JP5142641B2 - Electronic equipment - Google Patents

Description

  The present invention relates to an electronic device, and more particularly, to an electronic device such as a monitoring control device or a protective relay device provided on a surface of a power panel such as a switchboard installed in a substation or the like.

  In general, a substation uses a transformer to step down a special high voltage supplied from a transmission line to a distribution voltage (for example, 6 kV class), and then branches the distribution voltage to a plurality of distribution systems. It is comprised so that it may supply. The switchboard is provided with a circuit breaker for opening and closing the distribution system, various detectors for detecting system state quantities such as voltage and current, a monitoring control device for monitoring the system state, a protective relay, and the like. The supervisory control device and the protective relay are generally formed as an electronic device having a digital electronic component such as a semiconductor logic circuit or a microprocessor, a display panel for displaying a system state such as voltage and current, and various operation switches arranged on the front surface. The electronic device is assembled with the front surface exposed to the surface of the switchboard.

  By the way, since substations and the like handle high voltages and large currents, electronic components installed on power panels such as switchboards need to take measures against noises such as electromagnetic waves. Generally, as a countermeasure against electromagnetic wave noise of an electronic component, it is known to surround the electronic component with a case or cover formed of a grounded shielding material to shield the electromagnetic wave noise (for example, Patent Documents 1 and 2). ). In addition, it has been proposed to shield electromagnetic wave noise by forming a shield ground pattern on the opposite surface or inner layer of a printed circuit board on which electronic components are mounted (for example, Patent Documents 3 and 4).

JP 2001-332873 A JP 63-253987 A JP 2003-86990 A JP 2000-114728 A

  By the way, the electronic device provided on the surface of the power board is required to have an external design, and the case of the electronic device is required to be formed of resin. In this case, in order to give a shielding property to the resin case or the like, it is conceivable to deposit metal vapor deposition or metal foil on the inner surface of the case or the like.

  However, there is a request to recycle waste from environmental protection, and it is difficult to separate and collect resin and metal when recycling shield materials with metal vapor deposition or metal foil on resin cases, etc. There is.

  Also, in the case of an electronic device provided on the surface of a power board installed in a substation or the like, when the operator operates an operation switch provided on the panel surface of the electronic device, static electricity charged on the operator's clothes or the like is There is a case where an electronic switch is discharged through a finger to cause malfunction or malfunction of an electronic component (hereinafter simply referred to as malfunction).

  However, in the prior art, no countermeasure is taken for countermeasures against static electricity noise of an electronic device provided on the surface of a power panel such as a substation.

  Therefore, the problem to be solved by the present invention is that in an electronic device provided on the surface of a power panel such as a substation, malfunction due to electrostatic noise and electromagnetic wave noise can be avoided, and resin and metal can be separated and collected. It is to reduce the difficult shield structure.

  Generally, a power panel of a substation or the like is a detector that detects the voltage and current of a high-voltage bus or distribution line, circuit breaker, high-voltage bus or distribution line that handles a high-voltage, large current in a metal housing (cubicle). It is formed by housing power devices such as. In addition, these power devices are usually arranged on the back side of the cubicle, and an electronic device in which a monitoring control device, a protective relay, and the like are housed in a case is provided on an open / close door provided on the front side of the cubicle. In general, an electromagnetic wave shield made of a metal partition plate is provided between the power device in the cubicle and the electronic device. In addition, since electromagnetic noise attenuates in inverse proportion to the square of the distance, if a space is secured between the power device in the cubicle and the electronic device, the influence of the electromagnetic noise on the electronic device can be reduced.

  On the other hand, since the electronic device installed in the opening provided in the door part of the cubicle is exposed to the surrounding environment, electromagnetic noise emitted to the environment from power equipment and power transmission lines that constitute a substation, etc. It becomes easy to be affected. For example, it may be considered that the operator operates the electronic device while contacting other parts by wireless communication means such as a mobile phone. In addition, the influence of electrostatic noise caused by static electricity charged on the operator being discharged to the operation switch or the like is great.

In view of the above, in order to solve the above-mentioned problems, the present invention provides a resin case to be mounted on a panel surface opening of a power panel in which power equipment is stored, a display provided on the front surface of the case, and an operation. In an electronic device comprising a switch and a semiconductor circuit component that is entirely covered by the case , the display and the operation switch are mounted on one surface of the wiring board, and the semiconductor circuit component is mounted on the wiring board. Mounted on the other surface, and among the one surface of the wiring board, at least a surface excluding a region where the display and the operation switch are mounted is covered with a conductive member, To do.

  That is, in the case of an electronic device provided by being housed in a resin case exposed on the front surface of the power panel, electromagnetic wave noise from the inside of the power panel can be obtained by placing a shield plate between the electronic device and the power device. Can be shielded. On the other hand, since the display and operation switches are not easily affected by electromagnetic noise, there is no problem even if they are placed on the front of the resin case, but semiconductor circuit components are not susceptible to electromagnetic noise entering from the front of the resin case. easily influenced. Therefore, a display and an operation switch that are not easily affected by electromagnetic noise are arranged on one side (front side) of the wiring board, and semiconductor circuit components and wiring patterns that are easily affected by electromagnetic noise are placed on the other side of the wiring board ( An electronic device caused by electromagnetic wave noise by covering the front side of the wiring board except for the area where the display unit and the operation switch are mounted with a conductive member and shielding the semiconductor circuit components and the wiring pattern. This is to avoid the malfunction. In addition, even when static electricity charged by the operator is discharged to the operation switch or the like and electrostatic noise is generated, the electrostatic noise can be shielded by the conductive member provided around the operation switch. In addition, electrostatic noise can be prevented from entering the wiring pattern. In addition, it is not necessary to deposit or laminate a metal foil on the resin case, and it is only necessary to cover the wiring board with a conductive member. be able to.

  In the present invention, the conductive member is preferably held at one potential level of a power supply voltage, a logic ground, and a frame ground.

  In addition, the wiring board is configured such that a wiring pattern connected to the semiconductor circuit component is formed on the other surface, and the display unit and the operation switch are connected to the wiring pattern by a conductor penetrating the wiring board. It is preferable. According to this, the semiconductor circuit component and the wiring pattern can be covered as wide as possible with the conductive member.

  The wiring board is formed of a multilayer board having three or more layers, and a wiring pattern connected to the semiconductor circuit component is formed on the inner layer of the multilayer board. The semiconductor circuit part, the display unit, and the operation switch penetrate the wiring board. It is possible to connect to the inner layer wiring pattern with the conductor provided.

  According to the present invention, in an electronic device provided on the surface of a power board such as a substation, malfunctions due to electrostatic noise and electromagnetic wave noise can be avoided, and a shield structure that is difficult to separate and collect resin and metal is reduced. be able to.

Hereinafter, the present invention will be described based on embodiments.
(Embodiment 1)
FIG. 1 is a front view and a side view of a characteristic part of an electronic device according to an embodiment of the present invention. FIG. 2 is a front view and a side view of the electronic device of the present embodiment. FIG. 3 is a functional block configuration diagram of the electronic apparatus according to the present embodiment. FIG. 4 is a schematic diagram of the inside of the switchboard to which the electronic device of this embodiment is applied.

  As shown in FIG. 4, the switchboard 40 can be attached to and detached from a high voltage bus 42 connected to the secondary side of the transformer of the substation via a circuit breaker in a metal housing 41, and the high voltage bus 42. Circuit breaker 43 having primary terminal 43a connected, distribution line 44 connected to a terminal to which secondary terminal 43b of breaker 43 is detachably connected, voltage and current of high voltage bus 42 and distribution line 44 And a detector group 45 for detecting the. Further, the electronic device 1 having a monitoring control and a protective relay function for monitoring the system state is mounted on the switchboard 40 with the front surface exposed in an opening formed in the door portion of the housing 41. . An electromagnetic wave shield 46 made of a metal partition plate is provided between the electronic device 1 and the high voltage bus 42 and the distribution line 44.

  As shown in FIG. 3, the electronic device 1 according to the present embodiment takes in the voltage and current detection signals 2 detected by the detector group 45 and converts them into signal levels that can be handled by semiconductor circuit components, A calculation unit 4 that takes in the detection signals 2 of the voltage and current converted by the conversion unit 3 and executes various predetermined calculations; a control unit 5 that outputs the calculation results of the calculation unit 4 to the liquid crystal display 7; The operation switch 6 for inputting an operation command to the control unit is provided.

  The conversion unit 3 includes a converter that converts the detection signal 2 of, for example, 100 V and several A level voltage and current output from the detector group 45 into the detection signal 2 of several V and several mA level handled by the semiconductor circuit. Configured. The arithmetic unit 4 is constituted by a digital semiconductor circuit such as a semiconductor logic circuit or a microprocessor, and takes in the voltage and current detection signals 2 to calculate the integrated state necessary for calculating the integrated power and the protective relay, Various operations such as a comparison operation with a set value are executed. In addition, when the calculation unit 4 detects an abnormality such as a short circuit of the distribution line 44 connected to the circuit breaker 43, the calculation unit 4 outputs a circuit break command to the circuit breaker 43. Based on a command input from the operation switch 6, the control unit 5 outputs the calculation result of the calculation unit 4 to the liquid crystal display 7 and displays it externally. For example, the system state quantities such as voltage, current, power, integrated power, etc. specified by the operation switch 6 are switched and displayed on the liquid crystal display 7.

  The electronic device 1 having such a function is housed in a resin case 8 as shown in FIG. 2, and is used by being attached to an opening formed on the surface of the switchboard 40 as shown in FIG. It is done. The operation switch 6 and the liquid crystal display 7 are mounted on the front surface 10 which is one surface of the wiring board 9, and the other semiconductor circuit components constituting the calculation unit 4 and the control unit 5 are on the other surface of the wiring substrate 9. The operation switch 6 and the liquid crystal display 7 are mounted on a certain rear surface 13 and arranged on the front surface side of the case 8.

  As shown in FIG. 1, the operation substrate 6 and the liquid crystal display 7 are mounted on the front surface 10 of the wiring board 9, and the surface excluding the region where these are mounted is covered with a conductive member 15. Although not shown, the conductive member 15 is connected to one potential level of a power supply voltage, a logic ground, and a frame ground. And the semiconductor circuit components which comprise the calculating part 4 and the control part 5 other than the operation switch 6 and the liquid crystal display 7, and the wiring pattern which connects them are formed in the back surface 13 of the wiring board 9. FIG.

  As described above, the switchboard 40 of the present embodiment includes the power of the high voltage bus 42 or the distribution line 44, the circuit breaker 43, the detector group 45, etc. that handle a high voltage and large current in a metal casing (cubicle) 41. The device is arranged on the back side of the housing 41. In addition, the electronic device 1 housed in the case 8 is provided on an opening / closing door provided on the front side of the housing 41. And between the electric power apparatus in the housing | casing 41 and the electronic device 1, the electromagnetic wave shield 46 which consists of metal partition plates is provided. For these reasons, even if the case 8 is made of resin, a space can be secured between the power device in the housing 41 and the electronic device 1, and electromagnetic noise that attenuates in inverse proportion to the square of the distance is generated by the electronic device 1. Can be reduced.

On the other hand, since the front surface of the electronic device 1 provided in the door portion of the housing 41 is exposed to the surrounding environment, the electronic device 1 is easily affected by electromagnetic noise emitted to the environment from a power transmission line such as a substation. In this respect, in this embodiment, the surface of the front surface 10 of the wiring board 9 excluding the area where the operation switch 6 and the liquid crystal display 7 are mounted is covered with the conductive member 15, so that the electromagnetic wave emitted to the environment shields the noise can be shut off semiconductor circuit components constituting the arithmetic unit 4 and a control unit 5, and the electromagnetic noise from entering the wiring pattern.

  In particular, it is conceivable that the operator operates the electronic device 1 while communicating with other parts by wireless communication means such as a mobile phone, but noise due to the radio waves can be shielded. In addition, there is a problem in that static electricity charged by the operator is discharged when the operation switch 6 is operated and electrostatic noise is generated. According to the present embodiment, the calculation unit 4 and the control unit 5 are connected by the conductive member 15. It is possible to prevent electrostatic noise from entering the semiconductor circuit components and the wiring patterns. As a result, malfunction of the electronic device 1 due to electromagnetic noise and electrostatic noise can be avoided.

Even if a resin having excellent design properties is used for the case 8 of the electronic device 1, there is no need to deposit or laminate a metal foil, and the shield structure can be limited to the wiring board 9. The burden to collect can be reduced.
(Embodiment 2)
FIG. 5 is a front view and a side view of a characteristic part according to another embodiment of the electronic device of the present invention. In the present embodiment, instead of the wiring substrate 9 having the three-layer structure of the embodiment of FIG. 1, a wiring substrate 16 having a four-layer structure is used, and the other points are the same as those in FIG. The description will be omitted.

  The wiring board 16 of the present embodiment has a wiring pattern formed on the inner layer 19, a surface layer 17 on which the operation switch 6 and the liquid crystal display 7 are mounted on both surfaces of the inner layer 19, an arithmetic unit 4 and a control unit 5. The back surface layer 18 on which the semiconductor circuit components are mounted is laminated. As in FIG. 1, the conductive member 15 is provided on the surface of the surface layer 17 and is connected to any one potential level of the power supply voltage, the logic ground, and the frame ground.

  In this embodiment, the wiring pattern is formed on the inner layer 19 as much as possible, and the surface of the back surface layer 18 on which the semiconductor circuit components are mounted is not covered with the conductive member.

  According to the present embodiment, the surface of the back layer 18 on which no component is mounted is covered with the conductive member and connected to any one potential level of the power supply voltage, the logic ground, and the frame ground. Compared to the embodiment, electromagnetic wave noise and electrostatic noise can be further shielded.

  As mentioned above, although the electronic device which concerns on this invention was demonstrated based on embodiment applied to the switchboard, it cannot be overemphasized that this invention is applicable not only to a switchboard but the general power panel which accommodated electric power equipment. Needless to say, the electronic device can be applied to devices having other functions of monitoring control and protective relay control as long as the electronic device includes a display and an operation switch.

It is the front view and side view of the characteristic part of the electronic device of Embodiment 1 of this invention. FIG. 2 is a front view and a side view of the electronic device according to the first embodiment. 1 is a functional block configuration diagram of an electronic device according to Embodiment 1. FIG. It is a schematic diagram inside the switchboard which applies the electronic device of Embodiment 1. FIG. It is the front view and side view of the characteristic part of the electronic device of Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic device 3 Conversion part 4 Operation part 5 Control part 6 Operation switch 7 Liquid crystal display 8 Case 9 Wiring board 10 Front surface 13 Back surface 15 Conductive member 40 Distribution board 41 Case 42 High voltage bus 43 Breaker 44 Distribution line 45 Detector group 46 Electromagnetic Shield

Claims (7)

A resin case to be mounted on the panel surface opening of the power panel in which the power device is stored, a display and an operation switch provided on the front surface of the case, and a semiconductor circuit component entirely covered with the case In an electronic device
The indicator and the operation switch are mounted on one side of the wiring board, the semiconductor circuit component is mounted on the other side of the wiring board, and at least the indicator and the one of the one side of the wiring board An electronic device, wherein a surface excluding a region where the operation switch is mounted is covered with a conductive member. The electronic device according to claim 1,
The electronic device is characterized in that the conductive member is held at one potential level of a power supply voltage, a logic ground, and a frame ground. The electronic device according to claim 1 or 2,
In the wiring board, a wiring pattern connected to the semiconductor circuit component is formed on the other surface, and the indicator and the operation switch are connected to the wiring pattern by a conductor provided through the wiring board. An electronic device characterized by being made. The electronic device according to claim 1 or 2,
The wiring substrate is formed of a multilayer substrate, and a wiring pattern connected to the semiconductor circuit component is formed in an inner layer of the multilayer substrate, and the semiconductor circuit component, the display, and the operation switch penetrate the wiring substrate. An electronic device, wherein the electronic device is connected to the wiring pattern of the inner layer with a conductor provided in the above-described manner. The electronic device according to claim 4.
An electronic device, wherein a surface of the wiring board on which the semiconductor circuit component is mounted is covered with a conductive member except for a region where the semiconductor circuit component is mounted. The electronic device according to claim 1,
The power board includes a high voltage bus connected to a secondary side of a transformer of a substation via a circuit breaker, a circuit breaker having a primary terminal connected to the high voltage bus, and a secondary terminal of the circuit breaker. A distribution board having a metal housing in which a connected distribution line, a detector for detecting voltage and current of the high-voltage bus and the distribution line are housed,
The electronic device further includes a conversion unit that converts a signal level of a detection signal output from the detector into a signal level of the semiconductor circuit component,
The semiconductor circuit unit takes in a voltage / current signal output from the conversion unit and executes a predetermined calculation, and a calculation result of the calculation unit based on a command of the operation switch to the display An electronic device comprising a control unit for outputting. The electronic device according to claim 6.
The arithmetic unit is a protective relay unit that takes in a voltage / current signal output from the conversion unit, detects an abnormality of a distribution line connected to the circuit breaker, and outputs a circuit break command to the circuit breaker. An electronic device characterized by the above.

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