Drilling machine water-cooling type direct-current micro-grid control system

Abstract

The invention discloses a drilling machine water-cooling type direct-current microgrid control system which comprises a generator set, a water-cooling type rectifier module, a direct-current bus, a battery module, a central controller, an inverter unit, a driving motor set, a brake unit, a brake resistor and a converter. A water-cooled rectifier module in the generator set is connected to a direct-current bus; the signal control end of the central controller is connected to the controlled end of each water-cooled rectifier module, and the battery control end of the central controller is connected to the controlled end of the battery module; the wire transmission end of the battery module is connected to a direct current bus; the direct current bus supplies energy to a load through a plurality of groups of inversion units and driving motor groups which are connected in sequence; the direct current bus is also connected with a brake unit and a converter, and the brake unit is also connected with a brake resistor; the power supply capacity of the system is adjusted according to load conditions, stable power supply under different loads is met, the response speed meets any abrupt change working conditions of well drilling, and the generator set always works in a high-efficiency area.

Description

Technical Field

[0001] The invention relates to the technical field of oil drilling equipment, and in particular to a drilling rig water-cooled direct current microgrid control system. Background Art

[0002] Oil drilling rigs are specialized machines used for oil and gas drilling. They are a combined unit consisting of multiple devices. They mainly include power units, power transmission units, lifting equipment, rotating equipment, circulation equipment, instruments and control systems, etc. The power unit of an electric drilling rig is connected to the grid to generate electricity from several generators, and the transmission unit uses DC drive or AC variable frequency drive to drive the mechanical equipment.

[0003] At present, during oil drilling production operations, internal combustion engine generator sets cannot operate at full load most of the time, deviating from the high-efficiency zone, resulting in low operating efficiency of the generator set and increased fuel / gas consumption. When drilling, in order to cope with the impact load, it is usually necessary to start an additional generator set, resulting in energy waste. Summary of the invention

[0004] The purpose of the present invention is to provide a drilling rig water-cooled DC microgrid control system, which can adjust the system power supply capacity according to the load conditions, meet the stable power supply under different loads, and the response speed meets any sudden changes in drilling conditions, so that the generator set always works in the high-efficiency area.

[0005] The technical solution adopted by the present invention is: A drilling rig water-cooled DC microgrid control system comprises a generator set, a water-cooled rectifier module, a DC bus, a battery module, a central controller, an inverter unit, a drive motor set, a brake unit, a brake resistor and a converter; each generator in the generator set is connected to the DC bus through a water-cooled rectifier module; the signal control end of the central controller is respectively connected to the controlled end of each water-cooled rectifier module, and the battery control end of the central controller is connected to the controlled end of the battery module; the transmission line end of the battery module is connected to the DC bus, and the central controller, the water-cooled rectifier module and the battery module constitute a DC microgrid control system; the DC bus supplies energy to the load through a plurality of inverter units and drive motor sets connected in sequence; the DC bus is also connected to a brake unit and a converter, and the brake unit is also connected to a brake resistor.

[0006] The generator set is composed of a plurality of permanent magnet synchronous generators.

[0007] The water-cooled rectifier module comprises a plurality of water-cooled rectifier controllers connected in parallel, the water-cooled rectifier controllers are connected to the power supply line between the generator set and the DC bus, and a main circuit breaker is also connected in series to the power supply line of each cold rectifier controller.

[0008] The battery module adopts a power battery pack, and the battery pack is connected to the DC bus through a fast-blow fuse and a main circuit breaker in sequence.

[0009] A pre-charging circuit and a fast-blow fuse are provided between the inverter unit and the DC bus.

[0010] The converter is powered by a 400V AC power supply at the well site.

[0011] The generator set, inverter unit and drive motor set all adopt water cooling for heat dissipation.

[0012] Compared with the prior art, the present invention has obvious advantages and beneficial effects. The present invention has at least the following advantages and beneficial effects: 1. The patent of this invention can realize automatic start and stop of the generator set according to the load, so that the generator set always works in the high-efficiency area. Compared with traditional drilling rigs, the unit energy consumption is lower and the energy-saving effect is obvious.

[0013] 2. The patent of this invention enables the battery to quickly bear the system impact load, respond faster and avoid the unstable operation of the generator set caused by the impact load.

[0014] 3. The patent of this invention can match more types of generator sets, such as multiple natural gas generator sets, multiple diesel generator sets, or a mixture of diesel generator sets and natural gas generator sets.

[0015] 4. The patent of this invention can provide DC power to the system within a certain period of time when a generator set fails, thereby increasing the reliability and stability of the system and ensuring the working efficiency of the system.

[0016] 5. The patent of this invention adopts water cooling and permanent magnet synchronous motor to make the whole system more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a circuit principle block diagram of the present invention. DETAILED DESCRIPTION

[0018] like Figure 1 As shown, the present invention includes a generator set 1, a water-cooled rectifier module 2, a DC bus 3, a battery module 4, a central controller 5, an inverter unit 6, a drive motor group 7, a brake unit 8, a brake resistor 9 and a converter 10. Each generator in the generator set 1 is connected to the DC bus 3 through a water-cooled rectifier module 2; the DC bus 33 supplies energy to the load transmission group, the load transmission group includes a winch transmission load, a turntable (top drive) transmission load and a mud pump transmission load, and the energy receiving ends of the load transmission group are all connected to the DC bus 3.

[0019] The signal control end of the central controller 5 is respectively connected to the controlled end of each water-cooled rectifier module 2, and the battery control end of the central controller 5 is connected to the controlled end of the battery module 4; the transmission line end of the battery module 4 is connected to the DC bus 3, and the central controller 5, the water-cooled rectifier module 2 and the battery module 4 constitute a DC microgrid control system. The central controller 5 adopts a CCU control unit, which is respectively connected to the water-cooled rectifier module 2 and the battery module 4 through CAN communication. The system can automatically control the start and stop of the generator set 1 according to the working conditions and load size, ensuring that the generator set 1 always operates in the high-efficiency area, and reasonably distributes the power output of the battery module 4 and the generator set 1.

[0020] The DC bus 3 supplies energy to the load through multiple groups of inverter units 6 and drive motor groups 7 connected in sequence; the DC bus 3 is also connected to a brake unit 8 and a converter 10, the converter 10 is powered by a 400V AC power supply at the well site, and the brake unit 8 is also connected to a brake resistor 9. The inverter unit 6 and the drive motor group 7 are both water-cooled. There is a pre-charge circuit and a fast-blow fuse between the inverter unit 6 and the DC bus 3. The drive motor generally adopts an AC variable frequency permanent magnet synchronous motor.

[0021] The generator set 1 is composed of multiple permanent magnet synchronous generators. The generator set 1 adopts a diesel generator set or a natural gas generator set 1, and the engine has a speed control system, and the target speed can be preset. The disadvantage of high generator matching cost is overcome, and the selection range of the generator set 1 is wider. The generator set 1 adopts water cooling for heat dissipation.

[0022] The water-cooled rectifier module 2 includes a plurality of water-cooled rectifier controllers connected in parallel, which are connected to the power supply line between the generator set 1 and the DC bus 3, and a main circuit breaker is also connected in series on the power supply line of each cold rectifier controller. A plurality of water-cooled rectifier modules 2 are networked in parallel, and the voltage back-end detection and lifting control is performed on the output end of each DC module to achieve the condition of consistent voltage and close to the preset value, thereby realizing balanced power distribution, and the control is easier than AC grid connection. That is, a plurality of water-cooled rectifier controllers connected in parallel adopt a closed-loop voltage lifting control method for DC grid connection to achieve voltage and power balance. By detecting the SOC voltage of the battery module 4 and the voltage on the DC bus 3, the central controller 5 automatically adjusts the voltage when networking.

[0023] The battery module 4 adopts a power battery pack, which is connected to the DC bus 3 in turn through a fast-blow fuse and a main circuit breaker. The battery module 4 is directly connected to the DC bus 3 to provide kinetic energy and can respond more quickly. The battery module 4 works in two modes: charging and discharging. When the generator set 1 has surplus power, the battery module 4 works in the charging mode, so that the generator set 1 has a high power output, remains in the high-efficiency zone, and reduces unit fuel consumption; when the generator set 1 has insufficient power, the battery module 4 works in the discharging mode to provide power for the system; when an impact load comes, the battery module 4 can be used to respond quickly and bear the impact load, and then slowly distribute it to the generator set 1 after the load is stable.

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] like Figure 1 As shown, each generator in the generator set 1 is connected to the receiving end of a water-cooled rectifier module 2, and the transmission end of the water-cooled rectifier module 2 is connected to the DC bus 3. The water-cooled rectifier module 2 is then connected to the DC bus 3 through a fast fuse and a DC circuit breaker. The fast fuse and the DC circuit breaker provide overcurrent, short circuit, and isolation protection for the system, and play a better protective role on the line; the signal control end of the central controller 5 is respectively connected to the controlled end of each water-cooled rectifier module 2, and the battery control end of the central controller 5 is connected to the controlled end of the battery module 4; the transmission end of the battery module 4 is connected to the DC bus 3, and the central controller 5, the water-cooled rectifier module 2 and the battery module 4 constitute a DC microgrid control system; the DC bus 3 supplies energy to the load through a plurality of groups of inverter units 6 and drive motor groups 7 connected in sequence; the DC bus 3 is also connected to a braking unit 8 and a converter 10, and the braking unit 8 is also connected to a braking resistor 9.

[0026] Among them, the battery module 4 is directly connected to the DC bus 3, which has a faster response speed and has the ability of dynamic power adjustment at the ms level, realizing dynamic compensation of short-term power of the DC microgrid, thereby ensuring the rapid active and reactive power exchange of the system, and effectively reducing voltage fluctuations, voltage sags, voltage and current waveform distortion and flicker, etc. When the power of the generator set 1 is surplus, the fuel consumption is high. At this time, the battery module 4 works in the charging mode, absorbing electric energy from the DC bus 3 to charge the battery module 4; after the battery module 4 is fully charged, the number of running generator sets 1 can be reduced, and the battery module 4 cooperates with the remaining generator sets 1 to reduce the fuel consumption of the generator set 1. During the drilling operation, the winch transmission device drives the load to be lifted and lowered, and the load changes quickly and with a large change range. The battery module 4 can respond quickly and can bear the impact load of the system to prevent the generator set 1 from being impacted.

[0027] The battery module 4, the water-cooled generator set 1 and the water-cooled rectifier module 2 together form a DC microgrid. The rectifier module adopts a PWM rectifier mode, and the voltage is infinitely adjustable, which avoids the impact current of the main circuit breaker directly closing. The rectifier power supply is electrically coupled as a current source, and the battery module 4 is a voltage source to ensure the voltage stability of the DC microgrid. The battery module 4 can be coupled with the generator set 1 to provide kinetic energy for the system. When the generator set 1 fails, the power will not be lost instantly, which further guarantees the reliability of the system. It can also be powered alone. The battery module 4 can power the system alone for a certain period of time and can be used as a backup power supply for the system. In addition, the battery module 4 itself is equipped with a management system for detection and protection, which belongs to the existing mature technology and will not be repeated here.

[0028] The water-cooled inverter and brake unit 8 are connected to remotely control and monitor the drilling conditions in real time, such as start and stop commands, forward and reverse rotation, output voltage, current, and power. When drilling, energy is fed back through the inverter unit 6 to raise the voltage on the bus and charge the battery module 44 according to the SOC state. When it is detected that the feedback current of the inverter unit 6 is greater than the maximum current allowed for charging of the battery module 4, the brake unit 8 is put into operation and the brake resistor 9 consumes the system feedback energy, thereby ensuring the safe charging of the battery module 4 and the stability of the system.

[0029] The inverter unit 6 and the drive motor group 7 form a power transmission circuit of the load transmission group, including a drawworks transmission load, a turntable transmission load and a mud pump transmission load. The energy receiving ends of the load transmission group are all connected to the DC bus 3 to provide power for the drilling rig drawworks, turntable and mud pump.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A water-cooled DC microgrid control system for a drilling rig, characterized by: It includes a generator set, a water-cooled rectifier module, a DC bus, a battery module, a central controller, an inverter unit, a drive motor set, a brake unit, a brake resistor and a converter; each generator in the generator set is connected to the DC bus through a water-cooled rectifier module; the signal control end of the central controller is respectively connected to the controlled end of each water-cooled rectifier module, and the battery control end of the central controller is connected to the controlled end of the battery module; the transmission line end of the battery module is connected to the DC bus, and the central controller, the water-cooled rectifier module and the battery module constitute a DC microgrid control system; the DC bus supplies energy to the load through multiple sets of inverter units and drive motor sets connected in sequence; the DC bus is also connected to a brake unit and a converter, and the brake unit is also connected to a brake resistor.

2. The drilling rig water-cooled DC microgrid control system according to claim 1 is characterized in that: The generator set is composed of a plurality of permanent magnet synchronous generators.

3. The drilling rig water-cooled DC microgrid control system according to claim 2 is characterized in that: The water-cooled rectifier module comprises a plurality of water-cooled rectifier controllers connected in parallel, the water-cooled rectifier controllers are connected to the power supply line between the generator set and the DC bus, and a main circuit breaker is also connected in series to the power supply line of each cold rectifier controller.

4. The drilling rig water-cooled DC microgrid control system according to claim 3 is characterized in that: The battery module adopts a power battery pack, and the battery pack is connected to the DC bus through a fast-blow fuse and a main circuit breaker in sequence.

5. The drilling rig water-cooled DC microgrid control system according to claim 4 is characterized in that: A pre-charging circuit and a fast-blow fuse are provided between the inverter unit and the DC bus.

6. The drilling rig water-cooled DC microgrid control system according to claim 5 is characterized in that: The converter is powered by a 400V AC power supply at the well site.

7. The drilling rig water-cooled DC microgrid control system according to claim 6 is characterized in that: The generator set, inverter unit and drive motor set all adopt water cooling for heat dissipation.

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