CN114696544A - Frequency conversion all-in-one machine for dragging petroleum turntable - Google Patents
Frequency conversion all-in-one machine for dragging petroleum turntable Download PDFInfo
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- CN114696544A CN114696544A CN202011631684.7A CN202011631684A CN114696544A CN 114696544 A CN114696544 A CN 114696544A CN 202011631684 A CN202011631684 A CN 202011631684A CN 114696544 A CN114696544 A CN 114696544A
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- 238000006243 chemical reaction Methods 0.000 title claims abstract description 48
- 239000003208 petroleum Substances 0.000 title description 3
- 230000017525 heat dissipation Effects 0.000 claims abstract description 102
- 238000001816 cooling Methods 0.000 claims abstract description 8
- 230000005855 radiation Effects 0.000 claims abstract description 3
- 239000003990 capacitor Substances 0.000 claims description 15
- 238000004146 energy storage Methods 0.000 claims description 13
- 238000004804 winding Methods 0.000 claims description 11
- 230000003139 buffering effect Effects 0.000 claims description 3
- 238000007599 discharging Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 4
- 238000004891 communication Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 238000005096 rolling process Methods 0.000 description 6
- 238000005553 drilling Methods 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
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- 230000033228 biological regulation Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000004880 explosion Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
- H02K11/30—Structural association with control circuits or drive circuits
- H02K11/33—Drive circuits, e.g. power electronics
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K1/00—Details of the magnetic circuit
- H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
- H02K1/12—Stationary parts of the magnetic circuit
- H02K1/20—Stationary parts of the magnetic circuit with channels or ducts for flow of cooling medium
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K1/00—Details of the magnetic circuit
- H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
- H02K1/22—Rotating parts of the magnetic circuit
- H02K1/32—Rotating parts of the magnetic circuit with channels or ducts for flow of cooling medium
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K5/00—Casings; Enclosures; Supports
- H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K5/00—Casings; Enclosures; Supports
- H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
- H02K5/12—Casings or enclosures characterised by the shape, form or construction thereof specially adapted for operating in liquid or gas
- H02K5/136—Casings or enclosures characterised by the shape, form or construction thereof specially adapted for operating in liquid or gas explosion-proof
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K5/00—Casings; Enclosures; Supports
- H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
- H02K5/20—Casings or enclosures characterised by the shape, form or construction thereof with channels or ducts for flow of cooling medium
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K5/00—Casings; Enclosures; Supports
- H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
- H02K5/22—Auxiliary parts of casings not covered by groups H02K5/06-H02K5/20, e.g. shaped to form connection boxes or terminal boxes
- H02K5/225—Terminal boxes or connection arrangements
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K9/00—Arrangements for cooling or ventilating
- H02K9/02—Arrangements for cooling or ventilating by ambient air flowing through the machine
- H02K9/04—Arrangements for cooling or ventilating by ambient air flowing through the machine having means for generating a flow of cooling medium
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M5/00—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases
- H02M5/40—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC
- H02M5/42—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters
- H02M5/44—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC
- H02M5/453—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC using devices of a triode or transistor type requiring continuous application of a control signal
- H02M5/458—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
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- 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
- H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
- H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
- H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using DC to AC converters or inverters
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K2205/00—Specific aspects not provided for in the other groups of this subclass relating to casings, enclosures, supports
- H02K2205/09—Machines characterised by drain passages or by venting, breathing or pressure compensating means
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Inverter Devices (AREA)
Abstract
The invention discloses a frequency conversion all-in-one machine for dragging an oil turntable. This frequency conversion all-in-one includes: a frequency converter for frequency-converting and outputting an alternating current from the outside; the motor is used for receiving the alternating current output by the frequency converter and executing different rotating speeds according to different alternating current frequencies so as to drag the oil rotating disc to run; and the heat radiation fan is connected with the frequency converter and is used for cooling the frequency converter and the motor. According to the frequency conversion all-in-one machine, the heat dissipation fan is arranged in a safe area, fresh air in the safe area is conveyed to the frequency conversion part through the air pipe, and then the heat dissipation air is conveyed to the motor part, so that the effect that the frequency conversion part and the motor part are simultaneously cooled through one heat dissipation fan is achieved. In addition, the frequency conversion all-in-one machine has the advantages of small size, good heat dissipation effect, excellent explosion-proof performance and the like.
Description
Technical Field
The present invention relates generally to the field of electric machine applications. More specifically, the invention relates to a frequency conversion all-in-one machine for dragging an oil turntable.
Background
In the field of oil drilling, the rotating disc serving as a rotating disc in eight systems is important drilling equipment. Which is used to drive the rotation of the drilling tool to fracture the rock formation for oil production. At present, the power equipment dragging the rotating disc is generally a diesel engine or a common motor. If the diesel engine is used for driving, more energy is consumed, and the efficiency is lower. When the motor is driven by a common motor, a variable frequency power supply is required to control the rotating speed of the motor. Therefore, a special frequency conversion device is required to be connected externally, so that the problems of more equipment, complex installation, inconvenient equipment movement, poor matching performance between the equipment, large overall occupied space and the like are caused.
Secondly, in the working process of the frequency conversion equipment and the motor, the heat productivity is large, and the running performance and the production efficiency of the equipment are seriously influenced. In the prior art, heat dissipation devices are generally arranged in each device for heat dissipation of the devices. The heat dissipation method has the advantages of poor heat dissipation effect, complex design, higher cost and larger occupied area. In addition, because the working area of the rotary table is close to the wellhead and the space equipment layout and personnel in the area are dense, once an explosion accident happens to the equipment in the working area, serious personnel and property loss can be caused.
Disclosure of Invention
In order to solve one or more problems in the background art, the invention provides a frequency conversion all-in-one machine which is used by matching a frequency converter, a motor and a cooling fan. The frequency conversion all-in-one machine controls the inversion unit of the frequency converter through the control unit, and then carries out frequency conversion on the three-phase alternating current and outputs the three-phase alternating current to the motor so as to change the rotating speed of the motor, thereby improving the working efficiency of the petroleum turntable. In addition, the frequency converter and the motor structural components are optimally distributed, so that the number of equipment is reduced, the integral size of the frequency converter and the motor structural components is reduced, the frequency converter and the motor structural components are more convenient to disassemble and move, and the frequency converter and the motor structural components are more stable to operate.
The invention particularly discloses a frequency conversion all-in-one machine for dragging an oil turntable. This frequency conversion all-in-one includes: a frequency converter for frequency-converting and outputting an alternating current from the outside; the motor is used for receiving the alternating current output by the frequency converter and executing different rotating speeds according to different frequencies of the alternating current so as to drag the oil rotating disc to operate; and the heat radiation fan is connected with the frequency converter and is used for cooling the frequency converter and the motor.
In one embodiment, the frequency conversion all-in-one machine of the present invention further includes: a first housing in which the frequency converter is housed; a second housing connected to the first housing and accommodating the motor therein; and a third case connected to the first case and accommodating the heat dissipation fan therein.
In another embodiment, the first housing interior comprises: the two ends of the frequency converter heat dissipation cavity are respectively connected with the first shell and the third shell so as to receive and send heat dissipation air from the heat dissipation fan to the second shell; a frequency converter control cavity which is communicated with the frequency converter heat dissipation cavity and accommodates the frequency converter therein; and the frequency converter inlet wire cavity is used for introducing a cable from the outside into the frequency conversion all-in-one machine.
In another embodiment, the all-in-one frequency converter further comprises an air duct. And two ends of the heat dissipation device are respectively connected with the frequency converter heat dissipation cavity and the third shell so as to form a channel for air circulation from the heat dissipation fan to the frequency converter through the air pipe.
In one embodiment, the second housing includes: the air inlet is connected with the frequency converter heat dissipation cavity and used for receiving heat dissipation air from the heat dissipation fan; the motor internal heat dissipation channel is used for guiding heat dissipation air from the air inlet so as to dissipate heat and cool the motor; and the end cover air outlet is used for discharging the heat dissipation air from the heat dissipation channel in the motor out of the frequency conversion all-in-one machine.
In another embodiment, the motor internal heat dissipation channel comprises an axial channel. Further, the axial passage includes: the shell axial channel is positioned between the second shell and the motor stator and is used for guiding the heat dissipation air along the axial direction of the motor so as to dissipate the heat of the stator of the motor; the rotating shaft axial channel is positioned between the radial ribs on the outer surface of the rotating shaft of the motor and is used for guiding the heat dissipation air along the axial direction of the motor so as to dissipate the heat of the rotating shaft of the motor; and the axial channel between the stator and the rotor is positioned between the stator and the rotor of the motor and is used for guiding the heat dissipation air along the axial direction of the motor so as to dissipate the heat of the stator and the rotor of the motor.
In yet another embodiment, the motor internal heat dissipation channel further comprises a radial channel. Further, the radial channel comprises: the stator radial channel is positioned in the stator radial direction of the motor and is used for guiding the heat dissipation air along the motor radial direction so as to dissipate the heat of the motor stator; and the rotor radial channel is positioned in the radial direction of the rotor of the motor and is used for guiding the heat dissipation air along the radial direction of the motor so as to dissipate the heat of the motor rotor.
In one embodiment, the frequency converter comprises: a rectifying unit for converting the alternating current from the outside into direct current; the direct current loop comprises a direct current bus and an energy storage capacitor and is used for buffering and storing the direct current output by the rectifying unit; an inverter unit configured to convert the dc power processed by the dc loop into an ac power having a frequency different from that of the ac power from the outside and output the ac power; and the control unit is configured to control the on-off of the switching element of the inversion unit so as to enable the inversion unit to output alternating currents with different frequencies.
In another embodiment, the cables introduced into the wire inlet cavity of the frequency converter meet the explosion-proof distance, and the windings on the motor stator adopt high-protection electromagnetic wires.
According to the frequency conversion all-in-one machine, the cavity of the frequency converter is separated, and the wire inlet cavity of the frequency converter is designed to be explosion-proof, so that explosion-proof distance between cables led into the frequency conversion all-in-one machine is met. Meanwhile, the frequency conversion all-in-one machine adopts high-protection electromagnetic wires as windings on the motor stator, so that dangerous temperature, electric arcs and sparks are not generated under normal or specified abnormal conditions. The design and the arrangement enable the frequency conversion all-in-one machine disclosed by the invention to have the advantage of good explosion-proof performance, so that the frequency conversion all-in-one machine is more suitable for application in the field of oil exploration.
In addition, the frequency conversion all-in-one machine arranges the heat dissipation fan in a safe area far away from the frequency converter and the motor, and the heat dissipation fan is communicated with the frequency converter through the air pipe, so that fresh air in the safe area is conveyed to the frequency converter through the heat dissipation fan, and heat dissipation is performed on heating elements in the frequency converter. Then, the heat dissipation air is sent into a motor cavity communicated with the frequency converter, and the heat dissipation air flows through the axial heat dissipation channels and the radial heat dissipation channels by arranging the plurality of axial heat dissipation channels and the plurality of radial heat dissipation channels in the motor cavity, so that the motor is effectively cooled. The frequency conversion all-in-one machine realizes the heat dissipation of the frequency conversion part and the motor part simultaneously through one heat dissipation fan, and has good heat dissipation effect through the heat dissipation design.
Drawings
The above-described features of the present invention will be better understood and its numerous objects, features, and advantages will be apparent to those skilled in the art by reading the following detailed description with reference to the accompanying drawings. The drawings in the following description are only some embodiments of the invention and other drawings may be derived by those skilled in the art without inventive effort, wherein:
FIG. 1 is a schematic diagram showing the components of a frequency conversion all-in-one machine according to an embodiment of the invention;
FIG. 2 is a side view showing a variable frequency kiosk according to an embodiment of the invention;
FIG. 3 is a perspective structural view showing a variable frequency all-in-one machine according to an embodiment of the invention;
FIG. 4 is a first housing structure view showing a variable frequency all-in-one machine according to an embodiment of the invention;
FIG. 5 is a structural diagram showing a heat dissipation channel inside a motor of the variable frequency all-in-one machine according to the embodiment of the invention;
FIG. 6 is a block diagram illustrating the components of a frequency converter according to an embodiment of the present invention; and
fig. 7 is a circuit schematic diagram illustrating an inverter unit according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 is a schematic diagram showing the components of a variable frequency all-in-one machine 100 according to an embodiment of the present invention.
As shown in fig. 1, the all-in-one inverter 100 of the present invention may include an inverter 101, a motor 102, and a cooling fan 103. Wherein the frequency converter may be disposed in the first housing 104 for frequency-converting and outputting the alternating current from the outside. The motor may be disposed in the second housing 105 to receive the ac power output from the frequency converter and perform different rotation speeds according to different frequencies of the ac power so as to drag a load. In one embodiment, the load may be, for example, an oil pan as shown in FIG. 3, which is used to drive rotation of a drilling tool to fracture the formation for oil production. The heat dissipation fan may be disposed in the third housing 106, connected to the frequency converter, and configured to dissipate heat and cool the frequency converter and the motor.
In one embodiment, the all-in-one inverter of the invention may further comprise a transformer, and the input of the transformer is high-voltage three-phase alternating current. In particular, the transformer may comprise an iron core (or magnetic core) and a coil, which may have two or more windings, wherein the winding connected to the high voltage network is a primary winding and the winding connected to the input of the frequency converter is a secondary winding. The transformer may transform alternating voltage, current and impedance. Generally, the voltage of the high-voltage three-phase alternating current transmitted by the high-voltage power grid is up to 100 kv or more, and the high-voltage three-phase alternating current is not suitable for use in devices such as motors. Therefore, it needs to be stepped down by a transformer in order to output a voltage suitable for the operation of the motor to the frequency converter. Meanwhile, matching between the alternating current input voltage and the direct current voltage output by the rectifying unit of the frequency converter can be realized, and high-voltage electric isolation between the high-voltage power grid and the rectifying unit of the frequency converter can be realized.
Fig. 2 and 3 are a side view and a perspective view respectively showing a variable frequency all-in-one machine 200 according to an embodiment of the present invention. The structure and the operation principle of the integrated frequency conversion machine 200 of the present invention are described below with reference to fig. 2 and 3.
As shown in fig. 2 and 3, the inverter all-in-one machine of the invention may include a first housing 201 accommodating an inverter, a second housing 202 accommodating a motor, a third housing 203 accommodating a heat dissipation fan, and a wind pipe 204. Specifically, the first housing may be fixedly coupled to one side of the second housing by bolts or screws, and the air duct fixedly couples the first housing and the third housing. The air pipe can be of a steel plate welding structure, one end of the air pipe is connected with an air outlet of the heat dissipation fan, and the other end of the air pipe is connected with the frequency converter heat dissipation cavity of the first shell, so that fresh air sent out by the heat dissipation fan reaches the frequency converter heat dissipation cavity through the air pipe, and heat dissipation is conducted on heating elements in the frequency converter. Further, the length of the air pipe can exceed 3 meters, so that the heat dissipation fan can be located in a safe area.
In one embodiment, the blower is a device that relies on input mechanical energy to increase the pressure of the gas and expel the gas. Which may include volute, collector and impeller components and which rely on eccentric operation of an offset rotor within the cylinder to vary the volume between the vanes in the rotor slots to draw, compress and expel air.
In particular, the collector may direct the gas towards the impeller and its geometry determines the gas flow conditions at the inlet of the impeller. The impeller is an important part in a centrifugal fan (as an example of the fan), and generally comprises four large parts, namely a wheel cover, a wheel disc, a blade and a shaft disc, and the connection mode of the structures is mainly welding and riveting. The impeller is responsible for the energy transfer process described by the euler equation, and the flow condition of the gas inside the impeller is influenced by the rotation of the impeller and the curvature of the surface, and is accompanied by phenomena of flow separation, backflow and secondary flow, so that the gas flow inside the impeller becomes very complicated. The volute of the fan is mainly used for collecting the gas coming out of the impeller, converting the kinetic energy of the gas into the static pressure energy of the gas by reducing the speed of the gas moderately and guiding the gas to flow out of the outlet of the volute.
Fig. 4 is a view showing the configuration of the first housing 400 of the inverter all-in-one machine according to the embodiment of the present invention.
As shown in fig. 4, the first housing 400 may include a frequency converter heat dissipation chamber 401, a frequency converter control chamber 402, and a frequency converter inlet chamber 403 inside. One outlet of the frequency converter heat dissipation cavity is communicated with one end of the air pipe in a sealing mode, and the other outlet of the frequency converter heat dissipation cavity is communicated with the third shell in a sealing mode so as to be used for receiving and sending heat dissipation air from the heat dissipation fan to the second shell. The frequency converter control cavity is communicated with the frequency converter heat dissipation cavity, and the frequency converter is accommodated in the frequency converter control cavity. Furthermore, the power devices of the frequency converter, such as the IGBT module and the rectifying unit, are mounted on the heat sink, and the heat sink is positioned on the channel through which the heat dissipation air flows, so that the heat on the heat sink can be taken away through the flow of the heat dissipation air, and the frequency converter is cooled.
In one embodiment, the frequency converter inlet wire cavity can accommodate wiring terminals, contactors and reactors for introducing cables from the outside into the frequency converter all-in-one machine. The wiring terminal is used for connecting a cable from the outside with a cable in the frequency converter. Further, the cable may include a power cable for supplying power to the inverter, and a communication cable for data communication of the inverter with an external device. Alternatively, the inlet wire cavity of the frequency converter can also accommodate a junction box, and a power cable interface and a data communication interface can be arranged on the junction box, so that three-phase alternating current from the outside can be led into the frequency conversion all-in-one machine through the power cable interface, and a communication cable for data communication from the outside can be led into the frequency conversion all-in-one machine through the data communication interface.
In another embodiment, the reactor may be, for example, a circuit composed of inductance elements, and is configured to perform voltage stabilization, current limitation, interference suppression, and other processing on externally input alternating current, and output the alternating current to the frequency converter. The contactor can be positioned between the reactor and externally input alternating current and is used for connecting or disconnecting the power supply of the frequency conversion all-in-one machine. Specifically, after the contactor coil circular telegram, coil current can produce magnetic field, and this magnetic field makes the iron core produce electromagnetic attraction and attracts the iron core to drive the contact action of contactor, thereby make the normally closed contact disconnection, and the linkage normally open contact is closed, so that supply power to the frequency conversion all-in-one. When the coil is powered off, the electromagnetic attraction disappears, the armature is released under the action of the release spring, so that the contact is restored, the normally open contact is opened, and the normally closed contact is linked to be closed, so that the power supply of the frequency conversion all-in-one machine is disconnected.
In another embodiment, the connection surface between the control cavity of the frequency converter and the second housing may be arranged with a plurality of holes or binding posts for cable to pass through, wherein the cable may include a power cable for connecting the frequency converter and the motor, so as to output the three-phase alternating current processed by the frequency converter to the motor, thereby driving the motor to operate. In an application scene, an independent base is arranged at the lower part of the second shell, and the type of the base is smaller than that of a base of a conventional motor, so that the base is convenient to disassemble and assemble. When the frequency conversion all-in-one machine is placed in a working scene, the base is in contact with the ground so as to enhance the stability of the frequency conversion all-in-one machine.
According to different safety level requirements, the shell of the frequency conversion all-in-one machine can be made into an explosion-proof shell so as to meet the explosion-proof requirement. Specifically, the first shell is divided into three cavities, and a certain explosion-proof distance is met between wiring terminals in the wire inlet cavity of the frequency converter, so that explosion-proof requirements are met between cables introduced by the first shell. Furthermore, the binding post can be externally sealed with a protective cover to prevent explosion. Based on the above, the variable-frequency all-in-one machine can be realized as an explosion-proof variable-frequency speed regulation all-in-one machine.
In one embodiment, when the frequency conversion all-in-one machine works, an external alternating current power supply cable or a communication cable can be connected with a corresponding interface on a junction box of the frequency conversion all-in-one machine in a plugging mode. Therefore, three-phase alternating current from the outside is input into the frequency conversion all-in-one machine through the junction box. Then, the three-phase alternating current passes through a cable inside the terminal box and is output to the reactor through the contactor. Then, the three-phase alternating current processed and output by the reactor is output to the frequency converter through a cable between the reactor and the frequency converter. And finally, outputting the three-phase alternating current processed and output by the frequency converter to a three-phase winding on a motor stator through a cable between the frequency converter and the motor so as to drive the motor to operate.
Fig. 5 is a structural view illustrating a motor internal heat dissipation path 500 of the inverter all-in-one machine according to an embodiment of the present invention.
As shown in fig. 5, the second housing internally houses a motor. The motor may include a stator, a rotor, a bearing, a shaft, and an end cap. And the stator can be wound with a three-phase winding which is used for connecting three-phase alternating current output by the frequency converter. Further, when the frequency conversion all-in-one machine is powered on, the three-phase alternating current generates a rotating magnetic field on the stator core, the rotating magnetic field generates electromagnetic torque on the rotor, the rotor rotates around the rotating shaft, and therefore the oil rotating disc is dragged to operate. In addition, in order to better realize the explosion-proof function of the inverter all-in-one machine, the winding on the stator of the motor can adopt high-protection electromagnetic wires so as to prevent the generation of overhigh temperature, electric arcs and sparks during the operation of the inverter all-in-one machine.
In one embodiment, the bearing may include rolling elements, an inner race, and an outer race. Further, the bearing of the motor may be divided into a rear bearing and a front bearing connected to the oil rotating disk. The front bearing and the rear bearing can be rolling bearings, and rolling bodies of the rolling bearings can be spheres or cylinders according to different application scenarios of the motor. In an application scenario, an inner ring of the bearing can be in interference connection with a motor rotating shaft, and an outer ring of the bearing can be fixedly connected with a motor end cover. When the motor runs, the motor rotating shaft and the bearing inner ring rotate together around the axis through rolling of the rolling bodies.
In one embodiment, the variable frequency all-in-one machine may further include an end cover for supporting and fixing the motor. Specifically, the end cover may include a front end cover and a rear end cover, wherein the front end cover may be circular in shape, so that the rotating shaft of the motor may penetrate through a middle inner diameter of the front end cover. Furthermore, the outer ring of the motor bearing is in interference connection with the inner diameter of the front end cover, and the inner ring of the bearing is in interference connection with the rotating shaft of the motor. Through the structural arrangement, the motor rotating shaft can rotate through the bearing.
In another embodiment, the second housing may further include an air inlet 501, a heat dissipation channel 500 inside the motor, and an end cover air outlet 502. The air inlet is connected with the frequency converter heat dissipation cavity and used for receiving heat dissipation air from the heat dissipation fan. The heat dissipation channel inside the motor is used for guiding heat dissipation air from the air inlet so as to dissipate heat and cool the motor. And the end cover air outlet is positioned on the front end cover and is used for discharging the heat dissipation air from the heat dissipation channel inside the motor out of the frequency conversion all-in-one machine.
In one embodiment, the motor internal heat dissipation channel may include an axial channel and a radial channel. Further, the axial passages may include a casing axial passage 503, a shaft axial passage 504, and a stator-rotor axial passage 505. The casing axial channel is positioned between the second casing and the motor stator and is used for guiding the heat dissipation air along the axial direction of the motor so as to dissipate heat of the stator of the motor. The rotating shaft axial channel is positioned between the spokes on the outer surface of the rotating shaft of the motor and is used for guiding the heat dissipation air along the axial direction of the motor so as to dissipate the heat of the rotating shaft of the motor. The axial channel between the stator and the rotor is positioned between the stator and the rotor of the motor and used for guiding the heat dissipation air along the axial direction of the motor so as to dissipate the heat of the stator and the rotor of the motor.
In another embodiment, the axial channels may include stator radial channels 506 and rotor radial channels 507. In particular, the stator radial channels are formed by digging radial grooves in the surface of the stator of the electric machine or by arranging radial holes inside the stator, so as to allow the cooling air to flow through the above-mentioned grooves or holes. Further, the rotor radial channels are formed by digging radial grooves in the surface of the motor rotor or by arranging radial holes inside the rotor so that heat dissipating air flows through the grooves or holes in the rotor. In operation, the stator radial channel and the rotor radial channel are used for guiding heat dissipation air along the radial direction of the motor so as to dissipate heat of the motor stator and the rotor. The heat dissipation principle of the frequency conversion all-in-one machine of the invention is briefly described below with reference to fig. 5.
When the frequency conversion all-in-one machine works, the heat dissipation fan operates, and external fresh air is sent into the first shell through the air pipe, so that heat dissipation and cooling are performed on the frequency converter. Then, the heat dissipation air flowing out of the heat dissipation cavity of the frequency converter enters the motor through the air inlet in the second shell, and is axially and radially guided through the heat dissipation channel in the motor, so that the heat dissipation air is used for dissipating heat and cooling each component of the motor, and finally the heat dissipation air is discharged from the air outlet of the end cover. The flow direction of the heat dissipation air inside the motor is shown by the arrows in fig. 5.
Fig. 6 is a block diagram illustrating the components of a frequency converter 600 according to an embodiment of the present invention.
As shown in fig. 6, the frequency converter 600 of the present invention may include a precharge circuit 601, a rectifying unit 602, a dc link 603, an inverting unit 604, and a control unit 605. In one embodiment, the rectifying unit may include a rectifier and a filter, and is configured to convert the alternating current output from the reactor into direct current. Further, the rectifier may include components with unidirectional conductivity, so that the components may be utilized to convert the ac power with high voltage and changing direction and magnitude output by the transformer into a unidirectional pulsating dc power. The filter is used for filtering alternating current components in the pulsating direct current voltage.
In another embodiment, the dc loop may include a circuit composed of a dc bus and an energy storage capacitor, and is configured to buffer and store the dc power output by the rectifying unit. As shown in fig. 6, the DC bus is composed of a DC + terminal and a DC-terminal, the energy storage capacitor C may include a plurality of capacitors, and further, the energy storage capacitor C may be an electrolytic capacitor. It can be understood that the energy storage capacitor C in the dc loop in fig. 6 may also be replaced by other energy storage components such as an energy storage inductor according to different application scenarios, and the number of the energy storage capacitors may be multiple.
In a further embodiment, the pre-charging circuit is arranged at an input of the rectifying unit and is configured to pre-charge an energy storage capacitor C in the dc loop with the ac power. When the frequency converter is powered up, the charging moment of the electrolytic capacitor in the direct current loop of the frequency converter is equivalent to a short-circuit state before no voltage is built up. In this case, since the dc voltage output from the rectifying unit is extremely high, the charging current is extremely high, and further, there is a possibility that the rectifying diode, the electrolytic capacitor on the dc bus, and other inverter components are damaged. For this reason, it is generally necessary to precharge an electrolytic capacitor in the dc circuit in order to limit the charging current from becoming excessive.
After the electrolytic capacitor is precharged, the rectifying unit can output direct current to the inverter unit through a direct current loop. Since the motor is an inductive load, its power factor is not always 1, regardless of the operating state of the motor. Therefore, there is always a reactive power exchange between the dc loop and the motor, which requires an energy storage element in the dc loop for buffering, so that the dc voltage output by the rectifying unit is always kept stable. Based on the above principle, the dc loop is configured to receive and store the dc power transmitted from the rectifying unit, and perform interference suppression and the like on the dc power.
In another embodiment, the control unit may be composed of a chip or system with processing capabilities for analysis, determination, and calculation, for example, it may be a digital signal processor (abbreviated "DSP"). Which is configured to control on and off of switching elements (e.g., IGBT modules) of the inverter unit so as to cause the inverter unit to output alternating currents of different frequencies. The control unit can also be used for controlling data communication with an upper computer and controlling the on-off of the pre-charging circuit.
In one embodiment, the inverter unit may include an inverter circuit formed by a plurality of inverter bridges, and is configured to convert the dc power processed by the dc loop into an ac power having a frequency different from that of an externally input ac power, and output the ac power to various types of motors including, for example, a permanent magnet reluctance motor. Further, the inverter bridge may be configured by a plurality of IGBT modules. The IGBT module may be a modular semiconductor product formed by bridge-packaging an insulated gate bipolar transistor chip (abbreviated as "IGBT") and a freewheeling diode chip (abbreviated as "FWD") through a specific circuit.
Specifically, the inverter unit may include an inverter bridge and a filter circuit, and is configured to convert the dc power output from the dc circuit into ac power with constant frequency, constant voltage or frequency and voltage regulation, so as to supply the permanent magnet reluctance motor with the ac power. In the working process of the inverter unit, the inverter bridge plays a key role in the process of converting direct current into three-phase alternating current. The inverter bridge is used for controlling the on-off of power switching elements on an upper bridge and a lower bridge of the inverter bridge through pulse width modulation signals generated by a control unit, so that three-phase alternating current with 120 degrees of phase difference is obtained on three output ends of the inverter bridge, and the three-phase alternating current is output to the motor. In one embodiment, the power switching elements may be, for example, "IGBT" modules, which have the advantages of high input impedance and low turn-on voltage.
Fig. 7 is a circuit schematic diagram illustrating an inverter unit 700 according to an embodiment of the present invention. It will be appreciated that fig. 7 is a specific circuit implementation of the inverter unit of the frequency converter.
As shown in fig. 7, the inverter unit 700 may include an inverter circuit composed of 6 IGBT modules VT1 to VT 6. Specifically, VT1 and VT2 constitute the first bridge circuit in series, and the U-phase voltage in the three-phase alternating current output by the inverter circuit is taken between VT1 and VT 2. The VT3 and the VT4 are connected in series to form a second bridge circuit, and the V-phase voltage in the three-phase alternating current of the inverter circuit is taken between VT3 and VT 4. The VT5 and the VT6 are connected in series to form a third bridge circuit, and the W phase voltage in the three-phase alternating current of the inverter circuit is taken between VT5 and VT 6. The operation of the inverter circuit will be briefly described below.
For convenience of description, one cycle time is divided into t1 to t 6. For a voltage U between the U-phase and the V-phaseUVIn other words, during the time period from t1 to t2, VT1 and VT4 are turned on simultaneously, the U-phase voltage is "+" and the V-phase voltage is "-", then the U-phase voltage is "+", and the V-phase voltage is "-", respectivelyUVIs "+", and UUVIs the bus voltage value. In the time period from t4 to t5, VT2 and VT3 are conducted at the same time, the U phase voltage is "-", the V phase voltage is "+", and the U phase voltage is "+", the U phase voltage isUVIs "-", and UUVIs the bus voltage value.
For voltage U between V phase and W phaseVWIn other words, within the time period from t3 to t4, VT3 and VT6 are conducted simultaneously, and the voltage of the V phase is equal to that of the V phaseIf "+", W phase voltage is "-", then U is setVWIs "+", and UVWIs the bus voltage value. And in the time period from t6 to t1, VT4 and VT5 are simultaneously conducted, the voltage of the V phase is negative, the voltage of the W phase is positive, and the voltage of the U phase is negativeVWIs "-", and UVWIs the bus voltage value.
For voltage U between W phase and U phaseWUIn other words, during the time period from t5 to t6, VT5 and VT2 are simultaneously conducted, at this time, the W phase voltage is "+", the U phase voltage is "-", and then the U phase voltage is "+", and then the U phase voltage isWUIs "+", and UWUIs the bus voltage value. And in the time period from t2 to t3, VT1 and VT6 are simultaneously conducted, the W phase voltage is negative, the U phase voltage is positive, and the U phase voltage is negativeWUIs '-', and UWUIs the bus voltage value.
From the above analysis, U isUV、UVWAnd UWUThe phases of the three phases are different by 120 degrees, and the amplitude values of the three phases are equal to the voltage value of the direct current bus. Therefore, as long as the on and off of the 6 IGBTs are controlled according to a certain rule, the direct current can be inverted into the three-phase alternating current. And the frequency of the inverted three-phase alternating current can be adjusted by changing the pulse width of the PWM signal through the control unit and further controlling the on-time of the IGBT on the premise that the on-rule is not changed.
In the working process of the frequency converter, firstly, alternating current output by the reactor is converted into low-current alternating current after being processed by the pre-charging circuit. Then, the rectifying unit converts the low-current alternating current into a low-current direct current, and the energy storage capacitor C in the direct current loop is pre-charged by the low-current direct current. And after the pre-charging process is finished, the pre-charging circuit is disconnected, and the alternating current output by the reactor is rectified by the rectifying unit to further output the direct current. Then, the dc power flows to the inverter unit after being subjected to energy storage, interference suppression, and the like in the dc circuit. And finally, the direct current is subjected to inversion processing by the inversion unit so as to be converted into alternating current with different frequency from the alternating current output by the reactor, and the alternating current is output to the motor, so that the motor is driven to operate. When the rotating speed of the motor needs to be changed, the control unit calculates the square wave pulse width of the PWM modulated signal by changing the frequency of the modulation signal, and adjusts the conduction time of the IGBT of the inverter according to the square wave pulse width, so that the inverter outputs three-phase alternating current with the frequency different from that of the original three-phase alternating current, and finally the rotating speed of the motor is changed.
It should be understood that the terms "first", "second", "third" and "fourth", etc. in the claims, the description and the drawings of the present invention are used for distinguishing different objects and are not used for describing a particular order. The terms "comprises" and "comprising," when used in the specification and claims of this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only, and is not intended to be limiting of the invention. As used in the specification and claims of this application, the singular form of "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be further understood that the term "and/or" as used in the specification and claims of this specification refers to any and all possible combinations of one or more of the associated listed items and includes such combinations.
Although the present invention is described in the above embodiments, the description is only for the convenience of understanding the present invention, and is not intended to limit the scope and application of the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (9)
1. A frequency conversion all-in-one for dragging oil carousel includes:
a frequency converter for frequency-converting and outputting an alternating current from outside;
the motor is used for receiving the alternating current output by the frequency converter and executing different rotating speeds according to different frequencies of the alternating current so as to drag the oil rotating disc to run; and
and the heat radiation fan is connected with the frequency converter and is used for cooling the frequency converter and the motor.
2. The variable frequency all-in-one machine of claim 1, further comprising:
a first housing in which the frequency converter is housed;
a second housing which is connected to the first housing and in which the motor is accommodated; and
and a third housing connected to the first housing and accommodating the heat dissipation fan therein.
3. The variable frequency all-in-one machine according to claim 2, wherein the first housing interior comprises:
the two ends of the frequency converter radiating cavity are respectively connected with the first shell and the third shell so as to receive and send radiating air from the radiating fan to the second shell;
a frequency converter control cavity which is communicated with the frequency converter heat dissipation cavity and accommodates the frequency converter therein; and
and the frequency converter inlet wire cavity is used for introducing a cable from the outside into the frequency conversion all-in-one machine.
4. The variable-frequency all-in-one machine according to claim 3, further comprising an air duct, wherein two ends of the air duct are respectively connected with the frequency converter heat dissipation cavity and the third shell, so that a channel for air circulation from the heat dissipation fan to the frequency converter is formed through the air duct.
5. The variable frequency all-in-one machine of claim 3, wherein the second housing comprises:
the air inlet is connected with the frequency converter heat dissipation cavity and used for receiving heat dissipation air from the heat dissipation fan;
the motor internal heat dissipation channel is used for guiding heat dissipation air from the air inlet so as to dissipate heat and cool the motor; and
and the end cover air outlet is used for discharging the heat dissipation air from the heat dissipation channel in the motor out of the frequency conversion all-in-one machine.
6. The variable frequency all-in-one machine of claim 5, wherein the motor internal heat dissipation channel comprises an axial channel comprising:
the shell axial channel is positioned between the second shell and the motor stator and is used for guiding the heat dissipation air along the axial direction of the motor so as to dissipate the heat of the stator of the motor;
the rotating shaft axial channel is positioned between the radial ribs on the outer surface of the rotating shaft of the motor and is used for guiding the heat dissipation air along the axial direction of the motor so as to dissipate the heat of the rotating shaft of the motor; and
and the stator-rotor axial channel is positioned between the stator and the rotor of the motor and is used for guiding the heat dissipation air along the axial direction of the motor so as to dissipate the heat of the stator and the rotor of the motor.
7. The variable frequency all-in-one machine of claim 5, wherein the motor internal heat dissipation channel further comprises a radial channel comprising:
the stator radial channel is positioned in the stator radial direction of the motor and is used for guiding the heat dissipation air along the motor radial direction so as to dissipate the heat of the motor stator; and
the rotor radial channel is positioned in the radial direction of the rotor of the motor and is used for guiding the heat dissipation air in the radial direction of the motor so as to dissipate the heat of the motor rotor.
8. The variable frequency all-in-one machine of claim 1, wherein the frequency converter comprises:
a rectifying unit for converting the alternating current from the outside into direct current;
the direct current loop comprises a direct current bus and an energy storage capacitor and is used for buffering and storing the direct current output by the rectifying unit;
an inverter unit for converting the dc power processed by the dc loop into an ac power having a frequency different from that of the ac power from the outside and outputting the ac power; and
and the control unit is configured to control the on-off of the switching elements of the inversion unit so as to enable the inversion unit to output alternating currents with different frequencies.
9. The frequency conversion all-in-one machine of claim 6, wherein the cables introduced into the inlet wire cavity of the frequency converter meet the explosion-proof distance, and the windings on the motor stator adopt high-protection electromagnetic wires.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011631684.7A CN114696544A (en) | 2020-12-31 | 2020-12-31 | Frequency conversion all-in-one machine for dragging petroleum turntable |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011631684.7A CN114696544A (en) | 2020-12-31 | 2020-12-31 | Frequency conversion all-in-one machine for dragging petroleum turntable |
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| CN112104140A (en) * | 2020-09-01 | 2020-12-18 | 合肥仙湖半导体科技有限公司 | Enhanced heat dissipation type double-frequency-conversion integrated variable frequency motor |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101286726A (en) * | 2008-06-12 | 2008-10-15 | 杭州西子孚信科技有限公司 | Driving device for electric machine and control method for driving motor |
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