Underground power supply and power control method

Abstract

The invention provides an underground power supply and a power control method, the underground power supply comprises an underground turbine generator, a three-phase rectification filtering module and an under-voltage locking overvoltage protection module, the underground turbine generator is used for generating a three-phase alternating current; the three-phase rectifying and filtering module is used for rectifying and filtering the three-phase alternating current to obtain direct current; and the under-voltage locking and overvoltage protection module is used for carrying out under-voltage locking and overvoltage protection on the direct current and outputting an external power supply voltage. According to the technical scheme, while-drilling data acquisition and MWD data transmission can be met, and a power supply is provided for underground high-power equipment such as a mud pulser.

Description

Background Art

[0002] With the increase in the world's demand for oil and gas and the development of conventional oil and gas reservoirs, oil and gas exploration and development are moving towards deep and ultra-deep layers, with well depths of up to 8,000-10,000 meters and bottom hole temperatures even exceeding 200°C. Oil and gas exploration equipment faces the challenge of high formation temperatures, and the rising ambient temperature places higher demands on the high temperature resistance and reliability of power supply design.

[0003] The Measurement While Drilling (MWD) system is an indispensable instrument for continuously monitoring the drilling trajectory. The high temperature resistance problem faced by the MWD instrument during the drilling process is becoming increasingly prominent. Whether the instrument can be efficiently and reliably powered in the ultra-high temperature environment underground will directly affect the working reliability of the entire underground instrument system. According to statistics, power failure accounts for about 30% of the reasons for the failure of the circuit of the drilling instrument. It can be seen that the high temperature resistant and highly reliable underground power supply module is one of the key factors for the successful drilling of deep and ultra-deep layers.

[0004] In addition, due to the downhole needs of drilling and MWD data transmission, the downhole power supply needs to provide power to downhole high-power equipment such as mud pulsers, and the power drive power needs to reach 600W-3KW, or higher power output needs. Due to the large output power, not only is it difficult to deal with the large electrical stress problem of the power switch tube and the rectifier tube, but the heat dissipation problem caused by system loss is also difficult to solve. Especially in high temperature environments, even if the components in the circuit system use specific high-temperature devices, high losses will cause serious temperature rise problems. This will lead to serious consequences: if the temperature rise is not controlled, the temperature of the system is likely to exceed the temperature resistance value of the device, which will affect the service life of the components, and more seriously, it will cause system failure.

[0005] During the drilling process, real-time transmission of downhole tool status, acquisition of first-hand formation information, and real-time control of downhole tools are all inseparable from a power supply that can work at high ambient temperature for a long time. The safe and reliable operation of the power supply is the prerequisite for the reliable operation of the entire downhole tool. In-depth research on high-temperature and high-power power supplies while drilling from the aspects of high-temperature power supply topology design, system high-temperature application improvement methods, and high-power power supply temperature rise improvement algorithms has important theoretical and practical significance. Summary of the invention

[0006] The present application provides a downhole power supply and power control method, which are used to provide reliable power supply for oil and gas downhole instruments in a high temperature environment to ensure safe and stable operation of the instruments.

[0007] In a first aspect, a downhole power supply is provided, comprising: a downhole turbine generator, a three-phase rectifier filter module and an undervoltage lockout overvoltage protection module, wherein:

[0008] The downhole turbine generator is used to generate three-phase alternating current;

[0009] The three-phase rectification and filtering module is used to rectify and filter the three-phase alternating current to obtain direct current;

[0010] The undervoltage lockout and overvoltage protection module is used to perform undervoltage lockout and overvoltage protection on the direct current and output an external power supply voltage.

[0011] In the above technical solution, by setting up a downhole turbine generator, a three-phase rectification and filtering module and an undervoltage lockout overvoltage protection module, the downhole turbine generator is used to generate three-phase alternating current; the three-phase rectification and filtering module is used to rectify and filter the three-phase alternating current to obtain direct current; the undervoltage lockout overvoltage protection module is used to perform undervoltage lockout and overvoltage protection on the direct current, and output an external power supply voltage; it can meet the needs of while-drilling data acquisition and MWD data transmission, and provide power for high-power downhole equipment such as mud pulsers. The power drive power needs to reach 600W-3KW, or higher power output requirements.

[0012] In a specific implementation scheme, a DC / DC conversion module is also included, wherein:

[0013] The DC / DC conversion module is used to perform DC / DC conversion on the external power supply voltage.

[0014] In a specific implementation scheme, the DC / DC conversion module includes:

[0015] 36V output DC / DC module, used to output 36 volts direct current;

[0016] 24V output DC / DC module, used to output 24 volt direct current.

[0017] In a specific implementation scheme, it also includes a speed signal processing module, wherein:

[0018] The speed signal processing module is electrically connected to the downhole turbine generator and is used to process the speed signal of the downhole turbine generator.

[0019] In a specific implementation scheme, it also includes an internal circuit power supply module, wherein:

[0020] The input end of the internal circuit power supply module is electrically connected to the undervoltage lockout overvoltage protection module;

[0021] The output end of the internal circuit power supply module is electrically connected to the 36V output DC / DC module, the 24V output DC / DC module and the speed signal processing module respectively.

[0022] In a specific implementation scheme, the filter capacitor in the three-phase rectification and filtering module includes a 10Uf capacitor with a withstand voltage of 240V and a temperature of 175°C arranged in parallel.

[0023] In a specific implementation scheme, the reverse breakdown voltage of the rectifier diode in the three-phase rectifier and filter module is not less than 200V.

[0024] In a specific implementation scheme, the DC / DC conversion module includes a linear voltage regulation system and a feedback and compensation network, wherein:

[0025] Linear voltage stabilization system for outputting 12V DC;

[0026] Feedback and compensation network to stabilize the output voltage.

[0027] In a specific implementation scheme, the downhole power supply uses multiple BUCK sub-modules connected in parallel for output.

[0028] In a second aspect, a power control method is provided, comprising the following steps:

[0029] The output current feedback circuit is designed using a droop control algorithm;

[0030] The output current feedback circuit is used to adjust the output voltage amplitude and output impedance characteristics, and to regulate the output power of the downhole power supply.

[0031] In the above technical solution, by setting up a downhole turbine generator, a three-phase rectification and filtering module and an undervoltage lockout overvoltage protection module, the downhole turbine generator is used to generate three-phase alternating current; the three-phase rectification and filtering module is used to rectify and filter the three-phase alternating current to obtain direct current; the undervoltage lockout overvoltage protection module is used to perform undervoltage lockout and overvoltage protection on the direct current, and output an external power supply voltage; it can meet the needs of while-drilling data acquisition and MWD data transmission, and provide power for high-power downhole equipment such as mud pulsers. The power drive power needs to reach 600W-3KW, or higher power output requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A structural block diagram of a downhole power supply provided in an embodiment of the present application;

[0033] Figure 2 A circuit diagram of a three-phase rectifier and filter module provided in an embodiment of the present application;

[0034] Figure 3 A circuit diagram of a speed signal processing module provided in an embodiment of the present application;

[0035] Figure 4A circuit diagram of an undervoltage lockout overvoltage protection module provided in an embodiment of the present application;

[0036] Figure 5 A circuit diagram of an internal circuit power supply module provided in an embodiment of the present application;

[0037] Figure 6 A circuit diagram of a DC / DC conversion module provided in an embodiment of the present application;

[0038] Figure 7 A schematic diagram of droop control provided in an embodiment of the present application;

[0039] Figure 8 A graph showing the working characteristics of the parallel submodules provided in the embodiment of the present application;

[0040] Fig. 9 A schematic diagram of a parallel current sharing design structure based on a droop method provided in an embodiment of the present application;

[0041] Fig.10 A flowchart of a downhole power supply control method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The present application is further described in detail below through the accompanying drawings and embodiments. Through these descriptions, the characteristics and advantages of the present application will become clearer and more specific.

[0043] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0044] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0045] To facilitate understanding of the downhole power supply and power control method provided in the embodiment of the present application, its application scenario is first explained. The downhole power supply and power control method provided in the embodiment of the present application is used to provide reliable power supply for oil and gas downhole instruments in a high temperature environment to ensure safe and stable operation of the instrument. The measurement while drilling (MWD) system is an indispensable instrument for continuous monitoring of the drilling trajectory. The high temperature resistance problem faced by the downhole instrument during drilling is becoming increasingly prominent. Whether the instrument can be efficiently and reliably powered in the ultra-high temperature environment underground will directly affect the working reliability of the entire downhole instrument system. According to statistics, power failure accounts for about 30% of the reasons for the failure of the circuit of the downhole instrument. It can be seen that the downhole power supply module with high temperature resistance and high reliability is one of the key factors for the success of deep and ultra-deep drilling. In addition, due to the downhole needs of drilling and the requirements of MWD data transmission, the downhole power supply needs to provide power to downhole high-power equipment such as mud pulsers, and the power supply driving power needs to reach 600W-3KW, or higher power output requirements. Due to the large output power, not only the large electrical stress problem of the power switch tube and the rectifier tube is difficult to handle, but also the heat dissipation problem caused by system loss is difficult to solve. Especially in high temperature environments, even if the components in the circuit system use specific high temperature devices, high losses will cause serious temperature rise problems. This will lead to serious consequences: if the temperature rise is not controlled, the temperature of the system is likely to exceed the temperature resistance of the device, which will affect the service life of the components, and more seriously, it will cause system failure. In the process of drilling, real-time transmission of downhole tool status, acquisition of first-hand formation information, and real-time control of downhole tools are inseparable from a power supply that can work at high ambient temperature for a long time. The safe and reliable operation of the power supply is the prerequisite for the reliable operation of the entire downhole tool. It is of great theoretical and practical significance to carry out in-depth research on high-temperature and high-power power supplies while drilling from the aspects of high-temperature power supply topology design, system high-temperature application improvement method, and high-power power supply temperature rise improvement algorithm. For this reason, the embodiment of the present application provides a downhole power supply and power control method to provide reliable power supply for oil and gas downhole instruments in high temperature environments and ensure safe and stable operation of the instruments. The following is a detailed description of the embodiments in conjunction with specific drawings.

[0046] refer to Figures 1 to 10 , Figure 1 A structural block diagram of a downhole power supply provided in an embodiment of the present application; Figure 2 A circuit diagram of a three-phase rectifier and filter module provided in an embodiment of the present application; Figure 3 A circuit diagram of a speed signal processing module provided in an embodiment of the present application; Figure 4 A circuit diagram of an undervoltage lockout overvoltage protection module provided in an embodiment of the present application; Figure 5 A circuit diagram of an internal circuit power supply module provided in an embodiment of the present application; Figure 6A circuit diagram of a DC / DC conversion module provided in an embodiment of the present application; Figure 7 A schematic diagram of droop control provided in an embodiment of the present application; Figure 8 A graph showing the working characteristics of the parallel submodules provided in the embodiment of the present application; Fig. 9 A schematic diagram of a parallel current sharing design structure based on a droop method provided in an embodiment of the present application; Fig.10 A flowchart of a downhole power supply control method provided in an embodiment of the present application.

[0047] exist Figure 1 In the embodiment of the present application, a downhole power supply is provided, including: a downhole turbine generator, a three-phase rectifier filter module and an undervoltage lockout overvoltage protection module, wherein:

[0048] The downhole turbine generator is used to generate three-phase alternating current;

[0049] The three-phase rectification and filtering module is used to rectify and filter the three-phase alternating current to obtain direct current;

[0050] The undervoltage lockout and overvoltage protection module is used to perform undervoltage lockout and overvoltage protection on the direct current and output an external power supply voltage.

[0051] In the above technical solution, by setting up a downhole turbine generator, a three-phase rectification and filtering module and an undervoltage lockout overvoltage protection module, the downhole turbine generator is used to generate three-phase alternating current; the three-phase rectification and filtering module is used to rectify and filter the three-phase alternating current to obtain direct current; the undervoltage lockout overvoltage protection module is used to perform undervoltage lockout and overvoltage protection on the direct current, and output an external power supply voltage; it can meet the needs of while-drilling data acquisition and MWD data transmission, and provide power for high-power downhole equipment such as mud pulsers. The power drive power needs to reach 600W-3KW, or higher power output requirements.

[0052] Specifically, the downhole power supply is an ultra-high power AC-DC power supply design that can work at 175 degrees Celsius for a long time under downhole drilling conditions. It is powered by three-phase AC power output by the downhole generator, outputs DC36V and DC 24V two-way DC power supply, and outputs the speed signal of the downhole turbine generator; it can meet the needs of downhole data acquisition and MWD data transmission, and provide power for downhole high-power equipment such as mud pulsers. The power drive power needs to reach 600W-3KW, or higher power output requirements; the main contents include high-temperature resistant and strong-drive BUCK power supply design, which contains three-phase rectification and filtering, DC / DC drive, high-speed digital isolation, gate driver, undervoltage lockout and overvoltage protection modules, etc.; it effectively solves the technical difficulties of high-temperature resistant and high-power reliable output drive of downhole downhole power supply, breaks through the industry's technical barriers, greatly reduces the dependence on external technology, and provides reliable technical guarantee for the development of oil and gas resource exploration towards ultra-deep and ultra-deep layers.

[0053] In a specific implementation scheme, a DC / DC conversion module is also included, wherein:

[0054] The DC / DC conversion module is used to perform DC / DC conversion on the external power supply voltage.

[0055] In a specific implementation scheme, the DC / DC conversion module includes:

[0056] 36V output DC / DC module, used to output 36 volts direct current;

[0057] 24V output DC / DC module, used to output 24 volt direct current.

[0058] In a specific implementation scheme, it also includes a speed signal processing module, wherein:

[0059] The speed signal processing module is electrically connected to the downhole turbine generator and is used to process the speed signal of the downhole turbine generator.

[0060] In a specific implementation scheme, it also includes an internal circuit power supply module, wherein:

[0061] The input end of the internal circuit power supply module is electrically connected to the undervoltage lockout overvoltage protection module;

[0062] The output end of the internal circuit power supply module is electrically connected to the 36V output DC / DC module, the 24V output DC / DC module and the speed signal processing module respectively.

[0063] In a specific implementation scheme, the filter capacitor in the three-phase rectification and filtering module includes a 10Uf capacitor with a withstand voltage of 240V and a temperature of 175°C arranged in parallel.

[0064] In a specific implementation scheme, the reverse breakdown voltage of the rectifier diode in the three-phase rectifier and filter module is not less than 200V.

[0065] In a specific implementation scheme, the DC / DC conversion module includes a linear voltage regulation system and a feedback and compensation network, wherein:

[0066] Linear voltage stabilization system for outputting 12V DC;

[0067] Feedback and compensation network to stabilize the output voltage.

[0068] In a specific implementation scheme, the downhole power supply uses multiple BUCK sub-modules connected in parallel for output.

[0069] Specifically, refer to Figure 2 The three-phase AC 110VAC output by the underground turbine generator is three-phase full-wave rectified through six Schottky diodes connected in pairs to form a bridge rectifier circuit. Considering the instability of the turbine generator, its output AC voltage fluctuation range is between 30-160VAC, and the reverse breakdown voltage of the diode should be no less than 200V. In the LC filter circuit, in order to achieve the filtering effect, the capacitance value of capacitor C1 is selected as 2200uF, and the withstand voltage is also selected to be greater than 200V. Due to the specific requirements of the underground environment, it is impossible to directly select large-capacity and high-voltage capacitors. The large-capacity capacitor is formed by connecting 10Uf 240V 175℃ withstand capacitors in parallel.

[0070] refer to Figure 3 The turbine generator speed processing module collects one-phase output of the three-phase AC generator, and inputs it to the non-inverting input terminal of the comparator COMP1 through the resistor R3 and the voltage regulator D1 for comparison with the reference voltage at the reverse input terminal of the comparator COMP1. Then COMP1 outputs a square wave signal F0 with the same frequency as the input signal.

[0071] refer to Figure 4 The DC voltage DC+ output by the three-phase rectifier filter is sent to the undervoltage lockout overvoltage protection module. The resistor R1 and the diode D1 generate a +15V voltage to power the components of this module. The comparator U1, the resistor R2, the resistor R3, the resistor R4 and the +5V reference voltage source constitute the window recognition system. The output end of the comparator U1 is connected to the inverter U2A, and the output end of U2A is connected to the gate of the N-channel field effect transistor Q2. Q2 further controls the conduction and cutoff of the P-channel field effect transistor Q1. The source and drain output VBUS of Q1 is used to power other modules.

[0072] refer to Figure 5 The three-phase rectifier and filter output DC VBUS is sent to the internal circuit power supply module and then stepped down by the N-channel field effect transistor Q1 to generate 55V VBIAS to power other functional modules.

[0073] refer to Figure 6 The input voltage of the DC / DC module is 5VDC, which is converted into an isolated DC power output through PWM signal modulation. The PWM modulation frequency is 200KHz. VBIAS supplies power to the DC-DC controller. The controller adjusts the duty cycle of the output signals LO and HO according to the feedback FB terminal voltage, and further controls the conduction and cutoff of Q1 and Q2 to store energy for the inductor L1, and generate stable 36V and 24V output voltages after filtering by the capacitor group. Figure 6 R1, R2, D4, D5, D6, D8, Q1, C5, C6, and C26 form a linear voltage regulation system, which outputs 12V DC to power U1. DCDC controller U1 is undervoltage locked when UVLO is lower than 1.215V and stops output. R4, R5, and R6 resistor network, corresponding to VBIAS higher than 14V, U1 starts to work. R7 and C7 suppress inductor current spikes. R8 controls the internal oscillator frequency of U1, that is, the PWM signal frequency R9, C10, C17, R10, and R22 form a feedback and compensation network, which stabilizes the output at 36V.

[0074] exist Fig.10 In the embodiment of the present application, a power control method is provided, comprising the following steps:

[0075] The output current feedback circuit is designed using a droop control algorithm;

[0076] The output current feedback circuit is used to adjust the output voltage amplitude and output impedance characteristics, and to regulate the output power of the downhole power supply.

[0077] In the above technical solution, by setting up a downhole turbine generator, a three-phase rectification and filtering module and an undervoltage lockout overvoltage protection module, the downhole turbine generator is used to generate three-phase alternating current; the three-phase rectification and filtering module is used to rectify and filter the three-phase alternating current to obtain direct current; the undervoltage lockout overvoltage protection module is used to perform undervoltage lockout and overvoltage protection on the direct current, and output an external power supply voltage; it can meet the needs of while-drilling data acquisition and MWD data transmission, and provide power for high-power downhole equipment such as mud pulsers. The power drive power needs to reach 600W-3KW, or higher power output requirements.

[0078] Specifically, in order to ensure high-power power drive output, multiple BUCK submodules are connected in parallel for output. In the parallel power supply system, due to the differences in the electrical parameters of each power submodule, even if the output voltage of the submodule is slightly different, the output current will be different. The output current feedback circuit is designed using a droop control algorithm to adjust the output voltage amplitude and output impedance characteristics to achieve the purpose of increasing the overall output power and meeting the needs of high-power applications.

[0079] The principle of droop control is explained by using two power supplies in parallel. The simplified system topology is shown in the figure below. Figure 7 shown.

[0080] Output current of the i-th power supply:

[0081]

[0082] The output power of a single module power supply can be obtained from the power calculation disclosure:

[0083] P i =I i *U PCC

[0084] Because inductive components do not play a role in DC power supply, so for Z i ∠θ=R i +Z CLi In terms of impedance, Z CLi is approximately equal to zero; hence the output power is:

[0085]

[0086] Observe the above formula to know that power and U i Therefore, adjusting the output power of the power supply can be achieved by changing the output voltage of the power supply.

[0087] The droop curve equation for a DC power supply is:

[0088] U=U0-m(P-P0)

[0089] Among them, U0 is the preset tracking value of voltage, P0 is the preset reference tracking value of power, and m is the droop coefficient in the droop link. Therefore, when the load changes, the bus voltage can be ensured to remain stable, thereby ensuring the normal operation of the load.

[0090] In the two submodules, Figure 8 The working characteristic curve of the parallel submodules shows that when the slopes of the characteristic curves of the submodules are equal, the output impedance of the modules is equal, but the no-load output voltage is different; when the slopes of the characteristic curves of the parallel submodules are different, it means that the output impedance is different, but the no-load output voltage is equal. When multiple power modules are connected in parallel, the difference between the output impedance and the no-load output voltage between the modules will be more obvious. Therefore, the most basic principle of the droop method is to adjust the difference in output impedance of each module, so as to achieve current sharing between the power submodules. Specifically, when each power submodule is running in parallel, the external characteristic slopes of the two submodules are adjusted to make the external characteristic slopes consistent, so as to achieve uniform distribution of load current between the submodules and optimize the overall performance and stability of the system.

[0091] At the same time, by applying Kirchhoff's law to each submodule with the same open circuit voltage, we can get:

[0092] U=U i -(Z i ∠θ)i i

[0093] So we can get:

[0094]

[0095] Therefore, it can be obtained that the output current of each module is inversely proportional to the output impedance of the module.

[0096] The essence of the droop method for current sharing of power modules is to change the equivalent resistance of the output end, such as Fig. 9 As shown in the figure, the sampled and amplified output current signal is combined with the voltage signal fed back by the module at the input of the voltage amplifier to form a comprehensive voltage input. This comprehensive voltage is then compared with the preset reference voltage, and the error voltage signal generated by the comparison is further amplified to adjust the working state of the pulse width modulator. The pulse width modulator outputs a square wave signal with a corresponding duty cycle to the driver according to the size of the error voltage, and the driver controls the switching state of the power circuit according to these signals, thereby accurately adjusting and outputting the required power.

[0097] According to the virtual short and virtual break principle of the operational amplifier circuit, the following formula can be obtained:

[0098] V ref =V o ·K v +i o ·K i

[0099] Thus we get:

[0100]

[0101] in is the open circuit voltage V oc , is a virtual output impedance R dummy , thus we can get:

[0102] V o =V oc -i o R dummy

[0103] Because the module current ratio is inversely proportional to the output impedance, the virtual output resistance R dummyTo achieve the reduction of power module current, the virtual output resistance R dummy To increase the current of the power module, and then achieve current sharing among the sub-modules of the power supply.

[0104] Those skilled in the art will appreciate that the present application may be implemented as a system, method or computer program product.

[0105] Therefore, the present disclosure may be specifically implemented in the following forms, namely: it may be completely hardware, it may be completely software (including firmware, resident software, microcode, etc.), or it may be a combination of hardware and software, generally referred to herein as a "circuit", "module" or "system". In addition, in some embodiments, the present application may also be implemented in the form of a computer program product in one or more computer-readable media, and the computer-readable medium may contain computer-readable program code.

[0106] Any combination of one or more computer-readable media can be used. Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable storage media can be, for example, but not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or devices, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: electrical connections with one or more wires, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. In this document, computer-readable storage media can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it.

[0107] Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art can change, modify, replace and modify the above embodiments within the scope of the present application. On this basis, a variety of replacements and improvements can be made to the present application, all of which fall within the scope of protection of the present application.

Claims

1. A downhole power supply, characterized in that: include: Downhole turbine generator, three-phase rectifier filter module and undervoltage lockout overvoltage protection module, among which, The downhole turbine generator is used to generate three-phase alternating current; The three-phase rectification and filtering module is used to rectify and filter the three-phase alternating current to obtain direct current; The undervoltage lockout and overvoltage protection module is used to perform undervoltage lockout and overvoltage protection on the direct current and output an external power supply voltage.

2. The downhole power supply according to claim 1, characterized in that: It also includes a DC / DC conversion module, wherein: The DC / DC conversion module is used to perform DC / DC conversion on the external power supply voltage.

3. The downhole power supply according to claim 2, characterized in that: The DC / DC conversion module comprises: 36V output DC / DC module, used to output 36 volts direct current; 24V output DC / DC module, used to output 24 volt direct current.

4. The downhole power supply according to claim 3, characterized in that: It also includes a speed signal processing module, wherein: The speed signal processing module is electrically connected to the downhole turbine generator and is used to process the speed signal of the downhole turbine generator.

5. The downhole power supply according to claim 4, characterized in that: It also includes an internal circuit power supply module, wherein: The input end of the internal circuit power supply module is electrically connected to the undervoltage lockout overvoltage protection module; The output end of the internal circuit power supply module is electrically connected to the 36V output DC / DC module, the 24V output DC / DC module and the speed signal processing module respectively.

6. The downhole power supply according to claim 5, characterized in that: The filter capacitor in the three-phase rectification and filtering module includes a 10Uf capacitor with a withstand voltage of 240V and a temperature of 175°C arranged in parallel.

7. The downhole power supply according to claim 6, characterized in that: The reverse breakdown voltage of the rectifier diode in the three-phase rectifier and filter module is not less than 200V.

8. The downhole power supply according to claim 7, characterized in that: The DC / DC conversion module includes a linear voltage stabilization system and a feedback and compensation network, wherein: Linear voltage stabilization system for outputting 12V DC; Feedback and compensation network to stabilize the output voltage.

9. The downhole power supply according to claim 8, characterized in that: The downhole power supply adopts multiple BUCK submodules connected in parallel for output.

10. A power control method, characterized in that: The following steps are involved: The output current feedback circuit is designed using a droop control algorithm; The output current feedback circuit is used to adjust the output voltage amplitude and output impedance characteristics, and to regulate the output power of the downhole power supply.

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