JP5706652B2 - DC voltage detector - Google Patents

Description

  The present invention relates to a DC voltage detector.

  For example, a DC voltage of about 1500 V (volts) is supplied from a substation to an overhead line (DC train line) that supplies power to the train. A DC voltage detector that detects the presence or absence of the DC voltage by measuring the DC voltage in the overhead line is used. Such a DC voltage detector includes a ground wire, and needs to be grounded to the rail (ground) via the ground wire. Such a DC voltage detector measures the DC voltage in the overhead line with the ground potential as a reference potential (see, for example, Patent Document 1).

JP 2001-221817 A

By the way, work such as construction and maintenance may be performed in a power failure state where power transmission to the overhead line is stopped. When working in such a power outage state, in order to ensure the safety of the worker, it is necessary to check the presence or absence of a DC voltage or the power outage state by detecting the electric power at each work location.
However, in the conventional DC voltage detector as described above, it is necessary to connect the ground wire to the rail when detecting the presence or absence of a DC voltage on the overhead wire or a power failure state. For this reason, if there are many places where the presence or absence of a DC voltage or a power failure state should be confirmed, it is necessary to perform grounding through the ground wire many times. For example, an operation of attaching and detaching the ground wire and an operation of winding and moving the ground wire are required. Furthermore, when the location where the presence or absence of the DC voltage or the power failure state should be confirmed is at a high place, it is necessary to connect the grounding wire for extension to the grounding wire for extension.
As described above, the conventional DC voltage detector as described above has a problem in that the convenience is lowered by grounding with the ground wire.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a DC voltage detector that does not need to be grounded by a ground wire and has improved convenience.

In order to solve the above problem, the present invention provides a measurement unit that detects a potential of a measurement target and measures the voltage of the measurement target using the potential of the reference potential unit as a reference, and a potential of the reference potential unit. A DC voltage obtained by boosting a voltage supplied from a DC power source is applied to the discharge electrode unit to generate plus / minus ions, and the generated plus / minus ions are discharged from the discharge electrode unit, and a virtual ground unit that includes the virtual ground unit. The discharge electrode portion includes a plurality of sets of positive electrodes that discharge positive ions and negative electrodes that discharge negative ions, and the positive electrodes and the negative electrodes are arranged on a circumference, and the positive electrodes and the Ma and the positive ions as the overall discharge electrode part when the wind is blowing from the outside toward the different second electrode polarity from the first electrode of the negative electrode Of the electrodes that are the positive electrode or the negative electrode, the angles with respect to the centers of the circles of the electrodes that are the positive electrode or the negative electrode are equal to each other, and the positive electrode and the negative electrode are It is a DC voltage detector characterized by being alternately arranged on the circumference.

  Further, the present invention is the above invention, comprising a lead electrode having a potential equal to that of the measurement target when being in contact with the measurement target, wherein the measurement unit vibrates an electric field radiated from the lead electrode. A voltage of the measurement object based on a change in a current flowing between the detection electrode and the reference potential unit, a detection electrode that collects charges in accordance with an electric field vibrated by the chopper unit, and a detection electrode And a lead-in electrode disposed at a predetermined distance from the chopper part or the detection electrode.

  Further, the present invention is characterized in that, in the above-mentioned invention, there is provided a static elimination switch portion that brings the lead electrode and the reference potential portion into a conductive state and makes the potential of the lead electrode equal to the reference potential portion. And

  Further, the present invention provides the alarm output unit for outputting an alarm and a test switch for outputting the alarm from the alarm output unit when a voltage equal to or higher than a predetermined value is measured by the measurement unit in the above invention. And the neutralization switch unit makes the conductive state between the lead-in electrode and the reference potential unit when the test switch unit outputs the alarm.

  Moreover, the present invention is characterized in that, in the above-mentioned invention, the virtual grounding portion includes a conductor portion covering the periphery of the discharge electrode portion.

  Moreover, the present invention is characterized in that, in the above invention, the discharge electrode portion is arranged to face the ground when the DC voltage detector is used.

  Further, the present invention is the above invention, wherein the virtual grounding unit generates a primary side alternating voltage that oscillates continuously or intermittently by a voltage supplied from the direct current power source, and the reference potential unit, respectively. A transformer having a primary side coil and a secondary side coil connected to each other, boosting the primary side AC voltage supplied to the primary side coil and outputting the boosted voltage to the secondary side coil as a secondary side AC voltage. A positive step-up rectifier circuit unit that positively rectifies and boosts the secondary side AC voltage and applies it to the positive electrode, and negatively rectifies and boosts the secondary side AC voltage to the negative electrode. And a negative step-up rectifier circuit portion to be applied.

  Further, the present invention is characterized in that, in the above-mentioned invention, the DC voltage detector includes a grounding portion for grounding the reference potential portion.

  Further, the present invention is the above invention, wherein the measurement unit includes a first resistor and a second resistor connected in series between the measurement target and the reference potential unit, the first resistor, and the And a voltage measuring unit that measures the voltage to be measured based on the voltage divided by the second resistor.

  Moreover, the present invention is characterized in that, in the above-mentioned invention, the discharge electrode portion includes the two sets.

  According to the present invention, in the DC voltage detector, the measurement unit detects the potential of the measurement target using the potential of the reference potential unit as a reference, and measures the voltage of the measurement target. Further, the virtual grounding unit applies a DC voltage boosted with reference to the potential of the reference potential unit to the discharge electrode unit to generate plus / minus ions, and discharges the generated plus / minus ions from the discharge electrode unit. In addition, the discharge electrode section includes a plurality of sets of positive electrodes that release positive ions and negative electrodes that release negative ions. The plus electrode and the minus electrode are arranged on the circumference, and among the electrodes that are the plus electrode or the minus electrode, the angles with respect to the center of the circle of the adjacent electrodes are equal to each other, and the plus electrode and the minus electrode Are alternately arranged on the circumference. As a result, an aerial circuit from the reference potential portion to the ground is formed by the virtual ground portion emitting positive and negative ions. Therefore, the DC voltage detector does not need to be grounded by the ground wire, and convenience can be improved.

It is a schematic block diagram which shows the DC voltage detector in 1st Embodiment. It is a block diagram which shows the arrangement | positioning of the electrode in the discharge electrode part by the embodiment. It is a graph which shows the effect of the DC voltage detector in the embodiment. It is a schematic block diagram which shows the DC voltage detector in 2nd Embodiment.

A DC voltage detector according to an embodiment of the present invention will be described below with reference to the drawings.
Here, a case where the measurement target is an overhead line (DC train line) that supplies power to the train will be described as an example.

<First Embodiment>
FIG. 1 is a schematic block diagram showing a DC voltage detector 1 according to this embodiment.
In this figure, the DC voltage detector 1 includes a lead-in electrode 10, a contact terminal 11, a measurement unit 20, a virtual ground unit 30, an alarm circuit unit 40, a test switch unit 51, a static elimination switch unit 52, and a reference potential unit 80. ing.

  The measuring unit 20 is, for example, a surface electrometer that measures the voltage of the overhead line 2 from the electric field radiated by the voltage of the overhead line 2. The measurement unit 20 is connected to the virtual ground unit 30 via the common terminal T1 of the reference potential unit 80. The measuring unit 20 measures the (ground) voltage of the overhead line 2 by measuring the potential of the overhead line 2 using the potential of the reference potential unit 80 as a reference. Moreover, the measurement part 20 outputs the control signal which outputs an alarm to the alarm circuit part 40 (alarm output part), when the measured voltage of the overhead wire 2 is more than a predetermined value.

The measurement unit 20 includes a chopper unit (21, 22), a detection electrode 23, a resistor 24, and a measurement circuit unit 25.
The chopper parts (21, 22) are formed by a conductor connected to the reference potential part 80. The chopper parts (21, 22) are disposed between the lead-in electrode 10 and the detection electrode 23, and vibrate at a predetermined frequency. The direction in which the chopper portions (21, 22) vibrate is, for example, a direction parallel to the surface of the detection electrode 23 facing the lead-in electrode 10 and a direction in which the chopper portion 21 and the chopper portion 22 face each other. As the chopper portion 21 and the chopper portion 22 vibrate, the distance between the chopper portion 21 and the chopper portion 22 changes periodically. As a result, the electric field passing between the chopper part 21 and the chopper part 22 vibrates from the lead-in electrode 10 toward the detection electrode 23. That is, the chopper parts (21, 22) vibrate the electric field radiated from the lead-in electrode 10.

  The detection electrode 23 is disposed to face the electric field emission surface of the lead-in electrode 10. The detection electrodes 23 are arranged at a predetermined distance from the chopper portions (21, 22). The detection electrode 23 is connected to the reference potential unit 80 via the resistor 24. The detection electrode 23 collects charges according to the electric field oscillated by the chopper parts (21, 22).

The resistor 24 has one end connected to the detection electrode 23 and the other end connected to the reference potential unit 80.
The measurement circuit unit 25 measures the potential of the overhead wire 2 based on a change in current flowing between the detection electrode 23 and the reference potential unit 80 via the resistor 24. Thereby, the measurement circuit unit 25 measures the (ground) voltage of the overhead line 2. Moreover, the measurement circuit unit 25 outputs a control signal that causes the alarm circuit unit 40 to output an alarm when the measured voltage of the overhead wire 2 is equal to or higher than a predetermined value.

The lead-in electrode 10 is formed of a conductor, and is disposed at a predetermined distance from the chopper portion (21, 22) or the detection electrode 23. That is, the distance interval between the lead-in electrode 10 and the chopper (21, 22) is a fixed interval W1. The lead-in electrode 10 is brought into contact with the overhead wire 2 via the contact terminal 11 when the DC voltage detector 1 confirms the presence or absence of the voltage of the overhead wire 2 or a power failure state. The lead-in electrode 10 has a potential equal to that of the overhead line 2 when it is brought into contact with the overhead line 2. Here, the confirmation of the power failure state is confirmation of a state in which no voltage is supplied to the overhead wire 2.
The contact terminal 11 is formed of a conductor and is connected to the lead-in electrode 10. The contact terminal 11 has, for example, a hook shape and is in contact with the overhead wire 2.

The virtual ground unit 30 is connected to the measurement unit 20 via the common terminal T1 of the reference potential unit 80. The virtual ground unit 30 applies a DC voltage obtained by boosting a voltage supplied from the DC power supply 31 with the potential of the reference potential unit 80 as a reference to the discharge electrode unit 70 to generate plus / minus ions. The virtual ground unit 30 discharges the generated plus / minus ions from the discharge electrode unit 70.
The virtual ground unit 30 includes a DC power supply 31, a diode 32, a capacitor 33, an oscillation circuit unit 34, a transformer unit 35, a switch unit 36, a negative boost rectifier circuit unit 100, a positive boost rectifier circuit unit 200, resistors (61, 62). ) And the discharge electrode unit 70.

The DC power supply 31 has a cathode terminal connected to the common line L <b> 1 and an anode terminal connected to one end of the switch unit 36. The DC power source 31 is, for example, a battery, and supplies a DC voltage to the oscillation circuit unit 34 via the switch unit 36 and the diode 32.
The diode 32 has an anode terminal connected to the other end of the switch unit 36 and a cathode terminal connected to the voltage supply line of the oscillation circuit unit 34. The diode 32 rectifies the current flowing from the DC power supply 31 to the oscillation circuit unit 34.

  The capacitor 33 has one end connected to the common line L1 and the other end connected to the cathode terminal of the diode 32. The capacitor 33 functions as a smoothing capacitor that stabilizes the voltage supplied from the DC power supply 31.

The oscillation circuit unit 34 is, for example, an oscillation circuit that oscillates intermittently. The oscillation circuit unit 34 generates an AC voltage (primary AC voltage) that intermittently oscillates with a voltage supplied from the DC power supply 31.
The oscillation circuit unit 34 includes a capacitor 341, a resistor 342, a bipolar transistor 343, and a diode 344.
The capacitor 341 and the resistor 342 are connected in series between the voltage supply line and one end of the primary side coil of the transformer unit 35. The resistor 342 limits the current for charging the capacitor 341 and the base current of the bipolar transistor 343. The capacitor 341 supplies a voltage to the base terminal of the bipolar transistor 343 by charging the electric charge. The time interval for intermittent oscillation is set by the time constant between the resistor 342 and the capacitor 341.

The bipolar transistor 343 has a collector terminal connected to the voltage supply line, a base terminal connected to a signal line connecting the resistor 342 and the capacitor 341, and an emitter terminal connected to the intermediate terminal of the primary side coil of the transformer unit 35. The bipolar transistor 343 brings the collector terminal and the emitter terminal into a conductive state when the capacitor 341 is charged with a charge and exceeds a predetermined voltage. Further, the bipolar transistor 343 brings the collector terminal and the emitter terminal into a non-conducting state when the capacitor 341 is discharged and becomes less than a predetermined voltage.
The diode 344 has an anode terminal connected to the emitter terminal of the bipolar transistor 343 and a cathode terminal connected to the collector terminal of the bipolar transistor 343. The diode 344 conducts between the emitter terminal and the collector terminal when the emitter terminal of the bipolar transistor 343 is at a higher potential than the collector terminal.

  The transformer unit 35 includes a primary side coil and a secondary side coil connected to the common line L1 of the reference potential unit 80, respectively. One end of the primary coil is connected to one end of the capacitor 341 and the other end is connected to the common line L1. The secondary coil is connected to the minus boost rectifier circuit unit 100 and the plus boost rectifier circuit unit 200, respectively. The transformer unit 35 boosts the primary AC voltage supplied to the primary coil and outputs the boosted secondary AC voltage to the secondary coil as a secondary AC voltage.

  The switch unit 36 is connected between the DC power supply 31 and the diode 32. The switch unit 36 is turned on by the user when the DC voltage detector 1 is used.

The negative boost rectifier circuit unit 100 negatively rectifies and boosts the secondary AC voltage supplied from the transformer unit 35. The negative boost rectifier circuit unit 100 applies a DC voltage boosted to the negative side with respect to the potential of the negative rectified and boosted common line L1 to the negative electrodes (71, 72) via the resistor 61. Here, the negative boost rectifier circuit unit 100 is an example using a five-fold voltage rectifier circuit.
The negative boost rectifier circuit unit 100 includes capacitors 101 to 105 and diodes 111 to 115.

The capacitor 101 and the diode 111 are connected in series between the terminals of the secondary coil of the transformer unit 35. The cathode terminal of the diode 111 is connected to the common line L1 via the transformer unit 35. The capacitor 101 and the diode 111 are supplied from the transformer unit 35 and negatively rectify the secondary AC voltage.
The diodes 112 to 115 are connected in series between the anode terminal of the diode 111 and one end of the resistor 61 so that the direction from the resistor 61 toward the diode 111 is the forward direction. The capacitor 102 is connected between the cathode terminal of the diode 111 and the cathode terminal of the diode 113, and the capacitor 103 is connected between the cathode terminal of the diode 113 and the cathode terminal of the diode 115. The capacitor 104 is connected between the cathode terminal of the diode 112 and the cathode terminal of the diode 114, and the capacitor 105 is connected between the cathode terminal of the diode 114 and the anode terminal of the diode 115.
The diodes 111 to 115 and the capacitors 101 to 105 function as a five-fold voltage rectifier circuit having five voltage multiplier circuits.

The positive boost rectifier circuit unit 200 positively rectifies and boosts the secondary AC voltage supplied from the transformer unit 35. The plus boosting rectifier circuit unit 200 applies a DC voltage boosted to the plus side with respect to the potential of the common line L <b> 1 subjected to plus rectification and boosting to the plus electrodes (73, 74) via the resistor 62. Here, the plus boost rectifier circuit unit 200 is an example using a 6-fold voltage rectifier circuit.
The plus boost rectifier circuit unit 200 includes capacitors 201 to 106 and diodes 211 to 216.

The capacitor 201 and the diode 211 are connected in series between the terminals of the secondary coil of the transformer unit 35. The diode 211 has an anode terminal connected to the common line L1 via the transformer unit 35. The capacitor 201 and the diode 211 are supplied from the transformer unit 35 and positively rectify the secondary AC voltage.
The diodes 212 to 216 are connected in series between the cathode terminal of the diode 211 and one end of the resistor 62 so that the direction from the diode 211 toward the resistor 62 is the forward direction. The capacitor 202 is connected between the anode terminal of the diode 212 and the anode terminal of the diode 214, and the capacitor 203 is connected between the anode terminal of the diode 214 and the anode terminal of the diode 216. The capacitor 204 is connected between the anode terminal of the diode 211 and the anode terminal of the diode 213, and the capacitor 205 is connected between the anode terminal of the diode 213 and the anode terminal of the diode 215. The capacitor 206 is connected between the anode terminal of the diode 215 and the cathode terminal of the diode 216.
The diodes 211 to 215 and the capacitors 201 to 205 function as a 6-fold voltage rectifier circuit including six voltage multiplication circuits.

The discharge electrode unit 70 includes a plurality of pairs of positive electrodes (73, 74) that emit positive ions and negative electrodes (71, 72) that emit negative ions. In the DC voltage detector 1 shown in FIG. 1, for example, two sets are provided.
The arrangement of the plus electrodes (73, 74) and the minus electrodes (71, 72) will be described later.

The alarm circuit unit 40 (alarm output unit) outputs an alarm based on the control signal supplied from the measurement unit 20. That is, the alarm circuit unit 40 outputs an alarm when the measurement unit 20 measures a voltage that is equal to or higher than a predetermined value. That is, an alarm is output when voltage is supplied to the overhead line 2.
The alarm circuit unit 40 includes a DC power supply 41, a light emitting diode 42, a speaker 43, and a switch unit 44.
The DC power supply 41 is a battery, for example, and supplies a voltage to the light emitting diode 42 and the speaker 43. The light emitting diode 42 outputs light as an alarm. The speaker 43 outputs a buzzer sound as an alarm.
The switch unit 44 is connected between the light emitting diode 42 and the speaker 43 and the DC power supply 41. The switch unit 44 brings the light emitting diode 42 and the speaker 43 and the DC power source 41 into a conductive state when the measuring unit 20 measures a voltage equal to or higher than a predetermined value. Thereby, the light emitting diode 42 and the speaker 43 output an alarm by light and a buzzer sound. Further, the switch unit 44 brings the light emitting diode 42 and the speaker 43 and the DC power supply 41 into a conductive state based on a signal supplied from the test switch unit 51.

  The test switch unit 51 is, for example, a switch such as a button switch, and is a switch that outputs an alarm from the alarm output unit 40. The test switch unit 51 is pressed by the user of the DC voltage detector 1 when confirming whether the alarm output unit 40 operates normally. The test switch unit 51 outputs a signal for making the switch unit 44 conductive when pressed by the user of the DC voltage detector 1. Moreover, the test switch part 51 outputs the signal which makes the static elimination switch part 52 mentioned later into a conduction | electrical_connection state, when the user of the DC voltage detector 1 is pressed down.

  The static elimination switch unit 52 is connected between the lead-in electrode 10 and the common terminal T1 of the reference potential unit 80. Based on the signal supplied from the test switch unit 51, the static elimination switch unit 52 brings the drawing electrode 10 and the common terminal T <b> 1 of the reference potential unit 80 into a conductive state, and sets the potential of the drawing electrode 10 to the reference potential unit 80. To the same potential. That is, when the test switch unit 51 outputs an alarm, the static elimination switch unit 52 brings the lead electrode 10 and the reference potential unit 80 into a conductive state.

  The reference potential unit 80 includes a common terminal T1 and a common line L1. The potential of the reference potential unit 80 is a reference potential in the DC voltage detector 1. Further, the reference potential unit 80 is a common potential that connects one end of the primary side coil of the transformer unit 35 and one end of the secondary side coil. In the DC voltage detector 1, the polarity and magnitude of the potential are determined based on the reference potential unit 80. Further, the potential of the reference potential unit 80 becomes equal to the ground by the virtual ground unit 30.

Next, the arrangement of the plus electrodes (73, 74) and the minus electrodes (71, 72) will be described.
FIG. 2 is a configuration diagram illustrating the arrangement of electrodes in the discharge electrode unit 70 according to the present embodiment.
In this figure, the plus electrodes (73, 74) and the minus electrodes (71, 72) are arranged at equal intervals on the circumference. Further, among the electrodes that are the plus electrodes (73, 74) or the minus electrodes (71, 72), the angles of the adjacent electrodes with respect to the center of the circle Z1 are equal to each other. Further, the positive electrodes 73 (or 74) and the negative electrodes 71 (or 72) are alternately arranged on the circumference. That is, the number of electrodes that are plus electrodes (73, 74) or minus electrodes (71, 72) is an even number (for example, four), and each electrode has a regular polygon having an even number of vertices (for example, for example, It is arranged at each vertex of (square). Further, the plus electrode 73 (or 74) and the minus electrode 71 (or 72) are alternately arranged at adjacent vertices of a regular polygon (for example, a square).

  The reason why the electrodes in the discharge electrode unit 70 are arranged as described above is that the reference potential in the virtual ground fluctuates when the wind blows when the presence / absence of the voltage of the overhead wire 2 or the power failure state is confirmed. Because there is. This is because positive ions and negative ions are caused to flow in the discharge electrode unit 70 and the balance between positive ions and negative ions is lost. In the DC voltage detector 1 in the present embodiment, by arranging the electrodes in the discharge electrode unit 70 as described above, fluctuations in the potential of the reference potential unit 80 due to the influence of wind can be reduced.

  For example, when the wind blows from the positive electrode 73 toward the negative electrode 71, the positive ions generated at the positive electrode 73 flow toward the negative electrode 71, so that the positive ions around the negative electrode 71 increase. For this reason, more negative ions are released from the negative electrode 71. Further, since the negative ions are reduced around the positive electrode 73, the positive ions released from the positive electrode 73 are suppressed. On the other hand, in this case, the wind blows from the negative electrode 72 toward the positive electrode 74. Therefore, between the negative electrode 72 and the positive electrode 74, the positive ions released from the positive electrode 74 are increased, and the negative ions released from the negative electrode 71 are suppressed, contrary to the positive electrode 73 and the negative electrode 71. Is done. As a result, in the DC voltage detector 1, the balance between the positive ions and the negative ions is partially lost, but the balance between the positive ions and the negative ions can be maintained as the entire discharge electrode unit 70. As a result, the DC voltage detector 1 can reduce fluctuations in the potential of the reference potential unit 80 due to the influence of wind.

The virtual ground unit 30 includes a conductor 75 that covers the periphery of the discharge electrode 70 in a cylindrical shape. Thereby, the virtual grounding part 30 can reduce the influence by disturbance. Moreover, since the conductor part 75 prevents that a positive electrode (73, 74) and a negative electrode (71, 72) hit a wind, the fluctuation | variation of the electric potential of the reference electric potential part 80 by the influence of a wind can be reduced.
Moreover, the discharge electrode part 70 is arrange | positioned facing the earth, when the DC voltage detector 1 is used.

Next, the operation of the DC voltage detector 1 in this embodiment will be described.
First, the voltage detection operation in which the DC voltage detector 1 checks the presence or absence of the voltage of the overhead wire 2 or the power failure state will be described.

First, in the DC voltage detector 1, the switch unit 36 is turned on by the user, and the contact terminal 11 is brought into contact with the overhead wire 2. When the switch unit 36 is in a conductive state, the virtual ground unit 30 causes the reference potential unit 80 to be virtually grounded so as to have a potential equal to the ground.
Further, the lead-in electrode 10 is brought into contact with the overhead wire 2 through the contact terminal 11 and has the same potential as the overhead wire 2. Thereby, the lead-in electrode 10 radiates an electric field toward the detection electrode 23. The chopper parts (21, 22) vibrate (change) the electric field passing between the chopper part 21 and the chopper part 22 by vibrating. The detection electrode 23 receives the change in the electric field and collects charges. Due to this charge concentration, an alternating current having the same frequency as the frequency of the chopper (21, 22) flows through the resistor 24.
The measurement circuit unit 25 measures the potential of the overhead wire 2 based on a change in current flowing between the detection electrode 23 and the reference potential unit 80 via the resistor 24. Thereby, the measurement circuit unit 25 measures the (ground) voltage of the overhead line 2. Moreover, the measurement circuit unit 25 outputs a control signal that causes the alarm circuit unit 40 to output an alarm when the measured voltage of the overhead wire 2 is equal to or higher than a predetermined value.

  The switch 44 of the alarm circuit unit 40 becomes conductive when the voltage of the overhead line 2 measured by the measurement circuit unit 25 is equal to or higher than a predetermined value (when voltage is supplied to the overhead line 2). As a result, a voltage is supplied from the DC power supply 41 to the light emitting diode 42 and the speaker 43. Therefore, when the voltage is supplied to the overhead wire 2, the alarm circuit unit 40 outputs a light and buzzer alarm. Thereby, the user can confirm the presence or absence of the voltage of the overhead line 2, or a power failure state.

  The lead-in electrode 10 may be charged due to the contact terminal 11 touching the user's clothes. When the lead-in electrode 10 is charged in this way, the lead-in electrode 10 cannot spontaneously discharge. Therefore, the measurement unit 20 measures the potential of the charged lead-in electrode 10 and may not be able to measure accurately. As a countermeasure against this, the DC voltage detector 1 includes a static elimination switch unit 52.

Based on the signal supplied from the test switch unit 51, the static elimination switch unit 52 brings the drawing electrode 10 and the common terminal T <b> 1 of the reference potential unit 80 into a conductive state, and sets the potential of the drawing electrode 10 to the reference potential unit 80. To the same potential. Here, the test switch unit 51 is pressed by the user when confirming whether the alarm output unit 40 operates normally. The user presses the test switch unit 51 before confirming the presence or absence of the voltage of the overhead wire 2 or the power failure state. When the test switch unit 51 is pressed by the user, the test switch unit 51 outputs a signal that makes the static elimination switch unit 52 conductive. That is, when the test switch unit 51 outputs an alarm, the static elimination switch unit 52 brings the lead electrode 10 and the reference potential unit 80 into a conductive state. Thereby, since the lead-in electrode 10 is neutralized to the same potential as the reference potential unit 80, the DC voltage detector 1 can accurately perform the voltage detection operation.
Further, the test switch unit 51 causes the alarm circuit unit 40 to output an alarm (alarm by sound and light) when pressed by the user.

Next, the operation of the virtual ground unit 30 will be described.
First, when the switch unit 36 is turned on by the user, the DC power supply 31 supplies a DC voltage to the oscillation circuit unit 34 via the diode 32. As a result, charges are charged in the capacitor 341 of the oscillation circuit section 34. The bipolar transistor 343 brings the collector terminal and the emitter terminal into a conductive state when the capacitor 341 is charged with a charge and exceeds a predetermined voltage. As a result, the oscillation circuit unit 34 intermittently oscillates at a high frequency by self-excited oscillation. That is, the oscillation circuit unit 34 has a larger value of the resistor 342 in order to reduce the base current of the bipolar transistor 343 and cause intermittent oscillation. The oscillation circuit unit 34 oscillates when a certain amount of charge is charged in the capacitor 341, and the oscillation stops when the charged charge is discharged. By repeating this, intermittent oscillation (primary AC voltage) occurs, and the transformer unit 35 boosts the primary AC voltage supplied to the primary coil and intermittently applies the secondary AC voltage to the secondary coil. Output.

Next, the negative boost rectifier circuit unit 100 negatively rectifies and boosts the secondary side AC voltage supplied from the transformer unit 35. The negative boost rectifier circuit unit 100 applies a DC voltage boosted to the negative side with respect to the potential of the negative rectified and boosted common line L1 to the negative electrodes (71, 72) via the resistor 61. The positive boost rectifier circuit unit 200 positively rectifies and boosts the secondary side AC voltage supplied from the transformer unit 35. The plus boosting rectifier circuit unit 200 applies a DC voltage boosted to the plus side with respect to the potential of the common line L <b> 1 subjected to plus rectification and boosting to the plus electrodes (73, 74) via the resistor 62.
Accordingly, the negative electrodes (71, 72) release negative ions, and the positive electrodes (73, 74) release positive ions.

In the positive electrodes (73, 74) and the negative electrodes (71, 72), the release of ions having the opposite polarity to the voltage polarity of the reference potential portion 80 with the ground as a reference potential is suppressed, and the release of ions having the same polarity is suppressed. Much done.
That is, when the reference potential portion 80 is positively charged, the potential difference between the negative electrodes (71, 72) is small from the ground, and the potential difference between the positive electrodes (73, 74) is large from the ground. Become. Thereby, in the virtual grounding part 30, the discharge | release of the negative ion by a negative electrode (71, 72) is suppressed, and discharge | release of the positive ion by a positive electrode (73, 74) increases with respect to a negative ion. Therefore, in this case, the virtual grounding portion 30 discharges from only the positive electrodes (73, 74) toward the ground. As a result, when positive ions emitted from the positive electrodes (73, 74) reach the ground, a positive aerial circuit from the reference potential portion 80 to the ground through the positive electrodes (73, 74) is formed. The positive charge leaks to the ground and is eliminated. That is, the virtual ground unit 30 virtually grounds the reference potential unit 80 with the potential of the reference potential unit 80 equal to the ground.

  On the other hand, when the reference potential unit 80 is negatively charged, the potential difference between the positive electrodes (73, 74) and the ground is small, and the potential difference between the negative electrodes (71, 72) is large from the ground. Become. Thereby, in the virtual grounding part 30, the release of positive ions by the positive electrodes (73, 74) is suppressed, and the release of negative ions by the negative electrodes (71, 72) increases with respect to the positive ions. Therefore, in this case, the virtual grounding portion 30 discharges from only the negative electrodes (71, 72) toward the ground. As a result, when negative ions emitted from the negative electrodes (71, 72) reach the ground, a positive aerial circuit is formed from the reference potential portion 80 to the ground through the negative electrodes (71, 72). The negative charge leaks to the ground and is neutralized. That is, the virtual ground unit 30 virtually grounds the reference potential unit 80 by setting the potential of the reference potential unit 80 equal to the ground.

  As described above, in the DC voltage detector 1, the measuring unit 20 measures the potential of the overhead line 2 (measurement target) by measuring the potential of the overhead line 2 (measurement target) with reference to the potential of the reference potential unit 80. The virtual ground unit 30 applies a DC voltage obtained by boosting a voltage supplied from a DC power source with the potential of the reference potential unit 80 as a reference to the discharge electrode unit 70 to generate plus / minus ions. The virtual ground unit 30 discharges the generated plus / minus ions from the discharge electrode unit 70. As a result, in the positive electrodes (73, 74) and the negative electrodes (71, 72), the release of ions having a polarity opposite to the voltage polarity of the reference potential portion 80 with the ground as a reference potential is suppressed, and the ions having the same polarity are released. A lot is done. As a result, in the virtual ground part 30, ions of the same polarity reach the ground, and an air circuit that reaches the ground from the reference potential part 80 through the discharge electrode part 70 is formed. Thereby, the DC voltage detector 1 can check the presence or absence of the voltage of the overhead wire 2 or the power failure state without grounding with the ground wire. Therefore, the DC voltage detector 1 does not need to be grounded by the ground wire, and convenience can be improved.

  In addition, the discharge electrode unit 70 includes a plurality (for example, two sets) of positive electrodes (73, 74) that emit positive ions and negative electrodes (71, 72) that emit negative ions. Further, the plus electrodes (73, 74) and the minus electrodes (71, 72) are arranged on the circumference. Further, the discharge electrode unit 70 has positive electrodes (73, 74) or negative electrodes (71, 72) of which the angles with respect to the centers of the circles of adjacent electrodes are equal to each other, and the positive electrode (73 , 74) and minus electrodes (71, 72) are alternately arranged on the circumference. Thereby, the DC voltage detector 1 can reduce the fluctuation of the potential of the reference potential unit 80 due to the influence of the wind. Therefore, the DC voltage detector 1 can measure the voltage of the overhead wire 2 with high accuracy and stability.

FIG. 3 is a graph showing the effect of the DC voltage detector 1 in the present embodiment.
In this figure, the graph shows the relationship between the voltage applied to the overhead line 2 and the measured voltage measured using the DC voltage detector 1. In this graph, the horizontal axis indicates the applied voltage [V] applied to the overhead wire 2. In addition, the left side of the vertical axis indicates the measured voltage [V] measured using the DC voltage detector 1, and the right side of the vertical axis indicates the wind speed [m / s] when the measurement is performed.
In this graph, the open square indicates the maximum measured value, and the black triangle indicates the minimum measured value. Further, black circles indicate the wind speed.
As this graph shows, the applied voltage of the overhead wire 2 and the measurement voltage are in a proportional relationship. Therefore, the DC voltage detector 1 can be used for confirming the presence or absence of the voltage of the overhead wire 2 or the power failure state.

  Further, as indicated by the white squares, black triangles, and black circles, the DC voltage detector 1 can reduce the influence of the wind, and can measure accurately and stably.

<Second Embodiment>
Next, another example of the DC voltage detector according to the present invention will be described.
FIG. 4 is a schematic block diagram showing the DC voltage detector 1a according to the present embodiment.
In this figure, the DC voltage detector 1 a includes a contact terminal 11, a measurement unit 20 a, a virtual ground unit 30, an alarm circuit unit 40, and a reference potential unit 80. In this figure, the same components as those in FIG. Further, the arrangement of the electrodes in the discharge electrode unit 70 is the same as that in the first embodiment shown in FIG.

  The measuring unit 20a is, for example, an electrometer that measures the voltage of the overhead wire 2 using resistance partial pressure. The measurement unit 20a is connected to the virtual ground unit 30 via the common terminal T1 of the reference potential unit 80. The measuring unit 20a measures the (ground) voltage of the overhead line 2 by measuring the potential of the overhead line 2 via the contact terminal 11 with the potential of the reference potential unit 80 as a reference. Moreover, the measurement part 20a outputs the control signal which makes the alarm circuit part 40 (alarm output part) output an alarm, when the measured voltage of the overhead wire 2 is more than a predetermined value.

The measuring unit 20 a includes a resistor 26 (first resistor), a resistor 27 (second resistor), and a voltage measuring unit 28.
The resistor 26 and the resistor 27 are connected in series between the overhead line 2 and the reference potential unit 80. The resistor 26 and the resistor 27 function as a resistance voltage divider that resistance-divides the voltage of the overhead line 2 into a voltage that can be measured by the voltage measuring unit 28.
The voltage measurement unit 28 measures the voltage across the resistor 27. The voltage measuring unit 28 measures the (ground) voltage of the overhead wire 2 based on the voltage divided by the resistors 26 and 27. Moreover, the voltage measurement part 28 outputs the control signal which makes the alarm circuit part 40 output an alarm, when the measured voltage of the overhead wire 2 is more than a predetermined value.

  The operation of the DC voltage detector 1a in the present embodiment is that the measurement unit 20 of the DC voltage detector 1 in the first embodiment is replaced with a measurement unit 20a that measures using resistance partial pressure, and This is basically the same except that the lead-in electrode 10 and the charge removal switch section 52 are not provided.

  As described above, the DC voltage detector 1 a includes the measurement unit 20 a and the virtual ground unit 30. The virtual grounding unit 30 performs virtual grounding by setting the potential of the reference potential unit 80 to a potential equal to the ground. Further, the measurement unit 20 a measures the voltage across the resistor 27. The voltage measuring unit 28 measures the voltage of the overhead wire 2 (ground) based on the voltage divided by the resistors 26 and 27. Thereby, the DC voltage detector 1a can confirm the presence / absence of the voltage of the overhead wire 2 or the power failure state without grounding with the ground wire. Therefore, the DC voltage detector 1a does not need to be grounded by the ground wire, and the convenience can be improved in the same manner as the DC voltage detector 1 in the first embodiment.

  Further, the arrangement of the electrodes in the discharge electrode unit 70 of the virtual ground unit 30 is the same as that in the first embodiment shown in FIG. Therefore, the DC voltage detector 1a can reduce fluctuations in the potential of the reference potential unit 80 due to the influence of wind. Therefore, the DC voltage detector 1a can measure the voltage of the overhead wire 2 with high accuracy and stability, like the DC voltage detector 1 in the first embodiment.

  Note that, according to the embodiment of the present invention, the DC voltage detector 1 (or 1a) measures the potential of the overhead wire 2 (ground to ground) by measuring the potential of the overhead wire 2 (measurement target) with reference to the potential of the reference potential unit 80. ) Applying a DC voltage obtained by boosting the voltage supplied from the DC power source 31 with the measuring unit 20 (or 20a) for measuring the voltage and the potential of the reference potential unit 80 as a reference to the discharge electrode unit 70 to generate positive and negative ions. And a virtual grounding unit 30 that emits the generated plus / minus ions from the discharge electrode unit 70. The discharge electrode unit 70 includes a plurality of sets of a plus electrode 73 (or 74) that emits plus ions and a minus electrode 71 (or 72) that emits minus ions, and the plus electrode 73 (or 74) and the minus electrode. The electrode 71 (or 72) is arranged on the circumference, and among the electrodes that are the plus electrode (73, 74) or the minus electrode (71, 72), the angle with respect to the center of the circle of the adjacent electrode is The positive electrodes 73 (or 74) and the negative electrodes 71 (or 72) are alternately arranged on the circumference at equal angles.

  Thereby, the DC voltage detector 1 (or 1a) can check the presence or absence of the voltage of the overhead wire 2 or the power failure state without grounding with the ground wire. Therefore, the DC voltage detector 1 (or 1a) does not need to be grounded by the ground wire, and convenience can be improved. Accordingly, the DC voltage detector 1 (or 1a) can reduce fluctuations in the potential of the reference potential unit 80 due to the influence of wind. As a result, the DC voltage detector 1 (or 1a) can measure the voltage of the overhead wire 2 with high accuracy and stability.

Moreover, the DC voltage detector 1 includes a lead-in electrode 10 that has a potential equal to that of the overhead wire 2 when it is in contact with the overhead wire 2 (measurement target). The measurement unit 20 includes a chopper unit (21, 22) that vibrates the electric field radiated from the lead-in electrode 10, a detection electrode 23 that collects charges according to the electric field vibrated by the chopper unit (21, 22), and a detection A measurement circuit unit 25 that measures the (ground) voltage of the overhead wire 2 based on a change in current flowing between the electrode 23 and the reference potential unit 80 is provided. The lead-in electrode 10 is disposed at a predetermined distance from the chopper portion (21, 22) or the detection electrode 23.
As a result, the distance between the lead-in electrode 10 and the detection electrode 23 is always constant. Therefore, the DC voltage detector 1 can measure the voltage of the overhead wire 2 with high accuracy and stability.

In addition, the DC voltage detector 1 includes a static elimination switch unit 52 that brings the lead-in electrode 10 and the reference potential unit 80 into a conductive state and sets the potential of the lead-in electrode 10 equal to the reference potential unit 80.
Thereby, since the lead-in electrode 10 is neutralized to the same potential as the reference potential unit 80, the DC voltage detector 1 can accurately perform the voltage detection operation.

The DC voltage detector 1 also outputs an alarm circuit unit 40 (alarm output unit) that outputs an alarm and an alarm from the alarm circuit unit 40 when a voltage greater than a predetermined value is measured by the measuring unit 20. And a test switch unit 51 for outputting. When the test switch unit 51 outputs an alarm, the static elimination switch unit 52 brings the lead electrode 10 and the reference potential unit 80 into a conductive state.
Thereby, the DC voltage detector 1 can neutralize the lead-in electrode 10 together with checking whether the alarm output unit 40 operates normally. Therefore, the DC voltage detector 1 can accurately perform a voltage detection operation while ensuring the safety of workers who perform work such as construction and maintenance.

Moreover, the virtual grounding part 30 is provided with the conductor part 75 which covers the circumference | surroundings of the discharge electrode part 70 (71-74).
Thereby, the DC voltage detector 1 (or 1a) can reduce the influence of disturbance. Further, the conductor 75 prevents the positive electrode (73, 74) and the negative electrode (71, 72) from being hit by the wind, so the DC voltage detector 1 (or 1a) has the reference potential portion 80 due to the influence of the wind. Fluctuations in the potential can be reduced.

Moreover, the discharge electrode part 70 is arrange | positioned facing the earth, when the DC voltage detector 1 (or 1a) is used.
Thereby, since positive ions or negative ions can easily reach the ground, a stable virtual ground can be obtained. In addition, it is possible to reduce dust and foreign matter from adhering to the discharge electrode unit 70.

In addition, the virtual ground unit 30 includes a primary side coil connected to the oscillation circuit unit 34 that generates a primary side alternating voltage that oscillates continuously or intermittently by a voltage supplied from the direct current power source 31 and a reference potential unit 80. And a secondary side coil, boosting the primary side AC voltage supplied to the primary side coil, and outputting the secondary side AC voltage as a secondary side AC voltage to the secondary side coil, and the secondary side AC voltage The positive step-up rectification circuit unit 200 applies positive rectification and boosting to the positive electrodes (73, 74), and the secondary AC voltage is negative rectified and boosted and applied to the negative electrodes (71, 72). And a negative boost rectifier circuit unit 100.
Thereby, the DC voltage detector 1 (or 1a) can efficiently emit plus / minus ions.

Further, the DC voltage detector 1 (or 1a) includes a grounding unit that grounds the reference potential unit 80.
Thereby, even when virtual grounding cannot be used (for example, in the case of rain, etc.), the DC voltage detector 1 (or 1a) can check the presence / absence of the voltage of the overhead wire 2 or the power failure state.

The measuring unit 20a includes a resistor 26 (first resistor) and a resistor 27 (second resistor), a resistor 26, and a resistor connected in series between the overhead line 2 (measurement target) and the reference potential unit 80. And a voltage measuring unit 28 that measures the voltage of the overhead wire 2 based on the voltage divided by the resistor 27.
Thereby, the DC voltage detector 1a does not need to be grounded by the ground wire, and convenience can be improved.

The present invention is not limited to the above embodiments, and can be modified without departing from the spirit of the present invention. In each of the above-described embodiments, a mode in which two sets of the plus electrode 73 (or 74) and the minus electrode 71 (or 72) are provided has been described, but a mode in which three or more sets are provided may be used.
Further, in each of the above-described embodiments, the discharge electrode unit 70 has been described so as to be disposed facing the ground when the DC voltage detector 1 (or 1a) is used. May be used. Further, the contact terminal 11 may have a hook shape or other shapes.

Moreover, although the form provided with the measurement part 20 and the measurement part 20a each was demonstrated, the form provided with both the measurement part 20 and the measurement part 20a, and switching and using either may be sufficient.
In each of the above embodiments, the reference potential unit 80 has been described as being virtually grounded by the virtual grounding unit 30. However, the virtual grounding unit 30 and a grounding unit that grounds the reference potential unit 80 by a ground line are described. It is possible to use either one of them. Thereby, even when virtual grounding cannot be used (for example, in the case of rain, etc.), the DC voltage detector 1 (or 1a) can check the presence / absence of the voltage of the overhead wire 2 or the power failure state.

In each of the above embodiments, the oscillation circuit unit 34 has been described as being intermittently oscillated, but may be continuously oscillating. In this case, the effect of virtual grounding is greater than that of intermittent oscillation.
Further, in each of the embodiments described above, the virtual grounding unit 30 has been described as having the conductor portion 75 that covers the periphery of the discharge electrode portion 70 (71 to 74), but an embodiment in which an insulator is used instead of the conductor may be used. . Thereby, the insulator part covering the periphery of the discharge electrode part 70 (71 to 74) prevents the positive electrode (73, 74) and the negative electrode (71, 72) from being exposed to the wind. (Or 1a) can reduce the fluctuation of the potential of the reference potential portion 80 due to the influence of the wind.

  In each of the above embodiments, the measurement circuit unit 25 or the voltage measurement unit 28 outputs a control signal that causes the alarm circuit unit 40 to output an alarm when the measured voltage of the overhead wire 2 is equal to or higher than a predetermined value. Although the form to output was demonstrated, the form which outputs a measured value to the alarm circuit part 40 may be sufficient. In this case, the alarm circuit unit 40 outputs an alarm when the measurement value supplied from the measurement circuit unit 25 or the voltage measurement unit 28 is equal to or greater than a predetermined value.

  Further, in each of the embodiments described above, the mode of measuring the voltage of the overhead line 2 that supplies power to the train as the measurement target has been described. However, as long as the DC voltage is measured, the configuration may be applied to other measurement targets. Good.

DESCRIPTION OF SYMBOLS 1, 1a DC voltage detector 2 Overhead wire 10 Lead-in electrode 11 Contact terminal 20, 20a Measurement part 21, 22 Chopper part 23 Detection electrode 24, 26, 27, 342 Resistance 25 Measurement circuit part 30 Virtual ground part 31, 41 DC power supply 32 344 Diode 33, 341 Capacitor 34 Oscillator circuit unit 35 Transformer unit 36, 44 Switch unit 40 Alarm circuit unit 42 Light emitting diode 43 Speaker 51 Test switch unit 52 Static elimination switch unit 61, 62 Resistance 70 Discharge electrode 71, 72 Negative electrode 73, 74 Positive electrode 75 Conductor portion 80 Reference potential portion 100 Negative boost rectifier circuit portion 200 Plus boost rectifier circuit portion 101, 102, 103, 104, 105 Capacitors 111, 112, 113, 114, 115 Diodes 201, 202, 203, 204, 05,206 capacitor 211,212,213,214,215,216 diode 343 bipolar transistor

Claims (10)

A measurement unit that measures the voltage of the measurement target by measuring the potential of the measurement target with reference to the potential of the reference potential unit,
A DC voltage obtained by boosting a voltage supplied from a DC power source with reference to the potential of the reference potential unit is applied to the discharge electrode unit to generate plus / minus ions, and the generated plus / minus ions are generated from the discharge electrode unit. A virtual grounding part for discharging, and
The discharge electrode part is
Equipped with multiple pairs of positive electrodes that release positive ions and negative electrodes that release negative ions,
The positive electrode and the negative electrode are:
The discharge electrode portion as a whole is arranged on the circumference when the wind blows from the outside toward the second electrode having a different polarity from the first electrode of the plus electrode and the minus electrode. In order to keep the balance between the ions and the negative ions, the positive electrodes or the negative electrodes among the electrodes that are adjacent to each other have an equal angle with respect to the center of the circle, and the positive electrodes and the negative ions. The DC voltage detector, wherein the electrodes are alternately arranged on the circumference. When it comes into contact with the measurement object, it has a lead-in electrode that has the same potential as the measurement object,
The measuring unit is
A chopper that vibrates the electric field radiated from the lead-in electrode;
A detection electrode that collects charges according to the electric field vibrated by the chopper,
A measurement circuit unit that measures the voltage of the measurement object based on a change in current flowing between the detection electrode and the reference potential unit;
The lead electrode is
It is arrange | positioned at the predetermined distance with the said chopper part or the said detection electrode. The DC voltage detector of Claim 1 characterized by the above-mentioned. 3. The direct current switch according to claim 2, further comprising: a static elimination switch unit that brings the drawing electrode and the reference potential unit into a conductive state so that the potential of the drawing electrode is equal to the reference potential unit. Voltage detector. An alarm output unit for outputting an alarm when a voltage equal to or higher than a predetermined value is measured by the measurement unit;
A test switch unit for outputting the alarm from the alarm output unit,
4. The DC voltage detector according to claim 3, wherein when the test switch unit outputs the alarm, the static elimination switch unit makes a conductive state between the lead-in electrode and the reference potential unit. 5. . The virtual grounding unit is
The DC voltage detector according to any one of claims 1 to 4, further comprising a conductor portion that covers the periphery of the discharge electrode portion. The discharge electrode part is
The DC voltage detector according to any one of claims 1 to 5, wherein when the DC voltage detector is used, the DC voltage detector is disposed to face the ground. The virtual grounding unit is
An oscillation circuit unit that generates a primary-side AC voltage that oscillates continuously or intermittently, using a voltage supplied from the DC power supply;
A primary side coil and a secondary side coil respectively connected to the reference potential unit; boosting the primary side AC voltage supplied to the primary side coil; A transformer that outputs an alternating voltage;
A positive boost rectifier circuit unit that applies positive rectification and boosting to the secondary side AC voltage, and that is applied to the positive electrode;
7. The direct current according to claim 1, further comprising: a negative step-up rectifier circuit unit that negatively rectifies and boosts the secondary AC voltage and applies the negative side rectified voltage to the negative electrode. Voltage detector. The DC voltage detector is
The DC voltage detector according to any one of claims 1 to 7, further comprising a grounding unit that grounds the reference potential unit. The measuring unit is
A first resistor and a second resistor connected in series between the measurement object and the reference potential unit;
From the voltage measurement part which measures the voltage of the said measuring object based on the voltage by which resistance division was carried out by the said 1st resistance and the said 2nd resistance, The above-mentioned from Claim 1 and Claim 5 characterized by the above-mentioned. The DC voltage detector according to claim 8. The DC discharger according to any one of claims 1 to 9, wherein the discharge electrode section includes two of the sets.

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