Impressed current cathodic protection method for offshore wind power based on photocurrent

Abstract

Offshore wind power impressed current cathodic protection method based on photocurrent, a centralized photovoltaic panel array is installed around the cage, the centralized photovoltaic panel array is electrically connected to the energy storage device, the energy storage device and the wind power supply system are connected to the constant potential instrument as a parallel power supply line, the constant potential instrument is connected to the auxiliary anode through the anode tail cable, and the constant potential instrument is electrically connected to the protected structure through the cathode convergence current; an electric control unit is installed in the constant potential instrument, and the electric control unit is used to automatically switch the access current of the constant potential instrument according to the working conditions; the protection current is adjusted in real time according to the real-time status information of the protected structure. This method integrates the multi-parameter adaptive PID strategy to better adapt to the complex and changeable offshore wind power environment, achieve more accurate and efficient potential control, and reduce corrosion.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrical anti-corrosion, and in particular relates to an offshore wind power impressed current cathodic protection method based on photocurrent. Background Art

[0002] The corrosion in the service environment of offshore wind power is very destructive. For the protection of steel structures in the full immersion area, there are usually two protection methods: sacrificial anode and impressed current. The principle of impressed current protection technology is to continuously output protective current to the steel structure through a constant potential device (external current is required) to reduce the corrosion of the steel structure. However, the energy consumption is large, especially when there is a fault inside the wind turbine, the impressed current device will not work properly and will not be able to protect the steel structure. Especially when the wind turbine is in a power outage for a long time, the risk faced by the steel structure will increase. An external auxiliary current is urgently needed as a supplement and emergency method. At the same time, it can also act as an internal light source when the wind turbine is out of power, so as to facilitate the operation of wind power operation and maintenance personnel. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an offshore wind power impressed current cathodic protection method based on photogenerated current. The method integrates a multi-parameter adaptive PID strategy to better adapt to the complex and changeable offshore wind power environment, achieve more accurate and efficient potential control, and reduce corrosion.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] Offshore wind power impressed current cathodic protection method based on photocurrent, the steps are:

[0006] A centralized photovoltaic panel array is installed around the cage, the centralized photovoltaic panel array is electrically connected to the energy storage device, the energy storage device and the wind power supply system are connected to the constant potential instrument as a parallel power supply line, the constant potential instrument is connected to the auxiliary anode through the anode tail cable, and the constant potential instrument is electrically connected to the protected structure through the cathode bus current;

[0007] An electric control unit is installed in the constant potential instrument, and the electric control unit is used to automatically switch the access current of the constant potential instrument according to the working conditions;

[0008] In the case of abundant sunlight, the electronic control unit controls the potentiostat to be powered solely by the centralized photovoltaic panel array;

[0009] When the sun is not abundant, the electronic control unit controls the constant potential instrument to be powered by the centralized photovoltaic panel array and the wind power supply system at the same time. If the power of the energy storage device is lower than the upper threshold value Q1, the centralized photovoltaic panel array power supply is disconnected, and the centralized photovoltaic panel array is used to charge the energy storage device.

[0010] In an emergency, the wind power supply system is powered off and the electronic control unit controls the constant potentiostat to be powered solely by the centralized photovoltaic panel array.

[0011] Preferably, the electronic control unit includes a sensor module, a data processing module and an adaptive control algorithm module;

[0012] The sensor module is used to monitor and collect real-time status information of the protected structure, and the sensor module includes a potential sensor, a current sensor, a temperature sensor, a humidity sensor and a salinity sensor;

[0013] The data processing module is used to receive the raw data from the sensor module, perform preprocessing including filtering and calibration, and forward the data to the adaptive control algorithm module;

[0014] The adaptive control algorithm module uses the PID control algorithm to make dynamic adjustments based on the real-time data provided by the data processing module.

[0015] Preferably, the process of dynamic adjustment using the PID control algorithm is as follows:

[0016] 1) Parameter preprocessing: First, perform appropriate preprocessing on each input signal, including temperature T, humidity H, current I, salinity S, and potential E; for example, normalization or standardization is performed to ensure that all signals are on the same scale to facilitate subsequent calculations and comparisons.

[0017] 2) Impact factor evaluation: Assign an impact factor to each input signal, where the impact factor of temperature T is wT, the impact factor of humidity H is wH, the impact factor of current I is wI, the impact factor of salinity S is wS, and the impact factor of potential E is wE. The impact factor is pre-set based on historical data analysis or expert knowledge or dynamically adjusted through online learning to reflect the degree of influence of different environmental factors on the corrosion rate;

[0018] 3) Fusion signal: Multiply the preprocessed signal with the corresponding weight and then add them together to form a comprehensive control error signal E total :

[0019] ;

[0020] Among them, E setpoint is the target potential; E measured is the actual measured potential; (E setpoint -E measured ) reflects the direct error in potential control.

[0021] Preferably, E total After that, E total Input into the PID controller for parameter adjustment and verification. The process is as follows:

[0022] 1) Use E directly total As the error, the proportional term output is calculated;

[0023] 2) For E total When performing integration, considering the integral saturation problem that may be caused by multiple variables, it may be necessary to set the integral limit;

[0024] 3) Calculate E total The rate of change of is used to predict and suppress overshoot.

[0025] Preferably, the PID controller performs adaptive adjustment on the potentiostat after processing the data, the steps are as follows:

[0026] 1) Initialization: Set PID parameters Kp, Ki, Kd, ​​and the influencing factors wT, wH, wI, wS, wE of each input signal.

[0027] 2) Real-time monitoring and processing: collect the actual values ​​of temperature T, humidity H, current I, salinity S, and potential E once every cycle and perform preprocessing;

[0028] 3) Calculate the comprehensive error: Calculate Etotal according to the above formula.

[0029] 4) PID calculation: Based on the comprehensive error E total , calculate the PID control output u ( t ):

[0030] ;

[0031] Where u(t) is the output of the controller; d is the differential time constant, and τ is an integral variable;

[0032] Represents the integrated error signal, Etotal ( τ ) is the integral from the time starting point 0 to the current time τ, which changes with time and reflects the effect of error accumulation over time;

[0033] K p , K i , K d Respectively represent the proportional, integral, and differential coefficients;

[0034] 5) Adaptive adjustment: According to the control effect and system feedback, adjust the PID parameters or the weight of each input online to optimize the control performance.

[0035] 6) Execution and feedback: Output u(t) to the potentiostat, adjust the output current or voltage, and continue to monitor the system status to form a closed-loop control.

[0036] Preferably, the data processing module uses a digital signal processor DSP or a microcontroller MCU to quickly process the data to ensure the accuracy and real-time performance of the data.

[0037] An offshore wind power impressed current cathodic protection system adopts the offshore wind power impressed current cathodic protection method based on photocurrent.

[0038] An electric control unit executes program instructions for the offshore wind power impressed current cathodic protection method based on photocurrent.

[0039] The present invention can achieve the following beneficial effects:

[0040] 1. By combining the photovoltaic technology with the traditional impressed current protection system, the present invention can still rely on solar energy to independently supply power when there is an internal fault in the wind turbine or the external power grid is unstable, continuously provide cathodic protection for the steel structure, effectively prevent corrosion, and greatly enhance the continuity of protection measures and the reliability of the system.

[0041] 2. The integrated electronic control unit and adaptive control algorithm module can dynamically adjust the protection strategy according to the real-time monitoring data, automatically optimize the current output, ensure the most suitable potential protection under various working conditions, avoid over-protection or under-protection, and improve the protection efficiency and intelligent level of resource utilization.

[0042] 3. In an emergency, the photovoltaic device not only provides power for corrosion protection, but also serves as emergency lighting, providing the necessary working lighting for the operation and maintenance personnel, ensuring the smooth progress of maintenance and inspection work, and improving the safety and efficiency of operations, which is particularly important at night or in dim environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0044] Figure 1 The electronic control unit control process of the present invention;

[0045] Figure 2 This is a structural diagram of the offshore wind power impressed current cathodic protection of the present invention.

[0046] In the figure: centralized photovoltaic panel array 1, energy storage device 2, cathode bus current 3, constant potential instrument 4, anode tail cable 5, auxiliary anode 6, protected structure 7, seawater 8. DETAILED DESCRIPTION

[0047] The preferred solution is Figure 1 As shown, the offshore wind power impressed current cathodic protection method based on photocurrent has the following steps:

[0048] S1. Install a centralized photovoltaic panel array around the cage, electrically connect the centralized photovoltaic panel array to the energy storage device, connect the energy storage device and the wind power supply system as a parallel power supply line to the constant potential instrument, connect the constant potential instrument to the auxiliary anode through the anode tail cable, and the constant potential instrument is electrically connected to the protected structure through the cathode bus current;

[0049] Specifically, a centralized photovoltaic panel array is deployed around the wind turbine cage to ensure maximum capture of solar energy. The photovoltaic panel array is connected to the energy storage device (such as a lithium battery pack) through cables, forming a preliminary energy supply link. The energy storage device is connected in parallel with the existing power supply system of the wind farm to jointly power the constant potential instrument. The constant potential instrument is connected to the auxiliary anode through the anode tail cable, and the cathode end is connected to the protected steel structure through the bus cable to form a complete cathodic protection circuit.

[0050] S2. Install an electronic control unit in the constant potential instrument, and the electronic control unit is used to automatically switch the access current of the constant potential instrument according to the working conditions; integrate the electronic control unit inside the constant potential instrument, including a sensor module, a data processing module and an adaptive control algorithm module. The sensor module is equipped with multiple sensors such as potential, current, temperature, humidity and salinity to monitor the environment and structural status in real time. The data processing module uses DSP or MCU to process sensor data and provides it to the adaptive control algorithm module for dynamic decision-making, and adjusts the protection strategy according to the PID algorithm.

[0051] Case 1: When there is abundant sunlight, the electric control unit controls the constant potential instrument to be powered solely by the centralized photovoltaic panel array;

[0052] Case 2: When the sunlight is not abundant, the electronic control unit controls the constant potential instrument to be powered by the centralized photovoltaic panel array and the wind power supply system at the same time. If the power of the energy storage device is lower than the upper limit threshold Q1, the centralized photovoltaic panel array is disconnected from the power supply, and the centralized photovoltaic panel array is used to charge the energy storage device;

[0053] Situation 3: In an emergency, the wind power supply system is powered off, and the electric control unit controls the constant potential instrument to be powered solely by the centralized photovoltaic panel array;

[0054] The electronic control unit intelligently switches the power supply according to the sunshine conditions. When there is sufficient sunshine, the photovoltaic panels are used first, and when there is insufficient sunshine, the wind power system is used as an auxiliary to ensure that the protection current is uninterrupted under any circumstances. When the power of the energy storage device is lower than the preset threshold, the charging mode of the energy storage device is automatically started to avoid excessive discharge and damage to the battery life. When the wind power system fails and loses power, it immediately switches to the photovoltaic panel power supply mode to maintain the cathodic protection function, while ensuring that the wind power operation and maintenance personnel have emergency lighting available inside the wind turbine.

[0055] S3. Adjust the protection current in real time according to the real-time status information of the protected structure.

[0056] The electronic control unit includes a sensor module, a data processing module and an adaptive control algorithm module;

[0057] The sensor module is used to monitor and collect real-time status information of the protected structure, and the sensor module includes a potential sensor, a current sensor, a temperature sensor, a humidity sensor and a salinity sensor;

[0058] The data processing module is used to receive the raw data from the sensor module, perform preprocessing including filtering and calibration, and forward the data to the adaptive control algorithm module;

[0059] The adaptive control algorithm module uses the PID control algorithm to make dynamic adjustments based on the real-time data provided by the data processing module.

[0060] The collected temperature, humidity, current, salinity and potential data are preprocessed, and different weight factors are assigned according to the degree of influence of environmental factors on corrosion. According to the assigned weights, the parameters are fused to form the control error signal E total , as the input of the PID controller. total Input into the PID algorithm, calculate the control output u(t) through the three links of proportion, integration and differentiation, and adjust the output of the constant potential instrument to achieve accurate control of the protection current. The process of dynamic adjustment using the PID control algorithm is as follows:

[0061] 1) Parameter preprocessing: First, each input signal is properly preprocessed, including temperature T, humidity H, current I, salinity S, and potential E;

[0062] 2) Impact factor evaluation: Assign an impact factor to each input signal, where the impact factor of temperature T is wT, the impact factor of humidity H is wH, the impact factor of current I is wI, the impact factor of salinity S is wS, and the impact factor of potential E is wE. The impact factor is pre-set based on historical data analysis or expert knowledge or dynamically adjusted through online learning to reflect the degree of influence of different environmental factors on the corrosion rate;

[0063] 3) Fusion signal: Multiply the preprocessed signal with the corresponding weight and then add them together to form a comprehensive control error signal E total :

[0064] ;

[0065] Among them, E setpoint is the target potential; E measured is the actual measured potential; (E setpoint -E measured ) reflects the direct error in potential control.

[0066] Get E total After that, E total Input into the PID controller for parameter adjustment and verification. The process is as follows:

[0067] 1) Use E directly total As the error, the proportional term output is calculated;

[0068] 2) For E total When performing integration, considering the integral saturation problem that may be caused by multiple variables, it may be necessary to set the integral limit;

[0069] 3) Calculate E total The rate of change of is used to predict and suppress overshoot.

[0070] The PID controller processes the data and performs adaptive adjustment on the constant potential instrument. The steps are as follows:

[0071] 1) Initialization: Set PID parameters Kp, Ki, Kd, ​​and the influencing factors wT, wH, wI, wS, wE of each input signal;

[0072] 2) Real-time monitoring and processing: collect the actual values ​​of temperature T, humidity H, current I, salinity S, and potential E once every cycle and perform preprocessing;

[0073] 3) Calculate the comprehensive error: Calculate Etotal according to the above formula;

[0074] 4) PID calculation: Based on the comprehensive error E total , calculate the PID control output u ( t ):

[0075] ;

[0076] Where u(t) is the output of the controller; d is the differential time constant, and τ is an integral variable;

[0077] Represents the integrated error signal, Etotal ( τ ) is the integral from the time starting point 0 to the current time τ, which changes with time and reflects the effect of error accumulation over time;

[0078] K p , K i , K d Respectively represent the proportional, integral, and differential coefficients;

[0079] 5) Adaptive adjustment: According to the control effect and system feedback, adjust the PID parameters or the weight of each input online to optimize the control performance;

[0080] 6) Execution and feedback: Output u(t) to the potentiostat, adjust the output current or voltage, and continue to monitor the system status to form a closed-loop control.

[0081] In this method, the data collected by the sensor module is preprocessed by the data processing module (including filtering and calibration) and then transmitted to the adaptive control algorithm module, which dynamically adjusts the control strategy according to the PID algorithm. The comprehensive control error E is calculated by combining the preprocessed temperature T, humidity H, current I, salinity S, potential E and other signals with their respective influencing factors (wT, wH, wI, wS, wE). total . E total Then, as the input of the PID controller, the control output u(t) is calculated through proportional, integral and differential operations. According to the calculated u(t), the constant potentiostat adjusts the output current or voltage to form a closed-loop feedback mechanism. The system will adjust the PID parameters and weight factors in real time according to the operating performance and feedback information to optimize the protection effect and energy efficiency. This method periodically collects environmental and structural status data and processes them quickly to ensure the real-time and accuracy of control decisions. According to the system operation feedback, the PID parameters and weight factors are continuously optimized online to respond to environmental changes and improve protection efficiency and energy utilization.

[0082] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. Offshore wind power impressed current cathodic protection method based on photocurrent, characterized in that The following steps are involved: A centralized photovoltaic panel array is installed around the cage, the centralized photovoltaic panel array is electrically connected to the energy storage device, the energy storage device and the wind power supply system are connected to the constant potential instrument as a parallel power supply line, the constant potential instrument is connected to the auxiliary anode through the anode tail cable, and the constant potential instrument is electrically connected to the protected structure through the cathode bus current; An electric control unit is installed in the constant potential instrument, and the electric control unit is used to automatically switch the access current of the constant potential instrument according to the working conditions; In the case of abundant sunlight, the electronic control unit controls the potentiostat to be powered solely by the centralized photovoltaic panel array; When the sun is not abundant, the electronic control unit controls the constant potential instrument to be powered by the centralized photovoltaic panel array and the wind power supply system at the same time. If the power of the energy storage device is lower than the upper threshold value Q1, the centralized photovoltaic panel array power supply is disconnected, and the centralized photovoltaic panel array is used to charge the energy storage device. In an emergency, the wind power supply system is powered off, and the electronic control unit controls the constant potentiostat to be powered solely by the centralized photovoltaic panel array; Adjust the protection current in real time according to the real-time status information of the protected structure; The electronic control unit includes a sensor module, a data processing module and an adaptive control algorithm module; The sensor module is used to monitor and collect real-time status information of the protected structure, and the sensor module includes a potential sensor, a current sensor, a temperature sensor, a humidity sensor and a salinity sensor; The data processing module is used to receive the raw data from the sensor module, perform preprocessing including filtering and calibration, and forward the data to the adaptive control algorithm module; The adaptive control algorithm module uses the PID control algorithm to make dynamic adjustments based on the real-time data provided by the data processing module; The process of dynamic adjustment using PID control algorithm is as follows: 1) Parameter preprocessing: First, each input signal is properly preprocessed, including temperature T, humidity H, current I, salinity S, and potential E; 2) Impact factor evaluation: Assign an impact factor to each input signal, where the impact factor of temperature T is wT, the impact factor of humidity H is wH, the impact factor of current I is wI, the impact factor of salinity S is wS, and the impact factor of potential E is wE. The impact factor is pre-set based on historical data analysis or expert knowledge or dynamically adjusted through online learning to reflect the degree of influence of different environmental factors on the corrosion rate; 3) Fusion signal: Multiply the preprocessed signal with the corresponding weight and then add them together to form a comprehensive control error signal E total : ； Among them, E setpoint is the target potential; E measured is the actual measured potential; (E setpoint −E measured ) reflects the direct error of potential control; Get E total After that, E total Input into the PID controller for parameter adjustment and verification. The process is as follows: 1) Use E directly total As the error, the proportional term output is calculated; 2) For E total When performing integration, considering the integral saturation problem that may be caused by multiple variables, it may be necessary to set the integral limit; 3) Calculate E total The rate of change of is used to predict and suppress overshoot; The PID controller processes the data and performs adaptive adjustment on the constant potential instrument. The steps are as follows: 1) Initialization: Set PID parameters Kp, Ki, Kd, ​​and the influencing factors wT, wH, wI, wS, wE of each input signal; 2) Real-time monitoring and processing: collect the actual values ​​of temperature T, humidity H, current I, salinity S, and potential E once every cycle and perform preprocessing; 3) Calculate the comprehensive error: Calculate Etotal according to the above formula; 4) PID calculation: Based on the comprehensive error E total , calculate the PID control output u ( t ): ； Where u(t) is the output of the controller; d is the differential time constant, and τ is an integral variable; Represents the integrated error signal, Etotal ( τ ) is the integral from the time starting point 0 to the current time τ, which changes with time and reflects the effect of error accumulation over time; K p , K i , K d Respectively represent the proportional, integral, and differential coefficients; 5) Adaptive adjustment: According to the control effect and system feedback, adjust the PID parameters or the weight of each input online to optimize the control performance; 6) Execution and feedback: Output u(t) to the constant potential instrument, adjust the output current or voltage, and continue to monitor the system status to form a closed-loop control; The data processing module uses a digital signal processor DSP or a microcontroller MCU to quickly process data to ensure the accuracy and real-time nature of the data.

2. An offshore wind power impressed current cathodic protection system, characterized in that: The offshore wind power impressed current cathodic protection method based on photocurrent according to claim 1 is adopted.

3. An electronic control unit, characterized in that: The executed program instructions are the offshore wind power impressed current cathodic protection method based on photocurrent according to claim 1.

Images