JPH0759394A - Electric driving gear device - Google Patents

Abstract

PURPOSE: To provide an electric driver of a work machine which enables the selective connection of a power converter according to a failure. CONSTITUTION: In an electric driver for a work machine which is connected to a power supply 36a and has a frequency converter 30, which outputs AC currents with a power supply frequency changing hourly to motors 16 and 18, a control unit 32 which detects failures is connected to elements 30, 36a, 36b, 16 and 18 of the driver with sensor lines 40-46. The control unit is constructed so as to produce various different circuit states with the frequency converter 30 according to the various failures.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric drive device for a working machine, for example, a spinning machine, which is connected to a power source and has a frequency converter for sending an alternating current having a power supply frequency which changes with time to a motor.

[0002]

2. Description of the Related Art Such a driving device is disclosed in International Patent Application W
It is known from O90-07595. In this publication, energy is fed back to the power converter in the event of a current loss of one of the connected motors in generator operation, which makes it possible to control other current loads or motors even after a current loss. It is described that the mechanical elements of can be regularly driven until the stationary state.

A number of manufacturers provide power converters for converting the supplied power AC voltage into a voltage of varying frequency. These power converters are configured so that they will be isolated from the power supply in the event of a failure, thereby preventing damage to the power converter.

However, there are operating conditions that are classified as faults but do not require the machine to be immediately shut down. If immediate disconnection of the machine from power would result in a machine sequence failure, efforts should be made to avoid immediate disconnection. In a spinning machine, for example, if the electric drive device is unconditionally cut off, the entire spun yarn is cut off, which requires a troublesome connecting work before the machine is newly started.

[0005]

SUMMARY OF THE INVENTION It is an object of the invention to provide an electric drive for a work machine which allows the selective connection of power converters in the event of a fault.

[0006]

This problem is that a control unit for detecting a fault is connected to an element of a driving device via a sensor line, and the control unit determines various circuit states depending on each fault. The problem is solved by constructing the frequency converter.

The electric drive of the invention makes the work machine less susceptible to disturbances.

[0008]

EXAMPLES In the following examples, a drive unit for a spinning machine will be described as an example. The first and second motors 16 and 18 are connected to the power supply 36a via the frequency converter 30. There is a so-called mechanical power supply 36b between the frequency converter 30 and the motors 16 and 18. The control 32 for the electric drive can be arranged separately from the frequency converter 30, but can also be integrated therein. The control unit 32 controls the elements 3 of the driving device via the plurality of sensor lines 40 to 46.
0, 16, 18, 36a, 36b. The sensor line can detect, for example, overloading, overheating, undervoltage or power failure of the electrical element. Overvoltage peaks and shorts are other obstacles of concern. These obstacles can be similarly detected by the control unit 32 via the sensor line. The control unit 32 and the frequency converter 30 are arranged so that they are interrupted only in the event of a predetermined disturbance such that the current supply of the motors 16, 18 destroys, for example, the components of the element. In that case, first of all, voltage peaks or short circuits are a problem. However, the load of the time-limited element and the load that gradually exceeds the threshold value are not a problem. When a relatively minor fault occurs in the electric drive, the evaluation of the fault causes the controller 32 to trigger a controlled stop of the drive. At that time, the frequency f of the frequency converter 30, and thus the number of revolutions n of the motors 16 and 18 is reduced according to a predetermined program, and the energy regeneration of the motor 18 is fed to the other elements 16 and 32 in accordance with WO90-.
It can be performed according to 07595. The rotational speed curve for the regular stop of the electric drive is the union of the curved branches a and b of FIG. This is because in the embodiment of the spinning machine, the rotational speeds of the two motors are proportionally reduced, and the driving of the first motor 16 and the shaft 20 for driving the draft mechanism shafts 12a, 12b, 12c of FIG. It means that the second motor 18 of is simultaneously in a stationary state. The shaft 20 has a plurality of belt discs 24,
In the case of a ring spinning machine, these belt discs drive the spindle 22 for winding the yarns via one belt 26 each. This yarn is delivered from the draft mechanism shafts 12a, 12b, 12c. If only one frequency converter 30 is provided for powering the motors 16 and 20, these motors rotate at the same frequency as synchronous or asynchronous motors. First
Motor 16 and draft mechanism shafts 12a, 12b,
The transmission 14 between 12c provides the required speed adaptation.

From the program memory 34, the control unit can retrieve the target value for lowering the converter frequency.
The controller 32 and the converter 80 can be incorporated into a module. The evaluation unit 32a analyzes the signals from the sensor lines 40 to 46, and the switching unit 30a of the converter 30 switches the operating state of the frequency converter 30.

In the second mode of operation of the electric drive, this drive immediately shuts off the frequency converter 30 and the downstream elements 16, 18, 32 in the event of an overvoltage or short circuit. In this second mode of operation, different mechanical drives can be brought to rest at different times.
According to FIG. 2, a curved branch a,
As a result, the rotational speed profile due to d is obtained, and the rotational speed profile due to the curved branches a and c occurs for the second motor 18. This causes different motors to be brought to rest in sequence. In the ring spinning machine, this mode of operation sometimes leads to damage of the entire yarn. However, all elements are
By switching to the non-voltage state immediately after the identification of the fault by item 2, it is possible to prevent the risk of personal injury or damage to the electric drive device. This is especially necessary when an erroneous current occurs due to an operator touching the electrical element.

[0011]

The present invention provides an electric drive for a work machine that allows selective connection of power converters in response to faults.

[Brief description of drawings]

FIG. 1 is a simple circuit diagram of an electric drive device.

FIG. 2 is a diagram showing the evolution of frequency or rotational speed over time for different operating states.

FIG. 3 is a schematic view of a driving device of a spinning machine.

[Explanation of symbols]

 16, 18 Motor 30 Frequency converter 32 Controller 40-46 Sensor line

Claims (5)

[Claims] 1. An electric drive device for a working machine, comprising a frequency converter (30) connected to a power supply (36a) and delivering an alternating current of a power supply frequency that changes with time to a motor (16, 18). The control unit (32) for detecting a failure is connected to the sensor line (40 to 4).
6) via drive element (30, 36a, 36b,
18) is connected to the control section, and the control section is configured to generate various different circuit states in the frequency converter (30) according to each fault. 2. The program memory (34) is a control unit (3).
2. The drive device according to claim 1, which is connected to 2). 3. The control unit (32) comprises an evaluation unit (32a) for faults, which evaluation unit is connected on the input side to the sensor lines (40 to 46). Drive. 4. The control unit (32) is connected via a control line (48) to a switching unit (30a) of a frequency converter (30), the switching unit being connected to the control line (48) at a predetermined distance. Shut off the frequency converter (30) only when the control signal is present,
4. The drive device according to claim 1, wherein the power supply frequency is reduced according to a program in the case of another control signal. 5. A motor (18) for one of the spindles (2)
2) configured to drive the other motor (1
6. The drive device according to claim 1, wherein 6) is configured to drive a draft mechanism (12) of the spinning machine.