WO2015093871A1

WO2015093871A1 - Apparatus and method for supplying hybrid power of offshore plant

Info

Publication number: WO2015093871A1
Application number: PCT/KR2014/012536
Authority: WO
Inventors: 정호영; 배영호
Original assignee: 대우조선해양 주식회사
Priority date: 2013-12-18
Filing date: 2014-12-18
Publication date: 2015-06-25

Abstract

The present invention relates to an apparatus and a method for supplying hybrid power by using regenerative power generated at an offshore plant. According to an embodiment of the present invention, provided is an apparatus for supplying hybrid power of an offshore plant, the apparatus comprising: a generator; an AC/DC converter converting, into direct current, alternating current generated from the generator so as to supply the direct current to a DC bus; a power load connected to the DC bus so as to generate regenerative power; a first power storage unit for storing power when a voltage of the DC bus is maintained at a level of a first threshold value or higher for a first time period, and supplying the stored power to the DC bus when the voltage of the DC bus is maintained at a level of a second threshold value or lower for a second time period; and a first resistance unit for consuming power when the voltage of the DC bus is maintained at the level of the first threshold value or higher for a third time period, wherein the third time period is longer than the first time period.

Description

Hybrid Power Supply and Method in Offshore Plant

The present invention relates to a hybrid power supply of an offshore plant, and more particularly, to a hybrid power supply apparatus and method using the regenerative power generated in the offshore plant.

As the international rapid industrialization and industry develop, the use of resources such as petroleum is gradually increasing. Therefore, stable production and supply of oil is becoming a very important problem at the global level.

For this reason, the development of marginal or deep sea oil fields, which have been neglected in recent years due to lack of economy, has become economic. Therefore, along with the development of the seabed mining technology, the development of offshore plants with drilling equipment suitable for the development of such oil fields is actively progressing.

Offshore plants are equipped with various drilling-related equipment, such as derrick systems, draw works, top drives, mud pumps, cement pumps, risers, and drill pipes, for drilling oil and gas in the seabed below. It is.

Drawworks are equipment for lifting and lowering drill pipes, inserting casings, and the like, including drums and motors. The drum receives power from the motor to regulate the lifting of the drill pipe by winding or unwinding the wire rope. The motor is adjustable in speed to adjust the speed of the drum, thereby adjusting the speed of the drill pipe.

Topdrive is a device that provides power for drilling and pipe fastening in drilling operations.

Offshore plants have fixed platforms for anchoring at one point offshore and floating offshore plants capable of drilling in deep waters of over 3,000 meters.

Floating offshore plants are equipped with a plurality of thrusters as propulsion devices for dynamic positioning by a main propulsion device or a computer. The thrusters are propellers installed on the bottom of the ship to change the direction of action of the propellers. These thrusters are normally used to navigate or enter the canal on their own without sailing or tug. The thruster is powered by a thruster motor connected to the thruster.

1 is a view showing a power supply system according to the prior art.

As shown in FIG. 1, AC power generated by the generator 110 is supplied to an AC bus, and the first AC / DC converter 121, the second AC / DC converter 122, and the third AC are supplied to the AC bus. The / DC converter 123 is connected.

The first AC / DC converter 121 converts the AC supplied from the AC bus into direct current and supplies the same to the first DC bus 131, and the DC / AC converter 141 is supplied from the first DC bus 131. DC is converted into AC and supplied to the first thruster motor 151.

The second AC / DC converter 122 converts the AC supplied from the AC bus into direct current and supplies it to the second DC bus 132, and the DC / AC converter 142 receives the second DC bus 132. DC is converted into AC and supplied to the second thruster motor 152.

The third AC / DC converter 123 converts the AC supplied from the AC bus into direct current and supplies the same to the third DC bus 133, and the third DC bus 133 includes a plurality of DC / AC converters ( 143 to 148 are connected. Each of the plurality of DC / AC converters 143 to 148 converts direct current supplied from the third DC bus 133 into alternating current so that the plurality of

drawworks motors

153, 154, 155, 158, 159, The

top drive

156, 157 of the supply to the motor connected to it.

The

drawworks motors

153, 154, 155, 158, 159 and the

top drive motors

156, 157 must repeat the operation of raising and lowering drilling equipment, such as a drill pipe, so that they rotate at rated speed and then rotate. There is a driving characteristic in which braking occurs frequently, such as sudden stop or rotation in the opposite direction, and the

thruster motors

151 and 152 also rotate at rated speed for dynamic position control and then suddenly stop rotation or rotate in the opposite direction. This is a frequently occurring driving feature. However, when braking occurs in the motor, regenerative power is generated. In addition, even when the thruster is rotated by disturbance, regenerative power is generated in the thruster motor.

When regenerative power is generated from the drawworks motor, the top drive motor, or the thruster motor, the voltage of the DC bus to which the drawworks motor, the top drive motor, or the thruster motor is connected increases. If the voltage rises above the limit the DC bus can accommodate, the DC bus trips.

Therefore, according to the prior art, resistors 161 to 166 are provided to consume regenerative power as heat to prevent tripping of the DC bus.

Figure 2 is a graph showing the power consumed in each component in the power supply system according to the prior art.

In FIG. 2, the power produced by the generator supplies the first load 220 and the AC / DC converter 260 through the distribution board. The AC / DC converter 260 converts alternating current into direct current and supplies it to the second load 240, and supplies it to the drawworks 230 through the DC / AC converter. The first load 220 and the second load 240 are loads consuming a constant power. On the other hand, the drawworks 230 continuously changes the amount of power consumed, and when the power is negative in FIG. 2, it indicates that regenerative power has occurred. The regenerative power generated at the drawworks 230 is consumed at the second load 240 or the resistor 250.

It can be seen that as the power consumption of the drawworks 230 changes rapidly, the power output of the generator 210 also changes rapidly. However, diesel generators use more fuel when the power output changes suddenly than when the power output is constant, and emits more exhaust gas as more fuel is used.

In addition, the generator must be able to change the output power quickly to properly supply power according to the rapidly changing power consumption of the drawworks motor, the top drive motor, and the thruster motor. However, the generator is a slow reaction speed, there is a problem that can not properly supply power in accordance with the rapidly changing power consumption of the drawworks motor, top drive motor, thruster motor. If power is not properly supplied to the drawworks motor, the top drive motor, and the thruster motor, there is a problem that a dangerous situation may occur due to the characteristics of the drilling operation. In addition, when a power failure occurs, a dangerous situation may be caused even when the power supply to the motor of the drawworks or the motor of the top drive is suddenly cut off.

That is, according to the prior art, the problem of wasting energy by consuming the regenerative power from the resistor, the fuel consumption and exhaust gas increase as the power output of the generator changes rapidly, the generator is a drawworks motor, the top drive motor, the thruster There are problems of not properly powering the motor and the possibility of dangerous situation in case of sudden power failure.

It is an object of the present invention to efficiently utilize regenerative power, to maintain a constant power output of a generator, to adequately supply power to a rapidly changing load, and to supply power in case of sudden power failure. It is to provide a hybrid power supply device and method.

According to an embodiment of the present invention for achieving the above object, a hybrid power supply apparatus of an offshore plant, the generator; An AC / DC converter for converting alternating current produced by the generator into direct current and supplying it to a DC bus; A power load coupled to the DC bus to generate regenerative power; A first power storage unit configured to store power when the voltage of the DC bus is greater than or equal to a first threshold for a first time, and supply the stored power to the DC bus if it is less than or equal to a second threshold for a second time; And a first resistor that consumes power when the voltage of the DC bus remains above the first threshold for a third time, the third time being longer than the first time. Is provided.

In particular, the hybrid power supply apparatus of the offshore plant may further include a first DC / DC converter connected to the DC bus, and the first power storage unit and the first resistor unit may be connected to the first DC / DC converter. .

In addition, a first DC / DC converter connected to the DC bus; And a second DC / DC converter connected to the DC bus, wherein the first power storage unit is connected to the first DC / DC converter and the first resistor unit is connected to the second DC / DC converter.

In addition, the first power storage unit may be an ultracapacity.

In addition, the power load may be drawworks.

In addition, the power load may be a top drive.

According to another embodiment of the present invention for achieving the above object, a hybrid power supply method of a marine plant, comprising the steps of: measuring the voltage of the DC bus; Storing power by the power storage unit when the voltage of the DC bus is maintained above the first threshold for a first time; The power storage unit supplies power to the DC bus if the voltage of the DC bus remains below a second threshold for a second time, and the DC bus is connected with a power load for generating regenerative power; A hybrid power supply method of an offshore plant is provided.

In particular, the hybrid power supply method of the offshore plant includes the step of the resistor consumes power when the voltage of the DC bus is maintained above the first threshold for a third time, the third time is greater than the first time Can be longer.

In addition, a first DC / DC converter may be connected to the DC bus, and the power storage unit and the resistor unit may be connected to the first DC / DC converter.

In addition, a first DC / DC converter and a second DC / DC converter are connected to the DC bus, the power storage unit is connected to the first DC / DC converter, and the resistor unit is connected to the second DC / DC converter. Can be.

In addition, the power storage unit may be an ultracapacity.

In addition, the power load may be drawworks.

In addition, the power load may be a top drive.

According to an embodiment of the present invention, the regenerative power generated from the drawworks motor, the top drive motor, and the thruster motor is stored using the power storage unit, and the drawworks motor, the top drive motor, and the thruster motor are stored. When the power consumption of the power supply increases rapidly, regenerative power can be efficiently used by supplying the power stored in the power storage unit, and the power output of the generator can be kept constant, thereby reducing the exhaust gas.

As an electric power storage unit, an ultra-capacity ultracapacity can be used to properly supply power to a load in which power consumption changes rapidly.

And, in the event of a transient or power outage, drilling equipment such as drawworks or topdrives can safely shut down by using the power stored in the power storage.

1 is a view showing a power supply system according to the prior art.

3 is a view showing a hybrid power supply apparatus of an offshore plant according to a first embodiment of the present invention.

4 is a view showing a hybrid power supply apparatus of a marine plant according to a second embodiment of the present invention.

5 is a view showing a hybrid power supply apparatus of a marine plant according to a third embodiment of the present invention.

6 is a view illustrating a process of storing power in a power storage unit in a hybrid power supply method of a marine plant according to an embodiment of the present invention.

7 is a diagram illustrating a process of supplying power from a power storage unit to a DC bus when power is insufficient in a hybrid power supply method of a marine plant according to an embodiment of the present invention.

8 is a diagram illustrating a process of supplying power from a power storage unit to a DC bus at a power failure in a hybrid power supply method of a marine plant according to an embodiment of the present invention.

9 is a graph showing power consumed by each component in the power supply according to the embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

First, a hybrid power supply apparatus of an offshore plant according to an embodiment of the present invention will be described with reference to FIGS. 3 to 5. 3 is a view showing a hybrid power supply of the offshore plant according to a first embodiment of the present invention, Figure 4 is a view showing a hybrid power supply of the offshore plant according to a second embodiment of the present invention, Figure 5 Is a diagram showing a hybrid power supply apparatus for an offshore plant according to a third embodiment of the present invention.

3 to 5, the hybrid power supply of the offshore plant according to the first embodiment of the present invention is a generator 310, AC / DC converter 320, DC bus (321), VFD (variable frequency drive) control unit 330, DC / DC converter (351 to 353), power load (361 to 363), power storage (371 to 373), resistor (381 to 383) and sensor (391) Include.

Generator 310 is a device for producing the power required in the offshore plant, is connected to the AC / DC converter 320 via the AC bus. Alternatively, the power produced by the generator 310 may be supplied to the AC / DC converter 320 after being changed to a voltage suitable for use in power loads in the transformer. The generator 310 may produce AC power as an alternator.

The AC / DC converter 320 converts the AC power produced by the generator 310 into direct current and supplies it to the DC bus 321.

The DC bus 321 supplies power to a power load connected to the DC bus 321. The power load using DC power may be directly connected to the DC bus 321, and the power load using AC power may be connected to the DC bus 321 through the DC / AC converters 341 to 343.

The power loads 361 to 363 shown in FIG. 3 are power loads using AC power and are connected to the DC bus 321 through the DC / AC converters 341 to 343. The DC / AC converters 341 to 343 convert the direct current supplied from the DC bus 321 into alternating current and supply them to the power loads 361 to 363.

The power loads 361 to 363 may be drawworks motors or top drive motors.

In FIG. 3, three drawworks motors 361 to 363 are connected to the DC bus 321 as a power load. However, the present invention is not limited thereto, and the number of drawworks motors and the top drive may be varied. The motor may be connected to the DC bus 321.

Since the drawwork motors 361 to 363 must repeatedly raise and lower the drilling equipment such as the drill pipe, the draw characteristics such as sudden stop of rotation or rotation in the opposite direction are frequently applied. Regenerative power is generated in the motors of the works.

The power storage units 371 to 373 store power by receiving power from the DC bus 321 when the voltage of the DC bus 321 maintains the first threshold or more for a first time, and stores the power, and the voltage of the DC bus 321. Maintaining below the second threshold for this second time provides power to the DC bus 321. For example, assuming that the DC bus 321 is for 720V and tripped when it is greater than 750V, the first threshold may be set to 740V.

The DC / DC converters 351 to 353 measure the voltage of the DC bus 321 and supply power from the DC bus 321 to the power storage units 371 to 373 when the voltage of the DC bus 321 is maintained above the first threshold for the first time. If power is stored in the power storages 371 to 373, and the voltage of the DC bus 321 remains below the second threshold for a second time, the power is stored from the power storages 371 to 373 to the DC bus 321. This flow allows power to be supplied from the power storages 371 to 373 to the DC bus 321.

When regenerative power is generated in the power loads 361 to 363, the voltage of the DC bus 321 rises. When the power consumption of the power loads 361 to 363 rises suddenly, the voltage of the DC bus 321 falls.

That is, when regenerative power is generated in the power loads 361 to 363, the voltage of the DC bus 321 rises, and when the voltage of the DC bus 321 remains above the first threshold for the first time, the DC / DC converter 351. 353 to 353 supply power to the power storage units 371 to 373 so that power is stored in the power storage units 371 to 373 so that the regenerative power generated from the power loads 361 to 363 is stored in the power storage units 371 to 373. 373).

When the power consumption of the power loads 361 to 363 suddenly rises, the voltage of the DC bus 321 goes down, and if the voltage of the DC bus 321 remains below the second threshold for a second time, the DC / DC converter ( Powers 351 to 353 flow from the power storages 371 to 373 to the DC bus 321 so that power is supplied from the power storages 371 to 373 to the DC bus 321. The power storages 371 to 373 may be at least one of an ultracapacitor, a capacitor, a battery, and a flywheel. In particular, when the power storage units 371 to 373 are ultracapacitors, when the power consumption of the power loads 361 to 363 rises suddenly because the response speed of the ultracapacitor is higher than that of the generator 310, the power loads 361 to 363 may be used. Can be powered up quickly.

Also, the power storage units 371 to 373 supply power to the DC bus 321 even in a transient state or a power failure. When the sensor 391 that detects a transient state or a power outage detects a transient state or a power outage, the sensing signal is transmitted to the DC / DC converters 351 to 353, and the DC / DC converters 351 to 353 power storage unit 371. To power from the 373 to the DC bus 321.

The sensor 391 may be installed in at least one of the switch board and the DC bus 321.

Drilling equipment such as drawworks and topdrives can cause dangerous situations if the power supply is suddenly interrupted. Thus, in the event of a transient or power outage, the power storages 371 to 373 supply power to the DC bus 321 so that the drilling equipment can be safely shut down.

The resistors 381 to 383 consume power when the voltage of the DC bus 321 remains above the first threshold for a third time. At this time, the third time is a longer time than the first time.

When regenerative power occurs in the power loads 361 to 363, the power storage units 371 to 373 store the power when the voltage of the DC bus 321 rises and remains above the first threshold for the first time. In addition, when the capacity of the power storage units 371 to 373 is full, the voltage of the DC bus 321 does not drop and continues to maintain the first threshold or more. Therefore, it may be determined that the voltage of the power storage units 371 to 373 is full that the voltage of the DC bus 321 maintains the first threshold or more for the third time. However, when regenerative power continues to occur in a state where the power storage units 371 to 373 are full, the voltage of the DC bus 321 may continue to increase, causing the DC bus 321 to trip. Therefore, when the voltage of the DC bus 321 is maintained above the first threshold for a third time, the DC / DC converters 351 to 353 cause the resistors 381 to 383 to consume power.

3 to 5 illustrate three power storage units 371 to 373 and three resistor units 381 to 383, but the present disclosure is not limited thereto and may include various numbers of power storage units and resistor units. have.

As shown in FIG. 3, each of the plurality of power storage units 371 to 373 may be connected to one of the plurality of resistor units 381 to 383 to the DC bus 321. That is, the first power storage 371 and the first resistor 381 are connected to the DC bus 321 through the first DC / DC converter 351, and the second power storage 372 and the second The resistor part 382 is connected to the DC bus 321 through a second DC / DC converter 352, and the third power storage part 373 and the third resistor part 383 are connected to a third DC / DC converter ( 353 is connected to the DC bus 321. As shown in FIG. 3, when the power storage unit and the resistor unit are connected to one DC / DC converter, the number of DC / DC converters required may be reduced, thereby reducing the size of equipment.

Alternatively, as shown in FIG. 4, each of the plurality of power storage units 371 to 373 and the plurality of resistor units 381 to 383 may be connected to a DC bus through separate DC / DC converters 451 to 456. 321 may be connected. That is, the first power storage 371 is connected to the DC bus 321 through the first DC / DC converter 451, and the second power storage 372 connects the second DC / DC converter 452. Connected to the DC bus 321 through the third power storage unit 373 is connected to the DC bus 321 through the third DC / DC converter 453, and the first resistor 381 connects to the fourth DC. Is connected to the DC bus 321 through the / DC converter 454, the second resistor 382 is connected to the DC bus 321 through the fifth DC / DC converter 455, and the third resistor ( 383 is connected to the DC bus 321 via a sixth DC / DC converter 456. As shown in FIG. 4, when each of the plurality of power storage units 371 to 373 and the plurality of resistor units 381 to 383 is connected to the separate DC / DC converters 451 to 456, the plurality of power storage units ( Each of the 371 to 373 and the plurality of resistors 381 to 383 may be operated independently.

Alternatively, as illustrated in FIG. 5, one power load 371 to 373 and one resistor 381 to 383 may be dependent on one power load 361 to 363. That is, when regenerative power is generated in the first power load 361, the regenerative power is stored in the first power storage 371, and when the capacity of the first power storage 371 is full, the first resistor 381 is consumed. do. When regenerative power is generated in the second power load 362, the regenerative power is stored in the second power storage unit 372, and when the capacity of the second power storage unit 372 is full, the second resistor unit 382 consumes it. do. When regenerative power is generated in the third power load 363, the regenerative power is stored in the third power storage 373, and when the capacity of the third power storage 373 is full, the third resistor 383 consumes the regenerative power. do.

When regenerative power is generated in the first power load 361, the first DC / AC converter 341 detects that regenerative power is generated in the first power load 361 and transmits a control signal to the first DC / DC converter 351. Send it. Then, when the first DC / DC converter 351 receives the control signal, power is supplied from the DC bus 321 to the first power storage 371 so that the first power storage 371 stores the power. . The first DC / DC converter 351 detects whether the capacity of the first power storage unit 371 is full, and when the capacity of the first power storage unit 371 is full, the first resistor unit 381. To consume power. In FIG. 3, although the first power storage 371 and the first resistor 381 are connected to one DC / DC converter 351, the first power storage 371 and the first resistor are shown. 381 may be implemented such that each is connected to a different DC / DC converter.

Next, a hybrid power supply method of an offshore plant according to an embodiment of the present invention will be described with reference to FIGS. 6 to 8. 6 is a view illustrating a process of storing power in a power storage unit in a hybrid power supply method of a marine plant according to an embodiment of the present invention, Figure 7 is a hybrid power supply method of a marine plant according to an embodiment of the present invention FIG. 8 is a diagram illustrating a process of supplying power from a power storage unit to a DC bus when power is insufficient, and FIG. 8 is a diagram illustrating a process of supplying power from a power storage unit to a DC bus when a power failure occurs in a hybrid power supply method of a marine plant according to an exemplary embodiment of the present invention. A diagram illustrating a process of doing so.

As shown in FIG. 6, when the voltage of the DC bus is measured (S610), when the voltage of the DC bus 321 is maintained above the first threshold for the first time, power is stored in the power storage unit (S620). If the voltage of the DC bus 321 is maintained above the first threshold for a second time, the resistor consumes power (S630).

As shown in FIG. 7, when the voltage of the DC bus 321 is measured (S710), if the voltage of the DC bus is maintained below the second threshold for a third time, the power stored in the power storage unit is transferred to the DC bus. Supply (S720).

When the sensor 391 detects a power failure (S810), the sensor 391 transmits a control signal to the DC / DC converter (S820), and when the DC / DC converter receives the control signal from the sensor 391, power is applied. The storage unit supplies the stored power to the DC bus (S830).

Next, the power consumed by each component in the power supply apparatus according to the embodiment of the present invention will be described with reference to FIG. 9. 9 is a graph showing power consumed by each component in the power supply according to the embodiment of the present invention.

As shown in FIG. 9, when regenerative power is generated in the power load, the regenerative power stored in the power storage unit is stored. When the power consumption of the power load suddenly increases, the low power storage unit supplies the stored power to the power load to generate power. You can see that the output remains constant.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims

In the hybrid power supply of the offshore plant,

generator;

An AC / DC converter for converting alternating current produced by the generator into direct current and supplying it to a DC bus;

A power load coupled to the DC bus to generate regenerative power;

A first power storage unit configured to store power when the voltage of the DC bus is greater than or equal to a first threshold for a first time, and supply the stored power to the DC bus if it is less than or equal to a second threshold for a second time; And

A first resistor that consumes power when the voltage of the DC bus is maintained above the first threshold for a third time period;

Wherein said third time is longer than said first time.
The method according to claim 1,

Further comprising a first DC / DC converter coupled to the DC bus,

And said first power storage and said first resistor are connected to said first DC / DC converter.
The method according to claim 1,

A first DC / DC converter coupled to the DC bus;

Further comprising a second DC / DC converter coupled to the DC bus,

And the first power storage portion is connected to the first DC / DC converter and the first resistor portion is connected to the second DC / DC converter.
The method according to claim 1,

The first power storage unit is an ultracapacity, hybrid power supply of the offshore plant.
The method according to claim 1,

And said power load is drawworks.
The method according to claim 1,

And said power load is a top drive.
In the hybrid power supply method of a marine plant,

Measuring the voltage of the DC bus;

Storing power by the power storage unit when the voltage of the DC bus is maintained above the first threshold for a first time;

If the voltage on the DC bus remains below a second threshold for a second time, the power storage unit supplies power to the DC bus,

And a power load for generating regenerative power is connected to the DC bus.
The method according to claim 7,

If the voltage of the DC bus remains above the first threshold for a third time, the resistor portion consuming power;

And said third time is longer than said first time.
The method according to claim 8,

A first DC / DC converter is connected to the DC bus,

The power storage unit and the resistor unit is connected to the first DC / DC converter, hybrid power supply method of a marine plant.
The method according to claim 8,

A first DC / DC converter and a second DC / DC converter are connected to the DC bus,

The power storage is connected to the first DC / DC converter and the resistor is connected to the second DC / DC converter.
The method according to claim 7,

The power storage unit is an ultracapacitor, hybrid power supply method of a marine plant.
The method according to claim 7,

And said power load is drawworks.
The method according to claim 7,

And said power load is a top drive.