Switching device with drive system and method for driving a switch

Abstract

The invention relates to a switching device having a switch (17) and a drive system (3). The drive system has a drive shaft (16) which connects the drive system to the switch (17), a motor (12) for driving the drive shaft (16), and a feedback system. The feedback system is designed to determine at least two values of the position of the drive shaft (16) and to generate a feedback signal on the basis of the at least two values. Furthermore, the drive system has a control device which is designed to influence the operation of the motor (12) in dependence on the feedback signal.

Description

TECHNICAL FIELD

[0001] The invention relates to a switching device having a switch and a drive system for the switch and to a method for driving a switch. BACKGROUND

[0002] In a substation there are many switches for different tasks and with different requirements. In order to manipulate the respective switches, these switches have to be driven by a drive system. These switches are in particular tap changers, load switches, selectors, double commutators, commutators, preselectors, power switches, load switches or circuit breakers.

[0003] Such tap changers are for example used for switching between different winding taps of an electrical operating device, for example a power transformer or an adjustable choke. Thereby it is possible for example to change the transmission ratio of the transformer or the inductivity of the choke. Double commutators are used for reversing the winding polarity during the operation of a power transformer.

[0004] All these switches constitute high-grade safety-relevant components of electrical operating devices, since the switching takes place during the operation of the operating device and thus for example is connected to an energy network. In extreme cases, disturbances in operation can have serious technical and economic consequences. SUMMARY

[0005] It is therefore the task of the invention to give an improved solution for driving a switch, in particular a tap changer, a load switch, a selector, a double commutator, a commutator, a preselector, a power switch, a load switch or a circuit breaker, by which the operating safety is improved.

[0006] The improved solution is based on the idea that the drive shaft for driving the switch is equipped with a feedback system, which can detect at least two values of the position of the drive shaft. The operation of the motor is influenced on the basis of a feedback signal generated from the two values.

[0007] According to the improved solution, a switching device is given, which comprises a switch and a drive system for the switch. The drive system has a drive shaft, which connects the drive system with the switch, a motor for driving the drive shaft and a feedback system. The feedback system is designed to determine at least two values of the position of the drive shaft and to generate a feedback signal on the basis of the at least two values. Furthermore the drive system has a control device, which is designed to influence the operation of the motor on the basis of the feedback signal.

[0008] According to at least one embodiment, the switch can be embodied as a tap changer or a load switch or a selector or a double commutator or a commutator or a preselector or a power switch or a load switch or a circuit breaker.

[0009] The term "value of the position of the drive shaft" also comprises such values of the measured variable from which the position of the drive shaft, if necessary within a tolerance range, can be unambiguously determined.

[0010] By determining at least two values of the position of the drive shaft, the control device can carry out a plausibility check of the position determination or a reconciliation of the two values and thereby increase the safety of the position determination and reduce the corresponding residual risk of an erroneous position determination. Furthermore, if a partial failure of the feedback device results in only one value of the position of the drive shaft being able to be determined, it is not necessary to immediately stop the drive shaft. At least the switch can be moved into a safe operating position despite the partial failure. The operating safety of the drive system, the switch and the operating device is thereby ultimately increased. Overall, the determination of two values of the position of the drive shaft increases the safety by reliably recognizing a partial failure and the availability by reliably guiding the transition to an end despite the partial failure.

[0011] According to at least one embodiment, the drive system is for driving a shaft of a switch, for example of an on-load tap changer, or a corresponding component of an on-load tap changer. Thereby, for example, the on-load tap changer is caused to carry out one or more operations, for example a switching between two winding taps of an operating device or a part of the switching, for example a load switching, a selector maneuver, a preselector maneuver or a double commutator maneuver.

[0012] According to at least one embodiment, the drive shaft is directly or indirectly, in particular via one or more gear mechanisms, connected to a switch, in particular to a shaft of the switch.

[0013] According to at least one embodiment, the drive shaft is directly or indirectly, in particular via one or more gear mechanisms, connected to a load switching switch, a selector, a double commutator, a commutator, a power switch, a load switch or a circuit breaker, in particular to a shaft of the load switching switch, the selector, the double commutator, the commutator, the power switch, the load switch or the circuit breaker.

[0014] According to at least one embodiment, the drive shaft is directly or indirectly, in particular via one or more gear mechanisms, connected to a motor, in particular to a motor shaft of the motor.

[0015] According to at least one embodiment, the position, in particular the absolute position, of the motor shaft corresponds to the position, in particular the absolute position, of the drive shaft. That is, from the position of the motor shaft the position of the drive shaft can be unambiguously inferred, if necessary within a tolerance range.

[0016] According to at least one embodiment, the influencing comprises a control, a regulation, a braking, an acceleration or a stopping of the motor. The regulation can for example comprise a position regulation, a speed regulation, an acceleration regulation or a torque regulation. At least in the case of such a regulation, the drive system can be said to constitute a servo drive system.

[0017] According to at least one embodiment, the drive system has a monitoring unit which is designed to monitor one or more operations of the switch, the on-load tap changer, the load switching switch, the selector, the double commutator, the commutator, the preselector, the power switch, the load switch or the disconnector by means of a feedback signal. The monitoring in particular comprises a monitoring of whether the respective operation or a part thereof is carried out as specified, in particular within a predefined time window.

[0018] According to at least one embodiment, the control device has a control unit and a power component for controlled or regulated supply of energy to the motor. The control unit is designed to actuate the power component in accordance with at least one setpoint value, in particular a position, speed or acceleration setpoint value.

[0019] According to at least one embodiment, the power component is designed as a converter or as a servo converter or as an equivalent electronic unit, in particular an all-electronic unit, for driving a machine.

[0020] According to different embodiments, the control device completely or partially contains a feedback system.

[0021] According to at least one embodiment, the feedback system is designed to determine a first value of the at least two values of the position of the drive shaft in accordance with a first method and a second value of the at least two values of the position of the drive shaft in accordance with a second method, the two methods being different from one another. At least one redundancy or even a diversified redundancy is thereby created, which further improves the operating safety.

[0022] The two methods can for example be based on the same or different technical or physical principles or use the same or different components (hardware components).

[0023] According to at least one embodiment, one of the at least two values of the position of the drive shaft is a first value of the absolute position of the drive shaft.

[0024] According to at least one embodiment, the other of the at least two values of the position of the drive shaft is a second value of the absolute position of the drive shaft.

[0025] The first and second values of the absolute position of the drive shaft can be compared by the control device, for example. In the event of a significant deviation, the control device can output a fault report or initiate a safety measure.

[0026] According to at least one embodiment, one of the at least two values of the position of the drive shaft is an incremental value of the position of the drive shaft or a value of the relative position of the drive shaft.

[0027] The first value and / or the second value of the absolute position can then be reconciled by the control device with the incremental value or the relative value, whereby the plausibility of the first value and / or the second value of the absolute position can be checked. In the event of a significant deviation, the control device can output a fault report and / or initiate safety measures.

[0028] According to at least one embodiment, the feedback system is designed to determine one of the at least two values of the position of the drive shaft from the rotor position of the motor.

[0029] According to at least one embodiment, the rotor position is an angular range in which the rotor of the motor is located, if necessary in combination with a fraction of a complete rotation of the rotor.

[0030] Depending on the design of the rotor, in particular the number of pole pairs, the position of the motor shaft or the absolute position can be determined precisely up to at least 180°, for example, by the control device. By means of the reduction by one or more gear mechanisms, the position accuracy of the drive shaft that can thereby be achieved can be increased considerably. The evaluation by the control unit here corresponds to a virtual encoder function to this extent. Thus, even in the event of a complete failure of the absolute value encoder of the feedback system, at least one emergency operation and / or the switching, in particular of a load tap changer, can be brought to a safe position.

[0031] According to at least one embodiment, the feedback system comprises an absolute value encoder which is designed and arranged to detect the absolute position of the drive shaft or of a further shaft connected to the drive shaft and to generate at least one output signal on the basis of the detected position. The feedback system is designed to determine one of the at least two values of the position of the drive shaft, in particular the first value and / or the second value of the absolute position, by means of the at least one output signal.

[0032] According to at least one embodiment, the absolute value encoder is fixed directly or indirectly on the motor shaft, the drive shaft or a shaft coupled thereto.

[0033] According to at least one embodiment, the absolute value encoder has a first output for outputting the first value or the second value of the absolute position and a second output for outputting an incremental value or a relative value of the position.

[0034] The term "absolute value encoder" comprises not only a device which determines the two values of the position in different ways, but also a device which comprises two separate encoders and at least one of the two separate encoders is an absolute value encoder.

[0035] According to at least one embodiment, the absolute encoder has a multi-turn rotary encoder.

[0036] According to at least one embodiment, the absolute encoder is designed to detect the position of the drive shaft or the other shaft by means of a first scanning method.

[0037] According to at least one embodiment, the absolute encoder is designed to additionally detect the position of the drive shaft or the position of the other shaft by means of a second scanning method independent of the first scanning method.

[0038] According to at least one embodiment, the first or second scanning method includes optical, magnetic, capacitive, resistive or inductive scanning methods.

[0039] According to at least one embodiment, the first scanning method differs from the second scanning method.

[0040] In at least one embodiment, the absolute encoder is shaped-locked to the drive shaft, motor shaft, or the other shaft.

[0041] In at least one embodiment, the absolute encoder is additionally force-locked or material-locked, for example by adhesive bonding, to a drive shaft, motor shaft, or the other shaft.

[0042] The use of form-locking connections and additional material or force-locking connections further enhances the fixation of absolute encoders and ultimately improves operational safety.

[0043] According to the improved scheme, a method for driving an on-load tap changer is also provided. The method includes: determining at least two values ​​of the absolute position of a drive shaft used to drive the on-load tap changer; generating a feedback signal based on the at least two values; and controlling a motor used to drive the on-load tap changer according to the feedback signal.

[0044] Other design forms and implementations of the method are directly derived from different design forms of the tap changer. In particular, the components and / or arrangements described for implementing the method can be implemented accordingly. Attached Figure Description

[0045] The invention is described in detail below with reference to the accompanying drawings and exemplary embodiments. Components that are identical, functionally identical, or have the same function may have the same reference numerals. Identical components or components with the same function may be explained only with respect to the drawing in which they first appear. They are not necessarily repeated in subsequent drawings.

[0046] In the attached diagram:

[0047] Figure 1A schematic diagram showing an exemplary embodiment of the switching device according to the improved scheme; and

[0048] Figure 2 A schematic diagram showing another exemplary implementation of the switching device according to the improved scheme is shown. Detailed Implementation

[0049] Figure 1 A schematic diagram of an exemplary embodiment of a switching device 1 according to an improved scheme is shown. The switching device includes a switch 17 and a drive system 3, the drive system being connected to the switch 17 via a drive shaft 16. The switch 17 may be an on-load tap changer, load switching switch, selector, double commutator, commutator, preselector, power switch, load switch, or circuit breaker. The drive system 3 includes a motor 12, which can drive the drive shaft 16 via a motor shaft 16 and optionally via a transmission mechanism 15. The control unit 2 of the drive system 3 has a power component 11, which includes, for example, a converter (not shown) for controlling or regulating energy supply to the motor 12, and a control unit 10 for operating the power component 11, for example, via a bus 18. The drive system 3 has an encoder system 13, which serves as a feedback system 4 or is part of a feedback system 4 and is connected to the power component 11. Furthermore, the encoder system 13 is directly or indirectly connected to the drive shaft 16.

[0050] The encoder system 13 is designed to detect a first value of the position of the drive shaft 16, particularly its angular position, such as its absolute angular position. For this purpose, the encoder system 13 may, for example, have an absolute encoder, particularly a multi-turn absolute encoder, fixed to the drive shaft 16, the motor shaft 14, or another shaft whose position is unilaterally associated with the absolute position of the drive shaft 16. For example, the position of the drive shaft 16 may be unilaterally determined from the position of the motor shaft 14, for example, by the transmission ratio of the transmission mechanism 15.

[0051] The fixing of an absolute encoder is implemented, for example, as a combination of form-locking connections and force-locking and / or material-locking connections.

[0052] Feedback system 4 is also designed to detect a second value for the position of drive shaft 16.

[0053] Therefore, the encoder system 13 can be designed to detect this second value, especially when using a different method than the method used to detect the position of the drive shaft 16.

[0054] Alternatively or additionally, the control device 2 can be designed to obtain a second value from the rotor position of the motor 12, i.e., it can actually have a virtual encoder for detecting the second value. For this purpose, inductive feedback via the movement of the rotor in the motor windings of the motor 12 can be used, for example. Because the intensity of the feedback changes periodically, the rotor position can be roughly determined, especially by means of signal analysis, such as FFT analysis. Since one full turn of the drive shaft 16 corresponds to multiple turns of the rotor, the position of the drive shaft 16 can thus be inferred with much higher accuracy.

[0055] The control device 2, especially the control unit 10 and / or the power component 11, is designed to control or regulate the motor 12 according to the feedback signal generated by the feedback system based on the first and second values.

[0056] The control device 2, such as the control unit 10, can, for example, reconcile two values ​​of the position of the drive shaft 16 and / or perform a reliability check on the position determination.

[0057] Figure 2 A schematic diagram showing another exemplary embodiment of the switching device 1 according to the improved scheme is shown, which is based on... Figure 1 The implementation form.

[0058] The switching device 1 optionally includes a switch cabinet 21, within which a control unit 10, a power unit 11, and an optional human-machine interface 19 are housed. The human-machine interface 19 is connected to the control unit 10 and can be used, for example, for control, maintenance, or configuration purposes during or outside of operation.

[0059] The motor 12, motor shaft 14, encoder system 13 and / or transmission mechanism 15 can be located inside or outside the switch cabinet.

[0060] The switching device 1, especially the control unit 10, is connected to the safety device 20, which has, for example, a power switch or circuit breaker, to disconnect the switching device 1 or the electrical operating devices associated with the switching device 1 from the energy network, for example, in the event of a failure or interference with the switching device 1.

[0061] The improved switching device 1 enhances the operational safety of the drive system 3, switch 17, and operating devices. The described dual position determination and corresponding adjustment reduce the residual danger of incorrect position determination.

[0062] List of reference numerals

[0063] 1 Switching device

[0064] 2 Control device

[0065] 3 drive system

[0066] 4 Feedback System

[0067] 10 Control Unit

[0068] 11 Power Components

[0069] 12 motors

[0070] 13 Encoder System

[0071] 14 Motor Shaft

[0072] 15. Transmission Mechanism

[0073] 16 drive shafts

[0074] 17 Switches

[0075] 18 bus

[0076] 19 Human-Computer Interface

[0077] 20 Safety devices

[0078] 21 Switchgear

Claims

1. A switching device (1) having a switch (17) and a drive system (3) for the switch (17), the drive system (3) comprising The drive shaft (16) connects the drive system (3) to the switch (17); A motor (12) with a rotor for driving the drive shaft (16); and Feedback system (4), the feedback system is designed for - Determine at least two values ​​for the position of the drive shaft (16); -To determine one of the at least two values ​​for the rotor position of the motor (12) and the position of the drive shaft (16) based on the rotor position, wherein, The rotor position combines the angular range of the motor's rotor with the number of complete rotations of the rotor; and - Generate a feedback signal based on the at least two values; as well as A control device (2) is designed to influence the operation of the motor (12) according to the feedback signal.

2. The switching device (1) according to claim 1, wherein, The feedback system is designed to determine each of the at least two values ​​of the position of the drive shaft (16) according to the assignment method. All methods used to obtain the at least two values ​​are either different from or the same as each other.

3. The switching device (1) according to claim 1 or 2, wherein, One of the at least two values ​​of the position of the drive shaft (16) is the first value of the absolute position of the drive shaft (16).

4. The switching device (1) according to claim 1 or 2, wherein, One of the at least two values ​​of the position of the drive shaft (16) is a second value of the absolute position of the drive shaft (16).

5. The switching device (1) according to claim 1 or 2, wherein, One of the at least two values ​​of the position of the drive shaft (16) is an incremental value of the position of the drive shaft (16) or a value of the relative position of the drive shaft (16).

6. The switching device (1) according to claim 1 or 2, wherein, The feedback system Includes an absolute encoder, which is designed and configured to detect the absolute position of the drive shaft (16) or the absolute position of another shaft connected to the drive shaft (16) and generate at least one output signal based on the detected position; and Designed to determine one of the at least two values ​​of the position of the drive shaft (16) by means of the at least one output signal.

7. The switching device (1) according to claim 6, wherein, The absolute encoder is implemented as a multi-turn rotary encoder.

8. The switching device (1) according to claim 6, wherein, The absolute encoder is designed to detect the position of the drive shaft (16) or the position of the other shaft using a first scanning method.

9. The switching device (1) according to claim 8, wherein, The absolute encoder is designed to additionally detect the position of the drive shaft (16) or the position of the other shaft using a second scanning method independent of the first scanning method.

10. The switching device (1) according to claim 8 or 9, wherein, The first scanning method includes optical, magnetic, capacitive, or inductive scanning methods.

11. The switching device (1) according to claim 6, wherein, The absolute encoder is shaped-locked to the drive shaft (16) or the other shaft.

12. The switching device (1) according to claim 11, wherein, The absolute encoder is additionally force-locked and / or material-locked connected to the drive shaft (16) or the other shaft.

13. The switching device (1) according to claim 1 or 2, wherein, The switching device (1) is an on-load tap changer or load switching switch or selector or double commutator or commutator or preselector or power switch or load switch or circuit breaker.

14. A method for driving a switch (17), the method comprising: Determine at least two values ​​for the absolute position of the drive shaft (16) used to drive the switch (17); -To determine one of the at least two values ​​for the rotor position of the motor (12) and the position of the drive shaft (16) based on the rotor position, wherein, The rotor position combines the angular range of the motor's rotor with the number of complete rotations of the rotor; A feedback signal is generated based on the at least two values; and The motor (12) used to drive the switch (17) is controlled according to the feedback signal.

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