JP2005114479A - Measuring circuit of electric information - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring circuit of electric information which multiplexes and collects the powers/voltages/currents of a multitude of individual apparatuses and characteristics of temperature/humidity, etc. altogether, is proper for a measuring acquisition system of electric information, usable as a general and standard hardware even with differences in power supply mode and existence of temperature/humidity measurement at every apparatus, capable of automatic renewal of parameters on a corresponding software, and is economical, compact and versatile. <P>SOLUTION: The measuring circuit of electric information contains a sensor part and a measuring part, and its sensor part detects voltage, current and preferably temperature and humidity. Each consists of a PT module, CT module and a resistor for converting current/voltage which has a specific resistance value and a temperature humidity module. The measuring part comprises an A/D convertor for converting the sensor output to digits and a CPU operationally processing the sensor output for obtaining desired electric information and is constituted so that the measuring part and the resistor are loaded on a measuring board. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a circuit for measuring the characteristics of a device related to power consumption, and more particularly, electrical information measurement suitable for an electrical information measurement and collection system that collects electrical information obtained by measuring the characteristics collectively. It relates to the circuit.

  In order to tackle global environmental issues, energy conservation and effective use of electric power are obliged in all fields. For that purpose, it is necessary to grasp the power usage situation in plants such as stores and factories, but there is a limit to grasping the situation only by measuring the power of the whole plant, and time series measurement for each individual device or system is performed. The history needs to be analyzed. That is, for that purpose, a system that measures and collects the electric energy for each individual device or system is indispensable.

  In addition, when grasping the power status of each individual device or system, not only the consumed power value but also the voltage and current values at that time, and in some cases, measurement data of the temperature and humidity around the individual device Is desirable.

  Conventionally, when measuring these voltages, currents, and electric energy, the voltage is converted to a low voltage signal by PT (Potential Transformer), the current is converted to a low current signal by CT (Current Transformer), and the product of the two is analogized. An electric power value is obtained by performing an arithmetic operation or digitally, a pulse signal is transmitted based on the electric power value, and the pulse signal is integrated to obtain an average electric energy within a predetermined time.

  When the average power amount or the like of the individual device is collected in a lump by the host device, a predetermined number of pulse trains (for example, 2000 / kWh) corresponding to a power value or the like determined from a watt hour meter or the like installed in the device. ) To the transmission line, and the host device counts this to obtain the amount of power at an arbitrary time interval, that is, the average amount of power.

  However, this method requires a transmission line for each individual device, and multiplexing is difficult.

  Conventionally, if you use a watt-hour meter of a quality level that passes the certification for commercial transactions, it is bulky and does not fit in the gap of the distribution board of the individual equipment, and occupies a large space with the transmission line and maintenance Management was troublesome.

  Conventionally, if you use a watt-hour meter of a quality level that passes the certification for commercial transactions, it is expensive and dedicated for the difference in power supply mode such as 50Hz / 60Hz, 3 phase / single phase / multi, 200V / 100V, etc. It was necessary to install and manage the watt hour meter for each individual device, which was expensive.

  In addition to this, when trying to measure and collect the temperature and humidity around the individual device, conventionally, a measurement circuit for that purpose must be newly constructed, which further exacerbates the above problems.

JP 2001-041985 A

  In order to solve the above-mentioned problems, a first object of the present invention is to obtain characteristics measurement data such as power / voltage / current and / or temperature / humidity related to power consumption of a large number of individual devices. Provided is an electrical information measurement circuit suitable for an electrical information measurement and collection system that collects the data in a lump, multiplexes and collects only necessary information for analysis by a host device. There is.

  Another object of the present invention is that it can be used as general-purpose, standard hardware and automatically update the corresponding software parameters even if the power supply mode and temperature / humidity measurement are different for each individual device. Another object of the present invention is to provide an electrical information measuring circuit suitable for an economical and compact electrical information measuring and collecting system.

An electrical information measuring circuit according to the present invention, which has been made to solve the above problems,
A sensor that detects voltage and current associated with power consumption of the device as analog signal values vv and vi that are proportional to each other, and an A / D converter that digitally converts the analog voltage values to obtain corresponding outputs VV and VI, respectively In an electrical information measurement circuit comprising a CPU (microprocessor unit) that obtains desired electrical information by performing arithmetic processing on the VV and VI,
The sensor for detecting the voltage is composed of a PT module equipped with a plurality of voltage / low voltage converters (PT), and the sensor for detecting the current is equipped with a plurality of current / small current converters (CT). A CT module and a current / voltage conversion resistor having a predetermined resistance value, and at least the current / voltage conversion resistor, the A / D converter, and the CPU are included in one measurement board. The PT module and the CT module are mounted on the measurement board via cables that transmit analog signals of the voltage and current, respectively.

  Preferably, the current / voltage conversion resistor is connected between the input terminal via the cable from the CT module and the A / D converter on the measurement board. A first type of jumper pin is provided that allows the predetermined resistance value to be selected from a plurality of the resistance values when grounding.

  Preferably, according to claim 3, further comprising a temperature / humidity module equipped with a sensor for detecting analog voltage values vt, vh proportional to the temperature and humidity of the device, and a cable for transmitting the analog voltage value, A temperature / humidity channel is further set on the measurement board, and a second type of jumper pin that can select the output of the temperature / humidity channel and the output of the channel is provided.

  Preferably, the measurement board includes a power supply mode (50 Hz / 60 Hz, 3 phase / single phase / multi, and / or 200 V / 100 V) and / or a temperature / humidity measurement mode for individual devices. In addition to the above specification, a DIP switch for performing type setting including a selection position of the first type and / or second type jumper pin is further provided.

  Preferably, according to claim 5, at least one of the PT module, the CT module, and the temperature / humidity module is fixed to a gap between system power wirings in the distribution board. It is characterized by that.

  INDUSTRIAL APPLICABILITY According to the present invention, it is suitable for an electrical information measurement and collection system that collects and collects characteristics such as power / voltage / current, temperature / humidity, etc. of a large number of individual devices at once, Economical, compact, versatile electrical information that can be used as general-purpose, standard hardware and automatically update the corresponding software parameters, regardless of the supply mode and temperature / humidity measurement Can be provided.

  The best mode for carrying out the present invention will be described with reference to FIG.

  Referring to FIG. 1, there is shown an overall circuit block diagram of a first embodiment according to claims 1 to 4 of the present invention.

  In FIG. 1, the electrical information measuring circuit according to the present invention includes a consumption voltage, a current, and currents of a plurality of devices (only the device 1 is shown as a representative example in the figure) fed by power lines R, S, and T. Measuring and measuring the temperature and humidity around the device, each of which is equipped with a sensor for voltage, current and temperature / humidity, a PT module, a CT module, a temperature / humidity module sensor unit, a measurement board, and the sensor unit and measurement Consists of multiple cables connecting the boards. Small white circles on the wiring of these sensor units, cables, and measurement boards indicate connection by Y terminals or connectors.

  In the figure, the power supply line assumes a single-phase three-wire system 100V or a three-phase three-wire system V connection, and in each case, R and T are live lines and S is grounded (neutral line). Changing the wiring in the case of a single-phase 200V or other three-phase connection method will be easy for the party.

In the PT module, the voltage between RS and TS is sensed as a power supply voltage common to a plurality of devices, and sent to the measurement board via the voltage signal cable.
If one measurement board is not enough, it can be sent to another measurement board simply by adding a voltage signal cable.
In the CT module, the current sensor CT1 senses the total current of the live line R, and the current sensor CT2 senses the current consumption of the device 1 and sends it to the measurement board.
In order to convert the sense current into a voltage, a resistor having a predetermined value is required. The resistor is connected not on the module but on the measurement board.
In the temperature / humidity module, the temperature and humidity around the device group are voltage-sensed and sent to the measurement board as well.

Referring to FIGS. 2 and 3, conceptual diagrams showing the outer shapes of the PT module and the CT module, respectively. All of them are disposed in the gaps between the system power wirings of the distribution plate, and are fixed to the vertical plane at the back of the distribution plate via rubber magnets.
In FIG. 2, the front view in the state which attached this PT module is shown. The module body has dimensions of width, 100 mm × height, 150 mm × depth, 25 mm. As an actual work, a voltage transformer (not shown) is connected to the system power wiring (R, S, T) via the Y terminal line at the upper part of the module, and the cable line with the Y terminal is provided at the lower part of the module. Just connect.

On the other hand, FIG. 3 shows a horizontal cross-sectional view with the present CT module attached. The dimensions of the module body are about width, 60 mm × height, 140 mm × depth, 45 mm. As actual work, the current transformer (CT) is connected to one of the system power wirings (R, S, T) via the Y terminal line on the front of the module (upper part of FIG. 3). It is only necessary to connect a twisted pair flat cable via a connector (preferably a MIL connector) at the lower part of FIG.
As described above, both the PT and CT modules can be easily set to be detachable in the gaps of the system power wiring, and the depth of the module is small, so that the modules can be easily placed inside the distribution board box.

  Thus, by configuring the sensor unit with three types of standardized modules, each module can be installed as appropriate in the gap of the distribution board according to the situation at the site, and PT, CT are coupled, Since it is only necessary to carry out standard cable work through the connector, the work of the individual sense part, which has been complicated conventionally, is simplified.

  Next, with respect to the measurement board, 16 jumper pins JTn (n = 3 to 18), analog buffer ABn (n = 1 to 18), and analog-digital conversion circuit A / Dn (n = 1 to 16) are included. It consists of an input channel, a microprocessor unit CPU, a serial interface RS485, a DIP switch, and the like.

  In this embodiment, the first two channels, the next 14 channels, and the last two channels are assigned to voltage, current, and temperature / humidity, respectively, and the last two channels of current and the temperature / humidity channel share A / D. The measurement board has been standardized, but other assignments can be made.

  The analog buffer ABn includes overvoltage protection diodes D1 and D2, capacitors C1 and C2, BPF (bandpass filter) including resistors R11, R12, and R13, and a buffer including an operational amplifier OP and a resistor R14. Capacitance and resistor values differ depending on channels such as voltage, current, and temperature / humidity. Especially in the case of temperature / humidity channels, C1 = ∞ (capacitance is removed, short circuit), R11 = ∞, R12 = ∞ (respectively resistors) Remove and release).

  The first type jumper pin JTn (n = 3 to 16) for the current channel is grounded through one of resistors R1 and R2 having two predetermined large and small values (for example, 1K ohm and 100 ohm). The measurement current range can be switched between two types, small and large.

  If the jumper pin is neutral, it can be used as a voltage channel. As a result, in the above power supply method, for example, both single-phase and three-phase systems can be processed by a single measurement board (multi-power supply method), or a three-phase four-wire third live line Voltage measurement is possible.

  Further, in this embodiment, the current sensors CT13 and CT14 and the temperature / humidity sensor share A / D, and the switching is set by the second type jumper switches JT17 and JT18. In this way, it is possible to standardize the hardware within the processing capability range of a 16-bit machine by giving the analog buffer a little redundancy.

  Various options shown in the above description, that is, power supply mode (50 Hz / 60 Hz, 3 phase / single phase / multi, and / or 200 V / 100 V) for individual devices, and / or temperature / humidity measurement mode In addition to the specification, the selection of the type 1 and / or type 2 jumper pins is carried out according to the working specifications during the construction in the field, and at the same time the type setting is made manually to the DIP switch. Do.

During actual operation, the CPU can automatically know the type setting status of its own measurement board and the equipment connected thereto by simply reading the state of the DIP switch.
Then, the CPU enables the A / D converter, digitizes each measurement value, selects a program according to the setting state, performs a predetermined calculation and storage process, and outputs the result to the outside. For example, communication can be performed via the serial interface RS485.

  By building a system in which one or more of the above measurement boards are connected to a host device via a serial interface, the hardware can be standardized for any individual setting status in the field, updating, changing, and maintaining the setting status. Confirmation can be easily performed only on the software.

  Furthermore, in this embodiment, the DIP switch is used for storing the measurement board / equipment type setting. However, if a CPU having a nonvolatile storage element such as a flash memory is used, the DIP switch can be omitted. Writing into the non-volatile memory element is programmed so as to be manually input to, for example, a PC, PDA, or mobile phone terminal and transmitted to the CPU via RS485.

  Further, in this embodiment, the jumper pin is used for the type setting of the measurement board. However, if a semiconductor switch is used, the jumper pin can be omitted. The semiconductor switch can be turned on / off by the CPU in accordance with a manual instruction from a PC, PDA, mobile phone terminal, or the like as described above.

  Furthermore, in this embodiment, an A / D converter and an operational amplifier are prepared for each channel. However, a part or all of them are shared, and a channel is sequentially switched by a semiconductor switch in accordance with a program instruction from the CPU for scanning. Can do.

1 is an overall circuit block diagram of an embodiment according to the present invention. FIG. It is a front view of PT module of the Example by this invention. It is a horizontal sectional view of CT module of the Example by this invention.

Claims (5)

A sensor that detects voltage and current associated with power consumption of the device as analog signal values vv and vi that are proportional to each other, and an A / D converter that digitally converts the analog voltage values to obtain corresponding outputs VV and VI, respectively In an electrical information measurement circuit comprising a CPU (microprocessor unit) that obtains desired electrical information by performing arithmetic processing on the VV and VI,
The sensor for detecting the voltage is composed of a PT module equipped with a plurality of voltage / low voltage converters (PT),
The sensor for detecting the current includes a CT module having a plurality of current / small current converters (CT) and a current / voltage conversion resistor having a predetermined resistance value.
At least the current / voltage conversion resistor, the A / D converter, and the CPU are mounted on one measurement board,
The PT module and CT module are connected to the measurement board via cables that transmit analog signals of the voltage and current, respectively.
Electrical information measuring circuit characterized by the above. When the input terminal is grounded by the current / voltage conversion resistor between the input terminal via the cable from the CT module and the A / D converter on the measurement board, the predetermined terminal is used. The first type of jumper pin that can be selected from a plurality of resistance values is provided,
The electrical information measuring circuit according to claim 1.   The apparatus further includes a temperature / humidity module including a sensor that detects analog voltage values vt and vh that are proportional to the temperature and humidity of the device, and a cable that transmits the analog voltage value. 3. The electricity according to claim 1, wherein a humidity channel is set, and a jumper pin of the second type is provided which can select an output of the temperature and humidity channel and an output of the channel. 4. Information measurement circuit.   In addition to specifying the power supply mode (50 Hz / 60 Hz, 3 phase / single phase / multi, and / or 200 V / 100 V) and / or temperature / humidity measurement mode for the individual device, 4. The electrical information measuring circuit according to claim 1, further comprising a DIP switch for performing type setting including a selection position of one type and / or a second type of jumper pin.   5. At least one of the PT module, the CT module, and the temperature / humidity module is fixed to a gap between the system power wirings inside the distribution board. Electrical information measurement circuit as described in 1.

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