Noise suppression power supply system based on underwater large-scale remote signal high-fidelity pickup

Abstract

The invention relates to a noise suppression power supply system based on underwater large-scale remote signal high-fidelity pickup, the noise suppression power supply system realizes background noise suppression and weak signal detection improvement in a deep and far sea environment, and the noise suppression power supply system comprises a DC / DC module, the DC / DC module is responsible for converting a DC375V high voltage transmitted by a deep sea station battery pack into a working voltage DC24V required by underwater equipment, and providing the working voltage DC24V to an underwater data acquisition circuit of the detection node electronic cabin; an SD50-1M5 module is adopted in the DC / DC module, a power supply is arranged in the SD50-1M5 module, an input filter is designed at the front stage, and a DC / DC converter is arranged at the rear stage; the input end of the input filter is provided with a silicon carbide diode, an input capacitor and an input protector. Compared with an existing mainstream power supply and transmission system, the noise suppression power supply system has obvious superiority in background noise suppression and weak signal detection capability.

Description

Technical Field

[0001] The invention relates to the field of underwater acoustic equipment design and power supply manufacturing, and in particular to a noise suppression power supply system based on underwater large-scale long-distance signal high-fidelity pickup. Background Art

[0002] With the country's strategic plan of going global, there is an increasing demand to deploy sensor nodes in vast areas of the deep sea. It has become a problem for the sensor array to collect a large number of real-time useful signals and transmit them over long distances. One is the buoy-type detector, which relies entirely on its own power supply system. The disadvantage is that the duty time is short and it cannot work for a long time. The information sent back is easy to be exposed. The bandwidth of satellite and wireless communication means is limited. It can only send back result information, and the real-time performance is poor, easy to be exposed, easy to be interfered, and the signal is easy to be intercepted.

[0003] Another method is to cascade multiple detection nodes through submarine optical cables. The return signal of submarine optical cables is stable and high-speed, but submarine cables are easily damaged. If the return route is too long and the optical power is insufficient, optical repeaters need to be added to establish an underwater remote power supply system to support the long-term stable operation of each underwater node.

[0004] Power supply over a distance of thousands of kilometers is also a bottleneck that needs to be broken through. At present, the mainstream method of the seabed observation network is to use the submarine optoelectronic composite cable to achieve negative pressure unipolar DC power supply. The advantages are high voltage long-distance transmission with low loss, and then converted to low voltage through the DC / DC module to supply underwater circuits. However, due to conversion efficiency and heat problems, only switching power supplies can be used. The electrical noise of the traditional switching power supply itself and the environmental noise introduced through the wires will cause great noise interference to the detection system for detecting weak underwater target signals, making the detection system invalid. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a noise suppression power supply system based on underwater large-scale remote signal high-fidelity pickup, the noise suppression power supply system can suppress background noise and improve the detection of weak signals in a deep sea environment, including a DC / DC module, the DC / DC module is responsible for converting the DC375V high voltage transmitted from the deep sea battery pack into the working voltage DC24V required by the underwater equipment, and providing it to the underwater data acquisition circuit of the electronic cabin of the detection node;

[0006] The DC / DC module uses the SD50-1M5 module, which is equipped with an input filter in the front-end design of the power supply and a DC / DC converter in the back-end; the input end of the input filter is equipped with a silicon carbide diode, input capacitor, and input protection, and the reverse withstand voltage of the diode is DC1200V, the rated current is 10A, the input capacitor uses 252 630V / 1uF ceramic capacitors in parallel, and the input protection part is a 5A fuse in series at the input end;

[0007] The SD50-1M5 module integrates a DC / DC core. The circuit of the DC / DC core adopts a fixed operating frequency, the output rectifier device uses MOSFET, and the output voltage is output by synchronous rectification control. At the same time, the input operating voltage range of the power module of the DC / DC core is DC200V~DC400V.

[0008] In one embodiment of the present invention, the DC / DC module adopts an optimized ultra-low ripple control DC power supply, adds a secondary LC filter in the back stage, and outputs a negative series capacitor connected to ground.

[0009] In one embodiment of the present invention, the input end of the DC / DC module is further provided with a surge suppression circuit, wherein the surge suppression circuit includes an X capacitor, a Y capacitor, a filter and a common mode inductor.

[0010] In one embodiment of the present invention, the common mode inductor uses a ferrite ring 18×10×10 (7K) as a magnetic core and is formed by winding a wire pair for 5 turns.

[0011] In one embodiment of the present invention, the output end of the SD50-1M5 module is provided with an output filter, in which a homemade common-mode inductor is used, and ceramic capacitors are connected in parallel before and after, with a total capacity of 968uF, and a 5A fuse is also added to the output end of the output filter.

[0012] In one embodiment of the present invention, a switch MOS tube is provided in the core of the DC / DC part for input overvoltage protection and withstand voltage design; a control chip is also provided for input undervoltage protection; and an overcurrent threshold of at least 5.2A is provided for output overcurrent protection.

[0013] The above technical scheme of the present invention has the following advantages over the prior art: the noise suppression power supply system described in the present invention realizes the noise suppression and high-fidelity signal pickup technology of large-scale remote power supply systems in deep-sea and deep-sea areas, making it possible for my country's seabed observation network to be deployed in the deep-sea and deep-sea areas. It has passed the prototype development and successfully deployed multiple underwater nodes in a deep-sea training area. Through a series of acoustic minimum detectable signal-to-noise ratio tests and verifications, it has obvious advantages in suppressing background noise and detecting weak signals compared with the current mainstream power supply and transmission systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0015] Figure 1 It is a schematic diagram of an underwater circuit of a noise suppression power supply system in the present invention;

[0016] Figure 2 It is a schematic diagram of the principle of SD50-1M5 in the power supply of the present invention;

[0017] Figure 3 It is a principle block diagram of the power module of the present invention;

[0018] Figure 4 It is a list of test items for the laboratory test platform of the present invention;

[0019] Figure 5 This is a noise comparison interface diagram of the battery power supply and the 375V shore-based power supply described in the present invention;

[0020] Figure 6 A comparison test list of the DC power supply after optimization design and before optimization as described in the present invention;

[0021] Figure 7 This is the noise comparison result interface diagram of the present invention;

[0022] Figure 8 It is a noise distribution comparison interface diagram on each frequency component after the DC power supply is optimized and designed according to the present invention;

[0023] Fig. 9 This is a comparison experiment interface diagram of the output noise of the battery and power supply plus various types of filters of the present invention;

[0024] Fig.10 This is a comparison interface diagram of the noise distribution of the battery and power supply and after filtering at each frequency component of the present invention;

[0025] Fig.11 This is an interface diagram showing the comparison results of the output noise after adding various levels of capacitors to ground according to the present invention;

[0026] Fig.12 It is the background noise spectrum output after being processed by the sonar system in the present invention. DETAILED DESCRIPTION

[0027] like Figure 1 As shown, this embodiment provides a noise suppression power supply system based on underwater large-scale remote signal high-fidelity pickup, wherein the underwater large-scale remote power supply system is constructed by adopting a negative pressure unipolar power supply mode, and the deep-sea base station provides 375V DC power supply, which is transmitted to the optoelectronic separation cabin through a watertight cable, and then negatively supplies power to each underwater node through the copper conductor of the optical cable, and is converted into 24V by the DC / DC module in the electronic cabin and provided to the underwater data acquisition circuit in the node. The external grounding component of the optoelectronic separation cabin serves as the power supply anode of the underwater system.

[0028] And specifically, the DC / DC module is:

[0029] The DC / DC module is responsible for converting the DC375V high voltage transmitted from the deep-sea battery pack into the DC24V working voltage required by the underwater equipment, and providing it to the detection node electronic compartment, where the DC / DC module converts it into the voltage required by the data acquisition circuit.

[0030] Specific technical indicators:

[0031] Output voltage: When the DC conversion module input voltage is in the range of 200V to 400V DC, the DC module output voltage should be 24V±1V.

[0032] Output power: ≥50W;

[0033] Ripple voltage: Vpp≤240mV;

[0034] With input undervoltage, output overcurrent, and load short-circuit protection functions;

[0035] Load regulation: ≤1%.

[0036] At the same time Figure 2 As shown in the power supply principle block diagram, the SD50-1M5 module power supply is designed with an input filter in the front stage, a DC / DC converter in the back stage, and a final filter output. It has the advantages of high efficiency, high reliability, high power density, etc., and has input undervoltage, output overcurrent, and load short-circuit protection functions;

[0037] Input filter design includes:

[0038] a. Input diode

[0039] The input filter part is designed with a silicon carbide diode at the input end. The diode has a reverse withstand voltage of DC1200V and a rated current of 10A. This diode can effectively reduce the input current oscillation caused by long-distance transmission, enhance the stability and reliability of the power supply, and at the same time...

[0040] b. Input capacitance

[0041] Considering the long-distance transmission of the busbar, the long-distance array cable will have parasitic inductance. A large amount of capacitors are needed at the input end of the power supply to eliminate its influence. Ordinary electrolytic capacitors have the disadvantage of electrolyte exhaustion after long-term work, and the film capacitors are too large. When designing the solution, a large number of ceramic capacitors are connected in parallel. 252 630V / 1uF ceramic capacitors are used in parallel in the circuit, and there is a spare capacitor capacity of 24uF. If necessary, the maximum input capacitor capacity can be increased to 276uF.

[0042] c. Input protection

[0043] There is a 5A fuse in series at the input end. When a short circuit occurs inside the DC module device, the input can be quickly cut off to isolate the fault and ensure the normal operation of other nodes.

[0044] DC / DC Design

[0045] The core of the DC / DC part is a mature power module. This series of power modules has been used in many occasions and has the characteristics of high reliability, high efficiency and easy use. The module has functions such as output overcurrent protection, short circuit protection and input undervoltage protection, which meet the functional requirements of the SD50-1M5 machine. Figure 3 As shown in the figure, the designed circuit adopts a half-bridge topology solution to convert the input high voltage into a stable low voltage, which is not affected by load and temperature changes. The circuit adopts a fixed operating frequency, and the output rectifier device uses MOSFET. The output voltage is output by synchronous rectification control, which has a higher working efficiency than diode rectification, and the working efficiency reaches 88%.

[0046] The module adopts the form of potting, which has excellent heat dissipation performance and can transfer the heat of the device to the bottom heat sink more effectively.

[0047] And include:

[0048] a. Input overvoltage protection, withstand voltage design

[0049] The working voltage range of the power module input is DC200V~DC400V. When the input voltage reaches DC440V (typical value), the power module will shut down the output. When the input voltage reaches DC460V, the power module will not operate and there is a risk of damage. When the input voltage returns to the normal input voltage range, the power module will resume normal operation. When the input voltage continues to rise to the limit value of the switch MOS tube, the internal components of the power module will be damaged due to high voltage breakdown. Therefore, when using this power supply, ensure that the power supply operates within DC200V~DC400V.

[0050] b. Input undervoltage protection

[0051] When the input voltage of the power module is lower than DC190V (typical value), the control chip will turn off the output to achieve the input undervoltage protection function. When the input voltage returns to the normal working voltage range of the power module, the power module resumes normal operation.

[0052] c. Output overcurrent protection

[0053] When the output current of the power module reaches the overcurrent threshold, the minimum overcurrent threshold is 5.2A. After the overcurrent, the output voltage will decrease to maintain the maximum power output. When the output impedance continues to decrease and the output voltage is lower than the current limiting shutdown voltage, the power supply will shut down the output. When the condition causing the power module output overcurrent is removed, the power output returns to normal.

[0054] d. Output short circuit protection

[0055] When the power module is in a short-circuit condition, it turns off the output, and when the short-circuit condition is cancelled, it returns to normal.

[0056] Output filter design includes:

[0057] a. Output filtering

[0058] In order to meet the ripple index, the output voltage of the DC-DC module must be filtered, otherwise the ripple index cannot be met. The common-mode inductor is a self-made part, using a ferrite magnetic ring 18×10×10 (7K) as the magnetic core, and a wire pair is wound 5 times to form a common-mode inductor. The front and back of the common-mode filter are connected in parallel with ceramic capacitors, with a total capacity of 968uF, which together with the common-mode inductor form a filter.

[0059] b. Output protection

[0060] To ensure the reliability of output overcurrent protection, a 5A fuse is added to the output end. When the power supply fails under the load, the module can isolate the fault under the action of its own overcurrent protection or fuse blowing.

[0061] The noise suppression power supply system described in this embodiment is specifically an optimized design of a DC / DC power supply, wherein the switching power supply has a larger noise floor than the linear power supply and is generally not used in a weak signal detection system, but due to conversion efficiency and heating issues, a linear power supply with a smaller noise floor cannot be applied to an underwater power supply system;

[0062] The pure lithium battery power supply system has good noise control for weak signal detection, but it is inconvenient to replace the underwater power supply battery, the duty time is short, and it cannot work for a long time;

[0063] Through long-term laboratory joint debugging and multiple scientific research sea trials, we have continuously summarized our experience and worked together to optimize the DC / DC power supply design. We have taken six noise suppression measures, including optimizing the ultra-low ripple control DC power supply, adding a secondary LC filter to the back stage, and grounding the output negative series capacitor, as follows: Figures 4 to 11 shown.

[0064] The optimized DC power supply consists of input filter circuit, surge suppression circuit, DC / DC conversion circuit, and output filter circuit. In order to achieve high-fidelity weak signal pickup, the design indicator is to control the ripple within 0.2% under the working voltage of 375V, which is comparable to the output noise of pure lithium batteries. Corresponding interference noise filtering and shielding measures need to be taken during the design, and the layout and wiring should be optimized. The design is carried out from several aspects, including circuit design, shell design, filter design and installation, and product grounding network design. In order to prevent the electromagnetic interference generated internally from the outside world, the power supply adopts an internal compartment design to process the input filter circuit, power conversion circuit, and output filter circuit.

[0065] The strategy adopted is to add X capacitors, Y capacitors, filters and common-mode inductors to the input to filter noise and interference. The function of this circuit is:

[0066] 1) It can effectively prevent the noise and surge voltage of the external electrical part from entering the power supply;

[0067] 2) It can effectively prevent the strong electromagnetic harmonic radiation generated by the high-speed conduction and cutoff of the switch tube inside the power supply from interfering with the external power supply, and reduce the external feedback noise voltage;

[0068] 3) The use of filters can prevent the instantaneous rise of current and effectively reduce the starting impact current.

[0069] 4) After the output power conversion circuit is matched with the system, some noise interference inside the power supply may be coupled to the outside world through the output line, interfering with other electrical equipment. For this, the same design as the input end is adopted, and common mode filter inductors and capacitors are added for filtering to achieve the purpose of suppressing EMI interference; specifically, the ripple voltage test results are shown in the following table.

[0070]

[0071] Low ripple output control reduces the electrical noise of the switching power supply to a level comparable to the noise floor of a pure lithium battery, becoming the key to high-fidelity signal acquisition and gaining the key ability to sense and identify weak underwater targets with only a single array element in deep sea conditions.

[0072] Furthermore, the measured data in the real ocean environment are as follows:

[0073] In July 2024, a sonar system was deployed in a typical sea area with a water depth of 2,000 meters. Figure 1 As shown in the figure, an underwater signal acquisition system was built. The ocean radiation noise was received through the sound pressure channel sensor and the vibration velocity Z channel sensor respectively. After being processed by the sonar system, the output background noise spectrum is as follows Fig.12 As shown in the figure, the background noise spectrum is a superposition of the ocean environment noise and the sonar system's own noise. The purple curve is the background noise spectrum collected by a sonar system deployed by a domestic peer in the same sea area. The blue curve is the background noise spectrum collected by a high-sensitivity sensor array newly researched by a scientific research team of a certain university. The orange and yellow are the background noises of the sound pressure channel sensor and the vibration velocity Z channel sensor collected using the technology of this project. It can be clearly seen that the measured data supports that the technology of this project is superior to the latest research results of domestic peers and universities in suppressing background noise in the full frequency band (0-500Hz).

[0074] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A noise suppression power supply system based on underwater large-scale remote signal high-fidelity pickup, the noise suppression power supply system can suppress background noise and improve the detection of weak signals in a deep sea environment, characterized in that: It includes a DC / DC module, which is responsible for converting the DC375V high voltage transmitted by the deep-sea battery pack into the DC24V working voltage required by the underwater equipment and providing it to the underwater data acquisition circuit in the electronic cabin of the detection node; The DC / DC module uses the SD50-1M5 module, which is equipped with an input filter in the front-end design of the power supply and a DC / DC converter in the back-end; the input end of the input filter is equipped with a silicon carbide diode, input capacitor, and input protection, and the reverse withstand voltage of the diode is DC1200V, the rated current is 10A, the input capacitor uses 252 630V / 1uF ceramic capacitors in parallel, and the input protection part is a 5A fuse in series at the input end; The SD50-1M5 module integrates a DC / DC core. The circuit of the DC / DC core adopts a fixed operating frequency, the output rectifier device uses MOSFET, and the output voltage is output by synchronous rectification control. At the same time, the input operating voltage range of the power module of the DC / DC core is DC200V~DC400V.

2. The noise suppression power supply system according to claim 1, characterized in that: The DC / DC module adopts an optimized ultra-low ripple control DC power supply, adds a secondary LC filter in the back stage, and connects the output negative series capacitor to ground.

3. The noise suppression power supply system according to claim 2, characterized in that: The input end of the DC / DC module is also provided with a surge suppression circuit, wherein the surge suppression circuit includes an X capacitor, a Y capacitor, a filter and a common mode inductor.

4. The noise suppression power supply system according to claim 3, characterized in that: The common mode inductor uses a ferrite ring 18×10×10 (7K) as the magnetic core and is wound with 5 turns of wire pairs.

5. The noise suppression power supply system according to claim 1, characterized in that: The output end of the SD50-1M5 module is provided with an output filter. The output filter uses a homemade common-mode inductor with ceramic capacitors connected in parallel before and after, with a total capacity of 968uF, and a 5A fuse is also added to the output end of the output filter.

6. The noise suppression power supply system according to claim 1, characterized in that: The core of the DC / DC part is equipped with a switching MOS tube for input overvoltage protection and voltage resistance design; there is also a control chip for input undervoltage protection; there is also an overcurrent threshold of at least 5.2A for output overcurrent protection.

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