KR101587468B1 - Speed control apparatus and method of multi motor - Google Patents

Abstract

The present invention relates to a multi-motor speed control device and a control method thereof. More particularly, the present invention relates to a multi-motor speed control device and a control method thereof, A drive unit for varying a frequency of a drive power applied to the motor to control a speed of the motor, and a plurality of switches arranged in a matrix manner between the drive unit and the motors, The variable speed drive and the multiple motors are connected in a matrix manner to control the speed of the multiple motors and the number of variable frequency drives is minimized to reduce the manufacturing cost.

Description

[0001] SPEED CONTROL APPARATUS AND METHOD OF MULTI MOTOR [0002]

The present invention relates to a multiple motor speed control apparatus and method, and more particularly, to a multiple motor speed control apparatus and method for controlling the speed of a multiple (multiple) motor provided on a ship.

Ships or offshore structures are equipped with hundreds of motors to drive various equipment, such as drilling equipment, loading equipment, and propulsion units, depending on the purpose of the ship.

Each motor is supplied with power from the generator and driven according to the control signal of the main control panel of the electric room.

The applicant of the present application has filed a patent application to the following patent document 1 on the technology of a ship's motor system.

Generators play an important role in ships and power generators, and the capacity and number of generators of generators play a major role in convenience of ship operation and energy saving.

In recent years, variable speed drives have been applied as motor speed control is required for reasons such as energy saving of a ship.

The following Patent Document 1 discloses a configuration of a multiple motor parallel drive control device for controlling a plurality of motors connected in parallel using a variable frequency drive.

On the other hand, a ship carrying crude oil or LNG is equipped with multiple motors for driving a cargo pump.

1 is a configuration diagram of a multi-motor speed control apparatus according to the prior art.

1, a conventional multiple motor speed control apparatus connects multiple motors 2 to a switchboard 1, and drives a variable frequency drive 3 for each motor 2 at a ratio of 1: 1 So that the speed of each motor 2 is controlled.

Here, each variable frequency drive 3 changes the frequency of a control signal applied from a control panel (not shown) to switch the power supplied from the switchboard to adjust the rotational speed of the motor.

An open / close switch (4) is provided between the switchboard (1) and each variable frequency drive (3) according to the control signal of the control panel.

Korean Patent Publication No. 10-2012-0013017 (published on February 14, 2012) Korean Patent Publication No. 10-2013-0117493 (published on October 28, 2013)

However, the variable frequency drive is an expensive apparatus. In the multi-motor speed control apparatus according to the related art, since the variable frequency drive is individually installed for each motor, the production cost increases.

Further, in the multi-motor speed control apparatus according to the related art, when an abnormality occurs in the variable frequency drive, the speed of the corresponding motor can not be controlled.

In addition, the conventional multi-motor speed control apparatus has a problem in that noise level and heat generation are high when the motor is driven and additional cost is increased when a separate cooling device is provided.

SUMMARY OF THE INVENTION An object of the present invention is to provide a multiple motor speed control device and a control method for controlling energy consumption by controlling speeds of multiple motors provided on a ship.

Another object of the present invention is to provide a multiple motor speed control device and a control method that can control the speed of multiple motors in a mattress manner to minimize the number of variable frequency drives.

In order to achieve the above-mentioned object, the multi-motor speed control device according to the present invention includes an electric power distribution board that receives power from a generator of a ship, a plurality of motors driven by receiving driving power from the power distribution board, A driving unit for varying a frequency of a driving power source applied to the motor to control a speed of a motor driven partly or entirely, and a plurality of switches arranged in a matrix manner between the driving unit and the motors, And a switching unit for selectively supplying or cutting off the driving power.

Wherein the driving unit includes a first variable frequency drive connected to each of the plurality of motors via a first bus, one end of the first bus is connected to the first variable frequency drive, And is connected to each motor by branching in a number corresponding to the number of motors.

Wherein the driving unit further includes a second variable frequency drive connected to the plurality of motors via a second bus, one end of the second bus is connected to the second variable frequency drive, the other end of the second bus is connected to the second variable frequency drive, And the motors are connected to the respective motors by branching in a number corresponding to the number of the motors.

The switching unit may include a first switch provided between the first variable frequency drive and each of the motors, and a second switch provided between the second variable frequency drive and each of the motors.

And the first and second switches operate in opposite directions when connected to the same motor.

The multi-motor speed control apparatus according to the present invention further includes a control panel for selectively generating a control signal to variably control the speed of a motor that selectively drives some or all of the plurality of motors, A control signal is generated so as to control part or all of the motors at the same speed or control them at different speeds.

In accordance with another aspect of the present invention, there is provided a method for controlling a multiple motor speed, the method comprising: (a) receiving power from a generator in a power distribution board and distributing the power; (b) (C) a step of varying a frequency of the drive power source by using a first variable frequency drive provided in the drive unit, and driving the drive power source And controlling the speed of the motor.

The multi-motor speed control method according to the present invention further includes the step of (d) controlling the speed of the multiple motors using the second variable frequency drive when an abnormality occurs in the first variable frequency drive provided in the driving unit .

The step (c) or step (d) selectively opens and closes the first and second switches provided between the driving unit and the multiple motors, thereby controlling part or all of the multiple motors at the same speed .

The step (c) or step (d) selectively opens and closes the first and second switches provided between the driving unit and the multiple motors to control the multiple motors at different speeds.

As described above, according to the multi-motor speed control device and the control method of the present invention, the speed of the multiple motors is controlled by connecting the variable-frequency drive and the multiple motors in a matrix manner, and the number of variable- Can be reduced.

According to the present invention, the speed of the multiple motors is controlled by using the first variable frequency drive, and when an error occurs in the first bus or the first variable frequency driver, The stability of the system can be improved.

Further, according to the present invention, compared to the case where the variable frequency driver and the motor are constituted in a one-to-one manner according to the prior art in the case of the moped driving, by reducing the noise level and the heat relatively, Can be obtained.

Further, according to the present invention, there is obtained an effect that part or all of the multiple motors can be controlled at the same speed or at different speeds.

1 is a configuration diagram of a multi-motor speed control apparatus according to the prior art,
2 is a configuration diagram of a multiple motor speed control apparatus according to a preferred embodiment of the present invention,
FIG. 3 is a flowchart illustrating steps of a method for controlling a multi-motor speed control apparatus according to a preferred embodiment of the present invention,
Fig. 4 is an operational state diagram for controlling the speeds of multiple motors in the multiple motor speed control apparatus shown in Fig. 2. Fig.
5 is an exemplary diagram showing an operation state in which multiple motors are controlled at different speeds in the first and second variable frequency drives;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a multi-motor speed control apparatus and a control method according to preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the present embodiment, for convenience of description, a description will be given using multiple motors for driving a cargo pump of a cargo carrying liquid cargo such as crude oil or LNG.

The plurality of motors for driving the cargo pump are driven partly or totally independently for the unloading of the liquid cargo, so that each of the motors must be capable of driving and controlling the speed individually.

Of course, the present invention is not limited to the cargo pump. It is needless to say that the present invention is not limited to the cargo pump, but may be modified to drive multiple motors applied to various types of equipment installed in accordance with the purpose of the ship or an offshore structure, It should be noted that

2 is a configuration diagram of a multiple motor speed control apparatus according to a preferred embodiment of the present invention.

As shown in FIG. 2, the multi-motor speed control apparatus 10 according to the preferred embodiment of the present invention includes an electric distribution board 11 that receives power from a generator (not shown) of a ship and distributes the electric power, A plurality of motors 12 driven by a drive power source and a control signal applied from the control panel 30 to drive some or all of the plurality of motors 12 to control the speed of the driven motor 12 And a driving unit 20 for varying the frequency of the driving power source applied to the motor 12.

The multiple motor speed control apparatus 10 according to the preferred embodiment of the present invention selectively drives some or all of the plurality of motors 12 and generates a control signal to variably control the speed of the driven motor 12 And a control panel 30 for controlling the operation of the apparatus.

The multiple motor speed control apparatus 10 according to the preferred embodiment of the present invention includes a plurality of switches 41 and 42 arranged in a matrix manner between the driving unit 20 and each motor 12, And a switching unit 40 for selectively supplying or cutting off the driving power supplied to each motor 12 according to the control signal of the control unit 40.

In this embodiment, the motor 12 functions to drive a cargo pump that pumps liquid cargo stored in the tanker.

For example, a ship may be equipped with six tankers, and three cargo pumps may be installed to pump the liquid cargo stored in each of the two tankers.

Each of the motors 12 is connected to the cargo pump through a shaft to provide a driving force.

The driving unit 20 includes a first variable frequency drive 22 connected to each of the plurality of motors 12 through a first bus 21.

In addition, when the first bus 21 or the first variable frequency drive 22 is in an abnormal state, the driving unit 20 continuously drives each of the motors 12 to control the speed of the motor 12, And a second frequency drive (24) connected via a second bus (23).

One end of each of the first and second buses 21 and 23 is connected to the first and second variable frequency drivers 22 and 24 respectively and the other end of the first and second buses 21 and 23 is connected to the motor 12, And may be connected to the respective motors 12.

The first and second variable frequency drives 22 and 24 function to change the frequency of the driving power supplied to each motor 12 according to a control signal of the control panel 30.

To this end, the first and second variable frequency drives 22,24 each comprise a power circuit, a controller in communication with the power circuit, a speed droop module for adjusting the torque current component and determining the speed reference signal, And a flux sharing module for determining the flux reference signal based on the magnetizing current component.

Here, the controller may determine a motor speed estimate and a motor flux estimate based on stator voltage and stator current measurements.

As such, the present invention minimizes the number of variable frequency drives for controlling a plurality of motor speeds, thereby reducing manufacturing costs.

The present invention controls the speed of multiple motors using a first variable frequency drive at normal times. When an error occurs in the first bus or the first variable frequency driver, the multiple buses and the second variable frequency drives are used to drive multiple motors Can be controlled.

As described above, the present invention can improve the stability of the system by providing the first variable frequency drive and the second variable frequency drive in the driving unit to systematically configure the redundancy.

On the other hand, between the switchboard 11 and the first and second variable frequency drives 22 and 24 of the drive unit 20, there are respectively provided a first open / close switch 25 which is opened and closed in accordance with a control signal of the control panel 30, An opening / closing switch 26 may be provided.

The switching unit 40 is provided between the first variable frequency drive 22 and each motor 12 and the first switch 41 and the second variable frequency drive 24 provided between the motors 12, 2 switch 42. In this case,

The first and second switches 41 and 42 can be individually opened and closed according to the control signal of the control panel 30.

In particular, the first and second switches 41 and 42 connected to the same motor 12 can be opened and closed as opposed to each other.

The control panel 30 drives the plurality of motors 12 using the first variable frequency drive 22 or the second variable frequency drive 24 and generates a control signal to control the speed of the driven motor 12 do.

The control panel 30 controls the first and second open / close switches 25 and 26 and the first and second switches 25 and 26 of the switching unit 40 so as to selectively drive only the motor 12 to be driven among the plurality of motors 12. [ (Not shown).

At the same time, the control panel 30 can control some or all of the plurality of motors 12 at the same speed or at different speeds.

The control panel 30 may be provided as a control unit of a power management system for managing the power of the ship or may be a separate controller communicably connected to the control unit.

3 and 4, a method of controlling a multiple motor speed control apparatus according to a preferred embodiment of the present invention will be described in detail.

FIG. 3 is a flowchart for explaining a control method of a multiple motor speed control apparatus according to a preferred embodiment of the present invention. FIG. 4 is a flowchart illustrating an operation state diagram for controlling the speed of multiple motors in the multiple motor speed control apparatus shown in FIG. to be.

FIG. 4 shows an operation state for controlling the speed of the entire multiple motors 12 in the first variable frequency drive 22.

In step S10 of FIG. 3, the power distribution board 11 distributes the power supplied from the generator.

At this time, the control panel 30 controls the first and second open / close switches 25 and 26 of the drive unit 20 and the first and second open / close switches 25 and 26 of the drive unit 20 so as to drive the cargo pump provided in the tanker, And second variable frequency drives 22 and 24, and the first and second switches 41 and 42 of the switching unit 40. [

For example, as shown in FIG. 4, the first variable frequency drive 22 selectively drives the motor 12 to be driven in accordance with the control signal of the control panel 30 in a steady state, 12 can be controlled (S12).

To this end, the control panel 30 controls the first switch 41 of the switching unit 40, which is formed in a matrix manner, to turn on the first opening / closing switch 25 and supply driving power to the motor 12 to be driven And generates a control signal to turn on some or all of them.

Then, the control panel 30 generates the target speed of the motor 12 to be driven in the first variable frequency drive 22 as a control signal.

Then, the first variable frequency drive 22 varies the frequency of the driving power source according to the received target speed.

Accordingly, the cargo pump connected to the driven motor 12 and the shafts connected to the respective shafts can be pumped to unload the liquid cargo stored in the tanker.

On the other hand, in step S14, the control panel 30 checks whether abnormality of the first bus 21 or the first variable frequency drive 22 occurs.

If an abnormality has occurred in the first bus 21 or the first variable frequency drive 22 as a result of the inspection in the step S14, the control panel 30 uses the second variable frequency drive 24, And the speed of the driven motor 12 can be controlled.

That is, the control panel 30 turns on the second switch 42 of the switching unit 40, which is formed in a matrix manner, to turn on the second open / close switch 26 and supply driving power to the motor 12 to be driven Or the whole is turned on.

Then, the control panel 30 generates the target speed of the motor 12 to be driven in the second variable frequency drive 24 as a control signal.

Then, the second variable frequency drive 24 controls the speed of the motor 12 driven by varying the frequency of the driving power according to the target speed received from the control panel 30 (S16).

Accordingly, the present invention can drive multiple motors using the second variable frequency drive even when an error occurs in the first variable frequency drive, and can continuously control the speed of the driven motor.

In step S18, the control panel 30 checks whether or not the motor drive stop command is inputted from the operator through the operation panel (not shown), and controls to repeat steps S14 to S18 until the motor drive stop command is input .

If the motor stop command is inputted in step S18, the control panel 30 stops controlling the multi-motor speed controller 10 and terminates the operation.

Through the above-described process, the variable frequency drive and the multiple motors can be configured in a matrix manner to minimize the number of variable frequency drives.

In the above embodiment, the control panel 30 controls the driving of the multiple motors 12 by using the first variable frequency drive 22 or the second variable frequency drive 24. However, But is not limited thereto.

The present invention can control the multiple motors 12 at different speeds by using the first variable frequency drive 22 and the second variable frequency drive 24.

For example, FIG. 5 is an exemplary diagram illustrating an operation state in which a plurality of motors are controlled at different speeds in the first and second variable frequency drives, respectively.

As shown in Fig. 5, the control panel 30 turns on the first and second open / close switches 25 and 26, turns on a part of each of the first and second switches 41 and 42, .

The control panel 30 generates a control signal so that some of the multiple motors 12 are driven by the first variable frequency drive 22 and others are driven by the second variable frequency drive 24. [

At this time, the control panel 30 generates a control signal to control the first and second variable frequency drives 22 and 24 to control the motors 12 to be driven at the same target speed or different target speeds, respectively.

As described above, the present invention can control the multiple motors to be driven at the same speed or at different speeds using the first and second variable frequency drives.

Although the invention made by the present inventors has been described concretely with reference to the above embodiments, the present invention is not limited to the above embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

In the above embodiment, a multi-motor for driving a cargo pump of a cargo carrying liquid cargo such as crude oil or LNG has been described. However, the present invention is not limited thereto.

That is, the present invention can be modified not only to control the cargo pump but also to control the speed of the driven motor and to drive multiple motors applied to various equipment installed in accordance with the purpose of the ship or an offshore structure.

The present invention is applied to a multiple motor speed control device technique for selectively driving multiple motors by configuring a variable frequency drive and multiple motors in a matrix manner and controlling the speed of a driven motor.

10: Multiple motor speed control device 11: Switchboard
12: motor 20:
21: first bus 22: first variable frequency drive
23: second bus 24: second variable frequency drive
25: first opening and closing switch 26: second opening and closing switch
30: Control panel 40:
41: first switch 42: second switch

Claims (10)

An electric distribution board which receives power from the generator of the ship and distributes it,
A plurality of motors driven by receiving drive power from the switchboard,
A driving unit for varying the frequency of driving power applied to the motor to control the speed of the motor driven to drive part or all of the plurality of motors,
And a switching unit which is composed of a plurality of switches configured in a matrix manner between the driving unit and the motors and selectively supplies or blocks driving power supplied to the motors,
The drive unit includes a first variable frequency drive connected to the plurality of motors via a first bus,
And a second variable frequency drive connected to each of the plurality of motors via a second bus and controlling the speed of the plurality of mats when an error occurs in the first variable frequency drive,
Wherein the switching unit includes a first switch provided between the first variable frequency drive and each motor,
And a second switch provided between the second variable frequency drive and each of the motors. The method according to claim 1,
One end of the first bus is connected to the first variable frequency drive,
And the other end of the first bus is branched into a number corresponding to the number of the motors and connected to each motor. 3. The method of claim 2,
One end of the second bus is connected to the second variable frequency drive,
And the other end of the second bus is branched in a number corresponding to the number of the motors and is connected to each motor. delete The method according to claim 1,
Wherein the first and second switches operate in opposite directions when connected to the same motor. The method according to any one of claims 1 to 3 and 5,
Further comprising a control panel for selectively generating a control signal to control the speed of the motor selectively driving some or all of the plurality of motors,
Wherein the control panel generates control signals for controlling some or all of the plurality of motors at the same speed or at different speeds. (a) receiving power from a generator in a distribution board and distributing the power,
(b) using a switching unit having a matrix structure between the driving unit and the multiple motors, supplying driving power distributed in the distribution board to a motor to be driven among the multiple motors,
(c) controlling a speed of a motor driven by varying a frequency of the driving power source using a first variable frequency drive provided in the driving unit; and
(d) controlling the speed of the multiple motors using the second variable frequency drive when an error occurs in the first variable frequency drive provided in the driving unit. delete 8. The method of claim 7,
Wherein the step (c) or step (d) selectively opens and closes the first and second switches provided between the driving unit and the multiple motors to control a part or all of the multiple motors at the same speed Multiple motor speed control method. 8. The method of claim 7,
Wherein the step (c) or step (d) selectively opens and closes the first and second switches provided between the driving unit and the multiple motors to control the multiple motors at different speeds. Control method.

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