JP2008289255A - Apparatus and method for monitoring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitoring apparatus that uses a small coil as power supply and detects a busbar temperature through simple circuitry. <P>SOLUTION: The monitoring apparatus includes: a sensor RF unit 3 that detects the temperature of a busbar and transmits the data of the detected temperature to the outside; a power supply unit 2 that has a power generating coil 2a for generating power by an alternating-current magnetic field produced by current passage through the busbar and a charging portion 2d for charging power generated by the power generating coil 2a and supplies power charged in the charging portion 2d to the sensor RF unit 3 for driving; and an enclosure 4 that houses the sensor RF unit 3 and the power supply unit 2 within a dimensional range not exceeding the busbar width and is fixed on the busbar. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a monitoring device that monitors abnormal heat generation of bus bars in a power distribution facility and a monitoring system using the same.

  When internal corrosion or the like occurs due to a change in the external environment over time, the bus bar in the power distribution facility increases the electrical resistance of the connection portion. When the bus bar is energized in this state, the connection portion may generate abnormal heat. As a technique for monitoring the abnormal heat generation of the bus bars in such a power receiving and distributing facility, for example, a power system and an electrical facility monitoring device disclosed in Patent Document 1 can be cited. In this monitoring device, a wireless sensor equipped with a temperature sensor, a CT (current transformer) and a data transmitter is installed in the bus bar, and the output of this CT is used for current detection, and also used for detecting the bus bar temperature by the temperature sensor. ing.

Japanese Patent Laid-Open No. 8-103022

  In the conventional monitoring apparatus, when CT is attached to the bus bar, a so-called through-type CT is used in which the bus bar is inserted into a through hole (square window) provided in the CT body. For this reason, the bus bar to which the penetrating CT is attached is in a state in which the CT protrudes on both sides thereof, and the other bus bars arranged adjacent to the bus bar need to be separated by the projected CT or more.

  In this case, in order to provide a conventional monitoring device while maintaining the insulation distance between adjacent bus bars, the arrangement interval of the bus bars must be set wide in consideration of the space occupied by the CT. As described above, the conventional monitoring device has a problem that it is difficult to apply to existing power distribution facilities where bus bar arrangement intervals are determined.

  In addition, a configuration is possible in which a solenoid coil having a dimension that does not protrude from both sides of the bus bar is used as a power supply source without using a through-type CT. However, in the solenoid coil, the magnetic flux does not form a closed loop. For this reason, even if the solenoid coil is applied as it is, the power generation efficiency is low, and sufficient electric power for driving the wireless sensor cannot be obtained.

  Further, in Patent Document 1, since the output of CT is directly used for current detection, a circuit such as an amplifier is required, and there is a problem that the circuit configuration of the monitoring device becomes complicated.

  The present invention has been made to solve the above-described problems, and has an object to obtain a monitoring device that can detect a busbar temperature with a simple circuit configuration using a small coil as a power source and a monitoring system using the same. To do.

  The monitoring device according to the present invention is a monitoring device that monitors the abnormal overheating of the bus bar, and includes a sensor unit that detects the temperature of the bus bar and a data transmission unit that transmits temperature data detected by the sensor unit to the outside. And a power generation coil that generates power using an alternating magnetic field generated by energizing the bus bar, and a charging unit that charges the power generated by the power generation coil. The power charged in the charging unit is supplied to the sensor processing unit. A power supply unit that is supplied and driven, and a housing that houses the sensor processing unit and the power supply unit within a size range that is less than or equal to the width of the bus bar and is fixed on the bus bar.

  According to the present invention, a sensor processing unit having a sensor unit for detecting the temperature of the bus bar, a data transmission unit for transmitting temperature data detected by the sensor unit to the outside, and an AC magnetic field generated by energizing the bus bar. A power generating unit for generating power, a charging unit for charging the power generated by the power generating coil, a power unit for supplying the power charged in the charging unit to the sensor processing unit for driving, and a width of the bus bar or less Since the sensor processing unit and the power source unit are housed within the dimensional range of the housing and the housing fixed on the bus bar, the small coil housed within the dimensional range of the bus bar width or less is used as the power source. There is an effect that it can be easily applied to existing facilities in which the bus bar arrangement interval is determined.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a wireless sensor used in the monitoring apparatus according to Embodiment 1 of the present invention. Moreover, FIG. 2 is a figure which shows the structure of the monitoring apparatus by Embodiment 1, FIG. 2 (a) is a side view, FIG.2 (b) cut along the AA line in FIG. 2 (a). Sectional drawing and FIG.2 (c) are sectional drawings cut | disconnected by the BB line in FIG.2 (b). In FIG. 2C, the description of the internal configuration of the wireless sensor 1 other than the power generation coil 2a and the thermistor 3d is omitted.

  1 and 2, the wireless sensor 1 is attached to the bus bar 5a, 5b in the vicinity of the bolt fastening portion 6 to constitute the monitoring device according to the first embodiment, and includes the power supply unit 2 and the sensor-RF unit 3 as shown in FIG. Prepare. The power supply unit 2 is a component that generates power to be supplied to the sensor-RF unit 3 by energizing the bus bars 5a and 5b, and includes a power generation coil 2a, a rectifier circuit 2b, a booster circuit 2c, a charging unit 2d, and a power supply circuit 2e. Is provided.

  As shown in FIG. 2B, the power generating coil 2a is composed of a solenoid coil having a width smaller than that of the bus bars 5a and 5b, and generates an AC voltage at both ends by energizing the bus bars 5a and 5b. The rectifier circuit 2b rectifies the AC voltage generated by the power generation coil 2a. The booster circuit 2c boosts the AC voltage rectified by the rectifier circuit 2b. The charging unit 2d is charged with an alternating voltage boosted by the booster circuit 2c. The power supply circuit 2 e supplies the power charged in the charging unit 2 d to the sensor-RF unit 3.

  The sensor-RF unit (sensor processing unit) 3 is driven by the electric power supplied from the power supply unit 2 to measure the energization amount to the bus bars 5a and 5b and the temperature of the bolt fastening unit 6, and to output the measurement result And includes a microcomputer 3a, an AD converter 3b, a temperature detection circuit 3c, a thermistor 3d, an antenna 3e, and a data transmission unit 3f.

  The microcomputer 3a is driven by the electric power supplied from the power supply unit 2, and controls the operations of the AD converter 3b, the temperature detection circuit 3c, and the data transmission unit 3f. The AD converter 3b converts the analog output of the temperature detection circuit 3c into digital data. The temperature detection circuit 3c outputs the detection result by the thermistor 3d as temperature measurement data. The thermistor 3d is installed on the surface of the bus bar 5b as shown in FIGS. 2B and 2C, and detects the surface temperature of the bus bar 5b.

  The power supply unit 2 and the sensor-RF unit 3 of the wireless sensor 1 are housed in the housing 4 shown in FIG. 2, and are installed on one of the bus bars 5a and 5b connected by bolts (in the example of FIG. 2, the bus bar 5b). Is done. In the housing 4, as shown in FIG. 2C, the power generating coil 2a is disposed on the surface of the bus bar 5b, and the back yoke 7 is provided so as to face the bus bar 5b.

  The back yoke 7 has a smaller width than the bus bar 5b like the power generation coil 2a, and is formed using a material having high magnetic permeability. A magnetic circuit is formed in which the magnetic flux generated by the power generation coil 2a flows to the back yoke 7 and is closed, whereby the magnetic flux density generated in the power generation coil 2a is increased and the power generation efficiency can be improved.

  In the bolt fastening portion 6, the through holes formed at the end portions of the bus bars 5 a and 5 b are overlapped, and the bolt 6 a is passed through the washer 6 c disposed on the bus bar 5 b side and the back yoke 7 disposed on the bus bar 5 a side. It is inserted into the hole and screwed with the nut 6b. Here, the washer 6 is formed integrally with the housing 4, and the bus bars 5 a and 5 b are bolted by the bolt fastening portion 6, and the wireless sensor 1 is installed on the bus bar 5 b, and the power generating coil 2 a The back yoke 7 is installed on the bus bar 5a side so as to face the bus bar 5a.

Next, the operation will be described.
FIG. 3 is a diagram schematically showing the operation of the monitoring system using the monitoring device in FIG. The receiver 8 shown in FIG. 3 is a receiver on the management device side that manages the busbar temperature, and includes a communication processing unit that can perform wired or wireless data communication with the data transmission unit 3f of the wireless sensor 1. It is realized by. The memory (storage unit) 8a records the data reception time from the data transmission unit 3f. The monitoring apparatus shown in FIG. 2 constitutes a monitoring system together with the receiver 8 in FIG.

  First, when energization of the bus bars 5a and 5b is started, an AC magnetic field is formed around the bus bars 5a and 5b, and an AC magnetic flux is generated in the power generating coil 2a which is a solenoid type coil. The AC magnetic flux generated in the power generating coil 2a flows to the back yoke 7 through the bus bar 5b, and forms a magnetic circuit in which the power generating coil 2a and the back yoke 7 are closed. As a result, the magnetic flux density generated in the power generating coil 2a is markedly greater than when the back yoke 7 is not provided.

  The AC voltage generated at both ends of the power generating coil 2a by the AC magnetic flux described above is rectified by the rectifier circuit 2b, boosted by the booster circuit 2c, and charging of the charging unit 2d is started. When the charging amount of the charging unit 2d exceeds a predetermined threshold value and the charging is completed, the power supply circuit 2e supplies the power stored in the charging unit 2d to the sensor-RF unit 3. Thereby, as shown in FIG. 3, the power supply of the sensor-RF supply unit 3 is turned on, and the discharging of the charging unit 2d is started. At this time, the thermistor 3d detects the temperature of the bus bar 5a, and the temperature detection circuit 3c outputs the detection result to the AD converter 3b as temperature measurement data.

  The microcomputer 3a outputs the temperature measurement data converted into a digital signal by the AD converter 3b to the data transmission unit 3f. The data transmission unit 3f transmits temperature measurement data to the receiver 8 through the antenna 3e under the control of the microcomputer 3a. When the transmission of the temperature measurement data is completed, the microcomputer 3a turns off the power. Thereby, discharging of the charging unit 2d is completed, and charging to the charging unit 2d is resumed in the same manner as described above using the AC voltage generated at both ends of the power generating coil 2a by energization of the bus bars 5a and 5b. .

  Further, since the charging speed to the charging unit 2d corresponds to the current flowing through the bus bars 5a and 5b, the average current value flowing through the bus bars 5a and 5b can be obtained based on the charging completion time of the charging unit 2d. For example, the relationship between the current flowing through the bus bars 5a and 5b and the charging completion time is obtained in advance by experiments, and the experiment is performed as information defining the relationship between the charging completion time of the charging unit 2d and the current value flowing through the bus bars 5a and 5b. A relational expression approximated from the data is set in the receiver 8, or table data of experimental data is stored in the memory 8 a of the receiver 8.

  Since the time until the wireless sensor 1 is activated and charging of the charging unit 2d is started and the temperature measurement data is transmitted in accordance with the charging completion time is constant, the data transmission interval of the wireless sensor 1 is set to the charging completion time. Can be considered. On the other hand, the receiver 8 can determine the data transmission interval of the wireless sensor 1 based on the data reception interval from the wireless sensor 1.

  As a result, the CPU of the receiver 8 records the data reception time from the wireless sensor 1 in the memory 8a, and uses the charging completion time obtained from the data reception interval in accordance with the above-described relational expression or table data. The value of the current flowing through 5a and 5b can be obtained. With this configuration, a circuit for current detection is unnecessary on the wireless sensor 1 side.

  As described above, according to the first embodiment, the electric power obtained from the power generation coil 2a, which is a solenoid coil, is boosted by the booster circuit 2c and charged in the charging unit 2d, and accumulated in the charging unit 2d. By adopting a so-called intermittent drive system in which the electric power is discharged to drive the wireless sensor 1, the wireless sensor 1 is sufficiently driven even with the power generating coil 2 a having a size that does not protrude from the side ends of the bus bars 5 a and 5 b. Can be made. Thereby, it can apply easily also to the existing power distribution equipment where the bus bar arrangement | positioning space | interval is decided.

  Further, according to the first embodiment, the value of the current flowing through the bus bars 5a and 5b is converted on the receiver 8 side from the data reception interval corresponding to the charging time of the charging unit 2d. A detection circuit is not required, and a simple circuit configuration can be obtained.

  Further, according to the first embodiment, since the housing 4 of the wireless sensor 1 and the washer 6c fixed to the bus bar by the bolt fastening portion 6 are integrated, it does not protrude from the side ends of the bus bars 5a and 5b. The wireless sensor 1 can be fixed to the bus bar. Thereby, it can apply easily also to the existing installation in which the bus bar arrangement | positioning space | interval is decided.

It is a block diagram which shows the structure of the wireless sensor used for the monitoring apparatus by Embodiment 1 of this invention. It is a figure which shows the structure of the monitoring apparatus by Embodiment 1. FIG. It is a figure which shows typically operation | movement of the wireless sensor in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Wireless sensor, 2 Power supply part, 2a Coil for power generation, 2b Rectifier circuit, 2c Booster circuit, 2d Charging part, 2e Power supply circuit, 3 Sensor-RF part (sensor processing part), 3a Microcomputer, 3b AD converter, 3c Temperature Detection circuit, 3d thermistor (sensor part), 3e antenna, 3f data transmission part, 4 housing, 5a, 5b bus bar, 6 bolt fastening part, 6a bolt, 6b nut, 6c washer, 7 back yoke, 8 receiver, 8a Memory (storage unit).

Claims (4)

In the monitoring device for monitoring abnormal overheating of the busbar,
A sensor processing unit having a sensor unit for detecting the temperature of the bus bar and a data transmission unit for transmitting temperature data detected by the sensor unit to the outside;
A power generating coil that generates electric power by an alternating magnetic field generated by energizing the bus bar; and a charging unit that charges electric power generated by the power generating coil, and the sensor processing unit receives the electric power charged in the charging unit. A power supply unit to be supplied and driven,
A monitoring apparatus comprising: a housing that houses the sensor processing unit and the power supply unit within a size range that is equal to or less than a width of the bus bar and is fixed on the bus bar.   The monitoring device according to claim 1, wherein a back yoke is provided at a position facing the bus bar of the power generation coil via the bus bar. A washer formed integrally with the outer surface of the housing,
The monitoring device according to claim 1, wherein the casing is fixed on the bus bar by bolting between the bus bars via the washer. In the monitoring system that monitors the bus bar for abnormal overheating,
The monitoring device according to any one of claims 1 to 3, wherein the temperature data is transmitted in accordance with a charging completion time of the charging unit;
A storage unit that stores information defining a relationship between a charging completion time of the charging unit and a current value flowing through the bus bar, and the charging completion time obtained based on a reception interval of temperature data from the monitoring device; A monitoring system comprising: a receiver for obtaining a value of a current flowing through the bus bar by comparing with information stored in a storage unit.

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