Patent Grant
7800872
The present invention relates to a switch-state monitoring device utilized in electric-power transmission/distribution facilities and electric-power reception facilities, and more particularly to a switch-state monitoring device suitable for monitoring the state of the operation characteristics of a switch, such as a disconnecting switch or an earthing switch, that opens and closes a main circuit by use of a motor.
A conventional switch-operation-characteristic monitoring device disclosed in Patent Document 1 is provided with an operation-time detection means for detecting the operation time of a switch; a parameter detection means for detecting the values of parameters that affect the operation time of the switch; an operation-time correction means for correcting the detection time of the operation-time detection means in accordance with the difference between the value detected by the parameter detection means and the reference value for the parameter; and a determination means for determining whether or not the operation time of the switch is abnormal, by comparing an setting value that serves as a reference value for the operation time of the switch and the operation time corrected by the operation-time correction means.
(Patent Document 1) Japanese Patent Laid-Open No. 2003-308751
Meanwhile, in the case a conventional monitoring device of this kind is applied to a state monitoring device for monitoring the state of the operation characteristics of a switch in which the moving body of a main circuit is driven by use of a motor, an abnormality in the switch can be detected, by monitoring the operation time of the switch; however, there has been a problem that, in the case where, due to gnawing in the moving body of the switch or depletion of grease, the motor is locked, the energization of the motor continues, whereby the motor burns out due to the continuous energization of the motor.
In consideration of the foregoing problem, the present invention provides a switch-state monitoring device that not only monitors the state of a switch but also prevents a motor burnout.
A switch-state monitoring device, according to the present invention, for a switch that opens and closes a main circuit by use of a motor is provided with an operating time measuring means for detecting an operating time for the motor when the switch is opened or closed; a first determination means for comparing an operating time for the motor detected by the operating time measuring means with an continuous-operating-capable setting time for the motor and determining whether or not the operating time for the motor has exceeded the continuous-operating-capable setting time; a protection means for halting energization for the motor, in the case where, based on an output of the first determination means, it is determined that the operating time for the motor has exceeded the continuous-operating-capable setting time; a second determination means for determining whether or not the operating time for the motor detected by the operating time measuring means has fallen outside an setting range with which it is determined whether or not an abnormality exists in the switch; and an output means for outputting an abnormality in the switch in the case where, based on an output of the second determination means, it is determined that the operating time for the motor has fallen outside the setting range.
Moreover, in the switch-state monitoring device according to the present invention, in the case where the operating time for the motor detected by the operating time measuring means has fallen outside the setting range with which it is determined whether or not an abnormality exists in the switch, the second determination means determines whether the operating time has exceeded the upper limit value or the lower limit value of the setting range; and an abnormal unit discrimination means discriminates an abnormal unit in the switch, based on the output of the second determination means.
A switch-state monitoring device, according to the present invention, for a switch that opens and closes a main circuit by use of a motor is provided with an operating current detection means for detecting an operating current for the motor when the switch is opened or closed; a first determination means for comparing an operating current for the motor detected by the operating current detection means with an operating-capable setting current value for the motor and determining whether or not the operating current for the motor has exceeded the operating-capable setting current value; a protection means for halting energization for the motor, in the case where, based on an output of the first determination means, it is determined that the operating current for the motor has exceeded the operating-capable setting current value; a second determination means for determining whether or not the operating current for the motor detected by the operating current detection means has fallen outside an setting range with which it is determined whether or not an abnormality exists in the switch; and an output means for outputting an abnormality in the switch in the case where, based on an output of the second determination means, it is determined that the operating current for the motor has fallen outside the setting range.
Moreover, in the switch-state monitoring device according to the present invention, in the case where an operating current for the motor detected by the operating current detection means has fallen outside the setting range with which it is determined whether or not an abnormality exists in the switch, the second determination means determines whether the operating current has exceeded the upper limit value or the lower limit value of the setting range; and an abnormal unit discrimination means discriminates an abnormal unit in the switch, based on the output of the second determination means.
In a switch-state monitoring device according to the present invention, because, in the case where an operating time for a motor exceeds the continuous-operating-capable setting time for the motor, energization for the motor is halted, a burnout of the motor can be prevented, and because, in the case where an operating time for a motor falls outside an setting range with which it is determined whether or not an abnormality exists in a switch, the abnormality in the switch is outputted, an abnormality in each different unit of the switch can be detected.
Moreover, in a switch-state monitoring device according to the present invention, because, in the case where an operating current for a motor exceeds the operating-capable setting current value for the motor, energization for the motor is halted, a burnout of the motor can be prevented, and because, in the case where an operating current for a motor falls outside an setting range with which it is determined whether or not an abnormality exists in a switch, the abnormality in the switch is outputted, an abnormality in each different unit of the switch can be detected.
A switch-state monitoring device according to the present invention will be explained with reference to the drawings.
The motor 10 is connected in series to the motor-operation-circuit switch 11a or 11b, thereby being connected between the power-source terminals of an operation power source 2; when a contact closing button 13a is closed, a contact closing coil 110a of the motor-operation-circuit switch 11a is excited, so that the motor-operation-circuit switch 11a is closed and the motor 10 is activated. In addition, reference character 13c is a self-holding contact that responds to the contact closing button 13a. Reference numeral 6 denotes a control power source. When the motor 10 is activated, a moving body (unillustrated), for the main circuit in the disconnecting switch 1, which is mechanically connected to the motor 10 is driven, so that the disconnecting switch 1 is driven in a contact-closing direction and the main contact of the disconnecting switch 1 is closed.
When the main contact of the disconnecting switch 1 is closed, the auxiliary b-contact 12b is opened and the contact closing coil 110a of the motor-operation-circuit switch 11a becomes unenergized, so that the self-holding contact 13c and the motor-operation-circuit switch 11a are opened, whereby the motor 10 stops. At this time, the auxiliary a-contact 12a, connected in series to a opening coil 10b of the motor-operation-circuit switch 11b, is closed. After that, a current flowing through the motor 10 is detected by a current transformer 14 inserted in the circuit for the motor 10; the detected current is supplied to a measuring unit 3.
In contrast, when a opening button 13b is closed, the opening coil 110b of the motor-operation-circuit switch 11b is excited, so that the motor-operation-circuit switch 11b is closed and the motor 10 is activated in a direction that is opposite to the direction when the disconnecting switch is closed. In addition, reference character 13d denotes a self-holding contact that responds to the contact closing button 13b. When the motor 10 is activated, the moving body (unillustrated), for the main circuit in the disconnecting switch 1, which is mechanically connected to the motor 10 is driven in a opening direction, so that the main contact of the disconnecting switch 1 is opened. When the main contact of the disconnecting switch 1 is opened, the auxiliary a-contact 12a is opened and the opening coil 110b of the motor-operation-circuit switch 11b becomes unenergized, so that the self-holding contact 13d and the motor-operation-circuit switch 11b are opened, whereby the motor 10 stops. At this time, the auxiliary b-contact 12b, connected in series to the contact closing coil 110a of the motor-operation-circuit switch 11a, is closed.
After that, a current flowing through the motor 10 is detected by the current transformer 14 inserted in the circuit for the motor 10; the detected current is supplied to the measuring unit 3. Additionally, the opening and closing states of the motor-operation-circuit switches 11a and 11b that detect the fact the motor 10 is activated or stopped is supplied to the measuring unit 3. In addition, the state monitoring device has the measuring unit 3, a correction unit 4, and a determination unit 5. In the case where the determination unit 5 determines that it is required to stop the motor 10, an abnormality stop contact 16 provided in the disconnecting switch 1 is opened so as to render an abnormality stop coil 17, connected to the abnormality stop contact 16, unenergized. As a result, an abnormality stop switch 17b, connected to the contact closing coils 110a and 110b of the motor-operation-circuit switches 11a and 11b, is opened, thereby rendering the contact closing coils 110a and 10b of the motor-operation-circuit switches 11a and 11b unenergized; thus, the motor-operation-circuit switches 11a and 11b connected to the motor 10 are opened, so that the motor 10 is separated from the power source 2, whereby the supply of electric power to the motor 10 is stopped.
In this situation, as represented in
Because, in Embodiment 1, a peak value I1 of the rising current 10a is determined mainly by the DC resistance value of the motor 10 and the power-source voltage, the value of the power-source voltage is calculated based on the peak value I1 of the rising current 10a. In addition, the operating time for the motor 10 is detected by measuring a time (T1+T2) during which the motor-operation-circuit switches 11a and 11b are closed; further, as a means for detecting a change in load force exerted on the motor 10, the operating current for the motor 10 is detected by use of the current transformer 14 inserted in the circuit for the motor 10 so that the change in load force, exerted on the motor 10, which consists of driving forces and frictional forces at the moving body and the main-circuit contact is detected.
By detecting the change in the operating current for the motor 10 being driven, the operating time for the motor 10 can be detected as the combination of an operating time T1 between the time instant when the motor 10 is activated and the time instant when the main-circuit contact makes contact and an operating time T2 between the time instant when the main-circuit contact makes contact and the time instant when the motor 10 stops. During the operating time T1 between the time instant when the motor 10 is activated and the time instant when the main-circuit contact makes contact, a change in the frictional force at the moving body of the disconnecting switch 1 can be detected based on a change in the operating time T1 and an accompanying change in an operating current I2.
That is to say, as represented in
In addition, as represented in
Additionally, in the case where the operating time (T1+T2) for the motor 10 exceeds the first setting value (continuous-operating-capable setting time) that is an abnormal value of the operating time or in the case where the operating current during the operating time (T1+T2) exceeds the second setting value (operating-capable setting current value) that is an abnormal value of the operating current, the determination unit 5 determines that an abnormality exists; then, the abnormality stop coil 17 in the disconnecting switch 1 is rendered unenergized so that the circuits of the contact closing coil 110a and the opening coil 110b for the motor-operation-circuit switches 11a and 11b are opened, whereby the contact closing coil 110a and the opening coil 10b are rendered unenergized; thus, the motor-operation-circuit switches 11a and 11b connected to the motor 10 are opened, whereby the motor 10 and the operation power source 2 are separated, so that the supply of electric power to the motor 10 is halted, thereby preventing heat generation and a burnout in the motor 10.
In addition, in the foregoing description, the operating times T1 and T2 and the operating currents I2 and I3 for the motor in the case where the switch is closed are described in detail; however, the operating times and the operating currents for the motor in the case where the switch is opened can be considered in the same way. The time between the time instant when the switch opening operation starts and the time instant when the moving body and the fixed body of the main circuit are separated, i.e., an operating time T3 (corresponding to the operating time T2) between the time instant when the switch opening operation starts and the time instant when, due to the separation of the moving body from the fixed body of the main circuit, the load decreases and the operating current for the motor decreases or an operating current I4 (corresponding to the operating current I3) and the second setting range are compared in the same way for making a determination. In the case where the operating time T3 or the operating current I4 falls outside the setting range, the determination “an abnormality in the switch” is outputted.
The time between the time instant when the main-circuit moving body and fixed body are separated and the time instant when the operation of the motor is completed, i.e., an operating time T4 (corresponding to the operating time T1) between the time instant when, due to the separation of the main-circuit moving body from the fixed body, the load decreases and the operating current for the motor decreases and the time instant when the operation of the motor is completed or an operating current I5 (corresponding to the operating current I2) and the first setting range are compared in the same way for making a determination. In the case where the operating time T4 or the operating current I5 falls outside the setting range, the determination “an abnormality in the switch” is outputted. Moreover, it is determined in the same way whether or not the operating time (T3+T4) for the motor exceeds the first setting value (continuous-operating-capable setting time) or whether or not the operating current during the operating time (T3+T4) exceeds the second setting value (operating-capable setting current value) that is an abnormal value of the operating current. In the case where the operating time (T3+T4) exceeds the first setting value or in the case where the operating current during the operating time (T3+T4) exceeds the second setting value, the motor 10 and the operation power source 2 are separated so that the supply of electric power to the motor 10 is halted.
The operating times T1 and T2 and the operating currents I1, I2, and I3 change in accordance with the ambient temperature, the power-source voltage supplied to the motor 10, and an operational interval, e.g., the time between the time instant when the disconnecting switch 1 closes and the time instant when the disconnecting switch 1 starts to open.
Additionally,
Meanwhile,
In accordance with the characteristics represented in
Next, with reference to a flowchart represented in
In contrast, in the case where no abnormality is found in the foregoing processing (the step 4), based on the detected power-source voltage (the voltage of the power source 2), the temperature detected by the temperature sensor 15, and the operational interval from the immediately previous operation, the correction coefficients for the power-source voltage, the ambient temperature, and the operational interval are determined in accordance with the characteristics represented in
In contrast, in the case where it is determined that any one of the corrected operating times T11 and T21 and the corrected operating currents I21 and I31 falls outside the setting ranges, a determination that an abnormality exists is outputted (the step 8), so that the abnormality is discriminated (the steps 10 to 13). That is to say, in the case where the operating time T11 or the corrected operating current I21 falls outside the first setting range, it is discriminated that an abnormality exists in the moving body of the disconnecting switch 1 (the steps 10 and 11); in the case where the operating time T21 or the operating current I31 falls outside the second setting range, it is discriminated that an abnormality exists in the main-circuit contact of the disconnecting switch 1 (the steps 10 and 12); in the case where the operating time T11 or the operating current I21 and the operating time T21 or the operating current I31, i.e., two or more parameters fall outside the first and second setting ranges, it is discriminated that an abnormality exists in the device of the disconnecting switch 1 (the steps 10 and 13); then, the corrected operating times T11 and T21 and the operating currents I21 and I31 are stored in relationship to the number of operations, and then the processing is ended. In addition, the abnormality recognition means is configures with the steps 10 to 13.
Additionally, in the foregoing description, it is determined in a comparison manner whether or not the corrected operating times T11 and T21 and the corrected operating currents I21 and I31 fall outside the first setting range and the second setting range; however, it goes without saying that, although the accuracy is slightly deteriorated, a method can be put to practical use in which it is determined in a comparison manner whether or not the uncorrected operating times T1 and T2 and the uncorrected operating currents I2 and I3 fall outside the first setting range and the second setting range.
As described above, in Embodiment 1, in the case where the operating time (T1+T2) or the operating current for the motor 10 exceeds the first setting value (continuous-operating-capable setting time) or the second setting value (operating-capable setting current value), the motor 10 is separated from the power source, so that abnormal heat generation and a burnout in the motor 10 can be prevented. Moreover, it is determined whether or not the state of the disconnecting switch 1 is abnormal, by comparing the operating times T1 and T2 or the operating currents I2 and I3 for the motor 10 with the first setting range or the second setting range; therefore, the state of the disconnecting switch 1 can be diagnosed. Still moreover, the operating times T1 and T2 and the operating currents I2 and I3 for the motor 10 are corrected in accordance with the power-source voltage, the ambient temperature, and the operational interval, which are parameters that affect the operating times T1 and T2 and the operating currents I2 and I3, and it is determined whether or not the state of the disconnecting switch 1 is abnormal, by comparing the corrected operating times T11 and T21 or the operating currents I21, and I31 with the first setting range or the second setting range; therefore, the state of the disconnecting switch 1 can accurately be diagnosed.
Moreover, by localizing the unit where an abnormality exists, the time for repair and maintenance can be reduced. Furthermore, because, by diagnosing the state of the disconnecting switch 1, the sign of an abnormality in the disconnecting switch 1 can be obtained at an early stage, it is possible to perform well-planned repair and maintenance, and, by checking trend information on the operating currents and the operating times that are stored in relationship to the number of operations, it can be ascertained whether or not the state of the disconnecting switch 1 is stable.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2006/305555 | 3/20/2006 | WO | 00 | 6/20/2008 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2005/111641 | 11/24/2005 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3629744 | Maier et al. | Dec 1971 | A |
| 3654535 | Hendry et al. | Apr 1972 | A |
| 3808503 | Hentschel | Apr 1974 | A |
| 4028736 | Willson et al. | Jun 1977 | A |
| 5784232 | Farr | Jul 1998 | A |
| 6055144 | Reid | Apr 2000 | A |
| 6144235 | Marano et al. | Nov 2000 | A |
| 6396228 | Guille et al. | May 2002 | B2 |
| 20020100674 | Rosen et al. | Aug 2002 | A1 |
| Number | Date | Country |
|---|---|---|
| 5-159686 | Jun 1993 | JP |
| 10-112237 | Apr 1998 | JP |
| 2003-308751 | Oct 2003 | JP |
| 2004-192441 | Jul 2004 | JP |
| WO 2005111641 | Nov 2005 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20090267714 A1 | Oct 2009 | US |
