KR100516790B1 - Multi function watt hour meter for midnight hour eletric power - Google Patents

Abstract

The present invention is to measure the amount of power used in homes and factories at the same time to measure the constant load and the midnight load at the same time to the low voltage electronic electricity meter for integrated midnight power to enable the meter reading from the remote location using the wireless communication module To measure the weighing value, in consideration of the active power, reactive power, and power factor, which are not considered in the conventional power metering method, the continuous power and the late night power are more accurately weighed, and the measured values are accumulated and the total accumulated weight, Weighing by time, monthly cumulative metering, active power and reactive power are stored in its own nonvolatile memory, and when the stored values are required to be transmitted externally, constant weighing value, midnight weighing value, hourly weighing, monthly accumulation Use the serial port for metering, continuous accumulation, active power and reactive power. Low voltage electronic electricity meter for midnight power, which transmits data to wireless modem for remote meter reading. The electricity meter is designed to measure the normal load and the night load at the same time with one current meter. When using the night load, the time switch for supplying power to the night load is driven when the time is stored in advance. It is a low voltage electronic electricity meter and can be used for single-phase two-wire and three-phase four-wire AC circuits.

Description

Multi-function low-voltage electronic telemetering meter for midnight power {Multi function watt hour meter for midnight hour eletric power}

The present invention relates to a multi-function integrated low-voltage electronic remote meter reading meter for midnight power, and more particularly, includes a time switch for supplying power to a late night at which electricity bills are reduced due to low power usage. In the wattmeter that can be metered at the same time by one wattmeter at the same time, the conventional wattmeter in the circuit portion measuring the usage used a separate current meter to measure the constant power and the midnight power, but in the present invention By using a current meter to measure the amount of late-night power and constant power, it is possible to accurately and complexly measure the amount of power based on the measured value by classifying the data according to electrical characteristics such as not only the total accumulated power but also the active power, reactive power, and power factor. Weighable, Weighed Value It is stored as digital data and can be transmitted remotely in a set time zone by dividing it into active power amount, reactive power amount, hourly weighing value, monthly accumulated weighing value and continuous cumulative weighing value according to regular power and midnight power using wireless communication. The present invention relates to an integrated low voltage electronic electricity meter for midnight power that can provide high quality power supply service with accurate power measurement and improved reliability.

       Midnight power is a power consumption that allows the utility company to differentiate between the daytime and the low-use time zone and apply the discount rate according to the power usage time.In order to measure the conventional midnight power and the regular power (general power) It is equipped with electricity meter to measure power at all times and midnight electricity meter to measure night power at the same time, operate time switch with clock function and load switching function, distribute load by time zone, and measure power consumption separately. Since the and time switches are separately installed, it is cumbersome and expensive to install and manage.

 As an electronic power meter with a built-in time switch function, which has been developed as a prior art that solves the above-mentioned problems, the Korean Patent Office published a public patent publication "Two kinds of electric power meter with a time switch function" (Publication No. 2000-8906, publication date). : 2000.2.15), but it is connected to the input power supply to supply the power proportional frequency for counting the power load for the general load and the power for the night load to count the power supply for the night load connected to the input power supply. A digital circuit unit for counting the output frequencies of the frequency converter unit and the general power / frequency converter unit to calculate the general load consumption and the midnight load usage, and a digital circuit unit for calculating the usage amount of the midnight power / frequency converter and a display unit for displaying the calculated values; A midnight power supply that supplies power to the midnight upon input of an open / close signal As a negative configuration, the watt-hour meter uses a multiplier and a power / frequency converter to measure the voltage and current values, converts the input power into pulses, counts the pulses generated, and accumulates the count values, and uses the currently used mid-load power amount. As a method of quantifying the amount of overload and general load, a transformer and a current transformer are used to quantify the constant power and the midnight power, and a transformer and a current transformer are used to measure the midnight power, respectively. And the amount of power is always measured, and in case of measuring the actual amount of power used, the frequency signal output from the power / frequency converting part is counted by the digital circuit part, and it has a factor of error occurrence, and the configuration of the peripheral circuit is complicated and the current consumption is large. It also allows us to diversify The amount of electricity measured as a charging method based on the metered value does not take into account the electrical characteristics of the detailed metered items such as effective power, reactive power, and power factor even when adding charges for the power used. This time period, monthly, and the current cumulative usage is divided into the active power and the reactive power, so it cannot be displayed on the display device, so a basic error occurs. As it is transmitted as it is, inaccurate data on the basis of the addition of the use of the electricity bill, the consumer's credibility to the power supply provider and the power supply plan can not be made accurately, there is a problem that can not implement high-quality power supply service.

 In addition, in order to obtain accurate measurement data for detailed electrical characteristics such as voltage, current, active power amount, reactive power amount, and power factor of the above-described power system, in addition to the general electricity meter, active power meter and reactive power meter manufactured by different companies having different measurement ranges Accurate measurement is difficult because it is necessary to connect and use devices such as power factor, time switch, and so on.In addition, it is necessary to check the measurement results individually and inaccurately at the measurement site as the administrator moves. There is a problem that it is impossible to check and control, causing unnecessary complaints and difficult response to failures.

 The present invention has been made in order to solve the above-mentioned problems, and includes a time switch for supplying power to the late night, and consumes the late night power and the continuous power as a single wattmeter separately for cumulative electric power data and various electrical characteristics. Integrated low-voltage integrated low-voltage integrated function for nighttime power metering by including the function to transmit the time-based measurement data accurately and complexly measured by separating the power system data to a remote handy terminal or repeater using a wireless remote modem. The purpose of the present invention is to provide an electronic remote meter reading meter, and in the conventional metering method, each current / voltage converter is weighed to measure the midnight power level and the constant power level. Not much late night The circuit was simplified to meter the constant power.

         DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to achieve the above object, the configuration of the present invention will be described in detail with reference to the accompanying drawings, and detailed descriptions of known components that may obscure the gist of the present invention will be omitted.

   The present invention provides a power meter having a time switch for supplying power to a late night and capable of simultaneously metering the consumed late night power and regular power by time with one watt hour meter,

The power supply circuit 11 supplies power to each device by using an input power supply, the power supply circuit 12 as a main power supply, and the power supply circuit 12 as an auxiliary power supply, and a power failure detection circuit 13 and a battery power supply to maintain a current state in case of power failure. A power supply unit 10 composed of an application circuit 14 and a voltage divider 20 connected to an input power source to reduce the applied voltage to an appropriate measurement level. It is composed of a current transformer (CT) 31 and a current / voltage converter (I / V) 32 to supply an analog signal to the microprocessor 41 in order to comprise a single power The circuit is simplified so that the constant power and the midnight power can be simultaneously measured using the / current converter. The voltage divider 20 and the current / voltage converter (I / V) 32 convert each analog output into a digital signal. A Microprocessor 41 for computing and storing converted digital inputs with built-in / D converter 41a and controlling the communication, and EEPROM 42 of non-volatile memory for storing weighing data according to time zones as a peripheral device. A display device 43 for displaying a value, a clock generator 44 for generating a clock signal to supply midnight power at a set time, and a key input unit for a user or meter reader to set various data necessary for meter reading or to control display. 45 is connected to the digital signal processing unit 40, the power supply unit 10, and the power / current conversion unit 30, which is composed of a remote metering modem 46 of a wireless communication circuit for transmitting meter reading data to an external device. As a time switch for opening and closing the late-night power according to the open / close signal input of 40, it is composed of a late-night power supply opening and closing unit 50, the entire night-time power and the continuous power in one meter Energy, active power, reactive power and power factor electrical properties by precisely separated by a combination of data measured, such as, storage, and is characterized in that the wireless transmission of measurement stored digital data to a remote location.

       As described above, the present invention integrates a single power meter in which a constant function and a late-night load are measured, a time switch function for opening and closing when using midnight power, and a complex function of wireless communication for transmitting a measured value through a wireless modem. On the basis of the accompanying drawings looks at in detail a preferred embodiment.

       The power supply unit 10, which receives input power and supplies internal operating power to each device of the watt-hour meter, includes a transformer 11 connected to the power supply as a main power source, and a power supply circuit 12 that receives its output in series. The power supply is applied to the digital circuit and the wireless remote meter reading modem by changing the AC power to DC power.The power failure compensation part of the auxiliary power supply adjusts the input DC voltage. The power outage detection circuit 13 and the microprocessor 41 receiving the output from the power supply determine the current power supply state and determine whether the current power supply state is normal or power failure. Switch to battery power supply (backup power supply) to supply power to microprocessor 41 of digital power signal processor 40 even in case of power failure And the battery power supply circuit 14 which maintains the current state by preventing the RAM (not shown) in the microprocessor 41 and the data of the EEPROM 42 from being lost and maintaining the time operation. It is a saving mode in case of power failure, which extends the power failure compensation time to the maximum.

        The power / current converter is a converter that changes the amount of power applied to the load to the voltage and current so that the microprocessor 41 can measure the power applied to the load in order to measure the amount of power applied, the voltage divider 20 and the power / Comprising a current converter 30, the voltage divider 20 to reduce the voltage applied to measure the amount of power to the measurement level to be applied directly to the microprocessor by direct voltage down according to the winding ratio of the primary side and secondary side The amount of power is converted by lowering the phase voltage of low loss, and the power / current converter 30 of the current transformer (CT) 31 and the current / voltage converter (I / V) 32 measures the current amount of the power line. A current value corresponding to the current value applied to the primary side flows to the secondary side to detect the current flowing in the power supply line, and outputs from the current transformer (CT) 31 are converted into a current / voltage converter (I / V) 32. ) In this case, the microprocessor 41 can measure the amount of current by converting it into a voltage proportional to the input current.As shown in FIG. The circuit was simplified so that the constant load and the midnight load are simultaneously measured by the operation of the late night power switch 50 which opens and closes the late night power according to the open / close signal input of the digital signal processor 40 at a predetermined time.

       Therefore, the above-described configuration converts a pulse width modulation signal into a frequency multiplier by a current transformer CT for detecting a current value, an instrument transformer PT for detecting a voltage value, and a pulse width modulation signal by a multiplication action. Peripheral circuit that converts the pulse width modulated signal by multiplier into frequency proportional to the output and outputs current / voltage converter to measure the amount of power at all times to measure existing power and night power The current and voltage converters used to separately measure the amount of power and the midnight power can be measured separately by using a single current / voltage converter to reduce the current consumption.

        The digital signal processor 40 that calculates and stores the amount of power used by calculating the input of the power / current converter 30 is a microprocessor 41 having an A / D converter 41a and a peripheral device having a lower function. EEPROM 42, display device 43, CLOCK generator 44, KEY SWITCH 45, and remote meter reading modem 46.

        The microprocessor 41 of a data processing and communication control function, having a predetermined program embedded therein, converts the analog values of the voltage and current amounts of the constant loads and the late loads, which are converted and directly applied by the power / current conversion unit, to the A / D converter 41a. It is a precise calculation method that considers phase difference between voltage and current by converting into digital value by using) and calculates by dividing active power usage, reactive power usage, power factor, etc. It is a central function of the multi-function control device that controls the data transmission.It is possible to simultaneously measure the amount of constant load and midnight load.The function calculates by time zone according to the user's setting. Set the desired time zone by operating the key switch 45 attached to the electricity meter. When the power consumption for time is accumulated by time zone, and user wants to see the power usage in the set time zone, simple load of the key, the active load of active power, active power, and total power of the time zone by the previous month and the present time through simple key operation The amount of power can be measured for the amount of use and the night load. The time zone can be set according to the user's requirements.

        In the present invention, the microprocessor 41 is effective considering the phase difference and the power factor of the voltage and the current, not the reading of the apparent power by the product of the measured voltage and the current that need to be readjusted out of the optimum value in calculating the amount of power by the calculation of the digital value. Accurate complex measurement of power, reactive power, power factor, etc. is possible, and digital filter (not shown) has the digital output of current and voltage of A / D converter 41a to filter and average the signal and remove noise Accurate measurement is possible by preventing operation error caused by.

        The EEPROM 42, which stores information processed by the microprocessor 41 as an external peripheral device of the microprocessor 41, is a nonvolatile memory so that the measured values can be maintained even in the case of a power failure. CLOCK generator is used to classify usage and save complex metering data such as current cumulative active power, current cumulative reactive power, previous month's cumulative active power, previous month's cumulative reactive power, previous month's cumulative maximum demand power, average monthly power factor and meter reading date. Is a device that generates a clock signal for driving the microprocessor 41, and the key switch 45, which consists of a menu, a movement, and an input key as a key input unit, has a measurement range necessary for meter reading of the instrument according to the environment of a user or a meter reader. Or adjust the time zone to freely set various data or control the display. As a device, the start and end time of night and week, the start and end time of power factor measurement time, the day of the week, year, month, day, hour, minute, meter reading, etc. Set by operation.

        The display device 43 which receives a signal output from the microprocessor 41 and digitally displays and displays weighing-related data and status on a liquid crystal screen such as an LCD or an LED, displays the values displayed according to the user's request. By dividing the weighing items such as current time, active power amount, and reactive power amount, and displaying them sequentially and alternately into display items such as current cumulative state, previous month cumulative state, average power factor, meter reading date, etc. It is expressed as a value.

        The measurement items of the display device 43 may include, for example, a date, a time, a cumulative active power amount in the previous month, a cumulative active power amount in the previous month, a cumulative reactive power amount in the previous month, a cumulative reactive power amount in the previous month, a maximum demand power in the previous month, an average power factor, a meter reading date, and the like. It checks the regular power and checks and displays the midnight power when the cycle comes.

       In addition, as a signal input / output interface means for transmitting the weighing data of the microprocessor 41 to the outside, the communication port of the transmission / reception terminal RX (TX) connected to the external remote meter reading modem 46 and the currently applied voltage are output for each predetermined amount. A pulse output port for sending a pulse is provided so that the remote meter reading modem 46 can count pulses and communicate with each other.

       As a method of transmitting and receiving power amount data between a remote metering modem and a meter using a remote metering modem applied to the present invention, a microprocessor (41) is used for each constant power consumption (for example, 1 Kw) using a pulse output port. In order to output the metering pulse to any output port), the remote metering modem 46 counts and accumulates the output value, and if the external handy terminal or the external relay device sends the metering data, the remote metering modem Secondly, by using the serial port, the electricity meter and the wireless modem are connected to the serial port by using the serial port. When the data transmission signal is received from the external handy terminal or relay device, the current meter is recorded. Active power, always reactive power, active power at night time, core It is a method of transmitting / receiving the amount of reactive power of the time zone by the preset time zone, monthly unit, and the current accumulated power in both directions according to the user's request.It is communicated by a predetermined protocol. Also, the process of setting the discount rate change is implemented.

        In addition, the midnight power switch 50 with a built-in electronic time switch is connected to the power supply unit 10, the power / current conversion unit 30 as a device for opening and closing the midnight power according to the open / close signal input of the digital signal processing unit 40 By using KEY SWITCH (45), the user can set the night time power use time and the time switch opening / closing function to supply the power to use the night load by automatically operating the switch when the set time is reached. The electronic switch is opened or closed by driving a motor not shown by the input of the control signal.

Hereinafter, the entire process of weighing, storing, displaying, reading, and sending data will be described according to an embodiment of the present invention.

Applying power to the device to initialize each circuit section to generate normal operating conditions (S1), and then analog signals of voltage and current by the A / D converter 41a built in the microprocessor 41 during the power metering process. Detects the data converted into the digital signal (S2), calculates the current power consumption accumulated by the predetermined power calculation program (S3), and compares the preset time switch time with the time of the microprocessor itself to operate the timer clock. By using the open / close signal input of the digital signal processing unit 40, the power amount measurement value by the time-of-night electricity supply and shut-off operation of the late-night power switch unit 50 is divided into regular (general power) power and late-night power consumption by time zones. And late-night load usage, current cumulative active power, current cumulative reactive power, previous month's cumulative active power, previous month's cumulative reactive power, The cumulative monthly maximum demand power, average power factor, and meter reading date are calculated and calculated for each measurement value and stored in the memory (EEPROM) of the microprocessor 41 (S4).

Subsequently, the display process displays the power data stored in the LCD or LED liquid crystal display device at regular intervals, and displays the amount of power for each item and time period and total used power (S5). If the stored data is loaded in the communication format, the remote metering modem 56 transmits the data to the user's handy terminal (S6). If there is no metering command or the data is sent, the process returns to the data metering step (S7). It is performed repeatedly, monitoring the power failure even during the metering and metering process, and when the power failure is automatically connected to the battery (spare power), so that the time and metering data is kept stable even at low power.

 As described above, the present invention includes a time switch for supplying power to the night, and consumes the night power and the continuous power as a single power meter separately to classify the accumulated power data and power system data according to various electrical characteristics. This is a multi-instrument device that can implement multiple complex functions by transmitting multiple time-measured measurement data to a handy terminal or repeater using a wireless remote modem. Compared to the method, the A / D converter embedded in the microprocessor is applied voltage and current, and the effective power, reactive power, power factor, etc. considering the phase difference and power factor of voltage and current, not the apparent power by simple product of voltage and current. It is now possible to measure precisely.

The present invention described above is not limited to the above-described embodiment as various substitutions and changes can be made by those skilled in the art without departing from the technical spirit of the present invention. .

As described above, the present invention is a power meter capable of precisely metering time-division at the same time by dividing the metering items into one electricity meter by maintaining the metered value even in the case of power failure, and consuming the midnight power and the regular power by one electricity meter. Simplified peripheral circuit of the electricity meter reduces the current consumption, and improves the method of calculating the amount of electricity by converting the conventional electricity into frequency and counts the analog / digital converter by applying the voltage and the amount of current. It enables measurement of active power, reactive power, and power factor considering the phase difference and power factor of voltage and current, not power, and adds time switch function to supply midnight power, and built-in remote meter modem Enables remote meter reading of active power, reactive power and total power It was made.

1 is a block diagram showing the configuration of a power meter according to the prior art

Figure 2 is a block diagram showing the overall configuration according to an embodiment of the present invention

3 is a flowchart illustrating the operation of the present invention.

<Explanation of symbols for main parts of drawing>

10: power supply unit 11: transformer

12: power supply circuit 13: power failure detection circuit

14: battery power supply circuit 20: voltage divider

30: power / current converter 31: current transformer

32: current / voltage converter 40: digital signal processing unit

41: Microprocessor 41a: A / D Converter

42: EEPROM 43: Display device

44: CLOCK 45: KEY SWITCH

46: remote meter reading modem 50: power supply for the night

Claims (3)

A power supply unit 10 for supplying power to each device device using an input power supply and a voltage divider 20 connected to the input power supply to reduce the applied voltage to an appropriate measurement level, and change the applied power amount to voltage and current amount. Microprocessor 41 with built-in power / current converter 30, A / D converter 41a, and EEPROM 42, display device 43, clock generator 44, KEY A digital signal processor 40, the power supply unit 10, and a power / current unit configured with a SWITCH 45 and a remote metering modem 46 to calculate and store the amount of power used by calculating the input of the power / current converter 30. It is connected to the conversion unit 30 and is a time switch for opening and closing the midnight power according to the open / close signal input of the digital signal processing unit 40, consisting of a late night power switch unit 50 having a time switch for supplying power to the midnight The late-night power and constant power consumption In the electricity meter that can be weighed at the same time by one hour meter and the metering data can be transmitted to a remote handy terminal or repeater using a wireless remote modem. The power supply unit 10 includes a transformer 11, a power supply circuit 12 as a main power supply, and a power supply circuit 12 as a main power supply and a power supply detection circuit 13 and a battery power supply circuit 14 to maintain a current state in case of power failure. In addition, the power / current converter 30 includes a current transformer (CT) 31 and a current / voltage converter (I / 31) for supplying an analog signal to the microprocessor 41 to measure the amount of power used at all times and the amount of power used at night. V) (32), which divides the midnight power and the continuous power into data by electrical characteristics such as total cumulative power, active power, reactive power, and power factor, etc. in one wattmeter to accurately measure, store, and store digitally. Multi-function integrated low-voltage electronic remote metering power meter for midnight power, characterized by wireless transmission of data remotely 2. The power source according to claim 1, wherein the microprocessor (41) comprises a voltage divider (20), a current transformer (CT) 31 and a current / voltage converter (I / V) 32 capable of metering general loads and midnight loads. / Current converter 30 directly receives the analog value of the voltage and current for the constant load and the midnight load is converted into a digital signal in the A / D converter 41a and calculated by considering the phase difference and power factor of the voltage and current Low power electronic remote metering power meter with integrated multi-function for midnight power, which measures power and reactive power with minimum power consumption A communication port of a transmitting and receiving terminal (RX) TX connected with an external remote meter reading modem 46 as a signal input / output interface means for transmitting the weighing data of the microprocessor 41 to the outside. Combined low-voltage electronic remote metering power meter for midnight power, characterized in that it has a pulse output port for sending a pulse so that the remote metering modem 46 can count pulses by outputting the voltage as an output pulse every certain amount.