JP2012039796A - Insulation deterioration monitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulation deterioration monitor capable of automatically measuring insulation resistance of a generator, as well as realizing an automatic solution of abnormal insulation deterioration when it occurs in the generator.SOLUTION: An insulation deterioration monitor 1 measuring insulation resistance of a generator 5, as well as monitoring whether or not the insulation resistance is deteriorated comprises: an insulation resistance measuring device 16 for measuring the insulation resistance of the generator 5; a timer 31 for making the insulation resistance measuring device 16 measure the generator 5 at a prescribed time interval; an insulation resistance improvement means 19 for improving insulation resistance deterioration when an abnormality occurs due to insulation resistance deterioration in the generator 5; and a controlling unit 18 for controlling the insulation resistance measuring device 16, the timer 31, and the insulation resistance improvement means 19, as well as for actuating the proper insulation resistance improvement means 19 (19a, 19b) according to a degree of insulation resistance deterioration measured by the insulation resistance measuring device 16.

Description

  The present invention relates to an insulation decrease monitoring device for monitoring, for example, whether or not the insulation resistance of a generator has decreased.

  Conventionally, for example, while the generator is stopped, the insulation resistance of the generator is automatically measured, and when it falls below a predetermined threshold, it can be determined as abnormal and the result can be output. An insulation drop monitoring device (insulation resistance measurement device) is known (see Patent Document 1).

JP 2009-294090 A

  The conventional insulation degradation monitoring device can monitor the insulation degradation of the generator, but when an abnormality is detected, it only outputs the abnormality. From the viewpoint of automatic monitoring, If the response can be automatically performed, the workability can be further improved.

  The present invention has been made in view of the above circumstances, and it is possible to automatically measure the insulation resistance of a generator, and to monitor an insulation drop that can automatically eliminate this abnormality when an abnormal insulation drop occurs in the generator. It is an object to provide an apparatus.

  An object of the present invention is to solve the above-described problems, and in an insulation reduction monitoring device that measures the insulation resistance of a generator and monitors whether or not the insulation resistance is lowered, the insulation resistance of the generator Insulation resistance measuring instrument that measures current, a timer for causing the insulation resistance measuring instrument to measure the generator at a predetermined time interval, and to improve this decrease when an abnormality occurs due to a decrease in the insulation resistance of the generator Insulation resistance improvement means for controlling the insulation resistance measuring instrument, timer, and insulation resistance improvement means, and operating the insulation resistance improvement means suitable for the degree of decrease in insulation resistance measured by the insulation resistance measuring instrument And a control unit for controlling the operation.

  According to such a configuration, the insulation resistance measuring instrument can measure the presence or absence of the insulation decrease of the generator periodically by the timer, and further, by operating the insulation resistance improvement means by the control unit of the generator, It becomes possible to automatically perform from the detection of the abnormality of the generator to the subsequent response.

  In addition, the insulation deterioration monitoring device according to the present invention is configured such that the control unit can set a timer so as to shorten the time interval of measurement of the insulation resistance by the insulation resistance measuring instrument when the insulation resistance is lowered. It is desirable.

  According to such a configuration, when the insulation drop occurs, the control unit can be set so as to shorten the time interval of measurement by the timer, so that the time when the insulation resistance improvement means must be operated can be grasped more accurately. become able to.

  In the insulation deterioration monitoring device according to the present invention, it is preferable that the control unit is configured to be able to control a switch for connecting / disconnecting a ground wire provided in the generator.

  According to such a configuration, when measuring the insulation resistance of the generator using an insulation resistance measuring instrument, the control unit controls the switch so as to cut off the switch and cuts off the ground line, which is necessary for measuring the insulation resistance. Preparations can be made automatically.

  According to the present invention, the insulation resistance of the generator can be automatically measured, and when an abnormal insulation drop occurs in the generator, this abnormality can be automatically eliminated.

It is a whole figure of an insulation fall monitoring device. It is a block diagram which shows a control part. A timer setting table is shown. It is a fragmentary figure which shows other embodiment of an insulation fall monitoring apparatus, (a) is the top view, (b) is the side view.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  1 to 3 show an embodiment of an insulation deterioration monitoring device according to the present invention. As shown in FIG. 1, the insulation reduction monitoring device 1 monitors the presence or absence of a decrease in insulation resistance of a generator 5 having a rotor winding 2, a stator winding 3, a collector ring (slip ring) 4, and the like. At the same time, when the insulation resistance decreases, measures are taken to recover it.

  The generator 5 induces electric power in the stator winding 3 when the rotor winding 2 magnetized in the stator winding 3 configured in a cylindrical shape rotates. A part of the generator 5 is provided with a ground wire 6, and the ground wire 6 is provided with a ground wire switch 7 for connecting and disconnecting the ground wire 6.

  The insulation lowering monitoring device 1 includes a brush 11 that contacts the collector ring 4 of the generator 5, an initial excitation circuit 12 for initial excitation of the rotor winding 2, and a rotor winding 2 that rotates to rotate the stator winding. A transformer 13 for stepping down the voltage induced in the line 3, a rectifier 14 for rectifying the AC power generated from the transformer 13 into a DC, a field breaker 15 for cutting off the field power supplied to the rotor winding 2, Insulation resistance measuring device (generally referred to as “Megger”) 16 for measuring the insulation resistance, an insulation resistance measuring switch 17 for connecting / disconnecting a measurement terminal of the insulation resistance measuring device 16 to / from the brush 11, and an insulation resistance monitor A control unit 18 for performing various controls of the apparatus 1 and a plurality of insulation resistance improving means 19 (19a, 19) that improve the decrease in insulation resistance when the insulation resistance of the generator 5 decreases and an abnormality occurs. 19b) That.

  The brush 11 maintains contact with the collector ring 4 while the rotor winding 2 is rotating, and slides relative to the collector ring 4 by the rotation of the collector ring 4. Composed. The initial excitation circuit 12 is for applying a predetermined voltage to the rotor winding 2 via the brush 11 and the collector ring 4 when starting the power generation by the generator 5.

  The rectifier 14 rectifies the power supplied from the transformer 13 and supplies field power (current) from the brush 11 to the collector ring 4 through the field breaker 15 in an inoperative state (not cut off). Is for. The field breaker 15 is operated by a signal from the control unit 18 to break the field circuit when measuring the insulation resistance of the generator 5 by the insulation resistance measuring device 16.

  In the present embodiment, one blower 19 a and one electric heater 19 b are employed as the insulation resistance improving means 19. The number of these blowers 19 a and electric heaters 19 b is not limited to this, and is appropriately selected according to the scale and number of the generators 5. The blower 19 a and the electric heater 19 b are connected to the control unit 18, and a blower operation switch 21 is provided between the blower 19 a and the control unit 18. An electric heater operation switch 22 is provided between the electric heater 19 b and the control unit 18.

  As shown in FIG. 2, the control unit 18 performs a measurement timing of the insulation resistance measuring device 16 every predetermined time, and a timer 31 capable of setting this time interval and the power supplied to the brush 11. A power detection means 32 for detecting the power, a determination means 33 for determining a measurement result by the insulation resistance measuring device 16, a breaker drive unit 34 for generating power for driving the field breaker 15, and an insulation resistance A switch driving unit 35 for driving the measurement switch 17, a switch driving unit 36 for generating electric power for driving the ground line switch 7, and a switch driving unit 37 for driving the blower operating switch 21 , A switch drive unit 38 for driving the electric heater operation switch 22, a CPU 41 for controlling these and performing a predetermined calculation, and a program necessary for the control are stored It includes a ROM 42, and a RAM43 which operates as a working memory.

  The control unit 18 can recognize whether the generator 5 is operating or stopped, and when it is stopped, operates the insulation resistance measuring device 16 to measure the insulation resistance of the generator 5. Further, the control unit 18 can appropriately change the setting of the timer 31 in accordance with the measurement result by the insulation resistance measuring device 16 and determine the timing of the subsequent measurement. Moreover, the control part 18 operates the insulation resistance improvement means 19 when the insulation resistance of the generator 5 is falling.

  Hereinafter, the control method of the insulation deterioration monitoring apparatus 1 by this control part 18 is demonstrated concretely.

  The control unit 18 can recognize whether or not the generator 5 is in operation by detecting the presence or absence of power supplied to the brush 11 by the CPU 41 and the power detection unit 32. When the electric power detection means 32 detects the electric power of the brush 11, it turns out that the generator 5 is driving | running and when electric power is not detected, the generator 5 has stopped.

  When the generator 5 is in operation, the ground wire switch 7 is on, and the ground wire 6 is in a state where the generator 5 is grounded. Further, when the generator 5 is in operation, the field breaker 15 is in an inoperative state (a state where the circuit is not cut off). Further, when the generator 5 is in operation, the insulation resistance measurement switch 17, the blower switch 21, and the electric heater switch 22 are turned off.

  When the control unit 18 recognizes that the power generator 5 is stopped by the power detection means 32, the control unit 18 transmits a signal to the field breaker 15 via the breaker driving unit 34 to activate the field breaker 15. To interrupt the field circuit. Further, the control unit 18 activates (turns off) the ground line switch 7 via the switch driving unit 36 to cut off the grounding of the grounding line 6.

  Further, the control unit 18 operates (ON) the insulation resistance measuring switch 17 via the CPU 41 and the switch driving unit 35 to connect the insulation resistance measuring device 16 to the brush 11 and the generator 5.

  In this state, the control unit 18 transmits a control signal to the insulation resistance measuring device 16, and upon receiving this signal, the insulation resistance measuring device 16 generates a predetermined measurement voltage and measures the insulation resistance of the generator 5. To do. Thereafter, the insulation resistance measuring instrument 16 transmits the measurement result (measurement value of the insulation resistance) to the control unit 18.

The control unit 18 determines whether or not the measurement result of the insulation resistance measuring device 16 is normal via the determination unit 33 and sets the time interval of the timer 31 according to the determination result. Specifically, a timer setting table is stored in the ROM 42 as shown in FIG. A threshold value (hereinafter referred to as “management value”) R of a plurality of resistance values is set as a criterion for measuring resistance. In the present embodiment, a case where three management values (hereinafter, referred to as a first management value, a second management value, and a third management value) R _{1 to} R ₃ are set is illustrated. The values of the management values R _{1 to} R ₃ are set in a relationship of R ₁ > R ₂ > R ₃ . The control unit 18 sets a timer time T (T _{1 to} T ₃ ) corresponding to a predetermined management value R (R _{1 to} R ₃ ) via the timer setting table in the ROM 42, the RAM 43, and the determination unit 33. Can do.

The management value R is not limited to the three cases of the first management value R _{1 to} the third management value R ₃ , and four or more management values R _{1 to} R _N (N is a positive integer). Can be set.

In the timer setting table, three timer times (hereinafter referred to as a first timer time, a second timer time, and a third timer time) T _{1 to} T ₃ are associated with the management values R _{1 to} R ₃ , respectively. Is set. The values of the timer times T _{1 to} T ₃ are set in a relationship of T ₁ > T ₂ > T ₃ (for example, T1: 60 minutes, T2: 30 minutes, T3: 10 minutes).

The control unit 18 determines whether or not the measured value (resistance) measured by the insulation resistance measuring instrument 16 is equal to or higher than the first management value R ₁ (for example, 100 MΩ). If the measurement results of insulation resistance meter 16 is first management value R ₁ or more, the control unit 18, together with the insulating state of the power generator 5 is determined to be normal, the first timer period subsequent measurement as performed by T _1, the setting of the timer 31.

The control unit 18 controls the insulation resistance measuring device 16 to measure the insulation resistance of the generator 5 when the timer 31 reaches the first timer time T ₁ via the CPU 41. As long as the measured value of the insulation resistance is equal to or greater than the first management value R ₁ , the control unit 18 sets the timer 31 to the first timer time T ₁ and uses the first timer time T ₁ as a reference. Repeat the measurement.

If the measurement of the insulation resistance of the generator 5 by the insulation resistance measuring instrument 16 is first less than the control value R _1, the control unit 18, whether the measurement value is a second management value R ₂ above, The determination is made via the determination means 33. When the measured value is equal to or greater than the second management value R ₂ , the control unit 18 sets the timer 31 to the second timer time T ₂ , determines that this state is abnormal, and sets the switch drive unit 37 and A control signal is transmitted to the blower 19a as the insulation resistance improving means 19 through the blower switch 21 to operate it.

When the timer 31 reaches the second timer time T ₂ , the control unit 18 activates the insulation resistance measuring device 16 again and measures the insulation resistance of the generator 5. At this time, the control unit 18 determines whether the measurement value is equal to or greater than the first management value R ₁ by the determination unit 33. If the measured value is the first management value R ₁ or more, the control unit 18, the insulation resistance improved means 19 (blower 19a), determines that the insulation resistance has returned to normal, the switch driver 37, switch blower The blower 19 a is stopped via 21.

Further, the control unit 18 sets the timer 31 to the first timer time T ₁ via the CPU 41 and continues the subsequent measurement based on the first timer time T ₁ . On the other hand, when the measured value is less than the first management value R ₁ , the control unit 18 determines whether or not the measured value is greater than or equal to the second management value R ₂ via the determination unit 33. When the measured value is equal to or greater than the second management value R ₂ , the control unit 18 continues to operate the blower 19a that has already been operated, and keeps the timer 31 at the second timer time T _2. a second reference timer time T _2, performing the subsequent measurement.

Also, if the measured value is less than the second management value R2, the control unit 18 determines the measured value whether a third control value R ₃ above, through the determination unit 33. When the measured value is equal to or greater than the third measurement R ₃ , the control unit 18 determines that the insulation state of the generator 5 is further deteriorated, and performs insulation via the switch drive unit 38 and the electric heater switch 22. The electric heater 19b as the resistance improvement means 19 is operated. Thereby, it will be in the state in which both the air blower 19a as the insulation resistance improvement means 19 and the electric heater 19b are act | operating.

Further, the control unit 18 takes the above measures, sets the timer 31 to the third timer time T ₃ , and performs subsequent measurements based on the third timer time T ₃ .

Further, when the measured value is less than the third management value R ₃ , the control unit 18 controls the determination unit 33 so that an alarm device as an external device disposed in the management center or the like issues an alarm. Send a signal.

As described above, the control unit 18 appropriately changes the timer time T (T _{1 to} T ₃ ) according to the degree of decrease in the insulation resistance of the generator 5, while measuring the measured value and the management value R (first management value). Repeat comparison of R ₁ ~ third management value R _3), depending on the degree of reduced insulation, insulation resistance improved means 19 (blower 19a suitable for improving this, electric heater 19b) selected by the operation To make it happen.

  When the generator 5 is started again, the control unit turns on the ground wire switch 7 and turns off the insulation resistance measurement switch 17 via the switch driving units 35 to 38, and further for the blower. The switch 21 and the electric heater switch 22 are turned off. Further, the control unit 18 puts the field breaker 15 into an inoperative state (break-off release state) via the breaker drive unit 35.

  According to the insulation lowering monitoring apparatus described above, while the generator 5 is stopped, the insulation resistance of the generator 5 is automatically monitored periodically to determine whether or not the insulation resistance is lowered. In this case, the insulation resistance improving means 19 (19a, 19b) suitable for improvement can be automatically operated in accordance with the degree of the decrease.

Furthermore, the insulation degradation monitoring device reduces the insulation resistance of the generator 5 by shortening the corresponding timer time T (T _{1 to} T ₃ ) as each control value R (R _{1 to} R ₃ ) becomes smaller. Accordingly, the monitoring interval is shortened to detect an abnormal state at an early stage, and the insulation resistance improving means 19 (19a, 19b) can be operated at an appropriate timing accordingly. .

  In addition, since the control unit 18 can automatically connect / cut off the grounding wire 6, preparations necessary for measuring the insulation resistance can be automatically made. The insulation resistance monitoring apparatus 1 further improves workability. Will be good.

  In addition, this invention is not restricted to said embodiment, A various change and deformation | transformation are possible.

  In the above embodiment, the brush 11 is always in contact with the slip ring, and when the generator 5 is stopped, the insulation resistance measuring switch 17 is activated and the measurement by the insulation resistance measuring device 16 is performed. Although shown, it is not limited to this. For example, by applying a pantograph, an extendable member such as a cylinder may be connected to the brush 11, and the brush 11 may be moved forward and backward to perform contact / release of contact with the collector ring 4.

  As a further modification, as shown in FIG. 4, for example, a rotation member 54 having a contact 53 is provided at the tip of a rotation shaft 52 that is rotatable by the motor 51, and the motor 51 is controlled by the control unit 18. By controlling, the contact 53 may be brought into contact with or released from the collector ring 4.

  The rotating shaft 52 is provided with two cams (hereinafter, one is referred to as “first cam” and the other is referred to as “second cam”) 56, 57, and two cams corresponding to the respective cams 56, 57 are provided. Limit switches (hereinafter, those corresponding to the first cam 56 are referred to as “first limit switch”, and those corresponding to the second cam 57 are referred to as “second limit switch”) 58 and 59 are provided in contact with each other. The first cam 56 and the first limit switch 58 are related so that the first limit switch 58 is activated when the contact 53 contacts the collector ring 4.

  The second cam 57 and the second limit switch 59 are related so that the second limit switch 59 operates when the contactor 53 is at a predetermined standby position away from the collector ring 4. In a state where the generator 5 is stopped, the control unit 18 rotates the rotation shaft 52 to one side in the rotation direction via the motor 51 to bring the contactor 53 into contact with the collector ring 4. When the contactor 53 comes into contact with the collector ring 4, the first limit switch 58 corresponding to the first cam 56 is activated, and this is detected by the control unit 18 to stop the motor 51. In this state, the control unit 18 can transmit a control signal to the insulation resistance measuring device 16 to measure the insulation resistance of the generator 5.

  When the generator 5 is activated, the control unit 18 detects this, and transmits a control signal to the motor 51 in order to separate the contact 53 of the rotating member 52 from the collector ring 4. By driving the motor 51, the rotation shaft 52 is rotated to the other side in the rotation direction, and the rotation member 54 is rotated so that the contact 53 is separated from the collector ring 4. When the rotation member 54 continues to rotate and reaches a predetermined standby position, the second limit switch 59 corresponding to the second cam 57 is activated. In this case, with the generator 5 stopped, the contact 53 is brought into contact with the collector ring 4, and the insulation resistance measuring device 16 connected to the contact 53 is used to measure the insulation resistance of the generator 5. be able to.

  In addition, a brake or the like for braking the rotation of the rotor winding 2 of the generator 5 can be used for the insulation lowering monitoring device 1. In this case, a contact is provided on the braking member of the brake that contacts a predetermined part of the rotor winding 2, the generator 5 is stopped, and the braking member contacts the rotor winding 2 for braking. At the same time, the contact resistance may be brought into contact with the rotor winding 2 and the insulation resistance measuring instrument 16 may measure the insulation resistance of the generator 5.

  DESCRIPTION OF SYMBOLS 1 ... Insulation fall monitoring device, 2 ... Rotor winding, 3 ... Stator winding, 4 ... Collector ring, 5 ... Generator, 6 ... Ground wire, 7 ... Ground wire switch, 11 ... Brush, 12 ... Initial Excitation circuit, 13 ... transformer, 14 ... rectifier, 15 ... field breaker, 16 ... insulation resistance measuring device (Megger), 17 ... insulation resistance measuring switch, 18 ... control section, 19 ... insulation resistance improving means, 19a ... Blower, 19b ... electric heater, 21 ... switch for blower, 22 ... switch for electric heater, 31 ... timer, 32 ... power detection means, 33 ... determination means, 34 ... breaker drive unit, 35 ... switch drive unit, 36 ... switch Drive unit 37 ... Switch drive unit 38 ... Switch drive unit 41 ... CPU 42 ... ROM 43 ... RAM 51 ... Motor 52 ... Rotation shaft 53 ... Contact 54 ... Rotation member 56 ... 1st cam, 57 ... 2nd Arm, 58 ... first limit switch, 59 ... the second limit switch

Claims (3)

In the insulation drop monitoring device that measures the insulation resistance of the generator and monitors whether this insulation resistance is lowered,
When an abnormality occurs due to a decrease in the insulation resistance of the generator, an insulation resistance measuring instrument for measuring the insulation resistance of the generator, a timer for causing the insulation resistance measuring instrument to measure the generator at a predetermined time interval, Insulation resistance improvement means for improving this drop, insulation resistance measuring instrument, timer, and insulation resistance improving means are controlled, and insulation suitable for the degree of reduction in insulation resistance measured by the insulation resistance measuring instrument And a controller for operating the resistance improving means.   The insulation lowering monitoring apparatus according to claim 1, wherein the control unit is configured to be able to set a timer so as to shorten a time interval of measurement of the insulation resistance by the insulation resistance measuring instrument when the insulation resistance is lowered.   The insulation lowering monitoring apparatus according to claim 1, wherein the control unit is configured to be able to control a switch that connects and disconnects a ground line provided in the generator.

Images