Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P5/00—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors
  • H02P5/46—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors for speed regulation of two or more dynamo-electric motors in relation to one another
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P5/00—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors
  • H02P5/46—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors for speed regulation of two or more dynamo-electric motors in relation to one another
  • H02P5/48—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors for speed regulation of two or more dynamo-electric motors in relation to one another by comparing mechanical values representing the speeds
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P5/00—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors
  • H02P5/46—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors for speed regulation of two or more dynamo-electric motors in relation to one another
  • H02P5/50—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors for speed regulation of two or more dynamo-electric motors in relation to one another by comparing electrical values representing the speeds

Definitions

• the present invention relates to a drive arrangement. Moreover, the present invention relates to a method of operating a drive assembly.
• PM LineStart Moto ⁇ ren Due to higher energy prices and a corresponding Ge ⁇ setz mecanic and standards on energy efficiency in electrical engineering moves into the focus. Be particularly ef ⁇ fizientes engine design win so-called "PM LineStart Moto ⁇ ren" so important. These are electric motors, the permanent magnets and a start-up or damper ⁇ cage wear on the rotor. These motors can run up to the power and However, these motors can also be operated with variable speed without a position encoder on a frequency converter.
• Variable speed drive arrangements are sometimes necessary from a pro ⁇ zesssicht. This is the case, for example, when the speed of a conveyor belt is to be set.
• variable speed drives offer massive energy savings potential ⁇ if they are used instead of mechanical solutions.
• a variable speed pump can be used instead of a throttle valve.
• Asynchronous machines have conditionally higher losses compared to permanent magnet synchronous machines, since the electric magnetization power has to be transmitted transformatively to the rotor.
• the magnetizing current of an asynchronous machine can be up to 70% of the rated current.
• the power range from 15 kW, however, the efficiencies of the asynchronous machines and permanent-magnet synchronous machines are almost comparable and the higher costs of the synchronous machines machines that are caused by the expensive rare earths, are not worthwhile.
• the power range between 0.5 and 15 kW which also forms the number one focus of asynchronous machines, a replacement of the asynchronous machines by permanently excited synchronous machines would be desirable if the additional costs remain within limits.
• asynchronous machines unlike the permanent-magnet synchronous machines, can be operated on any frequency inverter without a sensor. This eliminates the cost of the encoder and the encoder cable. In addition, the cabling effort and space can be saved. By contrast, no method for sensorless control of permanent-magnet synchronous machines has yet been established on the market. This problem can be circumvented by the use of synchronous machines with a damper cage on the rotor. Such engine concepts run without pendulum vibrations on the grid. With appropriate design, they are even able to run up from standstill to synchronous frequency.
• the drive assembly according to the invention comprises at least two electrical machines each having a rated speed aufwei ⁇ sen, at least one inverter for driving the electric machine and a connecting means for connecting the electrical machine with the frequency converter or a power supply network, wherein the connection means is adapted to control the electrical machines) simultaneously electrically connected to the frequency converter, and the frequency converter is adapted to operate at the same time electrically connected to frequency converter electrical machines at a lower speed than the rated speed.
• the at least two electrical machines of the drive arrangement can be designed as asynchronous machines, permanently excited synchronous machines or as so-called PM linear start motors.
• a frequency converter With a frequency converter, the speed of electrical machines can be adjusted.
• the electrical machines can be coupled directly to the power grid, ie the electrical machines are not connected to the frequency converter.
• a connection device can be used, which controls a corresponding switching device with a control device.
• the switching device can be designed as a semiconductor switch, electromechanical contactor, power relay or the like.
• the at least two electric machines When the at least two electric machines are operated at a speed different from their rated speed, the at least two electric machines can be operated in parallel with the frequency converter. In particular, the at least two electric machines are operated at a speed that is less than the rated speed.
• a single frequency converter can be used, which has a lower rated electrical power than the sum of the electrical nominal powers of the electric motor. provided. This means a significant cost savings compared to a frequency converter with a larger rated electrical power or more frequency converters.
• the drive assembly includes at least one supply means and the connection means is adapted to control an electric Ver ⁇ bond at least one of the electric machine optionally with the drive, the drive device and / or the power grid.
• the at least two electric machines can be electrically connected to the other components of the drive arrangement individually via a switching device, which is controlled by the control device.
• the components can be interconnected, with which an energy-efficient operation of the drive assembly is possible.
• the at least one supply device is designed as a further frequency converter.
• the at least two electrical machines can both be operated together with reduced speed at one of the frequency converter.
• the frequency converters can be used to start or start up the electrical machines.
• an electric machine can be coupled to a frequency converter.
• at least one of the electrical machines can also be connected directly to the energy supply network. Thus, the electric machines can be operated efficiently depending on the current application.
• the frequency converters are designed for different power ratings.
• the frequency conversion be selected with the appropriate rated power. For example, one frequency converter with a rated power of 5 kW and another frequency converter with a rated power of 10 kW can be provided. If the at least two electrical machines require an electric power of 4 kW in total when operating with redu ⁇ ed speed, they can be operated at the frequency which has a rated power of 5 kW. This enables energy-efficient operation of the electrical machines.
• the at least one supply device is designed as a soft start device.
• a soft start device allows, for example, a reduction of the inrush current of the electric machine. This can be enabled for example by a respective phases ⁇ angle control. Depending on the rated power or current required electrical power of the electrical machines, these can be operated with the soft starter or the frequency converter. If electric machines of different design, for example asynchronous machines, synchronous machines or PM Linestart motors, are used in the drive arrangement, these can be operated correspondingly at the soft-start device or the frequency converter.
• the at least one supply device is designed as an electrical storage device.
• the electrical storage device can be arranged in a DC link of the drive arrangement.
• one of the electrical machines this can be stored in the electrical storage device ⁇ rule.
• the electric machine can be connected during braking by means of the connecting device with the electrical storage device.
• the stored energy in the electrical storage device can be used to start up or to operate at least one further electrical machine by the electrical storage device is connected by means of the connection ⁇ device with this electrical machine. In this way, the energy generated in the drive device can be easily used.
• At least one of the electrical Ma ⁇ machines can be used as energy storage like a flywheel.
• a flywheel for example, the rotor of the electric machine or arranged on the rotor flywheel is suitable.
• the electric machine can also be gekop ⁇ pelt with a separate flywheel or flywheel. In this case, the electric machine can first be accelerated by means of the frequency converter to rated speed.
• the provided or stored by the electric machine mechanical energy can be in turn ver ⁇ applies, at least to start another electric machine.
• the inventive method for operating a drive ⁇ arrangement comprises providing at least two elekt ⁇ step machines, each having a nominal speed, the driving of the two electrical machines having at least one frequency converter, connecting the electrical machine with the frequency converter or a power supply network with a Connecting means, the simultaneous electrical connection of the electrical machines to the frequency converter by the connecting means and the operation of the electrical machines simultaneously connected to frequency inverter at a lower speed than the rated speed.
• FIGURE shows a schemati ⁇ cal representation of a drive assembly.
• the embodiment described in more detail below represents a preferred embodiment of the present invention.
• the FIG shows a drive device 10 in a schematic view.
• the drive device 10 comprises at least two electrical machines 12, 14, 16.
• the drive arrangement 10 comprises three electrical machines 12, 14 and 16.
• the electrical machines 12, 14, 16 can be in the form of an asynchronous machine, as a permanent-magnet synchronous machine or as so-called PM Linestart Moto ⁇ Ren be formed.
• the electrical machines 12, 14, 16 have different electrical power ratings on ⁇ .
• the electrical machines 12, 14, 16 can be used for example for pumps, fans or conveyor belts.
• the drive arrangement 10 comprises a frequency converter 18.
• the frequency converter 18 is coupled to a power supply network 20. Between the power supply network 20 and the frequency converter 18, a contactor 22 is connected.
• the frequency converter 18 is configured to adjust the frequency and / or the amplitude of the electrical voltage provided by the power supply network 20.
• Each of the electric machines 12, 14, 16 is electrically connected to a switching device 24, which has three switching positions.
• the switching devices 24 can each be controlled individually with a control device 26.
• the electrical machines 12, 14, 16 are each connected to the frequency converter 18. connected.
• the electrical machines 12, 14, 16 are connected to an electrical line element 28, which in turn is connected to the power supply network 20.
• the electrical machines 12, 14, 16 are connected neither to the frequency converter 18 nor to the energy supply network 20. In the middle switching position, the electric machines 12, 14, 16 can be completely switched off.
• the electrical machines 12, 14, 16 can be switched off individually with the control device 26. Likewise, the electric machines 12, 14, 16 can be individually towed up to the frequency converter 18. Furthermore, the electric machines 12, 14, 16 can be individually connected to the power supply network 20.
• the connecting device 30 may additionally have a corresponding sensor with which the rotational speed of the electrical machines can be detected. If the electric machines 12, 14, 16 are to be operated at a speed that is less than their rated speed, the electric machines 12, 14, 16 can be operated in parallel on the frequency converter 18. This operating mode of the drive assembly 10 is particularly suitable when the electrical power required by the electric machines 12, 14, 16 drops significantly with their speed. This is the case with pumps, for example. These drives the Torque ⁇ ment increases roughly with the square of speed. The required electrical power typically increases cubic with speed. For example, if four electric machines 12, 14, 16 are operated with a rated electrical power of 2 kW each with the power supply network 20, they require a total power of 8 kW.
• the drive arrangement 10 can also comprise at least one further supply device (not shown here).
• the supply device can be another frequency converter, a soft starter or an electrical energy storage device.
• at least one of the electrical machines 12, 14, 16 are electrically connected to the frequency converter 18, the further supply device and / or the power supply network 20.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Control Of Multiple Motors (AREA)

Priority Applications (1)

Applications Claiming Priority (1)

Publications (1)

Family

ID=45976292

Family Applications (1)

Country Status (1)

Cited By (4)

Citations (10)

• 2012
  • 2012-04-02 WO PCT/EP2012/055943 patent/WO2013149639A1/fr not_active Ceased

Patent Citations (10)

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