switch 193.

The display unit 191 is a means for displaying the amount of power generated by the MCU 180, the alarm unit 192 is visually displayed to the user when the overcurrent detection signal generated by the overcurrent observation unit 182 of the MCU 180 is generated. Or means for outputting an alarm signal so that it can be recognized by hearing, and the overcurrent cutoff switch 193 operates when the overcurrent detection signal is generated by the overcurrent observing unit 182 of the MCU 180 to cut off the overcurrent by causing a safety accident. It is a means to prevent. The display unit 191, the alarm unit 192 and the over-current cut-off switch 193 may use a known means as it is, it is obvious to those skilled in the art, detailed description is omitted because it is not directly related to the present invention. .

In the above, while the preferred embodiment of the present invention has been described, it should be noted that this is exemplary and not limiting. Those skilled in the art to which the present invention pertains will be capable of various modifications and changes within the essential scope of the invention as grasped by the embodiments, claims and drawings.

1 is a block diagram showing an embodiment of an internal configuration of an electric power meter for power distribution having an overcurrent observing unit according to the present invention.

2 is a flowchart illustrating an overcurrent signal generation process performed by the overcurrent observation unit.

Claims (4)

In the electric power meter for power distribution having an overcurrent observation unit for measuring the power consumption of the load electrically connected to the power supply of the distribution system, and detects the overcurrent of the distribution system, An instrument current transformer for detecting a current output signal proportional to the current consumed by the load; An instrument transformer for detecting a voltage output signal proportional to the load voltage of the wiring; A temperature sensor attached to a primary side of the current transformer for detecting the voltage, the temperature sensor detecting a voltage proportional to a temperature of an electronic electricity meter for a power distribution; A first surge protector composed of a capacitor connected in parallel with an inductor connected in series with the secondary line of the instrument current transformer to block a surge to an A / D converter and remove noise; A second surge protector composed of a resistor and a capacitor connected in parallel with an inductor connected in series with the secondary line of the instrument transformer to block the surge to the A / D converter and to remove the noise; An amplifier amplifying the voltage detected by the temperature sensor to generate a temperature output signal; A current output signal detected by the instrument current transformer and input through the first surge protector, a voltage output signal detected by the instrument transformer and input through the second surge protector, and a temperature output signal generated by the amplifier An A / D converter for converting the digital signals into digital signals; A power amount calculating unit for calculating a power amount from the current output signal and the voltage output signal which is converted into a digital signal through an A / D converter, and calculates an average estimated value of the current temperature output signal, A micro-controller unit (MCU) including an overcurrent observing unit configured to generate an overcurrent sensing signal in comparison with an average estimated value of a temperature output signal, and a memory unit storing the amount of power and an average estimated value of a current temperature output signal; And Output unit for outputting the power amount and the overcurrent detection signal generated by the MCU Electronic electricity meter for a distribution having an overcurrent observation unit for detecting an overcurrent of the distribution system comprising a. The method of claim 1, The overcurrent observing unit of the MCU calculates an average estimated value of the current temperature output signal and compares it with the average estimated value of the immediately stored temperature output signal to generate an overcurrent detection signal when the reference value is greater than a reference value for a predetermined error. An electronic power meter for power distribution comprising an overcurrent observing unit for detecting overcurrent of a power distribution system. The method of claim 2, The overcurrent monitoring unit of the MCU, the average estimated value for the current temperature output signal

(here,

Is

Is an average estimate of the first temperature output signal,

Is

And an overcurrent observing unit for detecting an overcurrent of the distribution system, characterized in that it is calculated according to the formula of the second temperature output signal value. The method of claim 1, The output unit may include a display unit for displaying the amount of power generated by the power amount calculation unit of the MCU, and an alarm signal for outputting an alarm signal so that the user may be visually or hearingly recognized when an overcurrent detection signal is generated by the overcurrent observation unit of the MCU. And an overcurrent observing unit for detecting an overcurrent of a power distribution system, comprising: an alarm unit and an overcurrent blocking switch which operates when an overcurrent detection signal is generated by the overcurrent observing unit of the MCU to block the overcurrent.

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