JP7189118B2 - Anomaly detector - Google Patents

Description

The present invention relates to an abnormality detection device for a brush lifting device of a wound-rotor induction motor.

A wound-rotor induction motor has a configuration in which a starting resistor is inserted between collector electrodes of three phases by a brush in order to suppress a starting current. When the rotation speed of the rotor increases to near the rated speed, the resistance value of the starting resistor becomes zero. Lift and separate the brush from the collector electrode to prevent brush wear.

Japanese Patent Laying-Open No. 57-170045 (Patent Document 1) discloses an example of a brush lifting device for a wound-rotor induction motor having such a configuration.

JP-A-57-170045

The brush pulling device as described above has a movable part that turns electrical connection on and off by means of a mechanical structure, such as pulling up and pulling down the brush, inserting a short-circuiting collar (female) into the collector electrode, and tripping. Such movable parts undergo aging or deterioration due to deterioration of lubricating grease, misalignment of the insertion position between the collector electrode (male) and the short-circuit collar (female), and the like.

Aging or deterioration may cause the moving parts to become stationary and damage the brush hoist. In such a case, the plant will be stopped and its restoration, etc., will cause great damage. Therefore, it is preferable to check the proper operation of the brush lifting device before damage occurs.

However, the moving part of the brush lifting device has a complicated structure, and it is difficult to visually check it from an inspection door or the like. Therefore, it is necessary to open the brush lifting device and disassemble it for inspection. It was labor intensive and costly.

The present invention was made to solve the above problems, and by detecting aging or deterioration without overhauling the brush lifting device, it is also possible to prevent serious damage to the moving parts of the machine. It is an object of the present invention to provide an anomaly detection device that becomes

The present disclosure relates to an abnormality detection device for a brush pulling device of a wound-rotor induction motor. The brush lifting device includes a short-circuiting collar for short-circuiting the collector electrodes of the wound induction motor, a switching mechanism for switching between the contact state and the separated state between the collector electrode and the brush, and an operating motor for operating the switching mechanism. and The abnormality detection device includes a sensor that detects an electrical parameter of the operating motor, a storage section that stores a basic waveform of the electrical parameter, and a determination of the electrical parameter detected by the sensor based on the basic waveform read from the storage section. , and a diagnosis unit for diagnosing an abnormality of the brush lifting device.

Since the abnormality detection device of the present disclosure determines the presence or absence of abnormality based on the current of the operating motor, the user can save the trouble of disassembling and inspecting the brush lifting device.

It is a figure which shows the structure of a main motor and a brush pulling-up apparatus. It is a schematic diagram showing the circuit configuration of the brush lifting device and the abnormality detection device. FIG. 11 shows the shorting collar and brush position of the brush hoist during traction motor off and on; FIG. 11 shows the shorting collar and brush position of the brush hoist at completion of traction motor start-up and during operation; FIG. 10 is a diagram showing a current waveform of the operating motor of the brush lifting device after the completion of starting the main motor; FIG. 10 is a diagram showing a current waveform of the operating motor of the brush lifting device when the main motor starts to stop; 4 is a flowchart for explaining abnormality detection processing of the brush lifting device according to Embodiment 1. FIG. 9 is a flow chart for explaining abnormality detection processing of the brush lifting device according to Embodiment 2. FIG. 10 is a flowchart for explaining abnormality detection processing of the brush lifting device according to Embodiment 3. FIG. FIG. 4 is a schematic diagram for explaining the position of a brake attached to an operating motor of the brush lifting device; FIG. 7 is a diagram showing the difference in change in residual voltage of the power supply of the operating motor between normal and abnormal braking. 14 is a flow chart for explaining abnormality detection processing of the brush lifting device according to Embodiment 4. FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings below, the same reference numbers are given to the same or corresponding parts, and the description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a diagram showing the configuration of a main motor and a brush lifting device. FIG. 2 is a schematic diagram showing the circuit configuration of the brush lifting device and the abnormality detection device.

1 and 2, main motor M1 is a wound-rotor induction motor and includes a stator ST and a rotor RT. Stator ST includes three-phase stator coils LU1, LV1, and LW1. Stator coils LU1, LV1, and LW1 are supplied with a three-phase AC current from a three-phase AC power supply 120 via a circuit breaker SW1.

Rotor RT includes rotor coils LU2, LV2, LW3 in which electromotive forces are induced by rotating magnetic fields from stator coils LU1, LV1, LW1. A brush lifting device 100 comprising collector electrodes CU, CV, CW, brushes BU, BV, BW, a short-circuit collar 40, a link mechanism LK, an operating motor M2, etc. is connected to the rotor coil.

Resistors RU, RV, and RW are connected to the brushes BU, BV, and BW to limit the current at startup. A control device 10 for supplying power is separately attached to the operating motor M2. Control device 10 includes contactor SW<b>2 and abnormality detection device 1 . The abnormality detection device 1 includes a current transformer 30, a voltage sensor 31, a contactor SW2, a transducer 20, a diagnostic circuit 15, and the like.

The operating motor M2 is an induction motor that drives the link mechanism LK of the brush lifting device 100. As shown in FIG. The operating motor M2 is supplied with power from the AC power supply 110 via the contactor SW2. Current transformer 30 detects the current of operating motor M<b>2 supplied from AC power supply 110 . Transducer 20 converts detection signal i of current transformer 30 into a signal suitable for diagnostic circuit 15 . A voltage sensor 31 detects the terminal voltage of the operating motor M2 and inputs it to the diagnostic circuit 15 . Diagnostic circuitry 15 is configured to store current data, determine aging or deterioration of the brush hoist, and the like. Further, the contactor SW2 includes a phase sequence switching circuit for switching the rotation direction of the operating motor M2 between forward rotation and reverse rotation. The link mechanism LK is provided with a limit switch (not shown) so that the operating motor M2 does not rotate forward or backward more than necessary.

A programmable controller, a personal computer, a microcomputer, or the like can be used as the diagnostic circuit 15 . The diagnostic circuit 15 includes a CPU (Central Processing Unit) 11 and a memory 12 . The memory 12 stores programs executed by the CPU 11 and data used. The CPU 11 performs an abnormality detection operation, which will be described later, and also controls the circuit breaker SW1 and the contactor SW2. The CPU 11 is an example of a diagnostic section, and the memory 12 is an example of a storage section.

Further, the diagnosis circuit 15 may output a signal for notifying alarm, trip, and maintenance timing to an alarm device 130 configured by a host DCS (Distributed Control System) or the like. In FIG. 2, a contact signal is illustrated, but this signal may be a communication signal as well as a contact signal.

FIG. 3 shows the shorting collar and brush position of the brush hoist during traction motor off and on. FIG. 4 is a diagram showing the shorted collar and brush position of the brush hoist after completion of traction motor start-up and during operation. Although the collector ring is actually divided into collector electrodes CU, CV, and CW for three phases as shown in FIG. 1, in FIGS. , CW are shown together.

A supplementary explanation will be given as to what kind of motor the main motor M1 having the brush pulling device 100 is. Traction motor M1 with brush hoisting device 100 is a three-phase induction motor with a wound rotor as rotor RT. The main motor M1, as shown in FIG. 3, contacts and slides the brushes BU, BV, BW and the collector electrodes CU, CV, CW at the time of starting, and connects the starting resistors RU, RV, RW to the rotor coil. do. This makes it possible to suppress the starting current and control the starting torque. The starting resistors RU, RV, and RW decrease in resistance as the rotation speed of the rotary shaft of the main motor M1 increases, and are set to zero when starting is completed.

After completion of start-up, as shown in FIG. insert into As a result, the ends of the rotor coils LU2, LV2, LW3 of the rotor are short-circuited, after which the brushes BU, BV, BW are pulled up to disconnect the starting resistors RU, RV, RW. As a result, the main motor M1 becomes the same as a normal squirrel cage induction motor.

FIG. 5 is a diagram showing a current waveform of the operation electric motor M2 from the start position of the brush lifting device to the brush lifting completion position after the completion of starting of the main motor. In FIG. 5, the operating electric motor M2 is energized at time t1 when the contactor SW2 is turned on, and an inrush current that sharply increases and decreases as the current iB until time t2 flows for a very short time (period T0). Stabilize. Then, it momentarily increases at time t3 when the terminal at the end of the collector ring is inserted into the short-circuit collar 40, and stabilizes again from time t3 to t4. Then, it momentarily increases at time t4 when the brush is pulled up from the collector ring, and stabilizes again from time t4 to t5. At time t5, the operation of the brush lifting device is completed and the current i becomes zero by opening the contactor SW2.

The operation time is, but not limited to, for example T0<1 (seconds), T1=7 (seconds), T2=2 (seconds), T3=1 (seconds).

FIG. 6 is a diagram showing a current waveform of the operation electric motor M2 from the brush lifting completion position to the start position of the brush lifting device when the main motor starts to stop. When stopped, the operation motor M2 is rotated in the opposite direction to that when started to move the brushes and the short-circuit collar in the opposite direction.

In FIG. 6, the operating motor M2 is energized at time t11 when the contactor SW2 is turned on, and an inrush current that sharply increases and decreases as the current iB until time t12 flows for a very short time (period T0). Stabilize. Then, it momentarily increases at time t13 when the brush comes into contact with the collector ring, and stabilizes again from time t13 to t14. Then, it momentarily increases at time t14 when the short-circuiting collar 40 is pulled out from the end terminal of the collector ring, and stabilizes again at time t14-t15. At time t15, the operation of the brush lifting device is completed and the current i becomes zero by opening the contactor SW2.

Excluding the period T0 during which the inrush current flows, the operation electric motor M2 for the brush lifting device drives the brush lifting device from the starting position to the brush lifting completion position, or in reverse operation from the brush lifting completion position to the starting position. If there is no abnormality due to aging, deterioration, etc., the current of the operating motor M2 at the same time has substantially the same value. This fact is used for anomaly detection. However, as shown in FIGS. 5 and 6, even if the brush lifting device is normal, the current of the operating motor M2 is not constant, and fluctuates during start-up and stop. For example, in the case of FIG. 5, current peaks occur at the time (t3) when the shorting collar 40 is connected to the collector terminal and at the time (t4) when the brushes BU, BV, BW are separated from the collector rings CU, CV, CW. Therefore, the current judgment value cannot be fixed at a constant value. Also, the inrush current changes depending on the input phase of the contactor SW2 with respect to the AC power supply 110 .

For this reason, the current data (time-current data) that changes with the time from when the contactor SW2 of the operating motor M2 for the brush lifting device in the above operation is turned on to when it is released is collected in a test at the time of shipment and used as basic data. , is stored in the memory 12 of the diagnostic circuit 15 in advance. The CPU 11 of the diagnostic circuit 15 compares the basic data with the time-current data of the operating motor M2 detected by the current transformer 30 during use after shipment, except for the period T0 of the inrush current. The period T0 of the inrush current can be obtained from the current waveform in the test before shipment.

If the brush pulling device 100 changes over time or deteriorates, the current of the operating motor M2 at the same time will increase from the basic data. For example, the current of the operation motor M2 increases due to the torque increase of the operation motor M2 when the short-circuit collar moves due to rust on the rotating shaft MS, rust on the gears of the link mechanism LK, and the like.

The diagnostic circuit 15 determines an abnormality such as aging or deterioration of the brush pulling device 100 by detecting an increase in the current of the operating motor M2. The diagnostic circuit 15 compares the increase in the current of the operating motor M2 with a time-varying threshold based on basic data. For example, ith1 and ith2 indicated by dashed lines in FIGS. 5 and 6 are thresholds that change with time.

If it is not necessary to immediately stop the brush lifting device 100, the diagnostic circuit 15 causes the alarm device 130 to output an alarm such as a warning lamp early. is 1.1 times the second threshold ith2. When the current of the operating motor M2 exceeds the second threshold value, an alarm is output to notify the user, so that early maintenance of the brush lifting device can be performed and damage can be prevented.

The output of the trip command for interrupting the power supply currents of the main motor M1 and the operating motor M2 is determined by a first threshold value ith1 larger than the second threshold value ith2. When the current of the operating motor M2 exceeds the first threshold value, the diagnostic circuit 15 cuts off the power supply current of the operating motor M2 and outputs a trip command to cut off the power of the main motor M1. For example, the first threshold ith1 is assumed to be a current value 1.4 times the current data collected at the time of shipment. By interrupting the power supply current of the operating motor M2 and immediately stopping the brush lifting device 100, it is possible to minimize the spread of the abnormality of the brush lifting device. Further, by shutting off the power supply of the main motor M1, it is possible to prevent current from continuously flowing through the brushes. It should be noted that the first threshold value ith1 may be the rated current of the operation electric motor M2 that makes it possible to prevent damage to the mechanical mechanism of the brush lifting device. Also, the set values of the first threshold value ith1 and the second threshold value ith2 should be changed in accordance with the conditions of the actual machine.

FIG. 7 is a flowchart for explaining abnormality detection processing of the brush lifting device according to the first embodiment. First, in step S1, the main motor M1 reaches a predetermined number of revolutions and a start switch (not shown) is turned on, or the breaker SW1 is released to stop the main motor and the stop switch is turned on. Alternatively, it determines whether or not a stop command has been received. If no command has been received (NO in S1), the diagnostic circuit 15 executes the process of step S1 again and waits for a command.

If the command has been received (YES in S1), the diagnostic circuit 15 determines in step S2 whether or not the inrush current period (T0 in FIGS. 5 and 6) has elapsed. While the inrush current period has not elapsed (NO in S2), the diagnostic circuit 15 waits for a time so as not to use the measured current value iB for abnormality determination.

If the inrush current period has passed (YES in S2), the diagnostic circuit 15 reads from the memory 12 basic current data corresponding to the elapsed time from the timing of receiving the start or stop command in step S3. Here, when the start switch is on, the current waveform pattern of the operating motor M2 from the start position of the brush lifting device to the brush lifting completion position after the completion of starting of the main motor M1 as shown in FIG. 5 is read. When the stop switch is on, the current waveform pattern of the operating motor M2 from the brush lifting completion position to the start position of the brush lifting device when the main motor M1 starts to stop is read. Then, in step S4, the diagnostic circuit 15 determines the first threshold ith1 and the second threshold ith2. For example, the second threshold ith2 can be set to a value 1.1 times the basic current data, and the first threshold ith1 can be set to a value 1.4 times the basic current data. Note that the first threshold ith1 may be a fixed value such as a rated current.

Note that it is conceivable that the power supply voltage of the operating motor M2 fluctuates. In such a case, when determining the threshold value in step S4, the terminal voltage of the operating motor M2 detected by the voltage sensor 31 is used to monitor the difference from the standard voltage when the basic current data is acquired. do. If there is a voltage difference, the diagnostic circuit 15 may determine the first threshold value ith1 and the second threshold value ith2 by correcting the current increase corresponding to the voltage increase.

Subsequently, in step S5, the diagnostic circuit 15 determines whether or not the current value i measured by the current transformer 30 is greater than the first threshold ith1.

When the current value i is greater than the first threshold value ith1 (YES in S5), in step S6, the diagnostic circuit 15 performs trip processing, i.e., cuts off the power supply to the main electric motor M1 and the operation electric motor M2 at the same time. A cutoff signal is transmitted to the circuit breaker SW1 and the contactor SW2 so as to do so. As a result, the apparatus can be stopped before the main electric motor M1 and the operation electric motor M2 are seriously damaged.

If the current value i is less than or equal to the first threshold value ith1 (NO in S5), in step S7, the diagnostic circuit 15 determines that the current value i measured by the current transformer 30 is greater than the second threshold value ith2. determine whether is greater than

If the current value i is greater than the second threshold value ith2 (YES in S7), in step S8, the diagnostic circuit 15 detects an alarm such as a warning lamp of the alarm device 130 indicating that the torque for moving the link mechanism LK is not sufficient. Warn the user that it's getting a little bigger. On the other hand, if current value i is less than or equal to second threshold value ith2 (NO in S7), diagnostic circuit 15 does not issue a warning in step S8.

Then, in step S9, the diagnostic circuit 15 determines whether or not the elapsed time from the timing at which the command to start or stop is received is longer than the determination time, which is the operation time of the operating electric motor M2. If the elapsed time is equal to or less than the determination time (NO in S9), the diagnostic circuit 15 returns the process to step S3 again to continue monitoring the current. If the elapsed time is longer than the determination time (YES in S9), the diagnostic circuit 15 terminates current monitoring.

As described above, the abnormality detection device of Embodiment 1 determines whether or not there is an abnormality based on the current of the operating motor M2, so that the user can save the trouble of disassembling and inspecting the brush lifting device. can.

In step S5, etc., when the current value i measured by the current transformer 30 is compared with the threshold value, by accumulating the data of the current, it is possible to manage the tendency of abnormality occurrence, and the maintenance timing can be improved. Also, it becomes possible to plan the replacement timing according to the period suitable for the actual machine. For example, even if the measured current value i does not reach the first threshold value, the accumulated current value i is statistically processed to find the rate of change over time, predict when it will reach a predetermined value, and make a maintenance plan. becomes possible.

[Embodiment 2]
When the frequency of the power supply voltage fluctuates, the rotation speed of the operating motor M2 may fluctuate accordingly. In the second embodiment, the timing for referring to the basic current data is corrected based on the frequency fluctuation of the power supply voltage.

FIG. 8 is a flowchart for explaining abnormality detection processing of the brush lifting device according to the second embodiment. In the flowchart of FIG. 8, processing of steps S11 and S12 is added between steps S2 and S3 in the flowchart of the abnormality detection processing of the first embodiment shown in FIG. Other parts have already been explained with reference to FIG. 7, so the explanation will not be repeated here.

In FIG. 8, after the inrush current period of step S2 has passed, the diagnostic circuit 15 acquires the frequency of the AC power supply 110 from a frequency detection device (not shown) in step S11. When the power supply frequency drops, the rotational speed of the operating electric motor M2 slows down. Conversely, when the power supply frequency increases, the rotational speed of the operating motor M2 increases. Therefore, the times of the first threshold ith1 and the second threshold ith2 shown in FIGS. 5 and 6 are shifted.

Therefore, the diagnosis circuit 15 calculates the elapsed time after correcting the frequency deviation in step S12. For example, if the power supply frequency has increased by 1.1 times, the diagnosis circuit 15 multiplies the current elapsed time by 1/1.1 to calculate the corrected elapsed time in step S12, and calculates the corrected elapsed time in step S3. , the first threshold ith1 and the second threshold ith2 corresponding to this elapsed time are read from the memory 12 and used.

By doing so, even when the power supply frequency fluctuates, it is possible to apply an appropriate threshold value and perform correct abnormality determination.

[Embodiment 3]
In Embodiment 1, it was necessary to record the basic current data at the time of starting and at the time of stopping. However, the movement of the link mechanism LK at the time of start and the movement of the link mechanism LK at the time of stop are opposite, and the rotation of the operating motor M2 is also reverse rotation. As can be seen from FIGS. 5 and 6, if the rotation frequency of the operating motor M2 is the same, there is a correlation between the current waveforms at the start and at the stop. Therefore, it is possible that the basic current data at startup can also be used at shutdown.

FIG. 9 is a flowchart for explaining abnormality detection processing of the brush lifting device according to the third embodiment. The flowchart of FIG. 9 has steps S21 and S22 added between steps S2 and S3 in the flowchart of the abnormality detection process of the first embodiment shown in FIG. Other parts have already been explained with reference to FIG. 7, so the explanation will not be repeated here.

In FIG. 9, after the inrush current period of step S2 has elapsed, the diagnostic circuit 15 checks in step S21 whether the rotation direction of the operating motor M2 is forward rotation (when starting) or reverse rotation (when stopping). is determined by which of the contactors SW2 is selected.

In step S21, if the direction of rotation is forward (at startup), the diagnostic circuit 15 determines the threshold using the basic current data corresponding to the elapsed time. On the other hand, in step S21, if the direction of rotation is reverse (when stopped), the diagnosis circuit 15 converts the current elapsed time to that for reverse rotation in step S22.

That is, in FIG. 5, if the basic current data iB from time t2 to t5 are stored in the memory 12, the data should be read from time t5 to time t2 during reverse rotation. For this reason, for example, if the elapsed time after conversion is tx and the elapsed time before conversion is t, then tx=t5−t, the basic current data iB in FIG. 5 is replaced with the basic current data in FIG. can be used. Then, the diagnostic circuit 15 reads the basic current data at the converted time and determines the threshold based on this.

By doing so, it is possible to save the labor and storage capacity of recording the basic current data.

[Embodiment 4]
In the fourth embodiment, detection of an abnormality in the brake added to the operating electric motor M2 of the brush lifting device will be described. The abnormality detection process shown in the fourth embodiment may be executed in combination with the abnormality detection processes shown in the first to third embodiments.

FIG. 10 is a schematic diagram for explaining the position of the brake attached to the operating motor M2 of the brush lifting device. The brake BK is provided to stop the rotating shaft of the operating electric motor M2 in a fixed state. For example, the brake BK is configured such that the brake is released by a solenoid while the operating electric motor M2 is energized, and the solenoid is turned off when the energization of the operating electric motor M2 is cut off, so that the brake is effective. The brake BK can prevent the rotating shaft of the operating motor from rotating while the operating motor is powered off after the completion of starting or after the completion of stopping.

FIG. 11 is a diagram showing the difference in change in the residual voltage of the power supply of the operating motor M2 between normal and abnormal braking. In normal operation, when the contactor SW2 is turned off, the rotation speed of the rotating shaft of the operation electric motor M2 decreases, and the residual voltage, which is the terminal voltage of the operation electric motor M2, also decreases. The terminal voltage data (time-voltage data) of the operating motor M2, which changes with time after the contactor SW2 is released, is collected in a test at the time of shipment, and stored in the memory 12 as the basic data as the waveform of the residual voltage at normal times as the basic voltage. Keep When the brake is abnormal, the reduction in the rotation speed of the operating electric motor M2 is delayed compared to when it is normal. Therefore, as with the basic current data in the first embodiment, it is possible to determine whether or not there is an abnormality in the brake by comparing it with the basic voltage corresponding to the elapsed time since the contactor SW2 was turned off.

FIG. 12 is a flow chart for explaining abnormality detection processing of the brush lifting device according to the fourth embodiment. 1 and 12, in step S101, diagnostic circuit 15 determines whether contactor SW2 is turned off.

When the contactor SW2 is turned off (YES in S101), the diagnostic circuit 15 starts measuring the elapsed time from that point. Then, in step S102, the basic voltage data is read out from the memory 12. FIG.

Subsequently, in step S103, it is determined whether or not the voltage difference between the residual voltage V measured by the voltage sensor 31 and the voltage corresponding to the elapsed time read from the basic voltage data is greater than a threshold value.

If the voltage difference is equal to or less than the threshold value (NO in S103), it is determined in step S104 whether or not the elapsed time is longer than a predetermined determination time. If the elapsed time is within the determination time (NO in S104), the diagnostic circuit 15 returns to step S102 and continues monitoring the residual voltage V. FIG.

If the voltage difference is greater than the threshold value (YES in S103), in step S105, alarm device 130 or the like is notified of the brake abnormality.

When the elapsed time exceeds the determination time in step S104 (YES in S104), or when brake abnormality is notified in step S105, the diagnostic circuit 15 terminates the brake abnormality detection process by monitoring the residual voltage V. Since the change in the residual voltage is basically monotonically decreasing, the residual voltage V at a predetermined time after the contactor SW2 is opened is compared with a reference value. may be configured to notify the

Finally, this embodiment will be summarized with reference to the drawings again.

The present disclosure relates to an abnormality detection device 1 for a brush lifting device 100 of a main motor M1, which is a wound-rotor induction motor. The brush lifting device 100 includes a switching mechanism (link mechanism LK) for switching between the contact state and the separated state between the collector electrodes CU, CV, and CW of the main electric motor M1 and the brushes BU, BV, and BW, and a switching mechanism. and an operating electric motor M2 to be operated. The abnormality detection device 1 includes a sensor (current transformer 30) that detects electrical parameters of the operating electric motor M2, a storage unit (memory 12) that stores the basic waveform of the electrical parameters, and a sensor (current transformer 30) that detects A diagnostic unit (CPU 11) that determines an electrical parameter based on the basic waveform read from the storage unit and performs an abnormality diagnosis of the brush lifting device 100. FIG.

With such a configuration, the user can know an abnormality of the brush lifting device 100 without disassembling the brush lifting device 100 and inspecting the inside in detail.

Preferably, as shown in FIGS. 5 and 6, the electrical parameter detected by the sensor (current transformer 30) is current, and the basic waveform is the current waveform iB of operating motor M2 measured in advance.

Preferably, as shown in step S2 of FIGS. 5, 6, and 7 to 9, the diagnosis unit (CPU 11) does not use the electrical parameters during the inrush current period T0 of the operating motor M2 for abnormality diagnosis. The electrical parameters after the inrush current period T0 of the operating motor M2 has elapsed are used for abnormality diagnosis.

By doing so, erroneous determination of abnormality can be avoided.

Preferably, the diagnosis unit (CPU 11) determines that the electrical parameter detected by the sensor (current transformer 30) at the detection time is a determination value (first threshold ith1 , second threshold ith2) (YES in S5 or S7 of FIG. 7), it is determined that the brush lifting device 100 is abnormal.

More preferably, the diagnosis unit (CPU 11) corrects the data corresponding to the detection time in the basic waveform according to the amount of variation in the power supply voltage, and sets the determination values (first threshold ith1, second threshold ith2) to stipulate.

More preferably, the diagnostic unit (CPU 11) uses, as the data corresponding to the detection time, the data of the basic waveform at the time obtained by correcting the detection time according to the fluctuation amount of the power supply frequency.

Specifically, the diagnosis unit (CPU 11) calculates the time obtained by multiplying the detection time by a coefficient determined based on the power supply frequency, and uses the data of the calculated time among the data included in the basic waveform as the judgment value. . Then, the diagnostic unit (CPU 11) determines that the brush lifting device 100 is abnormal when the electrical parameter detected by the sensor (current transformer 30) at the detection time is greater than the determination value.

With such a configuration, it is possible to determine an abnormality based on the same basic data even when the power supply frequency fluctuates.

Preferably, when the diagnosis unit (CPU 11) determines that the brush lifting device 100 is abnormal, it cuts off the power supply of the operation electric motor M2 and also cuts off the power supply of the main electric motor M1.

With such a configuration, main electric motor M1 and brush lifting device 100 can be stopped before they are seriously damaged.

Preferably, the basic waveforms are the first waveform shown in FIG. and a second waveform shown in FIG. 6 obtained when rotating in a second direction (stop, reverse). The diagnosis unit (CPU 11) determines the electrical parameter detected by the sensor (current transformer 30) based on the first waveform read from the memory 12 when the operating motor M2 rotates in the first direction. , the electrical parameter detected by the sensor (current transformer 30) is determined based on the second waveform read from the memory 12 when the operating motor M2 rotates in the second direction.

With such a configuration, it is possible to determine whether the brush lifting device 100 is abnormal when the main motor is started and stopped.

Preferably, the basic waveform is the waveform shown in FIG. 5 obtained when the operating motor M2 rotates in the first direction (normal rotation at startup). As shown in FIG. 9, when the operating motor M2 rotates in the second direction opposite to the first direction (reverse rotation when stopped), the diagnostic unit (CPU 11) reads out the basic waveform from the opposite direction while reading the sensor. A decision value is determined for comparing electrical parameters sensed at (current transformer 30). It should be noted that the waveform shown in FIG. 6 at the time of stop may be used as the basic waveform, and this may be read from the opposite direction at the time of start-up.

By adopting such a configuration, the basic data can be obtained only once, and the storage capacity for storing it can be halved.

Preferably, the brush pulling device 100 further includes a brake BK for stopping the rotating shaft MS of the operating motor M2. The electrical parameter is the terminal voltage (residual voltage V) of the operating motor M2, and the basic waveform is the previously measured voltage waveform of the operating motor M2. When the difference between the terminal voltage at the measurement time and the voltage corresponding to the measurement time determined based on the basic waveform is larger than a threshold while the brake BK is in operation, the diagnosis unit (CPU 11) Judged as abnormal.

With such a configuration, it is possible to determine whether or not there is an abnormality in the brake BK of the operating electric motor M2.

The embodiments disclosed this time should be considered as examples and not restrictive in all respects. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

Reference Signs List 1 abnormality detection device, 10 control device, 11 CPU, 12 memory, 15 diagnostic circuit, 20 transducer, 30 current transformer, 31 voltage sensor, 40 short-circuit collar, 100 brush lifting device, 110 three-phase AC power supply, 120 three-phase AC power supply Power source, 130 alarm device, BK brake, BU, BV, BW brush, CU, CV, CW collector electrode, LK link mechanism, LU1, LV1, LW1 stator coil, LU2, LV2, LW3 rotor coil, M1 traction motor, M2 operation Motor, MS Rotating shaft, RT Rotor, RU, RV, RW Resistor, ST Stator, SW1 Circuit breaker, SW2 Contactor.

Claims (10)

An abnormality detection device for a brush lifting device of a wound-rotor induction motor,
The brush lifting device is
a short-circuiting collar for short-circuiting the collector electrodes of the wound-rotor induction motor and a switching mechanism for switching between a contact state and a separation state between the collector electrodes and the brushes;
and an operation electric motor that operates the switching mechanism,
The abnormality detection device is
a sensor for detecting electrical parameters of the operating motor;
a storage unit that stores the basic waveforms of the electrical parameters;
an abnormality detection device, comprising: a diagnosis unit that determines an electrical parameter detected by the sensor based on the basic waveform read from the storage unit, and diagnoses an abnormality of the brush lifting device. the electrical parameter is current;
2. The abnormality detection device according to claim 1, wherein said basic waveform is a current waveform of said operating motor measured in advance. wherein the diagnosis unit does not use the electrical parameter during the inrush current period of the operation motor for the abnormality diagnosis, and uses the electrical parameter after the inrush current period of the operation motor has passed for the abnormality diagnosis. Item 2. The abnormality detection device according to item 1. The diagnostic unit determines that the brush lifting device is abnormal when the electrical parameter detected by the sensor at the detection time is greater than a determination value determined based on data corresponding to the detection time in the basic waveform. The abnormality detection device according to claim 1, wherein 5. The abnormality detection device according to claim 4, wherein said diagnosis unit corrects data corresponding to said detection time in said basic waveform according to a variation amount of a power supply voltage to determine said judgment value. 5. The anomaly detection device according to claim 4, wherein said diagnosis unit uses data of said basic waveform at a time obtained by correcting said detection time according to a fluctuation amount of power supply frequency as said data corresponding to said detection time. 2. The abnormality detection device according to claim 1, wherein said diagnosis unit cuts off power to said operating motor and also cuts off power to said wound-rotor induction motor when it determines that said brush lifting device is abnormal. The basic waveform includes a first waveform obtained when the operating motor rotates in a first direction, and a basic waveform obtained when the operating motor rotates in a second direction opposite to the first direction. a second waveform;
The diagnostic unit determines an electrical parameter detected by the sensor based on the first waveform read from the storage unit when the operating motor rotates in the first direction, and determines the operating motor. 2. The abnormality detection device according to claim 1, wherein the electrical parameter detected by said sensor is determined based on said second waveform read out from said storage unit when rotates in said second direction. The basic waveform is a waveform obtained when the operating motor rotates in a first direction, and the diagnosis section detects the basic waveform when the operating motor rotates in a second direction opposite to the first direction. 2. The abnormality detection device according to claim 1, further determining a judgment value for comparing electrical parameters detected by said sensor while reading said basic waveform from the opposite direction. The abnormality detection device is
further comprising a brake for stopping the rotating shaft of the operating electric motor;
the electrical parameter is the terminal voltage of the operating motor;
The basic waveform is a voltage waveform of the operating motor measured in advance,
The diagnosing unit detects that the difference between the terminal voltage at the measurement time and the voltage corresponding to the measurement time determined based on the basic waveform is larger than a threshold while the brake is operating. 2. The anomaly detection device according to claim 1, which determines that the anomaly of

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