Standby power supply system of electrically-driven workover rig and control method of standby power supply system

Abstract

The invention relates to the technical field of oil field workover treatment, in particular to a standby power supply system of an electrically-driven workover rig and a control method of the standby power supply system. The system comprises a direct-current generator, a hydraulic driving system and a control unit, the direct-current generator is fixed on the electrically-driven workover rig and is connected with a direct-current circuit of a frequency converter on the electrically-driven workover rig through a circuit; the hydraulic driving system is respectively connected with the direct-current generator and the electrically-driven workover rig, and is used for driving a rotor of the direct-current generator to rotate to generate power by driving hydraulic oil in the hydraulic driving system; and the frequency converter, the direct-current generator and the hydraulic driving system are respectively connected with the control unit for controlling the starting or closing of the frequency converter, the direct-current generator and the hydraulic driving system. The problems that an electrically-driven workover rig cannot work continuously due to frequent power failure of a well site, an existing standby power supply system needs to occupy too large space on the workover rig, and the manufacturing cost is high are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oilfield workover operation, and particularly relates to a standby power supply system of an electric drive workover rig and a control method thereof. BACKGROUND

[0002] The electric drive workover rig is generally used to lift and lower the oil pipe and the sucker rod in the workover operation. At present, the power supply of the electric drive workover rig developed by various enterprises is connected to the power input end of the control cabinet through the low-voltage side (380V) of the well site transformer, and the alternating current 380V voltage is transmitted to the direct drive motor (alternating current asynchronous motor) through the rectification and inversion of the frequency converter, and the alternating current 380V voltage is also supplied to the control circuit of the frequency converter through the alternating current power module. At present, compared with the conventional workover rig, the electric drive workover rig needs to add electrical devices such as direct drive motor and control cabinet, and the reserved space on the vehicle of the electric drive workover rig is very small, almost reaching the limit.

[0003] The reserved capacity of the well site transformer is not large, and one transformer often supplies power to multiple pumping units, and the load fluctuation is large. After the electric drive workover rig is connected to the well site transformer, the reserved capacity of the transformer becomes very small or even zero, so during the workover process, if the nearby pumping unit has an impact load of starting and stopping, the transformer and the line relay protection will act, causing the well site to be short of power for a short time, and the power-off maintenance time needs several hours. During this period, the electric drive workover rig can only suspend operation, even collect the derrick and return to the factory, and then operate the next day. Not only does this greatly reduce the workover efficiency, but also it cannot complete the workover operation task required by the production department on time, causing great economic losses to the enterprise.

[0004] In view of this problem, some enterprises have developed a dual power supply system, which installs an alternating current synchronous generator on the vehicle. When the well site is powered off, the alternating current synchronous generator is provided with rotating power through the engine and the transfer case, and the alternating current generated by the alternating current synchronous generator provides power for the electric drive workover rig to perform workover operation. This scheme also needs to occupy a large space on the vehicle. During the operation process, the direct drive motor periodically consumes some reactive power, and the alternating current synchronous generator needs to supply a large part of the reactive power to the electric drive system. According to the current electrical technology, if the rated reactive power of the alternating current synchronous generator is to match the reactive power periodically consumed by the direct drive motor during the operation process, a large alternating current synchronous generator with a rated power at least 2.5 times the rated power of the direct drive motor needs to be selected, which means that the alternating current synchronous generator occupies a large space, and the manufacturing cost of the electric drive workover rig is greatly increased. SUMMARY

[0005] The application provides an electric drive workover rig backup power supply system and a control method thereof, to solve the problem that the electric drive workover rig cannot continuously work due to frequent power outage of a well site, and the existing backup power supply system needs to occupy a large space on the workover rig truck and has a high manufacturing cost.

[0006] According to an aspect of the application, an electric drive workover rig backup power supply system is provided, comprising a DC generator, a hydraulic drive system and a control unit. The DC generator is fixed on the electric drive workover rig, and the DC generator is connected with a DC circuit of a frequency converter on the electric drive workover rig through a line. The hydraulic drive system is connected with the DC generator and the electric drive workover rig respectively, and the hydraulic drive system is used to drive the rotor of the DC generator to rotate to generate electricity through driving the hydraulic oil inside. The frequency converter, the DC generator and the hydraulic drive system are connected with the control unit for controlling the start or shutdown thereof.

[0007] Preferably, the hydraulic drive system comprises a hydraulic oil pump, a hydraulic oil tank, a hydraulic motor and a driving mechanism. The driving mechanism is connected with the hydraulic oil pump, the hydraulic oil pump is connected with the hydraulic oil tank, and the hydraulic oil tank is connected with the hydraulic motor. The hydraulic oil pump is connected with the hydraulic motor, and the hydraulic motor is connected with the rotor of the DC generator. The driving mechanism is connected with the control unit, and the driving mechanism is used to drive the hydraulic oil pump to start and pressurize the hydraulic oil in the hydraulic oil tank and then transmit the hydraulic oil to the hydraulic motor.

[0008] Preferably, the driving mechanism is: an engine on the electric drive workover rig truck, a gearbox connected with the engine and a power takeoff connected with the gearbox. The power takeoff is connected with the hydraulic oil pump.

[0009] Preferably, the hydraulic oil pump of the hydraulic drive system is fixed below the chassis of the electric drive workover rig truck. The hydraulic motor is fixed on the electric drive workover rig truck.

[0010] Preferably, the application further comprises a ball valve and a filter. The ball valve and the filter are arranged on the pipeline between the hydraulic oil tank and the hydraulic oil pump.

[0011] Preferably, the application further comprises a hydraulic electromagnetic valve. The hydraulic electromagnetic valve is arranged on the pipeline between the hydraulic oil pump, the hydraulic oil tank and the hydraulic motor. The hydraulic electromagnetic valve is connected to the control unit.

[0012] Preferably, the hydraulic oil pump is connected to the hydraulic motor and the hydraulic oil tank through hydraulic hose lines respectively.

[0013] Preferably, the system further comprises a DC power module. The DC power module is connected to the DC generator and the control circuit of the frequency converter respectively, and is configured to convert the real-time voltage output by the DC generator into a predetermined voltage and transmit the voltage to the control circuit.

[0014] Preferably, the control unit comprises a programmable controller, an engine control unit, and a circuit breaker. The programmable controller is connected to the engine control unit and the frequency converter respectively, and the engine control unit is connected to the hydraulic drive system. The circuit breaker is arranged on the line between the DC generator and the frequency converter, and is connected to the programmable controller.

[0015] According to an aspect of the present application, a control method of a backup power supply system of an electric drive workover rig is provided, comprising: When the control unit detects that the frequency converter of the electric drive workover rig is powered off, the hydraulic drive system is started; After the hydraulic drive system is started, the internal hydraulic oil drives the rotation of the rotor of the DC generator, so that the DC generator generates DC power, which is transmitted to the frequency converter through the line, and the control unit controls the rectifier circuit of the frequency converter to be closed through the control circuit of the frequency converter. The control unit detects the real-time DC voltage of the DC circuit of the frequency converter through the control circuit of the frequency converter, and determines whether the real-time DC voltage is within a predetermined DC voltage range. If not, the control unit adjusts the rotation speed of the rotor of the DC generator through the hydraulic drive system until the real-time DC voltage is within the predetermined DC voltage range.

[0016] Preferably, the method for driving the rotor of the DC generator to rotate by the internal hydraulic oil after the hydraulic drive system is started, comprises: The control unit controls the engine on the electric drive workover rig truck to start, and drives the hydraulic oil pump to start through the gearbox and the power takeoff. After the hydraulic oil pump is started, the hydraulic oil in the hydraulic oil tank is pumped out, pressurized, and transmitted to the hydraulic motor through the pipeline, so that the hydraulic motor operates to drive the rotor of the DC generator to rotate.

[0017] Preferably, the method for adjusting the rotation speed of the rotor of the DC generator by the hydraulic drive system, comprises: The control unit adjusts the rotation speed of the hydraulic motor and the hydraulic oil pump by controlling the rotation speed of the engine to increase or decrease, thereby adjusting the rotation speed of the rotor of the DC generator.

[0018] The present application has at least the following beneficial effects: The application provides an electric drive workover rig backup power supply system and a control method thereof. The DC circuit of the DC generator is directly connected with the frequency converter of the electric drive workover rig, so that the use of an AC synchronous generator with large power and volume is avoided. The electric drive workover rig backup power supply system has the advantages of small volume and weight, small space occupation, low manufacturing and using cost, simple installation and operation, and the like, and can achieve the purpose of uninterrupted operation. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings incorporated in the specification and forming a part thereof illustrate embodiments that are in accordance with the present application and together with the description are used to explain the principles of the application.

[0020] Figure 1 Fig. 1 shows a front view of an electric drive workover rig according to an embodiment of the present application; Figure 2 Fig. 2 shows a top view of an electric drive workover rig according to an embodiment of the present application; Figure 3 Fig. 3 shows a main circuit schematic diagram of an electric drive workover rig according to an embodiment of the present application; Figure 4 Fig. 4 shows a structural schematic diagram of an electric drive workover rig backup power supply system according to an embodiment of the present application; Figure 5 Fig. 5 shows a device connection block diagram of an electric drive workover rig backup power supply system according to an embodiment of the present application.

[0021] In the drawings, 1 is a two-type chassis vehicle, 2 is a derrick, 3 is a control cabinet, 4 is a winch, 5 is an operating room, 6 is a direct drive motor, 7 is a hydraulic system, 8 is an engine, 9 is a gearbox, 10 is a power takeoff, 11 is a hydraulic oil pump, 12 is a hydraulic hose line, 13 is a hydraulic electromagnetic valve, 14 is a hydraulic motor, and 15 is a DC generator. DETAILED DESCRIPTION

[0022] Various exemplary embodiments, features, and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numbers in the drawings represent functionally the same or similar elements. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

[0023] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0024] The term "and / or", as used herein, merely describes association between associated objects, and can indicate that three cases, such as A and / or B, can exist, that is, A exists alone, A and B exist together, and B exists alone. In addition, the term "at least one" herein indicates any one of multiple or any combination of at least two of multiple, for example, at least one of A, B and C can indicate any one or more elements selected from the set consisting of A, B and C.

[0025] In addition, in order to better illustrate the present application, numerous specific details are given in the following specific embodiments. Those skilled in the art should understand that the present application can also be implemented without some specific details. In some examples, methods, means, elements and circuits well known to those skilled in the art are not described in detail, in order to highlight the main idea of the present application.

[0026] Figure 1 A front view of an electric drive workover rig according to an embodiment of the present application is shown; Figure 2 A top view of an electric drive workover rig according to an embodiment of the present application is shown; Figure 3 A schematic diagram of a main circuit of an electric drive workover rig according to an embodiment of the present application is shown; Figure 4 A schematic diagram of a structure of a standby power supply system of an electric drive workover rig according to an embodiment of the present application is shown; Figure 5 A device connection block diagram of a standby power supply system of an electric drive workover rig according to an embodiment of the present application is shown. As Figures 1-5 shown, a standby power supply system of an electric drive workover rig includes a DC generator 15, a hydraulic drive system and a control unit; the DC generator 15 is fixed on the electric drive workover rig, and the DC generator 15 is connected to a DC circuit of a frequency converter on the electric drive workover rig through a line; the hydraulic drive system is connected to the DC generator 15 and the electric drive workover rig respectively, and the hydraulic drive system is used to generate electricity by driving the rotor of the DC generator 15 to rotate; the frequency converter, the DC generator 15 and the hydraulic drive system are respectively connected to the control unit for controlling the start or shutdown thereof.

[0027] In the embodiment of the present application, the main structure of the electric drive workover rig is shown in Figure 1 and Figure 2 It mainly consists of two types of chassis car 1, derrick 2, control cabinet 3, winch 4, operating room 5, direct drive motor 6, hydraulic system 7 and other main components. All components are installed on the outrigger of the two types of chassis car 1, the control cabinet 3 is provided with a frequency converter for driving the direct drive motor 6 to work, the direct drive motor 6 drives the winch 4 to rotate, and the winch 4 drives the wireline to raise and lower the tubing and sucker rod through the derrick 2.

[0028] When the standby power supply system is not installed, the original electric drive workover rig is connected with the well site transformer for power supply, and the principle diagram of the main circuit is shown in Figure 3 The well site AC 380V power supply is connected to the power input end of the frequency converter control cabinet through the low voltage side (380V) of the well site transformer. A circuit breaker QF1 is arranged on the line between the transformer and the frequency converter. The well site AC 380V power supply is transmitted to the frequency converter through the circuit breaker QF1 for power supply. After passing through the rectifier circuit, the DC circuit and the inverter circuit of the frequency converter, the power is transmitted to the AC motor (direct drive motor 6). At the same time, the low voltage side of the transformer is connected to the AC power module through QF1. The AC power module adjusts the AC 380V voltage output by the transformer to a voltage that can be used by the control circuit, and converts it into DC power, which is transmitted to the control circuit of the frequency converter for power supply.

[0029] The control circuit collects the number of revolutions of the direct drive motor 6 through the photoelectric encoder, and controls the number of revolutions of the direct drive motor 6 by controlling the pulse angle of the rectifier circuit and the inverter circuit in the frequency converter. After the direct drive motor is started, the winch 4 is driven to rotate, and the workover rig starts to work.

[0030] When the standby power supply system of the application is installed, the circuit breaker QF1 between the frequency converter and the transformer is connected with the control unit; the DC generator 15 is fixed on the type II chassis of the electric drive workover rig, and the output end of the DC generator 15 is connected to the input port of the DC circuit of the frequency converter through the line.

[0031] When the relay protection of the well site transformer acts, the circuit breaker QF1 is tripped. After the control circuit detects that the circuit breaker QF1 is disconnected, it is indicated that a power failure has occurred. The control unit controls the hydraulic drive system to start and drive the rotor of the DC generator 15 to rotate for power generation. The DC power generated by the DC generator 15 is transmitted to the DC circuit of the frequency converter through the line, and then transmitted to the inverter circuit of the frequency converter through the DC circuit. After the DC power is converted into AC power with variable frequency through the inverter circuit, it is transmitted to the direct drive motor 6, thereby providing operating power for the direct drive motor 6. After the direct drive motor 6 restores power supply, it continues to drive the winch 4 to rotate for workover operation. At the same time, the output DC power of the DC generator 15 is transmitted to the control circuit of the frequency converter for power supply after voltage regulation.

[0032] In the present application, the hydraulic drive system comprises a hydraulic oil pump 11, a hydraulic oil tank, a hydraulic motor 14 and a driving mechanism; the driving mechanism is connected to the hydraulic oil pump 11, the hydraulic oil pump 11 is connected to the hydraulic oil tank, and the hydraulic oil tank is connected to the hydraulic motor 14; the hydraulic oil pump 11 is connected to the hydraulic motor 14, and the hydraulic motor 14 is connected to the DC generator 15 rotor; the driving mechanism is connected to the control unit, and the driving mechanism is used to drive the hydraulic oil pump 11 to start, so that the hydraulic oil in the hydraulic oil tank is pressurized and then transmitted to the hydraulic motor 14.

[0033] In the embodiment of the present application, when the control circuit detects that the circuit breaker QF1 is disconnected, the control driving mechanism starts to transmit power to the hydraulic oil pump 11 to drive the hydraulic oil pump 11 to operate. After the hydraulic oil pump 11 starts, the hydraulic oil stored in the hydraulic oil tank is sucked into the hydraulic oil pump 11 to form pressure oil, and the hydraulic oil pump 11 transmits the pressure oil to the hydraulic motor 14 through the pipeline to drive the hydraulic motor 14 to rotate. The hydraulic motor 14 is mechanically connected to the DC generator 15 through a flange pair disc; after the hydraulic motor 14 starts, the rotor of the DC generator 15 is driven to rotate, so that the DC generator 15 generates electric energy, and the direct current generated by the DC generator 15 is directly connected to the direct current circuit of the frequency converter, and after being converted into alternating current with variable frequency through the inverter circuit of the frequency converter, the alternating current is used to supply power to the direct drive motor.

[0034] In the present application, the driving mechanism is that the engine (8) on the electric drive workover truck, the gearbox (9) connected to the engine (8), and the power takeoff (10) connected to the gearbox (9); the power takeoff (10) is connected to the hydraulic oil pump (11).

[0035] In the embodiment of the present application, the hydraulic oil pump 11 and the power takeoff 10 installed on the side of the two-class chassis vehicle are mechanically connected through a flange pair disc. When power supply is needed, the control unit controls the two-class chassis vehicle engine 8 to start, the power of the engine 8 is transmitted to the power takeoff 10 through the two-class chassis vehicle gearbox 9 connected thereto, and the power takeoff 10 drives the hydraulic oil pump 11 to operate.

[0036] The engine 8, the gearbox 9 and the power takeoff 10 are original devices on the electric drive workover truck. When the electric drive workover truck works, the vehicle is generally stopped at the original position without starting, and the engine 8 on the vehicle is in an idle state. By using the engine 8 and the gearbox 9 on the vehicle as a power source, it is not necessary to add additional power equipment, so that the space occupation on the vehicle can be reduced and the use cost can be reduced. The hydraulic oil tank can be the hydraulic oil tank in the original hydraulic system of the electric drive workover truck, that is, the vehicle and the hydraulic drive system share the same oil tank, so that the space occupation on the vehicle can be further reduced.

[0037] In the application, the hydraulic oil pump 11 of the hydraulic drive system is fixed below the chassis of the electric drive workover locomotive; and the hydraulic motor 14 is fixed on the electric drive workover locomotive.

[0038] In the embodiment of the application, the engine 8, gearbox 9, power take-off 10 and hydraulic oil pump 11 of the two-class chassis vehicle are arranged at the bottom of the two-class chassis vehicle, the hydraulic oil pump 11 is small in size and can be installed at the bottom of the vehicle without occupying space on the vehicle. The hydraulic motor 14 and the DC generator 15 are connected together and fixed on the electric drive workover locomotive, and the hydraulic motor 14 and the DC generator 15 are also small in size and do not need to occupy too much space on the vehicle.

[0039] In the application, the ball valve and the filter are further included; the ball valve and the filter are arranged on the pipeline between the hydraulic oil tank and the hydraulic oil pump 11.

[0040] In the embodiment of the application, the control unit is connected with the ball valve. When power supply is performed, the control unit controls the ball valve to be opened. After the hydraulic oil pump 11 is started, the hydraulic oil in the hydraulic oil tank is pumped out, passes through the filter and the ball valve on the pipeline and enters the hydraulic oil pump 11. The filter is used to filter impurities in the hydraulic oil to prevent the impurities from entering the hydraulic oil pump 11; and the ball valve is used to prevent the hydraulic oil in the hydraulic oil tank from entering the pipeline and the hydraulic oil pump 11 when the hydraulic oil pump 11 stops running.

[0041] In the application, the hydraulic electromagnetic valve 13 is further included; the hydraulic electromagnetic valve 13 is arranged on the pipeline between the hydraulic oil pump 11, the hydraulic oil tank and the hydraulic motor 14; and the hydraulic electromagnetic valve 13 is connected with the control unit.

[0042] In the embodiment of the application, when power supply is performed, the control unit controls the hydraulic electromagnetic valve 13 to be opened. After the hydraulic oil pump 11 is started, the hydraulic oil in the hydraulic oil tank is pumped out and pressurized, then is transmitted to the hydraulic motor 14 through the pipeline and the hydraulic electromagnetic valve 13; and the hydraulic oil output by the hydraulic motor 14 when the hydraulic motor 14 runs enters the hydraulic oil tank through the pipeline and the hydraulic electromagnetic valve 13.

[0043] The hydraulic electromagnetic valve 13 is used to, when power supply is not needed or the engine 8 of the electric drive workover locomotive starts vehicle running, close the hydraulic electromagnetic valve 13 to prevent the hydraulic oil from entering the hydraulic motor 14 and prevent the hydraulic motor 14 from starting to rotate.

[0044] In the application, the hydraulic oil pump 11 is connected with the hydraulic motor 14 and the hydraulic oil tank through the hydraulic hose pipeline 12 respectively.

[0045] In the embodiment of the present application, the hydraulic oil pump 11 is connected with the hydraulic oil tank and the hydraulic electromagnetic valve 13 through the corresponding hydraulic hose line 12 respectively; the hydraulic motor 14 is connected with the hydraulic electromagnetic valve 13 and the hydraulic oil tank through the corresponding hydraulic hose line 12 respectively.

[0046] By using the hydraulic hose line 12 for connection, the hydraulic motor 14 and the DC generator 15 can be arranged at any position on the electric drive workover truck, and the space occupied by the hydraulic motor 14 and the DC generator 15 installed together is not large, and a fixed position is not required, so that the arrangement mode is more flexible.

[0047] In the present application, a DC power supply module is further included; the DC power supply module is connected with the DC generator 15 and the control circuit of the frequency converter respectively, and is used for converting the real-time voltage output by the DC generator 15 into a predetermined voltage and then transmitting the predetermined voltage to the control circuit.

[0048] In the embodiment of the present application, the voltage output by the DC generator 15 when generating electricity is too large, and when supplying power to the control circuit, it needs to be first stepped down to the voltage available to the control circuit, that is, the predetermined voltage. Since the output of the DC generator 15 is DC, an AC-DC conversion circuit does not need to be additionally set, and a DC power supply module capable of voltage regulation can be directly used for power supply, so that the use cost can be further saved.

[0049] In the present application, the control unit includes a programmable controller, an engine 8 control unit and a circuit breaker; the programmable controller is connected with the engine 8 control unit and the frequency converter respectively, and the engine 8 control unit is connected with the hydraulic drive system; the circuit breaker is arranged on the line between the DC generator 15 and the frequency converter, and the circuit breaker is connected with the programmable controller.

[0050] In the embodiment of the present application, the programmable controller PLC is connected with the control circuit of the frequency converter, the circuit breaker QF1, the ball valve and the hydraulic electromagnetic valve 13 respectively. The engine 8 control unit ECU is connected with the engine 8 of the hydraulic drive system.

[0051] The DC generator 15 is connected to the DC circuit of the frequency converter through the circuit breaker QF2, and is also connected to the control circuit of the frequency converter through the circuit breaker QF2 and the DC power supply module to supply power. The programmable controller PLC is connected with the control circuit and the engine 8 control unit ECU of the two types of chassis vehicles respectively to communicate with each other.

[0052] When the well site power supply fails, the circuit breaker QF1 is opened, the programmable controller PLC controls the circuit breaker QF2 to be closed, controls the hydraulic electromagnetic valve 13 and the ball valve to be opened, and sends a signal to the control circuit to control the conduction angle of the rectifier circuit to be closed; at the same time, the programmable controller PLC sends a signal to the engine 8 control unit ECU to control the engine 8 to start through the engine 8 control unit ECU. After the engine 8 starts, the hydraulic oil pump 11 is driven to operate through the gearbox 9 and the power take-off 10, the hydraulic oil in the hydraulic oil tank is pumped out and pressurized through the ball valve and the filter, and then transmitted to the hydraulic motor 14 through the hydraulic electromagnetic valve 13, and the rotor of the direct current generator 15 is driven to rotate for power generation through the hydraulic motor 14; the direct current output by the direct current generator 15 is transmitted to the control circuit for power supply after passing through the circuit breaker QF2 and the direct current power supply module.

[0053] In the application, a control method of a standby power supply system of an electric drive workover rig comprises: Step S01: When the control unit detects that the frequency converter of the electric drive workover rig is powered off, the hydraulic drive system is controlled to start; In the embodiment of the application, when the well site power supply is normal, the electric drive workover rig is connected to the well site AC 380V power supply, the circuit breaker QF is closed, the 380V power supply supplies power to the frequency converter and the control circuit of the frequency converter, the AC 380V power supply is frequency-converted through the frequency converter to drive the direct drive motor 6 to operate, the direct drive motor 6 drives the winch 4 to rotate, and the electric drive workover rig starts operation.

[0054] When the well site 380V power supply fails, the circuit breaker QF1 is opened, and the programmable controller PLC of the control unit sends a signal to the engine 8 control unit ECU to control the engine 8 of the hydraulic drive system to start.

[0055] Step S02: After the hydraulic drive system starts, the rotor of the direct current generator 15 is driven to rotate by the internal hydraulic oil to make the direct current generator 15 generate direct current, which is transmitted to the frequency converter through the circuit, and the control unit controls the rectifier circuit of the frequency converter to be closed through the control circuit of the frequency converter; In the application, the method for driving the rotor of the direct current generator 15 to rotate by the internal hydraulic oil after the hydraulic drive system starts, comprises: the control unit controls the engine 8 on the electric drive workover rig to start, and drives the hydraulic oil pump 11 through the gearbox 9 and the power take-off 10; after the hydraulic oil pump 11 starts, the hydraulic oil in the hydraulic oil tank is pumped out, pressurized, and then transmitted to the hydraulic motor 14 through the pipeline to drive the rotor of the direct current generator 15 to rotate.

[0056] In the embodiment of the present application, after the engine 8 is started, power is transmitted to the hydraulic oil pump 11 through the gearbox 9 and the side power take-off 10 of the two-axle vehicle, to drive the hydraulic oil pump 11 to operate; the hydraulic oil pump 11 sucks the hydraulic oil in the hydraulic oil tank into the inside through the hydraulic hose line 12 to form pressure oil, and then transmits the pressure oil to the hydraulic motor 14 through the hydraulic electromagnetic valve 13, to drive the hydraulic motor 14 to operate; when the hydraulic motor 14 operates, the rotor of the DC generator 15 rotates, and the DC generator 15 outputs DC power.

[0057] After the DC generator 15 operates stably, the programmable controller PLC controls the circuit breaker QF2 to be closed, so that the DC power enters the DC circuit of the frequency converter; at the same time, the DC power also enters the DC voltage module, is transformed by the DC voltage module, i.e., is stepped down to a predetermined voltage, and is transmitted to the control circuit for power supply.

[0058] After the control circuit of the frequency converter is powered on, the programmable controller PLC sends an instruction to the control circuit, so that the control circuit controls the conduction angle of the rectifier circuit to be closed, so that the rectifier circuit is in a closed state; the control circuit controls the inverter circuit to start working, and the DC power entering the DC circuit is inverted into AC power with variable frequency, and then is transmitted to the direct drive motor 6 to drive it to operate. After the direct drive motor 6 operates, the winch 4 is driven to operate, so that the electric workover rig starts to work.

[0059] Step S03: The control unit detects the real-time DC voltage of the DC circuit of the frequency converter through the control circuit of the frequency converter, and judges whether the real-time DC voltage is within the predetermined DC voltage range; if not, the control unit adjusts the rotation speed of the rotor of the DC generator 15 through the hydraulic drive system, until the real-time DC voltage is within the predetermined DC voltage range.

[0060] In the present application, the method for the control unit to adjust the rotation speed of the rotor of the DC generator 15 through the hydraulic drive system comprises: the control unit adjusts the rotation speed of the rotor of the DC generator 15 by controlling the rotation speed of the engine 8 to increase or decrease, and adjusting the rotation speed of the hydraulic oil pump 11 and the hydraulic motor 14 to increase or decrease.

[0061] In the embodiment of the present application, during the operation of the electric workover rig, the control circuit detects the real-time DC voltage of the DC circuit of the frequency converter in real time, and feeds back the real-time DC voltage value to the programmable controller PLC; when the real-time DC voltage value is greater than or less than the required value of the system, i.e., when the real-time DC voltage deviates from the predetermined DC voltage range, The programmable controller PLC sends a control command to the engine 8 control unit ECU to adjust the engine 8 revolutions per minute of the second type chassis vehicle; if the real-time direct current voltage is lower than the predetermined direct current voltage range, the engine 8 revolutions per minute is adjusted to decrease, and if the real-time direct current voltage is higher than the predetermined direct current voltage range, the engine 8 revolutions per minute is adjusted to increase; then through the gearbox 9, the power take-off 10, the hydraulic oil pump 11, the hydraulic hose line 12, the hydraulic electromagnetic valve 13, the hydraulic motor 14, and the direct current generator 15 rotor, the revolutions of the direct current generator 15 rotor are adjusted to increase or decrease, so as to achieve the purpose of adjusting the real-time direct current voltage and meet the demand of the frequency converter direct current circuit.

[0062] When the electric drive workover rig operation is completed, the control is disconnected, the circuit breaker QF2 is closed, and the engine 8 is turned off. When the well site power failure is removed and the power is restored, and the electric drive workover rig operation is not completed, the circuit breaker QF2 is disconnected, the engine 8 is turned off, the circuit breaker QF1 is closed, the on-off angle of the rectifier circuit is opened, and the well site alternating current 380V power source is connected; the alternating current 380V voltage drives the direct drive motor through the frequency converter, and the electric drive workover rig continues to operate.

[0063] It can be understood that the above-mentioned various embodiments of the present application can be combined with each other to form a combined embodiment without deviating from the principle logic. Due to the limited space, the present application will not be described again.

[0064] Those skilled in the art can understand that in the above-mentioned method of the specific embodiment, the writing order of each step does not mean a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0065] In the prior art, in view of the problem that the well site power failure workover rig cannot continuously operate, some enterprises have developed oil-electric dual-power workover rigs, which are used to transmit power to the winch through the diesel engine 8 on the second type chassis vehicle through the transfer case, the transmission shaft, and the angle transmission case to perform workover operation. This oil-electric dual-power workover rig needs to install the transfer case, the transmission shaft, the hydraulic torque converter, and the angle transmission case on the second type chassis vehicle frame, which needs to occupy a lot of space on the vehicle. Since the space reserved on the electric drive workover rig vehicle is already very small, it is not possible to implement this scheme in actual operation. Moreover, the transfer case, the transmission shaft, the hydraulic torque converter, and the angle transmission case are very expensive and heavy, and the hydraulic system of the electric drive workover rig also needs to be changed to a mechanical and motor drive two-system, which further increases the manufacturing cost of the electric drive workover rig. If an alternating current synchronous generator is used, not only the active power and the direct drive motor need to be matched, but also the reactive power and the direct drive motor need to be matched. The existing synchronous alternating current generator generates very little rated reactive power, so in order to match the reactive power of the direct drive motor 6, an alternating current synchronous generator with a large capacity needs to be selected. In this way, the synchronous alternating current generator not only increases a lot in size and volume, but also increases a lot in cost.

[0066] The standby power supply system of the electric drive workover rig can provide power for the electric drive workover rig when the power supply of the well site fails, thereby ensuring normal workover operation. The direct current output by the direct current generator 15 is directly connected to the direct current circuit of the frequency converter. Since the direct current does not involve the problem of reactive power compensation, the capacity of the direct current generator 15 can be selected according to the rated capacity of the direct drive motor 6, and only needs to be slightly larger than the capacity of the direct drive motor 6. In this way, the volume and cost of the direct current generator 15 can be greatly reduced. The hydraulic part only needs to increase a hydraulic oil pump 11 at the bottom of the vehicle to realize the driving of the direct current generator 15, without occupying the space on the vehicle, and with lower cost and weight. The control unit is arranged to automatically switch control after power failure, and the number of revolutions of the hydraulic oil pump 11 is changed through the detected voltage value, the engine 8, the gearbox 9 and the power takeoff 10, so as to change the number of revolutions of the rotor of the hydraulic motor 14 and the direct current generator 15, thereby achieving the purpose of automatically adjusting the direct current voltage. The control unit is arranged to make the operation simpler, thereby reducing labor costs and improving work efficiency.

[0067] The above has described the embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical application or improvement of the technology in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A backup power supply system for an electrically driven well workover rig, characterized in that, include: DC generator (15), hydraulic drive system and control unit; The DC generator (15) is fixed on the electric drive workover machine, and the DC generator (15) is connected to the DC circuit of the frequency converter on the electric drive workover machine through a line; The hydraulic drive system is connected to the DC generator (15) and the electric workover rig respectively. The hydraulic drive system is used to generate electricity by driving the rotor of the DC generator (15) to rotate by driving the internal hydraulic oil. The frequency converter, DC generator (15), and hydraulic drive system are respectively connected to the control unit for controlling their start-up or shutdown.

2. The backup power supply system for the electric workover rig according to claim 1, characterized in that, The hydraulic drive system includes: a hydraulic oil pump (11), a hydraulic oil tank, a hydraulic motor (14), and a drive mechanism; The drive mechanism is connected to the hydraulic oil pump (11), the hydraulic oil pump (11) is connected to the hydraulic oil tank, and the hydraulic oil tank is connected to the hydraulic motor (14). The hydraulic oil pump (11) is connected to the hydraulic motor (14), and the hydraulic motor (14) is connected to the rotor of the DC generator (15); The drive mechanism is connected to the control unit. The drive mechanism is used to drive the hydraulic oil pump (11) to start, pressurize the hydraulic oil in the hydraulic oil tank and transmit it to the hydraulic motor (14).

3. The backup power supply system for the electric workover rig according to claim 2, characterized in that, The driving mechanism is: The electric well repair locomotive has an engine (8), a gearbox (9) connected to the engine (8), and a power take-off (10) connected to the gearbox (9). The power take-off (10) is connected to the hydraulic oil pump (11).

4. The backup power supply system for the electric workover rig according to claim 2, characterized in that: The hydraulic oil pump (11) of the hydraulic drive system is fixed below the chassis of the electric workover vehicle; The hydraulic motor (14) is fixed on the electric workover vehicle.

5. The backup power supply system for the electric workover rig according to claim 2, characterized in that, Also includes: Ball valves and filters; The ball valve and the filter are disposed on the pipeline between the hydraulic oil tank and the hydraulic oil pump (11).

6. The backup power supply system for the electric workover rig according to claim 2, characterized in that, Also includes: Hydraulic solenoid valve (13); The hydraulic solenoid valve (13) is installed on the pipeline between the hydraulic oil pump (11), the hydraulic oil tank, and the hydraulic motor (14). The hydraulic solenoid valve (13) is connected to the control unit.

7. The backup power supply system for an electrically driven workover rig according to any one of claims 2-6, characterized in that: The hydraulic pump (11) is connected to the hydraulic motor (14) and the hydraulic tank via hydraulic hoses (12).

8. The backup power supply system for the electric workover rig according to claim 1, characterized in that, Also includes: DC power supply module; The DC power supply module is connected to the control circuit of the DC generator (15) and the frequency converter respectively. The DC power supply module is used to convert the real-time voltage output by the DC generator (15) into a predetermined voltage and then transmit it to the control circuit.

9. The backup power supply system for an electrically driven workover rig according to any one of claims 1-8, characterized in that, The control unit includes: a programmable controller, an engine (8) control unit, and a circuit breaker; The programmable controller is connected to the engine (8) control unit and the frequency converter respectively, and the engine (8) control unit is connected to the hydraulic drive system; The circuit breaker is installed on the line between the DC generator (15) and the frequency converter, and the circuit breaker is connected to the programmable controller.

10. A control method for a backup power supply system of an electrically driven well workover rig, characterized in that, include: When the control unit detects that the inverter of the electric workover rig has lost power, it controls the hydraulic drive system to start. After the hydraulic drive system is started, it drives the rotor of the DC generator (15) to rotate by driving the internal hydraulic oil, so that the DC generator (15) generates DC power and transmits it to the frequency converter through the line. The control unit controls the rectifier circuit to shut down through the control circuit of the frequency converter. The control unit detects the real-time DC voltage of the inverter's DC circuit through the inverter's control circuit and determines whether the real-time DC voltage is within the predetermined DC voltage range. If not, the control unit adjusts the rotation speed of the rotor of the DC generator (15) through the hydraulic drive system until the real-time DC voltage is within the predetermined DC voltage range.

11. The control method for the backup power supply system of the electric workover rig according to claim 10, characterized in that, The method by which the hydraulic drive system drives the rotor of the DC generator (15) to rotate by driving the internal hydraulic oil after startup includes: The control unit controls the engine (8) on the electric workover vehicle to start, and drives the hydraulic oil pump (11) to start through the gearbox (9) and power take-off (10); After the hydraulic oil pump (11) is started, it draws out the hydraulic oil from the hydraulic oil tank, pressurizes it and transmits it to the hydraulic motor (14) through the pipeline, so that the hydraulic motor (14) runs and drives the rotor of the DC generator (15) to rotate.

12. The control method for the backup power supply system of the electric workover rig according to claim 11, characterized in that, The method by which the control unit adjusts the rotational speed of the rotor of the DC generator (15) via a hydraulic drive system includes: The control unit adjusts the rotational speed of the DC generator (15) by increasing or decreasing the rotational speed of the engine (8) during operation, thereby increasing or decreasing the rotational speed of the hydraulic oil pump (11) and the hydraulic motor (14).

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