KR200354526Y1 - Electronic watt-hour meters with electric power control function - Google Patents

Abstract

The present invention relates to an electronic power meter having a power supply control function, connected in parallel with the power supply side (1S, 2S) and a voltage signal conversion unit for converting into a voltage signal corresponding to the input voltage, and in series with the power supply side (1S) A current signal converting unit connected to the current signal connected to the input current, an analog MUX alternately selecting signals corresponding to voltages and currents output from the voltage signal converting unit and the current signal converting unit; A signal converter configured to convert an analog signal of voltage and current selected by the analog MUX into a digital signal; A central processing unit that calculates a power consumption and calculates a current value by multiplying a digital signal corresponding to the voltage and current converted by the A / D conversion unit; and The operating current value calculated by the central processing unit according to the operation switch to be input and the electric charge payment information input through the operation switch is compared with the allowable current limit value, and the load side 1L and 2L from the power supply side 1S and 2S. Digital circuit unit consisting of a relay control circuit for controlling the power supplied to the; And a power supply connected between the power supply side 1S and 2S and the load side 1L and 2L and turned on / off according to a control signal of the relay control circuit to be supplied from the power supply side 1S and 2S to the load side 1L and 2L. It characterized in that it comprises a power switch for opening and closing the.

According to the present invention, electric bill payment information and current limit values are input and stored in the meter, so that the limit current can be used for households of legal guardians, persons with disabilities and low-income households. The power supply and shutdown can be freely controlled through the relay control inside the meter.

Description

Electronic watt-hour meters with electric power control function

The present invention relates to an electronic electricity meter for measuring electricity consumption, and more specifically, a power control function for supplying low-income people with disabilities and persons living with welfare to minimize the need for living, and cut off the power supply when more power is used. It relates to an electronic power meter having a.

In general, a wattmeter is an instrument for measuring the power and power of direct current or alternating current used in homes, stores, buildings, and factories, and is also called an integrated wattmeter. An electronic wattmeter is commonly used to measure AC power.

As described in Korean Utility Model No. 0273234 (Utility Model Application No. 2002-0003951), the electronic wattmeter includes a method of integrating a voltage and a current signal with an integrator, obtaining a signal proportional to the power, and digitizing and displaying the voltage. There is a method of digitizing the current signal with an analog-to-digital converter and digitally displaying the power by using a central processing unit.

Such a conventional electricity meter simply accumulates and measures the power consumed by the power load, the amount of power, the power factor, and the like, and displays the accumulated value of the electricity when the customer does not pay an electric bill. ) To cut off the electricity supply by cutting the wire outside the meter.

However, if low-income people, people with disabilities, and those who are living in the last few months have not paid their electricity bills for several months, they will not be able to use the electricity necessary for the minimum life at the time of cold weather due to power cuts. There is a social problem that causes death by fire because there is a case of heating with something like a portable gas burner instead of a lighting lamp.

In order to protect people's welfare and livelihoods of low-income people, people with disabilities, and people living in Korea, there is a tendency to use the 'minimum life force' necessary for minimum survival.

Therefore, the present invention was devised to solve the above-mentioned conventional problems, and an object of the present invention is to input and store electricity bill payment information and current limit values in a meter to limit the households of legal guardians, the disabled, and low-income families. It is to provide an electronic electricity meter with a power control function that allows the use of less than the current, and when using more current, the power control function to free the power supply and shutdown through the relay control inside the meter without cutting the wire from the outside.

Another object of the present invention, if the electricity bill is not paid after the electricity bill, the power supply is easy to operate the power control operation because it normally supplies electricity through a simple switch operation so that customers can use the electricity freely for any load desired by the customer It is to provide an electronic electricity meter with a control function.

In order to achieve the above object, the electronic wattmeter having a power control function according to the present invention detects a current variation of the AC power supplied from the power supply side 1S and 2S to the load side 1L and 2L to control power supply and interruption. In the electronic watt-hour meter, a voltage signal converting unit connected in parallel with the power supply sides 1S and 2S to convert into a voltage signal corresponding to an input voltage, and connected in series with the power supply side 1S to correspond to an input current. A current signal converting unit converting the current signal, an analog MUX alternately selecting signals corresponding to voltages and currents output from the voltage signal converting unit and the current signal converting unit, a voltage selected by the analog MUX, A signal converter comprising an A / D converter for converting an analog signal of a current into a digital signal; A central processing unit that calculates a power consumption and calculates a current value by multiplying a digital signal corresponding to the voltage and current converted by the A / D conversion unit; and The operating current value calculated by the central processing unit according to the operation switch to be input and the electric charge payment information input through the operation switch is compared with the allowable current limit value, and the load side 1L and 2L from the power supply side 1S and 2S. Digital circuit unit consisting of a relay control circuit for controlling the power supplied to the; And a power supply connected between the power supply side 1S and 2S and the load side 1L and 2L and turned on / off according to a control signal of the relay control circuit to be supplied from the power supply side 1S and 2S to the load side 1L and 2L. It characterized in that it comprises a power switch for opening and closing the.

The current signal converter is composed of a current transformer and a secondary terminal resistor of the current transformer, one line of the primary side of the current transformer is connected to the power supply side (1S), and the other wire is connected to the relay of the power switch.

1 is a control block diagram of an electronic power meter having a power supply control function according to an embodiment of the present invention,

2 is a detailed configuration diagram of a signal conversion unit applied to the present invention;

3 is an overall operation flowchart of the electronic wattmeter according to the present invention,

4 is an operation flowchart showing a power supply control function of the electronic watt-hour meter according to the present invention;

5 is a power control graph of the present invention electronic electricity meter when the electric bill is paid,

6 is a power control graph of the present invention electronic watt-hour meter when no electricity bill is paid.

Explanation of symbols on the main parts of the drawings

10: power meter 40: power circuit

50: signal conversion unit 51: voltage signal conversion unit

52: current signal conversion unit 53: MUX

54: A / D converter 60: digital circuit

61: central processing unit 64: operation switch

66: relay control circuit 80: power switch

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a control configuration diagram of an electronic power meter having a power control function according to an embodiment of the present invention, the electronic power meter 10 of the present invention is a power circuit unit 40, a signal conversion unit 50, a digital circuit unit 60 ), The display unit 70, and the power supply opening and closing unit 80, and four terminals 1S, 2S, 2L, and 1L on the outside.

The external four terminals 1S, 2S, 2L, and 1L are composed of power supply terminals 1S and 2S and load side terminals 1L and 2L, respectively, and the power supply terminals 1S and 2S are KEPCO (power supply company). It is connected to the supply side supplied from the load side, and the load side terminals 1L and 2L are connected to the customer load.

The power circuit unit 40 receives AC power from the power supply sides 1S and 2S to rectify and convert the AC power into DC voltages required by the electronic parts of the circuit inside the instrument. A circuit 42 and an electrostatic compensation unit 43.

The primary side of the power transformer 41 is connected to the power supply terminals 1S and 2S, and its output is connected to the power supply circuit 42 in series. The output of the power supply circuit 42 is supplied to the operating power of each circuit part electronic component constituting the instrument. The power failure compensator 43 is an auxiliary power supply circuit supplied to maintain the weighing data and the clock function at the time of power failure.

The signal converter 50 is a circuit for converting an analog AC voltage and a current input to the electricity meter 10 into a digital value, and includes a voltage signal converter 51 and a current signal converter 52. , MUX 53 and A / D conversion section 54.

The voltage signal conversion unit 51 is connected in parallel with the power supply side 1S, 2S, one line of the current signal conversion unit 52 is connected in series with the power supply side 1S, and the other line is the power switching unit 80. ).

A micro voltage signal corresponding to each voltage and current output from the voltage signal and current signal converters 51 and 52 is applied to the input of the analog MUX 53. The analog MUX 53 alternately selects the voltage and current signals to supply them to the A / D converter 54, and the A / D converter 54 converts the analog signals into digital signals. The converted digital signal is input to the central processing unit 61 of the digital circuit unit 60.

The digital circuit unit 60 is composed of a central processing unit 61, an oscillation circuit 62, a nonvolatile memory 63, an operation switch 64, a clock circuit 65 and a relay control circuit 66, The digital value output from the A / D converter 54 of the signal converter 50 is applied to the CPU 61. The oscillation circuit 62 is used as an oscillator necessary for the central processing unit 61 to operate, and is connected to the crystal connection terminal of the central processing unit 61.

The nonvolatile memory 63 is used as a memory for storing data measured and calculated in the central processing unit 61, and the operation switch 64 is a data input device for various setting (input) values required for the meter to operate. It is used as a general input / output port of the central processing unit 61.

The clock circuit 65 is a circuit for generating hours, minutes, seconds, years, months, days, and the like, and the relay control circuit 66 controls the operation of the power switch 80 to cut off and supply power. One side is connected to the general input / output port of the central processing unit 61, and the other side is connected to the excitation coil of the power switch unit 80.

The display unit 70 is configured with an LCD 71 to display metering data to an electric user (customer), and the power switch unit 80 is connected to a power supply side through a relay control circuit 66 of the central processing unit 61. It is composed of a relay for supplying and interrupting power applied to the load side 1L, 2L from 1S, 2S.

2 is a detailed configuration diagram of the signal conversion unit 50 applied to the present invention, and the output of the voltage signal conversion unit 51 and the output of the current signal conversion unit 52 are input terminals a of the analog MUX 53. and b), respectively, and the current signal conversion unit 52 is composed of a current transformer 521 and a secondary terminal resistor 522. One line of the primary side of the current transformer 521 is connected to the power supply 1S. The other wire is connected to the relay of the power switch (70).

The output terminal com of the analog MUX 53 is applied to the input of the sample and hold 541 of the A / D converter 54, which is the voltage or current currently selected by the analog MUX 53. The A / D converter 542 converts the voltage signal corresponding to the signal into a digital value by keeping the value unchanged during the processing of the A / D converter 542.

The output of the A / D converter 542 is transmitted to the ADC memories 543 and 544 to store digitalized converted values corresponding to the analog voltage and current at the input side, and then to central processing of the digital circuit unit 60. To the device 61.

Hereinafter, the effect of the electronic wattmeter having the power control function configured as described above will be described.

First, AC power supplied from the power supply sides 1S and 2S is applied from the power supply transformer 41 primary side of the power supply circuit unit 40 to voltage step down to a predetermined voltage. In step 41), the AC voltage dropped to several tens of volts is rectified through the power supply circuit 42 and converted into a DC voltage.

The DC voltage output from the power supply circuit 42 is used for the electricity meter for normal operation, and the voltage from the power failure compensator 43, which is an auxiliary power supply circuit, is supplied to maintain the metering data and the electronic clock function at the time of power failure.

In addition, the power supplied from the power supply company, that is, the AC power supplied from the power supply sides 1S and 2S, is supplied through the voltage signal conversion unit 51 and the current signal conversion unit 52 of the signal conversion unit 50. The electronic component is converted into a voltage signal of several volts which can be processed without being damaged, and the output of the voltage signal converter 51 and the output of the current signal converter 52 are input terminals a, b) is entered.

The analog MUX 53 alternately selects the input voltage and current signals and supplies them to the A / D converter 54, and the A / D converter 54 converts the analog signals of the selected voltage and current into digital signals. The data is converted and input to the central processing unit 61 of the digital circuit unit 60.

In more detail, the signal conversion unit 50 is a circuit for converting an analog AC voltage and a current input to the electricity meter 10 into a digital value so that the central processing unit 61 can process the signal. The signal conversion unit 50 operates the relay of the power switching unit 80 when the current for the purpose of the present invention flows to cut off the power supplied to the load side 1L, 2L, or when the current flows below It is important to supply electricity without shutting off the power supply, so the focus is on the sensing method of the current signal and the conversion to digital values.

If the primary side current of the current transformer 521 of the current signal conversion unit 52 is Ipri and the secondary current is Isec, the secondary current of the current transformer 521 is equal to 1 (1 / N) of the windings of the current transformer 521. Output is obtained.

Therefore, the secondary current Isec of the current transformer 521 is

Isec = (1 / N) * Ipri

When the terminating resistor 522 is connected to both ends of the secondary side of the current transformer 521, a change in current can be obtained as a voltage.

The voltage Vr across the terminal resistor 522 is

Vr = Isec * R [V].

The voltage Vr value across the terminal resistor 522 is supplied to the sample and hold 541 through the analog MUX 53, converted into a digital value by the A / D converter 542, and stored in the ADC memory_current 544. do.

In a similar manner, the signal input from the voltage signal converter 51 is also converted into a digital value by the A / D converter 542 and stored in the ADC memory_voltage 543.

The digital signals corresponding to the two voltages and currents converted as described above are input to the central processing unit 61, and the digital signals corresponding to the voltage and current signals are multiplied to calculate the power used. Data such as power measured and calculated by the central processing unit 61 is stored in the nonvolatile memory 63.

On the other hand, when the power consumption calculated by the central processing unit 61 is larger than the allowable current limit value when the electric charge is not paid, the operation of supplying and cutting off electricity through the relay control circuit 66 and the power switch unit 80. To control.

In other words, if the low-income group, the handicapped, and those who are subject to the welfare of the present invention do not pay the electricity bill due to unavoidable circumstances, the "supply and cutoff operation of the power source" to use only the "minimum living electricity" will be described in detail. Same as

First, in the case of 1) paying electricity bills,

If the electricity bill is paid, the power supply is not cut off so that electricity can be freely used. A detailed description will be made using the flowcharts of FIGS. 4 and 5.

2) If you fail to pay the electricity bill,

The average monthly household power consumption is about 300 kWh, and customers who use electricity below 100 kWh are generally called low-income families, and the average monthly electricity rate is about 4,400 won.

If so, what is the average current to use below 100kWh per month?

Power (kWh) = Voltage x Current x Power Factor x Time in a Month

Current = power amount / (voltage x power factor x time for one month)

Normally, since most of the assumption loads are resistance loads, assuming a power factor of 1.0, which is a phase difference between voltage and current, the average current is as follows.

Average current = 100000Wh / (220V x 1.0 x 24 hours x 30 days)

≒ 0.63 A

In this design, low-income people with disabilities and people who are not eligible for welfare do not receive electricity shortages immediately. The value obtained from the calculation of was set at 0.63A. Of course, you can change this value to any other value between 0 and 2A.

However, in the present invention, this value is set to 0.5 A for convenience of explanation.

This value is defined as " allowable maximum current limit value " and is input to the wattmeter 10 using the operation switch 64. The meter also enters information about whether the electricity bill has been paid.

In other words, the "allowable maximum current limit value" in the case of not paying an electric charge is a value which is a reference value for blocking if a few amperes (A) or more.

Therefore, when a current lower than the "permissible current limit value" is used without paying an electric charge, electricity is supplied without interrupting electricity.

On the other hand, if a current higher than the "permissible current limit value" is used without paying an electric charge, the central processing unit 61 controls the relay control circuit 66 to turn off the power switching unit 80 to supply electricity to the load sides 1L and 2L. When the supply is cut off and the value becomes lower than the "permissible current limit value", the power supply switch 80 is turned on again to supply electricity to the load sides 1L and 2L.

Next, the overall operation of the inventive electronic wattmeter will be described with reference to FIG. 3.

3 is an overall operation flowchart of the electronic wattmeter according to the present invention.

First, power is supplied to the electricity meter to initialize the operation.

In the "initialization" routine, the input and output ports are designated as inputs or outputs in order to obtain the desired operation, and the electronic components included in the circuit configuration are allowed to operate normally.

The main routines include power calculation, time and date generation, content display, key (switch) operation, power off and supply, and data storage subroutines. These subroutines are executed repeatedly.

The power calculation subroutine uses the ADC memory_voltage 543 and the ADC memory_current 544, which are the calculation results of the A / D converter 542 of FIG. 2, to calculate the power and amount of power used by the load sides 1L and 2L. Calculate and calculate the value of the current flowing.

The time and date generation subroutines are subroutines that create the seconds, minutes, hours, and dates required for operation in the electricity meter 10.

The content display subroutine is a subroutine for displaying the weighing data on the external LCD 71. The key (switch) operation subroutine is for setting and changing data or parameters necessary for the operation of the electricity meter 10 according to the key operation. It is a subroutine to perform, and the data storage subroutine is a subroutine that periodically stores the weighing data in the nonvolatile memory 63 in preparation for power failure.

Power-off and supply subroutines are subroutines to achieve the object of the present invention. What is the current value of? Is a subroutine that performs the actual power off and supply operation to the customer's load based on the comparison of the current current value and the set current limit value.

Next, the power control operation of the electronic watt-hour meter according to the load current variation when the electric charge is paid and the non-payment in the present invention will be described with reference to FIGS. 4 to 6.

4 is an operation flowchart illustrating a power control function of the electronic watt-hour meter according to the present invention, FIG. 5 is a power control graph of the electronic watt-hour meter of the present invention when the electric bill is paid, and FIG. 6 is a case where the electric bill is not paid. , As a power supply control graph of the inventive electronic watt-hour meter, in FIG. 4, S denotes a step.

First, in the case of paying the electricity bill, since the electricity bill is paid as shown in the graph of FIG. 5, even when electricity is freely used regardless of the current limit value or less, the electricity is continuously supplied without shutting off the power.

This is the same way that current customers use electricity at home. In this case, the operation determines whether or not the electric bill is paid first when entering the power-off and supply subroutine (S10).

If the electric charge is paid (YES), the overcurrent CNT (counter), the low current CNT and the power cut flag are cleared, the power is supplied to the load side (1L, 2L), and the process returns to the main routine (S11).

Whether the electricity meter 10 has paid the electricity bill is determined using the "electricity bill payment flag". In the first factory, the electricity meter 10 is produced and shipped, and at the time of shipment, the electricity bill payment flag is set to zero.

When electricity bill payment Flag = 0, it is a mode where electricity can be freely used in the same way that current customers use electricity at home,

If the electricity bill payment Flag = 1, it indicates that the electricity bill was not paid, and the KEPCO employee inputs the information that the electricity bill was not paid using the operation switch 64 of the electricity meter 10. This causes the electricity bill payment flag of the electricity meter 10 to be "1".

This means that in order to protect livelihoods, it is possible to use the "minimum living power" necessary for the minimum living, and to operate the electricity to cut off the electricity supply if more electricity is used.

In the case where the electric charge is not paid in step S10, the current current value ≤ current limit value is used by moving along the path of NO (S20) 92,93 indicated by dotted lines of the upper graph shown in FIG. Since 94 uses a current below the current limit value (ie minimum living power), electricity can be used without shutting down the power supply.

On the other hand, in the case of "current current value> current limit value," the power meter 10 cuts off the power supply since the current limit value is used without paying an electric charge as a part corresponding to 90,91 indicated by a dotted line in the upper graph of FIG. Do not supply power to the load.

Without electricity bill (NO) Power cut-off and supply operation according to the current value is indicated on the X-axis of the upper curve of Figs. 4 and 6 in the order of ①②③ .... ⓗⓘⓙ in each order. Description of the power interruption and supply operation performed by (10) is as follows.

① Since the current value is smaller than the current limit value, the current value ≥ current limit value of FIG. 4 is moved along the path of NO in the determination routine S20 to clear (0) the overcurrent CNT, and whether the low current CNT is 3 or more. (S22) Since it is the first time to enter this routine, it is 3 or less. Accordingly, the low current CNT is increased by 1 along the path of NO and returned to the main routine (S23).

As a result, there is no power interruption and low current CNT = 1, overcurrent CNT = 0, power interruption Flag = 0.

② As the current current value is greater than the current limit value, the current current value ≥ current limit value of FIG. 4 is moved along the path of YES in the determination routine (S20) to clear (0) the low current CNT, and (S30) the power-off state. It is judged whether the power is supplied (S40), but before the power is cut off, it is moved along the path of NO to determine whether the overcurrent CNT is 3 or more. (S50) Since it is first entered into this routine, it is 3 or less. Therefore, the overcurrent CNT is increased by 1 along the path of NO and returned to the main routine (S51).

As a result, there is no power interruption and low current CNT = 0, overcurrent CNT = 1, power supply disconnect flag = 0.

③ Since the current current value is smaller than the current limit value, the current current value ≥ current limit value is moved along the path of NO in the determination routine (S20) of FIG. 4 to clear (0) the overcurrent CNT, and whether the low current CNT is 3 or more. (S22) Since it is the first time to enter this routine, it is 3 or less. Accordingly, the low current CNT is increased by 1 along the path of NO and returned to the main routine (S23).

As a result, there is no power interruption and low current CNT = 1, overcurrent CNT = 0, power interruption Flag = 0.

④ Again, since the current current value is smaller than the current limit value, the current current value ≥ current limit value of FIG. 4 is moved along the path of NO in the determination routine (S20) to clear (0) the overcurrent CNT, and the low current CNT is 3 It is judged whether or not it is abnormal. (S22) Although this routine has been entered twice in a row, it is still 3 or less. Therefore, the low current CNT is increased by one along the path of NO and returned to the main routine (S23).

As a result, there is no power interruption and the low current CNT = 2, the overcurrent CNT = 0, and the power off flag = 0.

Since the current current value is larger than the current limit value, the current current value ≥ current limit value of FIG. 4 is moved downward along the path of YES in the routine S20 to clear the low current CNT (S30). It is determined whether the state is blocked (S40), and since the power is still cut off, it moves along the path of NO. It is determined whether the overcurrent CNT is 3 or more (S50). Since the low current is first entered into this routine, it is 3 or less. Therefore, the overcurrent CNT is increased by 1 along the path of NO and returned to the main routine (S51).

As a result, there is no power interruption and low current CNT = 0, overcurrent CNT = 1, power supply disconnect flag = 0.

(6) As described above, since the current current value is larger than the current limit value, in the "current current value ≥ current limit value" determination routine (S20) of FIG. 4, the current current value is moved downward along the path of YES to clear the low current CNT. It is determined whether the state is blocked (S40), and since the power is still cut off, it moves along the path of NO. It is determined whether the overcurrent CNT is greater than or equal to three (S50). The second routine is entered in succession but is less than or equal to three. Therefore, the overcurrent CNT is increased by one again along the path of NO and returns to the main routine (S51).

As a result, there is no power interruption and low current CNT = 0, overcurrent CNT = 2, and power supply disconnect flag = 0.

⑦ Also, since the current current value is larger than the current limit value, the current current value ≥ current limit value shown in FIG. 4 is moved downward along the path of YES in the routine S20 to clear the low current CNT. It is determined whether the state is blocked (S40), and since the power is still cut off, it moves along the path of NO. It is determined whether the overcurrent CNT is 3 or more. (S50) Since the third time has been entered in this routine continuously, it is equal to 3. Therefore, move down along the path of YES and clear the overcurrent CNT to 0. (S60) And set the power-off flag (flag) to 1, then (S70) cut off the power and return to the main routine. (S80)

As a result, the power-off operation is performed and the low current CNT = 0, the overcurrent CNT = 0, and the power-off flag = 1.

Since the current current value is greater than the current limit value, the current current value is greater than the current limit value, and then moves downward along the path of YES in the "current current value ≥ current limit value" determination routine of FIG. 4 to clear the low current CNT. If it is determined that the state is blocked (S40), the power is cut off (power off Flag = 1), so it moves along the path of YES. Then, the power cut operation is continued and the process returns to the main routine (S80).

As a result, the power-off operation is maintained and the low current CNT = 0, the overcurrent CNT = 0, and the power-off flag = 1.

9. Again, since the current current value is smaller than the current limit value, the current current value ≥ current limit value of FIG. 4 is moved along the path of NO in the determination routine (S20) to clear the overcurrent CNT (S21), and the low current CNT is It is judged whether or not it is 3 or more. (S22) Since an overcurrent flows and first enters this routine, it is 3 or less. Accordingly, the low current CNT is increased by 1 along the path of NO and returned to the main routine (S23).

As a result, the power cut operation is maintained and the low current CNT = 1, the overcurrent CNT = 0, and the power cut Flag = 1.

Since the current current value is smaller than the current limit value, the current current value ≥ current limit value of FIG. 4 is moved along the path of NO in the determination routine (S20) to clear the overcurrent CNT (S21), and the low current CNT is 3 It is determined whether or not it is abnormal. (S22) Since this second routine has been entered continuously, CNT = 2 but is still 3 or less. Therefore, along the path of N, the low current CNT is increased by one again and returns to the main routine (S23).

As a result, the power cut operation is maintained and the low current CNT = 2, the over current CNT = 0, and the power cut Flag = 1.

Since the current current value is smaller than the current limit value, the current current value ≥ current limit value of FIG. 4 is moved along the path of NO in the determination routine (S20) to clear the overcurrent CNT (S21), and the low current CNT is 3 It is judged whether it is abnormal. (S22)

It is the same as 3 since it entered this routine the third time in a row. Therefore, move down along the path of YES to clear the low current CNT to 0. (S25) And reset the power off flag (flag) to 0, and then (S26) to supply power to the load. Supply and return to the main routine (S27).

As a result, the power supply operation is performed, resulting in low current CNT = 0, overcurrent CNT = 0, and power cutoff flag = 0.

In addition, since the current current value is smaller than the current limit value, the current current value ≥ current limit value of FIG. 4 is moved along the path of NO in the determination routine (S20) to clear the overcurrent CNT (S21), and the low current CNT is 3. It is judged whether it is abnormal. (S22)

The low current CNT at above ⑪ is 1 since it first entered this routine after it was cleared. Therefore, it moves to the right along the path of NO to increase the low current CNT by 1 and return to the main routine (S23).

As a result, the power supply operation is maintained and the low current CNT = 1, the overcurrent CNT = 0, and the power-off flag = 0.

Since the current current value is larger than the current limit value, the current current value ≥ current limit value of FIG. 4 is moved downward along the path of YES in the routine S20 to clear the low current CNT. Judging whether or not the state (S40), because the state is turned on (power off Flag = 0) is moved along the path of NO. It is determined whether the overcurrent CNT is 3 or more (S50).

It is less than 3 because it is the first time to enter this routine again after the low current. Therefore, the overcurrent CNT is increased by 1 along the path of NO and returned to the main routine (S51).

As a result, the power supply operation is maintained and the low current CNT = 0, the overcurrent CNT = 1, and the power cutoff flag = 0.

Since the present current value is larger than the current limit value as described above, the "current current value ≥ current limit value" determination routine of FIG. 4 moves downward along the path of YES to clear the low current CNT. (S30) It is determined whether the state is blocked (S40), the power supply state (power off Flag = 0), so it moves along the path of NO. It is determined whether the overcurrent CNT is 3 or more. (S50)

A second time in this routine, but less than three. Therefore, the overcurrent CNT is increased by one again along the path of NO and returns to the main routine (S51).

As a result, the power supply operation is maintained and the low current CNT = 0, the overcurrent CNT = 2, and the power-off flag = 0 are obtained.

In addition, since the current current value is larger than the current limit value, in the " current current value ≥ current limit value " determination routine S20 of FIG. 4, the current current value is moved downward along the path of YES to clear the low current CNT. It is determined whether the state is blocked (S40), the power supply state (power off Flag = 0), so it moves along the path of NO.

It is determined whether the overcurrent CNT is 3 or more. (S50) Since the third routine has been entered continuously, it is equal to three. Therefore, move down along the path of YES and clear the overcurrent CNT to 0. (S60) And set the power cut flag to 1 and then turn off the power and return to the main routine. )

As a result, the power-off operation is performed and the low current CNT = 0, the overcurrent CNT = 0, and the power-off flag = 1.

Since the current current value is greater than the current limit value, the current current value is greater than the current limit value. In the determination routine S20 of FIG. 4, the low current CNT is cleared by moving downward along the path of YES. S30) It is determined whether the power is cut off state (S40), and the power cut state (power cut Flag = 1), so it moves along the path of YES. Then, the power cut operation is continued and the process returns to the main routine (S80).

As a result, the power-off operation is maintained and the low current CNT = 0, the overcurrent CNT = 0, and the power-off flag = 1.

Ⓕ is the same operation as ⑨, ⓖ is the same operation as ⑩, ⓗ is the same operation as ⑪, ⓘ is the same operation as ⑫, ⓙ is the same operation as ⑬.

What has been described above is just one embodiment for implementing an electronic power meter having a power control function according to the present invention, the present invention is not limited to the above-described embodiment, it is usually within the technical spirit of the present invention Of course, various modifications are possible by those who have the knowledge of.

As described above, according to the electronic watt-hour meter with a power control function according to the present invention, if the low-income people, the disabled, and the people living in the household have not paid the electric bill for several months, they do not take the power cut action immediately. In order to use the minimum living power necessary for the minimum life of one lamp and one heater, and to cut off the electricity supply when using more electricity, Social welfare, such as the occurrence of deaths caused by fires, can be solved, and the "minimal power of living" can be used even in the case of unavoidable circumstances in households that need to be socially protected. There is an effect that can contribute to.

In addition, the present invention frees the power supply and interruption through the relay control inside the meter, there is an effect that the electricity supplier can solve the problem of cutting the wire outside the meter to cut off the power supply.

In addition, the present invention does not pay the electricity bill, but when the electricity bill is paid again, the power supply operation is simple because the electricity is supplied normally through a simple switch operation so that the customer can use the electricity freely for any load desired by the customer. There is.

Claims (4)

In the electronic watt-hour meter that detects the current fluctuation amount of the AC power supplied from the power supply side (1S, 2S) to the load side (1L, 2L) to control the power supply and interruption, A voltage signal converting unit connected in parallel with the power supply side 1S and 2S to convert into a voltage signal corresponding to the input voltage, and connected in series with the power supply side 1S to convert into a current signal corresponding to the input current; An analog MUX alternately selecting signals corresponding to respective voltages and currents output from the current signal converter, the voltage signal converter and the current signal converter, and an analog signal of the voltage and current selected by the analog MUX. A signal converter configured to convert the digital signal into an A / D converter; A central processing unit that calculates a power consumption and calculates a current value by multiplying a digital signal corresponding to the voltage and current converted by the A / D conversion unit; and The operating current value calculated by the central processing unit according to the operation switch to be input and the electric charge payment information input through the operation switch is compared with the allowable current limit value, and the load side 1L and 2L from the power supply side 1S and 2S. Digital circuit unit consisting of a relay control circuit for controlling the power supplied to the; And It is connected between the power supply side (1S, 2S) and the load side (1L, 2L) and turned on / off according to the control signal of the relay control circuit to supply power supplied from the power supply side (1S, 2S) to the load side (1L, 2L) Power switch opening and closing Electronic electricity meter having a power control function, characterized in that configured to include. The method of claim 1, The current signal converter is composed of a current transformer and a secondary terminal resistor of the current transformer, One line of the primary side of the current transformer is connected to the power supply side (1S) and the other line is an electronic power meter having a power control function, characterized in that connected to the relay of the power switch. The method of claim 1, When the electric charge is paid, the central processing unit displays the calculated amount of used power on the LCD while performing a power supply operation from the power supply side 1S and 2S to the load side 1L and 2L, regardless of the used current value. Electronic electricity meter having a power control function, characterized in that. The method of claim 1, If the electric charge is not paid, the central processing unit performs a power supply operation when the current value is less than the allowable current limit value, and turns off the power switch through the relay control circuit when the current value is greater than the allowable current limit value. And an electric power meter having a power supply control function, which cuts off power supplied from the power supply side (1S, 2S) to the load side (1L, 2L).