JP2006090923A - Management system for electric power - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a management system for electric power capable of reducing the cost, in addition to resolving complicated work operations accompanying laying operation of communication lines and construction of systems. <P>SOLUTION: An electric energy sensor 104 is equipped with a sampling means 104a for sampling the electric current and voltage detected from branch distribution lines in buildings to convert into digital signals; a high-pass filter 104b removing offset components from the outputs; a phase-adjusting means 104c for adjusting the phases of electric current and voltage; a multiplication means 104d for carrying out an operation of the instantaneous electric power from the outputs; and a low-pass filter 104e for integrating the instantaneous electric power to obtain electrical energy. A central control system 501 inside a building 500 performs communication between the electrical energy sensors 104 and 204 via a trunk communications network 502, a protocol converter 503, an optical network 600 and branch communication lines 110 and 210 and the like, and thus operates management of electric power by collecting the electrical energy measured by the electrical energy sensors 104 and 204. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a power management system that performs power management on a center device side through measuring instruments installed in a plurality of dispersed areas.

  In recent years, with increasing interest in energy conservation, there are an increasing number of businesses and consumers who introduce BEMS (Building and Energy Management System) and HEMS (Home Energy Management System) in the building management system. It is starting to turn. Under such circumstances, monitoring the current power usage situation is the basis of energy conservation measures, and the necessity of power measurement is also necessary from the viewpoint of the so-called energy conservation law (the law on the rational use of energy). In recent years, it has increased rapidly.

Because of these circumstances, on the customer side, it is possible to increase the speed and labor saving of meter reading data processing by automating meter reading, and to reduce the amount of power used by appropriate load on / off control. Realization is desired.
In view of these problems, the applicant has conducted extensive research and has already established an automatic power meter reading system that performs power management by communicating between the center side and a meter reading terminal connected via a relay terminal / communication line. Patent application has been filed and has already been patented as Patent Document 1 below.

  That is, the invention described in Patent Document 1 is connected to a main computer and a sub computer installed on the center side and connected to each other via a network, a relay terminal branched from the main computer, and the relay terminal via a communication line. A meter reading terminal, a watt-hour meter with a pulse transmitter connected to the meter reading terminal and a control circuit, and an opening / closing unit for turning on / off the load via the control circuit, and the main computer or the sub computer A function to perform meter reading and load on / off remote control by exchanging command / response signals with the meter-reading terminal for automatic meter-reading, as well as collective measurement and load information collection In a power automatic meter reading system having a function of displaying collected data in real time on a screen and printing it out, at predetermined intervals Power demand calculation means for storing the measured value of the needle and predicting the accumulated power consumption is provided, and the control circuit and the switching unit are connected to the transmission / reception unit, logic unit, relay contact, magnet coil, switching transmission / reception mechanism, switching contact and switching A contact state monitoring unit is used.

Japanese Patent No. 3202005 (Claim 1, [0006] to [0015], FIG. 1, FIG. 4, etc.)

However, in this type of system, there is a demand to improve usability over the current situation and to further reduce the cost by improving the workability of system construction.
However, in the prior art, the main computer on the center side and the repeater, and the repeater and the plurality of meter-reading terminals are connected by, for example, a communication line of RS485 standard which is a kind of serial communication standard. . In this case, if there is a need to further divide a number of communication lines and perform detailed power management at many points on each communication line, a watt-hour meter with a pulse transmitter and a meter-reading terminal are installed on each communication line. Each has to be installed at each location, which has been a major problem in terms of improving system construction and reducing costs.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a power management system that eliminates troublesome work associated with laying communication lines and system construction, and that can reduce costs.

In order to solve the above-mentioned problem, the invention according to claim 1 measures the power consumption amount of one or a plurality of buildings by a power amount sensor arranged in each building, and centrally manages the power consumption amount via a data transmission path. In the power management system in which this central management device transmits power to the device and manages the power of each building,
The electric energy sensor
Sampling means for sampling current and voltage detected from branch distribution lines in the building and converting them into digital signals, first filter means for removing offset components from the output of the sampling means, and output from the first filter means A phase adjusting means for adjusting the phase of the current and the voltage, a calculating means for calculating the instantaneous power from the output of the phase adjusting means, and a second power for obtaining the electric energy by integrating the instantaneous power output from the calculating means. And a filter means,
The data transmission path includes a backbone communication line to which the central management device is connected, a bus-type connectable branch communication line to which the electric energy sensor is connected, and a protocol for mutually converting communication protocols between these two lines And at least conversion means,
The central management device collects the electric energy measured by the electric energy sensor by communicating with the electric energy sensor via the trunk communication line, the protocol conversion unit, and the branch communication line. Power management is performed.

The invention described in claim 2 is the invention according to claim 1,
The branch communication line is an open network such as a LON (Local Operating Network, registered trademark of Echelon, USA) network.

The invention described in claim 3 is the invention according to claim 1 or 2,
The data transmission path has an optical network connected between a plurality of buildings,
Optical converters are respectively interposed between the optical network and the backbone communication line and the branch communication line.

The invention described in claim 4 is any one of claims 1 to 3,
The electric energy sensor
A means for updating the integrated power amount while sequentially integrating the power amount measured at a minute time interval is provided.

According to the present invention, a branch communication line as an open network is installed in a building, and a plurality of electric energy sensors are connected to these branch communication lines, respectively, and the amount of power used is measured by digital calculation, and the central management The apparatus can control various controllers such as an air conditioner and an illumination connected to the same hierarchy of the branch communication line while collectively managing the power consumption.
For this reason, it is possible to construct a power management system with a small amount of wiring and a simple configuration and low cost compared to the conventional method of measuring the amount of power using a watt-hour meter with a pulse transmitter and a meter reading terminal. .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, FIG. 1 shows a schematic configuration of a power management system that manages the amount of power used in buildings such as offices, schools, hospitals, factories, and the like. A system that collectively manages the amount of power used in a building is illustrated.
For the sake of convenience, some of the power lines for commercial power supply, branch distribution lines, and consumer electrical equipment as loads are not shown.

In FIG. 1, reference numerals 100 and 200 denote independent buildings. Here, for convenience, the first building and the second building are assumed. Although not shown, it is assumed that a plurality of buildings (No. 3, No. 4, No. 4, etc.) exist in parallel.
Reference numeral 500 denotes a building in which a central management device 501 for collectively managing the power consumption of the plurality of buildings described above is installed, and is designated as the Nth building for convenience.
Further, 600 is an optical network for transmitting data between the building 500 and the buildings 100, 200,. Here, instead of the optical network 600, a network using metal cables may be used.

In the building 500, a basic communication line 502 of a LAN (Local Area Network) standard such as Ethernet (registered trademark) is provided. The basic communication line 502 includes a central management device 501 including a personal computer and a server, and a printer. 508 etc. are connected. As a communication interface in the backbone communication line 502, the RS485 standard, which is a serial communication standard suitable for long-distance communication, is used.
In addition, a protocol converter 503 and an optical converter 504 are sequentially connected to the backbone communication line 501, and a plurality of power amount sensors 507 are connected via a router 506 in order to manage the power consumption of the building 500 itself. It is connected. Note that the electric energy sensor 507 has a function of detecting the electric energy used by measuring the voltage and current supplied from the branch distribution line to the load.

Optical converters 101 and 201 in the buildings 100 and 200 are connected to the optical converter 504 via an optical network 600, respectively.
First, the building 100 is a building having a power receiving room into which commercial power is drawn, and includes a signal converter 103 including an optical converter 101 connected to the optical network 600 and a router 102 connected to the optical converter 101. Yes.

The router 102 is connected to a branch communication line 110 capable of bus-type connection of devices such as an electric energy sensor, and the branch communication line 110 is connected to a power monitoring sensor 105 and a plurality of electric energy sensors 104. .
The branch communication line 110 is, for example, an open network such as a LON (Local Operating Network, registered trademark of Echelon, USA) network, and the power monitoring sensor 105 and the power amount sensor 104 using LONTalk (registered trademark of the company) as a communication protocol. And the central management device 501 transmit data and control signals.

The power monitoring sensor 105 is a sensor that monitors the instantaneous power by measuring the voltage and current at the power receiving point, and has substantially the same configuration as the power amount sensor 104 described later.
The electric energy sensor 104 is a sensor having a function of detecting the electric energy used by measuring the voltage and current supplied to the load from the branch distribution line and transmitting this data to the central management device 501 via the communication port. Yes, it has a configuration as shown in FIGS.

That is, a voltage signal is input to the electric energy sensor 104 from a branch distribution line 112 such as a single-phase two-wire low-voltage distribution line to which a load (not shown) is connected, and a clamp CT (current transformer) 111 is also provided. A current signal is input via the.
The electric energy sensor 104 has a digital operation function as shown in FIG. 3, and includes a communication port, an I / O (input / output) port, a memory, and the like which are not shown.

In FIG. 3, a sampling means 104a converts a sampled voltage / current analog signal into a digital signal and takes it as instantaneous value information. The high-pass filter 104b as the first filter means is inserted for the purpose of removing the offset component (DC component) generated at the analog input section of the sampling means 104a.
The phase adjustment unit 104c performs phase adjustment by performing a delay process in order to correct a phase shift between the voltage and the current generated in the analog input unit, or in some cases a time shift at the time of sampling.
The multiplying unit 104d multiplies the instantaneous value of the phase-adjusted voltage / current and calculates the instantaneous power.
The low-pass filter 104e substantially performs an integration operation by removing a low-frequency ripple component twice the power supply frequency included in the output value of the multiplying means 104d, and calculates the electric energy from the instantaneous power.

FIG. 4 is a conceptual diagram showing a hardware configuration of the calculation unit of the electric energy sensor 104.
This electric energy sensor 104 can measure the voltage, current, and electric energy of eight circuits at the maximum, and measures the effective voltage value, effective current value, and electric power every second by a timer corresponding to each circuit. Each energy measurement LSI 104A is provided. The outputs of these LSIs 104A are input to the main CPU 104B and scaled to calculate voltage / current / power and power factor (cosφ).
As is well known, the relationship between apparent power, active power, and reactive power is as shown in FIG. 5, where the effective voltage value and effective current value are E and I, respectively, and the phase difference between them is φ.

Here, the product of electric power and time is electric energy, and the electric energy sensor 104 of the present embodiment obtains electric power per second. Therefore, as shown in Equation 1, the current measured electric power and time (1 / 3600) The latest integrated electric energy can be obtained by obtaining the increment of the electric energy by the product of [time] and adding this to the integrated electric energy up to the previous time. That is, it is possible to update the integrated power amount every second according to Equation 1.
[Formula 1]
Latest accumulated electric energy [kWh] = integrated electric energy up to the previous time (one second ago) [kWh] + (current measured power / 3600) [kWh]
Thereby, compared with the case where the watt-hour meter with a pulse transmitter is used like the prior art, it can suppress that an integration error becomes large especially at the time of low electric power.

The integrated power amount obtained by Equation 1 is output to the LONCPU (neuron chip) 104C, and the final power amount after the LONCPU 104C performs unit conversion, data check, etc. is used as a data collection command from the central management device 501. Output in response.
The electric energy output from the electric energy sensor 104 in this way is converted into an optical signal by the signal converter 103 via the branch communication line 110 in FIG. 1 and further sent to the optical converter 504 in the building 500 via the optical network 600. And converted into an electrical signal. The transmission data may include a power factor as necessary.

The electrical signal converted by the optical converter 504 is sent to the protocol converter 503, converts the communication protocol on the branch communication line 110 side into the communication protocol on the backbone communication line 502 side, and is taken into the central management apparatus 501.
Through the operation as described above, the central management apparatus 501 can collect the power consumption (integrated power consumption) of the building 100 every second.

On the other hand, the building 200 performs air conditioning control, lighting control, and the like in addition to managing the amount of power used, and the branch communication line 210, which is an open network, similarly to the branch communication line 110 in the building 100, has a plurality of power supplies. A quantity sensor 204, an air conditioning controller 205, and a lighting controller 207 are connected. Reference numeral 206 denotes an air conditioner controlled by the controller 205, and 208 denotes a lighting fixture controlled by the controller 207.
Although not shown, various controllers and loads can be further connected to the branch communication line 210.

  In the configuration of FIG. 1, the backbone communication line 502, the protocol converter 503, the optical converters 504, 101, 201, the optical network 600, the routers 102, 202, the branch communication lines 110, 210, etc. Is configured.

The configuration of the electric energy sensor 204 in the building 200 in FIG. 1 is the same as that of the electric energy sensor 104, and the air conditioning controller 205 and the lighting controller 207 are also connected to the central management device 501 or LONCPU (neuron chip) corresponding to the LON network. Data transmission with other devices is possible.
For this reason, the central management apparatus 501 can collectively perform monitoring, operation control, and the like of the air conditioner 206 and the lighting fixture 208 together with the management of the power consumption in the building 200 using the power sensor 204. For example, when the amount of power used exceeds the contract value, it is possible to enhance the energy saving effect by suppressing the air conditioner 206 and the lighting fixture 208.

  As described above, in the present embodiment, a plurality of power sensors are connected to the branch communication lines 110 and 210, which are open networks, and various controllers are connected to construct a distributed control system. It is possible to realize a system capable of controlling air conditioning equipment and lighting equipment with a small amount of wiring while centrally managing the power consumption in the building.

It is a schematic block diagram which shows embodiment of this invention. It is a figure which shows the connection state of the electric energy sensor in embodiment. It is a block diagram which shows the digital calculation function of the electric energy sensor in embodiment. It is a conceptual diagram which shows the hardware constitutions of the calculating part of the electric energy sensor in embodiment. It is a vector diagram which shows the relationship between apparent power, active power, and reactive power.

Explanation of symbols

100, 200, 500: Building 101: Optical converter 102: Router 103: Signal converter 104: Electric energy sensor 104a: Sampling means 104b: High pass filter 104c: Phase adjustment means 104d: Multiplication means 104e: Low pass filter 104A: Energy measurement LSI
104B: Main CPU
104C: LONCPU
105: Power monitoring sensor 110: Branch communication line 111: Clamp CT
112: Branch distribution line 201: Optical converter 202: Router 203: Signal converter 204: Electric energy sensor 205: Air conditioning controller 206: Air conditioner 207: Lighting controller 208: Lighting fixture 210: Branch communication line 501: Central management device 502: Core communication line 503: Protocol converter 504: Optical converter 506: Router 507: Electric energy sensor 600: Optical network

Claims (4)

The power consumption of one or a plurality of buildings is measured by a power sensor arranged in each building, the power consumption is transmitted to a central management device via a data transmission path, and this central management device manages the power of each building. In the power management system that performs
The electric energy sensor
Sampling means for sampling current and voltage detected from branch distribution lines in the building and converting them into digital signals, first filter means for removing offset components from the output of the sampling means, and output from the first filter means A phase adjusting means for adjusting the phase of the current and the voltage, a calculating means for calculating the instantaneous power from the output of the phase adjusting means, and a second power for obtaining the electric energy by integrating the instantaneous power output from the calculating means. And a filter means,
The data transmission path includes a backbone communication line to which the central management device is connected, a bus-type connectable branch communication line to which the electric energy sensor is connected, and a protocol for mutually converting communication protocols between these two lines And at least conversion means,
The central management device collects the electric energy measured by the electric energy sensor by communicating with the electric energy sensor via the trunk communication line, the protocol conversion unit, and the branch communication line. A power management system characterized by performing power management. In the power management system according to claim 1,
The power management system, wherein the branch communication line is an open network. In the power management system according to claim 1 or 2,
The data transmission path has an optical network connected between a plurality of buildings,
A power management system, wherein an optical converter is interposed between the optical network and the backbone communication line and the branch communication line. In the electric power management system according to any one of claims 1 to 3,
The electric energy sensor
A power management system comprising means for updating an integrated electric energy while sequentially integrating electric energy measured at minute time intervals.

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