Impressed current cathodic protection power supply equipment

Abstract

The utility model discloses impressed current cathodic protection power supply equipment, which relates to the technical field of jacket protection and comprises a main circuit system and a control system. The main circuit system comprises an AC-DC inlet wire rectification module and a DC-DC voltage regulation module. The input end of the AC-DC incoming line rectification module is connected with a three-phase alternating current power supply, and outputs a high-voltage direct current with a set boost value through the incoming line filtering unit and the three-phase APFC rectification boost and power factor correction unit based on the IGBT and the PWM in sequence. The input end of the DC-DC voltage regulation module is connected with the high-voltage direct current, and the direct current is output to an anode bar after being subjected to stable voltage regulation through a direct current filtering unit, a high-frequency inversion unit, a high-frequency voltage regulation unit, an output rectification unit based on an MOS (Metal Oxide Semiconductor) tube, an output filtering unit and an output switch unit in sequence, so that impressed current cathode protection on the jacket is realized; according to the utility model, the inherent problems of low power factor and high harmonic pollution of the traditional three-phase rectification can be solved, and the problem of low power efficiency of the traditional rectification circuit can be solved.

Description

Technical Field

[0001] This utility model relates to the field of conductor protection technology, and in particular to an impressed current cathodic protection power supply device. Background Technology

[0002] Oil and natural gas are the world's most important fossil fuels. With onshore oil and gas resources gradually being depleted, offshore oil and gas fields are developing rapidly. The stability and durability of the jacket structure—the main supporting structure for near-shore oil and gas development platforms—are crucial. Corrosion prevention is an unavoidable issue regarding the stability and durability of its structure. The jacket structure sits on the seabed, its legs extending into the sea mud, its main body immersed in seawater (a strong electrolyte), and the portion extending above the sea surface is constantly subjected to the scouring of waves and intense sunlight. The alternating wet and dry conditions create a very harsh environment conducive to rapid corrosion. Cathodic protection is an important method to prevent steel structures from being corroded by seawater, effectively extending the lifespan of offshore platforms. Cathodic protection is divided into impressed current method and sacrificial anode method, both based on the same principle. Depending on the different corrosive environments in actual engineering projects, the specific operating conditions of the protected structure, and technical and economic considerations, both methods can be applied.

[0003] Currently, my country generally uses the sacrificial anode method to protect fixed jacket platforms. However, due to the large area requiring protection, the sacrificial anode method necessitates a massive number of sacrificial anodes. This increases the platform's load, raises the design requirements for the steel structure's load-bearing capacity, and adds extra costs. Furthermore, it exacerbates stress corrosion, posing potential risks to the platform, and the resulting heavy metal ions from dissolution can pollute the marine ecosystem. Moreover, as the service life of platforms using sacrificial anode protection increases, many jacket platforms are approaching or even exceeding the original design life of their cathodic protection systems, necessitating life-extension repairs. For deep-water offshore platforms, the installation cost of sacrificial anodes by divers would far exceed the cost of the materials themselves.

[0004] Compared to sacrificial anode methods, impressed current cathodic protection offers advantages such as rapid installation, low installation costs, and high current output. It does not increase the load on the platform despite the increased protection area. Furthermore, impressed current cathodic protection systems do not generate heavy metal ions and produce less pollution, making it an environmentally friendly cathodic protection technology. Especially for jack-up platforms, given their structural characteristics, sacrificial anode methods are unsuitable. Moreover, since their legs are constantly exposed to seawater and sea mud, the corrosive environment is harsh and could negatively impact production safety and the platform's lifespan in the long run. Therefore, impressed current cathodic protection is an economical, reliable, and practical protection technology.

[0005] However, the technology used in existing power supplies is outdated, and impressed current cathodic protection devices have the following main problems:

[0006] 1. The incoming circuit topology still uses the three-phase uncontrolled rectifier from several years ago, resulting in a low power factor and excessive harmonic content.

[0007] 2. The output circuit topology still uses a passive rectifier circuit, which causes electrical energy to be wasted as heat, resulting in low power efficiency.

[0008] Due to the aforementioned problems, existing impressed current cathodic protection power supply equipment still suffers from generally low efficiency, low power factor, and serious harmonic content issues. Utility Model Content

[0009] This invention provides an impressed current cathodic protection power supply device to overcome the above-mentioned technical problems.

[0010] To achieve the above objectives, the technical solution of this utility model is as follows:

[0011] An impressed current cathodic protection power supply device, connected to a three-phase AC power supply and an anode rod, includes: a main circuit system and a control system electrically connected to the main circuit system;

[0012] The main circuit system includes an AC-DC input rectifier module and a DC-DC voltage regulator module; the input terminal of the AC-DC input rectifier module is connected to a three-phase AC power supply, the output terminal is connected to the input terminal of the DC-DC voltage regulator module, and the output terminal of the DC-DC voltage regulator module is connected to the anode rod.

[0013] The AC-DC input rectifier module includes an input filter unit and a rectifier boost and power factor correction unit connected in sequence.

[0014] The input filtering unit is used to filter the input three-phase AC power and output the filtered three-phase AC power; the rectification boost and power factor correction unit is used to rectify, boost and correct the power factor of the filtered AC power through a three-phase APFC circuit equipped with multiple IGBT switches and PWM switches, and output the corrected DC power boosted to the set value.

[0015] The DC-DC voltage regulation module includes a DC filter unit, a high-frequency inverter unit, a high-frequency voltage regulation unit, an output rectifier unit, an output filter unit, and an output switch unit connected in sequence.

[0016] The DC filtering unit is used to filter the corrected DC power and output the filtered DC power; the high-frequency inverter unit is used to invert the filtered DC power into AC power; the high-frequency voltage regulation unit is used to regulate the AC power to a set value; the output rectifier unit is used to convert the input AC power into pulsating DC power through a synchronous rectifier circuit with multiple MOS transistors; the output filtering unit is used to filter the pulsating DC power and output the final filtered DC power; the output switch unit is used to output the final filtered DC power to the anode rod.

[0017] Furthermore, the three-phase APFC circuit includes: first to third inductors, first to sixth IGBT switching transistors, first to sixth PWM switches, a first capacitor, and a first resistor;

[0018] One end of each of the first to third inductors is connected to the input filter unit; the other end of the first inductor is connected to the emitter of the first IGBT switch and the collector of the sixth IGBT switch; the other end of the second inductor is connected to the emitter of the second IGBT switch and the collector of the fifth IGBT switch; the other end of the third inductor is connected to the emitter of the third IGBT switch and the collector of the fourth IGBT switch; the collectors of the first to third IGBT switches are connected in sequence, and the emitters of the fourth to sixth IGBT switches are connected in sequence; one end of the first capacitor is connected to the collector of the third IGBT switch and one end of the first resistor, and the other end is connected to the emitter of the fourth IGBT switch and the other end of the first resistor; the gates of the first to sixth IGBT switches are connected to the first to sixth PWM switches.

[0019] Furthermore, the output rectifier unit includes a first synchronous rectifier circuit and a second synchronous rectifier circuit;

[0020] The first synchronous rectification circuit includes a fifth MOSFET, a sixth MOSFET, a fourth inductor, and a fifth inductor; the second synchronous rectification circuit includes a seventh MOSFET, an eighth MOSFET, a sixth inductor, and a seventh inductor.

[0021] The drains of the fifth and seventh MOSFETs are connected to one end of the fourth and sixth inductors, respectively. The sources of the fifth and seventh MOSFETs are connected to the drains of the sixth and eighth MOSFETs, respectively. The sources of the sixth and eighth MOSFETs are connected to one end of the fifth and seventh inductors, respectively. The other ends of the fourth to seventh inductors are all connected to one end of the filter capacitor in the output filter unit. The sources of the fifth and seventh MOSFETs and the drains of the sixth and eighth MOSFETs are connected to the other ends of the filter capacitor in the output filter unit.

[0022] Furthermore, the high-frequency inverter unit includes: first to fourth MOSFETs and high-frequency capacitors;

[0023] The drain of the first MOSFET is connected to the drain of the second MOSFET, and the source is connected to the drain of the third MOSFET; the source of the second MOSFET is connected to the drain of the fourth MOSFET and one end of the high-frequency capacitor; the source of the third MOSFET is connected to the source of the fourth MOSFET.

[0024] Furthermore, the high-frequency voltage regulation unit includes: a resonant inductor, a first high-frequency transformer, and a second high-frequency transformer;

[0025] One end of the resonant inductor is connected to the other end of the high-frequency capacitor, and the other end of the resonant inductor is connected to the input side of the first high-frequency transformer. The input side of the first high-frequency transformer and the source of the first MOSFET are connected to the input side of the second high-frequency transformer. The output side of the first high-frequency transformer is connected to the drain of the fifth MOSFET and the source of the sixth MOSFET. The output side of the second high-frequency transformer is connected to the drain of the seventh MOSFET and the source of the eighth MOSFET.

[0026] Beneficial effects: This utility model provides an impressed current cathodic protection power supply device, which has the following advantages:

[0027] 1. A three-phase APFC circuit with IGBT switching transistors and PWM switching transistors is set up to replace the original three-phase diode rectifier bridge and filter capacitor design. The circuit is actively controlled by PWM modulation and IGBT switching transistors to dynamically shape the input current waveform, so that the current waveform tracks the voltage waveform in real time and is accurately shaped. This improves the power utilization efficiency on the grid side and reduces the harmonic content, thereby solving the problems of low power factor and high harmonic pollution inherent in traditional three-phase rectification.

[0028] 2. By replacing the traditional rectifier circuit with diodes with a synchronous rectifier circuit equipped with multiple MOSFETs, the original "passive unidirectional conduction" can be converted into "active control switching". The structure of the MOSFET determines that the circuit loss is determined by the on-resistance. Compared with the forward conduction voltage drop loss caused by traditional diodes, the on-resistance can significantly reduce the loss in the circuit and solve the problem of low power efficiency of traditional rectifier circuits. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 A block diagram of an impressed current cathodic protection power supply device provided by this utility model;

[0031] Figure 2 Circuit design diagram of the rectifier boost and power factor correction unit provided by this utility model;

[0032] Figure 3 This is the overall circuit design diagram of the DC-DC voltage regulation module provided by this utility model;

[0033] Figure 4 The graph shows the power factor and current harmonic rate results when using a conventional three-phase controlled rectification in one embodiment.

[0034] Figure 5 The diagram shows the power factor and current harmonic rate results when using the rectifier boost and power factor correction unit provided by this utility model in one embodiment.

[0035] Figure 6 A power consumption diagram for one embodiment using a conventional passive rectifier circuit;

[0036] Figure 7 The diagram shows the power consumption results when using the output rectifier unit of this invention in one embodiment. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0038] This embodiment provides an impressed current cathodic protection power supply device, which is connected to a three-phase AC power supply and an anode rod, such as... Figure 1 As shown, it includes a main circuit system and a control system electrically connected to the main circuit system for controlling the operation of the main circuit system;

[0039] The main circuit system includes an AC-DC input rectifier module and a DC-DC voltage regulator module; the input terminal of the AC-DC input rectifier module is connected to a three-phase AC power supply, the output terminal is connected to the input terminal of the DC-DC voltage regulator module, and the output terminal of the DC-DC voltage regulator module is connected to the anode rod.

[0040] The AC-DC input rectifier module includes an input filter unit and a rectifier boost and power factor correction unit connected in sequence.

[0041] The input filtering unit is used to filter the input three-phase AC power and output the filtered three-phase AC power; the rectification boost and power factor correction unit is used to rectify, boost and correct the power factor of the filtered AC power through a three-phase APFC circuit equipped with multiple IGBT switches and PWM switches, and output the corrected DC power boosted to the set value.

[0042] The DC-DC voltage regulation module includes a DC filter unit, a high-frequency inverter unit, a high-frequency voltage regulation unit, an output rectifier unit, an output filter unit, and an output switch unit connected in sequence.

[0043] The DC filtering unit is used to filter the corrected DC power and output the filtered DC power; the high-frequency inverter unit is used to invert the filtered DC power into AC power; the high-frequency voltage regulation unit is used to regulate the AC power to a set value; the output rectifier unit is used to convert the input AC power into pulsating DC power through a synchronous rectifier circuit with multiple MOS transistors; the output filtering unit is used to filter the pulsating DC power and output the final filtered DC power; the output switch unit is used to output the final filtered DC power to the anode rod.

[0044] Specifically, the AC-DC input rectifier module is used to rectify the input three-phase AC power supply, perform a first DC-DC conversion on the input three-phase AC power, adjust it to a set value, and output the rectified DC power to the DC-DC voltage regulator module; the DC-DC voltage regulator module is used to invert the input rectified DC power to obtain high-frequency AC power, and perform a second DC-DC conversion and filtering on the high-frequency AC power, outputting the final filtered DC power to the anode rod;

[0045] like Figure 1 As shown, the control system is used to set voltage and current values ​​according to actual needs, detect the three-phase voltage and frequency output by the input filter unit, the DC bus voltage at the output of the DC filter unit, the current and voltage on the primary side of the input transformer and the current and voltage on the secondary side of the output transformer in the high-frequency voltage regulation unit, and the output voltage and current at the output of the output filter unit. It drives the operation of the rectifier boost and power factor correction unit, the high-frequency inverter unit and the output rectifier unit through the drive control circuit to perform voltage and current conversion and regulation in the circuit.

[0046] The control system is also used to analyze the output data of each unit to determine whether the equipment has malfunctioned.

[0047] In this invention, the control system is a digital centralized control platform with a high-performance DSP / MCU as its core. Sampling, driving, and judgment are all conventional technical means in this field, and the specific circuit structure will not be described in detail.

[0048] In a specific embodiment, the incoming line filtering unit adopts an LC low-pass filter network;

[0049] In this embodiment, the incoming line filter unit is used to suppress or eliminate conducted interference and radio interference generated by the incoming line voltage;

[0050] Specifically, it can eliminate common-mode and differential-mode interference, preventing interference to the power grid and other digital equipment when the input voltage is applied. By installing the three-phase AC input terminal, especially in situations with high electromagnetic environment requirements, it effectively improves the electromagnetic compatibility of the system, thereby helping to improve the operational stability and reliability of the entire system.

[0051] In a specific embodiment, the rectification, boost, and power factor correction unit uses a three-phase APFC circuit to rectify, boost, and correct the power factor of the filtered AC power, outputting a corrected DC power boosted to a set value. The three-phase APFC circuit is as follows: Figure 2 As shown, it includes: a first inductor L1, a second inductor L2, a third inductor L3, a first IGBT switch IGBT1, a second IGBT switch IGBT2, a third IGBT switch IGBT3, a fourth IGBT switch IGBT4, a fifth IGBT switch IGBT5, a sixth IGBT switch IGBT6, a first PWM switch PWM1, a second PWM switch PWM2, a third PWM switch PWM3, a fourth PWM switch PWM4, a fifth PWM switch PWM5, a sixth PWM switch PWM6, a first capacitor C1, and a first resistor R1;

[0052] One end of each of the first to third inductors is connected to one of the three phases of the input filter unit; the other end of the first inductor is connected to the emitter of the first IGBT switch and the collector of the sixth IGBT switch; the other end of the second inductor is connected to the emitter of the second IGBT switch and the collector of the fifth IGBT switch; the other end of the third inductor is connected to the emitter of the third IGBT switch and the collector of the fourth IGBT switch; the collectors of the first to third IGBT switches are connected in sequence, and the emitters of the fourth to sixth IGBT switches are connected in sequence; one end of the first capacitor is connected to the collector of the third IGBT switch and one end of the first resistor, and the other end is connected to the emitter of the fourth IGBT switch and the other end of the first resistor; the gates of the first to sixth IGBT switches are connected to the first to sixth PWM switches.

[0053] In this embodiment, the rectification boost and power factor correction unit receives filtered three-phase AC power and achieves high power factor rectification through an active control strategy, outputting a stable DC voltage. Each IGBT switch receives an independent PWM drive signal to achieve real-time tracking and precise shaping of the input current waveform and phase, thereby boosting the input power factor to near 1 and reducing the total harmonic distortion of the input current to below the standard limit. It can adaptively maintain the stability of the DC bus voltage over a wide input voltage range, while also possessing low switching losses and high power conversion efficiency.

[0054] Taking a three-phase 6kW (2kW per phase) system as an example, Figure 3 The graph shows the power factor and current harmonic rate of a traditional three-phase controlled rectifier. The power factor is 0.728 and the current harmonic rate is 89.87%. Figure 4 The diagram shows the results of using the rectifier boost and power factor correction unit. The power factor using the rectifier boost and power factor correction unit is 0.995, and the current harmonic rate is 3.86%. This embodiment can solve the problems of low power factor and high harmonic pollution inherent in traditional three-phase rectification.

[0055] In a specific embodiment, the DC filter unit uses a series filter capacitor and a smoothing reactor for filtering;

[0056] Using filter capacitors reduces the AC ripple coefficient, making the DC output of the power supply smooth and stable, reducing the impact of alternating ripple current on the circuit, and also absorbing current fluctuations generated during circuit operation and interference introduced through the AC source, making the electronic circuit's performance more stable.

[0057] Using smoothing reactors reduces AC ripple components and filters out some harmonics, reducing interference to communication along DC lines and avoiding instability caused by harmonics; by limiting the AC component superimposed on the DC current, the rectified current remains continuous, reducing current ripple and improving the input power factor.

[0058] The design of DC filter units using filter capacitors and smoothing reactors is a common technique in this field, and those skilled in the art know how to connect two electronic devices to achieve filtering functionality.

[0059] In a specific embodiment, such as Figure 5 As shown, the high-frequency inverter unit includes: a first MOSFET M1, a second MOSFET M2, a third MOSFET M3, a fourth MOSFET M4, and a high-frequency capacitor Cr;

[0060] The drain of the first MOSFET is connected to the drain of the second MOSFET, and the source is connected to the drain of the third MOSFET; the source of the second MOSFET is connected to the drain of the fourth MOSFET and one end of the high-frequency capacitor; the source of the third MOSFET is connected to the source of the fourth MOSFET.

[0061] The first to fourth MOSFETs can convert DC power into the required AC power. The high-frequency interference signal generated by the MOSFETs is filtered by the high-frequency capacitor to remove noise and interference signals, thereby improving the quality and reliability of the beneficial signal.

[0062] In a specific embodiment, such as Figure 5 As shown, the high-frequency voltage regulation unit includes: a resonant inductor Lr, a first high-frequency transformer T1, and a second high-frequency transformer T2;

[0063] One end of the resonant inductor is connected to the other end of the high-frequency capacitor, and the other end of the resonant inductor is connected to the input side of the first high-frequency transformer. The input side of the first high-frequency transformer and the source of the first MOSFET are connected to the input side of the second high-frequency transformer. The output side of the first high-frequency transformer is connected to the drain of the fifth MOSFET and the source of the sixth MOSFET. The output side of the second high-frequency transformer is connected to the drain of the seventh MOSFET and the source of the eighth MOSFET.

[0064] Specifically, by setting a resonant inductor Lr and controlling its magnitude using the output current, the range of soft switching can be increased, the dependence of soft switching on load current can be reduced, thereby improving power efficiency and conducted electromagnetic interference immunity.

[0065] By using two high-frequency transformers to reduce the AC voltage to the required level, providing electrical isolation between the input and output, the equipment can be protected from voltage spikes and surges, energy can be transferred from the input to the output, and the magnitude of the output voltage can be controlled to meet the needs of different loads.

[0066] In a specific embodiment, such as Figure 5 As shown, the output rectifier unit includes a first synchronous rectifier circuit and a second synchronous rectifier circuit.

[0067] The first synchronous rectification circuit includes a fifth MOSFET M5, a sixth MOSFET M6, a fourth inductor L4, and a fifth inductor L5; the second synchronous rectification circuit includes a seventh MOSFET M7, an eighth MOSFET M8, a sixth inductor L6, and a seventh inductor L7.

[0068] The drains of the fifth and seventh MOSFETs are connected to one end of the fourth and sixth inductors, respectively. The sources of the fifth and seventh MOSFETs are connected to the drains of the sixth and eighth MOSFETs, respectively. The sources of the sixth and eighth MOSFETs are connected to one end of the fifth and seventh inductors, respectively. The other ends of the fourth to seventh inductors are all connected to one end of the filter capacitor in the output filter unit. The sources of the fifth and seventh MOSFETs and the drains of the sixth and eighth MOSFETs are connected to the other ends of the filter capacitor in the output filter unit.

[0069] Taking three-phase 6kW (2kW per phase) operation as an example, Figure 6 The graph shows the power consumption when using a traditional passive rectifier circuit. The power consumption using the traditional rectification method is 342.38W. Figure 7 The power consumption of the output rectifier unit in the example is 57.78W. A dedicated power MOSFET with extremely low on-state resistance is used to replace the rectifier diode to reduce rectification losses. It can be converted from the original "passive unidirectional conduction" to "active control switching". The MOSFET structure determines that the circuit loss is determined by the on-resistance. Compared with the forward voltage drop loss caused by the traditional diode, the on-resistance can significantly reduce the loss in the circuit and solve the problem of low power efficiency of the traditional rectifier circuit.

[0070] In a specific embodiment, the output filtering unit also uses a filter capacitor Co;

[0071] In power supply circuits, output voltage often fluctuates due to changes in load and fluctuations in the power supply itself. Filter capacitors absorb these fluctuations, keeping the output voltage stable. When the voltage rises, the filter capacitor absorbs excess energy; when the voltage drops, the filter capacitor releases energy, thus ensuring stable circuit operation.

[0072] In a specific embodiment, the output switching unit uses a relay to control the output of voltage and current;

[0073] Relays are used to control whether to output current or voltage and to prevent external voltage backflow.

[0074] In a specific embodiment, such as Figure 1 As shown, the control system includes a main control unit, a three-phase AC voltage detection circuit, a three-phase frequency detection circuit, a DC voltage detection circuit, a transformer primary current and voltage detection circuit, a transformer secondary current and voltage detection circuit, an output current and voltage detection circuit, a front-end drive control circuit for the rectifier boost and power factor correction unit, a back-end drive control circuit for the high-frequency inverter unit, a back-end drive control circuit for the output rectifier unit, and a fault judgment module.

[0075] The fault diagnosis module is connected to each detection circuit and is used to receive the sampling data from each detection circuit and perform fault analysis.

[0076] The main control unit is electrically connected to each detection circuit, each drive control circuit and fault judgment module. It is used to receive the output voltage and current set values ​​set by the external host computer, send trigger signals to trigger each detection circuit to perform detection, and send drive signals to control each drive control circuit to drive the corresponding unit to work.

[0077] The active unit uses the sampling data from the three-phase AC voltage detection circuit and the three-phase frequency detection circuit to determine whether the three-phase input conditions meet the preset requirements. When the requirements are met, the active unit controls the rectifier boost and power factor correction unit to start working through the front-end drive control circuit of the rectifier boost and power factor correction unit. The active unit rectifies, boosts, and corrects the power factor of the filtered three-phase voltage and current, and outputs corrected DC power boosted to the set value.

[0078] The DC filter unit filters the corrected DC voltage boosted to the set value and detects the DC voltage. The main control unit receives the sampling data from the DC voltage detection circuit and the set values ​​of output voltage and current, and sends drive signals to drive the high-frequency inverter unit through the subsequent drive control circuit and the output rectifier unit through the subsequent drive control circuit. Based on the comparison between the sampling data from the output current and voltage detection circuit and the set values ​​of output voltage and current, the system outputs the voltage when the set values ​​are reached and sends drive signals again to drive each circuit to work when the set values ​​are not reached, so that the final output current and voltage meet the set requirements, realizing closed-loop regulation to stabilize the output.

[0079] The fault diagnosis module receives the sampling results sent by each detection circuit, performs fault analysis using its built-in fault diagnosis logic, and sends the fault analysis results to the main control unit in real time. The main control unit receives the analysis results from the fault diagnosis module and, when a fault is determined to occur, sends a drive signal to control each drive control circuit to stop working. It then notifies the technical personnel through the host computer to execute the corresponding protection action.

[0080] The control process and implementation method of the main circuit system by the various functional modules and circuits in the control system of this utility model are common technical means in this field. Those skilled in the art know how to use the control system to realize the control function. Therefore, this application only briefly describes the control content of the control system and does not elaborate on the specific implementation method and design steps.

[0081] The usage process of this utility model is as follows:

[0082] The three-phase output voltage of the transformer is connected to this utility model. The three-phase AC voltage detection circuit and the three-phase frequency detection circuit detect whether the frequency and phase of the filtered three-phase voltage meet the requirements. When the design requirements are met, the main control unit receives the set output current and voltage signals from the host computer and sends a drive signal to the front-end drive control circuit of the rectification boost and power factor correction unit. This drives the rectification boost and power factor correction unit in the AC-DC input rectifier module to work, stabilizing the rectified DC voltage at the set value.

[0083] When the filtered DC voltage and current meet the design requirements, the main control unit sends a drive signal to the corresponding drive control circuit in the DC-DC voltage regulation module. This drives the high-frequency inverter unit and the high-frequency voltage regulation unit to invert the input DC power into AC power, adjust the input AC voltage, and then drive the output rectifier unit to convert the AC power into pulsating DC power. The output filter unit then converts the pulsating DC power into smooth DC power, thus obtaining the set current and voltage. At this point, the host computer sends a power output command, and the main control unit sends a signal to the output switch unit, causing the current and voltage to be applied to the anode rod, achieving impressed current cathodic protection.

[0084] This invention can be applied to jacket structures on offshore oil platforms: Offshore oil platform jacket structures are immersed in seawater for extended periods and face severe corrosion threats. Cathodic protection power supplies play a crucial role in this process. Typically, an impressed current cathodic protection system is used, with the power supply (such as a potentiostat) installed on the platform.

[0085] The cathodic protection power supply outputs direct current, which enters the seawater through auxiliary anodes installed in the seawater surrounding the jacket. The jacket acts as the cathode; under the influence of the current, cathodic polarization occurs on the metal surface, inhibiting corrosion. For example, on some large offshore oil platform jackets, the power supply of the impressed current cathodic protection system can flexibly adjust the output current according to the corrosion status of different parts of the jacket, ensuring that the entire jacket is under good protection.

[0086] This cathodic protection method effectively extends the service life of the jacket structure. Compared to not using cathodic protection measures, it can extend the service life of the jacket structure by 15-20 years. Simultaneously, through the coordinated operation of the potential monitoring device and the power supply, the potential of the jacket structure can be monitored in real time, facilitating the timely detection and handling of potential corrosion problems.

[0087] This invention can also be applied to the foundation of offshore wind turbine jackets: the foundation of offshore wind turbine jackets also requires cathodic protection. Because they are located in a marine environment, waves, tides, and seawater salt can all cause corrosion to the jacket foundation. Cathodic protection power supplies are used to provide corrosion protection for the foundation.

[0088] Impressed current cathodic protection is generally used. The current generated by the power supply is released into the seawater through the anode, making the metal of the jacket foundation the cathode, thus preventing the metal from losing electrons and corroding. In some large offshore wind farms, the cathodic protection power supply system for the jacket foundation can automatically adjust the output current according to changes in environmental parameters such as seawater temperature and salinity, ensuring the stability of the protection effect.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. An impressed current cathodic protection power supply device, connected to a three-phase AC power supply and an anode rod, characterized in that, include: The main circuit system and the control system electrically connected to the main circuit system for controlling the operation of the main circuit system; The main circuit system includes an AC-DC input rectifier module and a DC-DC voltage regulator module; the input terminal of the AC-DC input rectifier module is connected to a three-phase AC power supply, the output terminal is connected to the input terminal of the DC-DC voltage regulator module, and the output terminal of the DC-DC voltage regulator module is connected to the anode rod. The AC-DC input rectifier module includes an input filter unit and a rectifier boost and power factor correction unit connected in sequence. The input filtering unit is used to filter the input three-phase AC power and output the filtered three-phase AC power; the rectification boost and power factor correction unit is used to rectify, boost and correct the power factor of the filtered AC power through a three-phase APFC circuit equipped with multiple IGBT switches and PWM switches, and output the corrected DC power boosted to the set value. The DC-DC voltage regulation module includes a DC filter unit, a high-frequency inverter unit, a high-frequency voltage regulation unit, an output rectifier unit, an output filter unit, and an output switch unit connected in sequence. The DC filtering unit is used to filter the corrected DC power and output the filtered DC power; the high-frequency inverter unit is used to invert the filtered DC power into AC power; the high-frequency voltage regulation unit is used to regulate the AC power to a set value; the output rectifier unit is used to convert the input AC power into pulsating DC power through a synchronous rectifier circuit with multiple MOS transistors; the output filtering unit is used to filter the pulsating DC power and output the final filtered DC power; the output switch unit is used to output the final filtered DC power to the anode rod.

2. The impressed current cathodic protection power supply device according to claim 1, characterized in that, The three-phase APFC circuit includes: first to third inductors, first to sixth IGBT switching transistors, first to sixth PWM switches, first capacitor, and first resistor; One end of each of the first to third inductors is connected to the input filter unit; the other end of the first inductor is connected to the emitter of the first IGBT switch and the collector of the sixth IGBT switch; the other end of the second inductor is connected to the emitter of the second IGBT switch and the collector of the fifth IGBT switch; the other end of the third inductor is connected to the emitter of the third IGBT switch and the collector of the fourth IGBT switch; the collectors of the first to third IGBT switches are connected in sequence, and the emitters of the fourth to sixth IGBT switches are connected in sequence; one end of the first capacitor is connected to the collector of the third IGBT switch and one end of the first resistor, and the other end is connected to the emitter of the fourth IGBT switch and the other end of the first resistor; the gates of the first to sixth IGBT switches are connected to the first to sixth PWM switches.

3. The impressed current cathodic protection power supply device according to claim 1, characterized in that, The output rectifier unit includes a first synchronous rectifier circuit and a second synchronous rectifier circuit; The first synchronous rectifier circuit includes a fifth MOSFET, a sixth MOSFET, a fourth inductor, and a fifth inductor; the second synchronous rectifier circuit includes a seventh MOSFET, an eighth MOSFET, a sixth inductor, and a seventh inductor. The drains of the fifth and seventh MOSFETs are connected to one end of the fourth and sixth inductors, respectively. The sources of the fifth and seventh MOSFETs are connected to the drains of the sixth and eighth MOSFETs, respectively. The sources of the sixth and eighth MOSFETs are connected to one end of the fifth and seventh inductors, respectively. The other ends of the fourth to seventh inductors are all connected to one end of the filter capacitor in the output filter unit. The sources of the fifth and seventh MOSFETs and the drains of the sixth and eighth MOSFETs are connected to the other ends of the filter capacitor in the output filter unit.

4. The impressed current cathodic protection power supply device according to claim 1, characterized in that, The high-frequency inverter unit includes: first to fourth MOSFETs and a high-frequency capacitor; The drain of the first MOSFET is connected to the drain of the second MOSFET, and the source is connected to the drain of the third MOSFET; the source of the second MOSFET is connected to the drain of the fourth MOSFET and one end of the high-frequency capacitor; the source of the third MOSFET is connected to the source of the fourth MOSFET.

5. The impressed current cathodic protection power supply device according to claim 3, characterized in that, The high-frequency voltage regulation unit includes: a resonant inductor, a first high-frequency transformer, and a second high-frequency transformer; One end of the resonant inductor is connected to the other end of the high-frequency capacitor, and the other end of the resonant inductor is connected to the input side of the first high-frequency transformer. The input side of the first high-frequency transformer and the source of the first MOSFET are connected to the input side of the second high-frequency transformer. The output side of the first high-frequency transformer is connected to the drain of the fifth MOSFET and the source of the sixth MOSFET. The output side of the second high-frequency transformer is connected to the drain of the seventh MOSFET and the source of the eighth MOSFET.

Images