Wave energy power supply system for offshore buoy equipment and control method thereof

Abstract

The application discloses a wave energy power supply system of a marine buoy device and a control method thereof. The marine buoy device comprises a buoy shell and a monitoring assembly arranged on the outer surface of the buoy shell. The wave energy power supply system comprises a charging battery assembly, a power generation assembly and a control assembly. The buoy shell is a fully-closed structure. The power generation assembly is arranged in the buoy shell and adopts an oscillating body type wave power generation structure based on a linear motor. When the buoy shell is impacted by waves, the power generation assembly is driven to generate power, and the monitoring assembly and the charging battery assembly are supplied with power. The control assembly acquires real-time power generation power of the power generation assembly and real-time SOC state information of the charging battery assembly, controls the charging battery assembly to charge and discharge, and controls the operating state of the monitoring assembly. By adopting the wave energy power supply system, the buoy does not need to be greatly changed, the buoy can be kept in a normal working state to the maximum extent, and the dormancy time caused by insufficient power is reduced.

Description

Technical Field

[0001] This invention relates to the marine field, and in particular to a wave energy power supply system and control method for a marine buoy device. Background Technology

[0002] Ocean buoys are automatic marine hydrological, water quality, and meteorological observation stations mainly composed of observation buoys anchored at sea. They can collect marine hydrological, water quality, and meteorological data required for marine scientific research, offshore oil (gas) development, port construction, and national defense construction on a long-term and continuous basis, especially data on severe weather and sea conditions that are difficult for survey vessels to collect.

[0003] In addition to their military applications, buoys are widely used as carriers of monitoring equipment, undertaking detection tasks such as anti-submarine warfare and anti-torpedo operations. This requires buoys to operate continuously for extended periods. However, due to limitations in power supply, buoys typically employ low-voltage and low-power equipment to reduce power consumption; otherwise, the equipment needs to operate in an intermittent mode, periodically working and then going into hibernation. Traditional buoys usually use rechargeable batteries to power the equipment, or a combination of solar panels and rechargeable batteries. While these methods reduce hibernation intervals, they are susceptible to weather conditions, making it difficult to maintain continuous normal operation. This deficiency is crucial for real-time monitoring and data acquisition. Furthermore, other forms of wave power generation devices, such as dual-buoy systems, require significant modifications to the buoy itself, compromising its stealth capabilities. Summary of the Invention

[0004] The purpose of this invention is to provide a wave energy power supply system and control method for marine buoy equipment. By adopting an integrated buoy with fully enclosed oscillating wave power generation, no major modifications to the buoy are required, and the buoy equipment can be continuously powered, so that the buoy can maintain normal operation to the greatest extent and reduce the dormancy time caused by insufficient power.

[0005] To solve the above-mentioned technical problems, a first aspect of the present invention provides a wave energy power supply system for a marine buoy device. The marine buoy device includes: a buoy shell and a monitoring component disposed on the outer surface of the buoy shell. The wave energy power supply system includes: a rechargeable battery component, a power generation component, and a control component.

[0006] The buoy shell is a fully enclosed structure;

[0007] The power generation component is located inside the buoy shell and adopts an oscillating wave power generation structure based on a linear motor.

[0008] When the buoy hull is subjected to wave impact, it drives the power generation component to generate electricity, which supplies power to the monitoring component and the rechargeable battery component.

[0009] The control component acquires the real-time power generation of the power generation component and the real-time SOC status information of the rechargeable battery component, controls the rechargeable battery component to charge and discharge, and controls the operating status of the monitoring component.

[0010] Furthermore, the monitoring component is disposed on the top upper surface of the buoy housing;

[0011] The rechargeable battery assembly is located at the bottom of the buoy housing;

[0012] The power generation component is disposed between the top of the buoy hull and the rechargeable battery component.

[0013] Furthermore, the power generation component includes: a linear motor stator, a linear motor mover, a first spring, and a second spring;

[0014] The two ends of the linear motor stator are respectively connected to the top wall of the buoy housing and the top of the rechargeable battery. The first spring, the linear motor mover and the second spring are sequentially sleeved on the linear motor stator. The two ends of the first spring are respectively connected to the top wall of the buoy housing and one side of the linear motor mover, and the two ends of the second spring are respectively connected to the top of the rechargeable battery and the other side of the linear motor mover.

[0015] Furthermore, when the SOC of the rechargeable battery assembly is less than a first preset power threshold, the control component controls the power generation component to supply power only to the rechargeable battery assembly and puts the monitoring component into a sleep state.

[0016] When the SOC of the rechargeable battery assembly is greater than or equal to the first preset power threshold and less than the second preset power threshold, the control component controls the monitoring component to be in continuous operation or intermittent operation state according to the power generation value of the power generation assembly.

[0017] When the SOC of the rechargeable battery assembly is greater than or equal to the second preset power threshold, the control component controls the monitoring component to operate continuously.

[0018] Furthermore, when the SOC of the rechargeable battery assembly is greater than or equal to the first preset power threshold and less than the second preset power threshold,

[0019] If the real-time power generation of the power generation component is less than the load power threshold, the control component controls the monitoring component to operate in an intermittent state.

[0020] If the real-time power generation of the power generation component is greater than or equal to the load power threshold required for the continuous operation of the monitoring component, the control component controls the monitoring component to be in a continuous operation state.

[0021] Furthermore, the control component includes: a model prediction controller based on the Thevenin model;

[0022] The Thevenin model includes: an equivalent power source, a first resistor, a parallel resistor, and a parallel capacitor. The positive terminal of the equivalent power source is connected in sequence to the first resistor, the parallel resistor, and the positive terminal of the load. The negative terminal of the equivalent power source is connected to the negative terminal of the load. The parallel capacitor and the parallel resistor are connected in parallel.

[0023] When the monitoring component is in an intermittent operation state, the model prediction controller obtains the operating time of the monitoring component in each buoy working cycle based on its state equation, objective function and constraints;

[0024] The objective function aims to maximize the buoy's operating time within the prediction period and minimize battery energy loss.

[0025] Furthermore, the state equation of the model predictive controller is:

[0026]

[0027] Where x(k+1) and x(k) are the state variables at times k+1 and k, u(k) is the control variable at time k, and r(k) is the disturbance variable at time k. The control variable u(k) at time k adopts the corresponding buoy working period T. float Operating time T of the internal monitoring component load The disturbance variable r(k) at time k is the real-time power generation P of the power generation component. WEC Δt is the sampling time interval, P float (k) represents the power required for continuous buoy operation at sea state k, U b (k) represents the output voltage of the rechargeable battery module at time k, η and Q N R represents the charge / discharge efficiency coefficient and capacity of a rechargeable battery assembly. c1 C1 is the parallel resistance value, C1 is the parallel capacitance value, and T is the parallel capacitance value. float R1 is the first resistor, representing the buoy's working cycle duration.

[0028] The objective function J of the model predictive controller is:

[0029]

[0030] Where w1 and w2 represent positive weighting coefficients, N is the maximum prediction period, i is the number of time steps forward from the current time, and T... load The working period T of the buoy float Operating time of internal monitoring components, I b Let R0 be the output current value of the rechargeable battery assembly, R0 be the first resistance value, u(k) be the control variable at time k, r(k) be the disturbance variable at time k, and P be the output current value of the rechargeable battery assembly. float (k) represents the power required for continuous buoy operation at sea state k, U b (k) represents the output voltage of the rechargeable battery assembly at time k;

[0031] The constraints of the model predictive controller include: SOC constraints, rechargeable battery component output current constraints, and control constraints.

[0032] The SOC constraint is as follows:

[0033] SOC min <SOC(k+i|k)<SOC max i = 1, 2, ..., N;

[0034] Among them, SOC min The first preset power threshold, SOC max The second preset power threshold is defined as N, which is the maximum prediction period, and i is the number of moments to be extrapolated from the current moment.

[0035] The output current constraint condition of the rechargeable battery assembly is:

[0036]

[0037] Among them, P float (k) represents the power required for continuous buoy operation at sea state k, T load (k+i|k) represents the operating time of the monitoring component of the buoy within each working cycle at the i-th future time, r(k+i|k) represents the wave power generation value at the i-th future time, and T float For the buoy's working cycle, U b (k) represents the output voltage of the rechargeable battery module at time k, I b max I is the battery's maximum output current. b min This is the maximum current absorbed by the battery;

[0038] The control constraints are as follows:

[0039] 0≤T load (k+i|k)≤T float i = 0, 1, ..., N-1;

[0040] Among them, Tload (k+i|k) represents the working time of the monitoring component within each working cycle of the buoy at the i-th time in the future.

[0041] Furthermore, the objective function J of the model predictive controller is:

[0042]

[0043] Wherein, U(k) is the control sequence starting from the current time k, r(k|k) is the wave power generation value at the current time k, and r(k+N-1|k) is the wave power generation value at the N-1th time after the current time k.

[0044] Accordingly, a second aspect of the present invention provides a control method for a wave energy power supply system of a marine buoy device, used to control the wave energy power supply system of the aforementioned marine buoy device, comprising the following steps:

[0045] The SOC of the rechargeable battery assembly is obtained based on the control component;

[0046] When the SOC of the rechargeable battery assembly is less than a first preset power threshold, the control component controls the power generation component to supply power only to the rechargeable battery assembly and puts the monitoring component into a sleep state.

[0047] When the SOC of the rechargeable battery assembly is greater than or equal to the first preset power threshold and less than the second preset power threshold, the control component controls the monitoring component to be in continuous operation or intermittent operation state according to the power generation value of the power generation assembly.

[0048] When the SOC of the rechargeable battery assembly is greater than or equal to the second preset power threshold, the control component controls the monitoring component to operate continuously.

[0049] Further, when the SOC of the rechargeable battery assembly is greater than or equal to the first preset power threshold and less than the second preset power threshold, the control component controls the monitoring component to operate in a continuous operation state or an intermittent operation state based on the power generation value of the power generation assembly, including:

[0050] If the real-time power generation of the power generation component is less than the load power threshold, the control component controls the monitoring component to operate in an intermittent state.

[0051] If the real-time power generation of the power generation component is greater than or equal to the load power threshold required for the continuous operation of the monitoring component, the control component controls the monitoring component to be in a continuous operation state.

[0052] Furthermore, the control component includes: a model predictive controller based on the Thevenin model, wherein the Thevenin model includes: an equivalent power source, a first resistor, a parallel resistor, and a parallel capacitor, wherein the positive terminal of the equivalent power source is sequentially connected to the first resistor, the parallel resistor, and the positive terminal of the load, the negative terminal of the equivalent power source is connected to the negative terminal of the load, and the parallel capacitor and the parallel resistor are connected in parallel.

[0053] If the real-time power generation of the power generation component is less than the load power threshold, the control component controls the monitoring component to operate in an intermittent state, including:

[0054] When the monitoring component is in an intermittent operation state, the model prediction controller obtains the operating time of the monitoring component in each buoy working cycle based on its state equation, objective function and constraints;

[0055] The objective function aims to maximize the buoy's operating time within the prediction period and minimize battery energy loss.

[0056] Furthermore, the state equation of the model predictive controller is:

[0057]

[0058] Where x(k+1) and x(k) are the state variables at times k+1 and k, u(k) is the control variable at time k, and r(k) is the disturbance variable at time k. The control variable u(k) at time k adopts the corresponding buoy working period T. float Operating time T of the internal monitoring component load The disturbance variable r(k) at time k is the real-time power generation P of the power generation component. WEC Δt is the sampling time interval, P float (k) represents the power required for continuous buoy operation at sea state k, U b (k) represents the output voltage of the rechargeable battery module at time k, η and Q N R represents the charge / discharge efficiency coefficient and capacity of a rechargeable battery assembly. c1 C1 is the parallel resistance value, C1 is the parallel capacitance value, and T is the parallel capacitance value. float R1 is the first resistor, representing the buoy's working cycle duration.

[0059] The objective function J of the model predictive controller is:

[0060]

[0061] Where w1 and w2 represent positive weighting coefficients, N is the maximum prediction period, i is the number of time steps forward from the current time, and T... loadThe working period T of the buoy float Operating time of internal monitoring components, I b Let R0 be the output current value of the rechargeable battery assembly, R0 be the first resistance value, u(k) be the control variable at time k, r(k) be the disturbance variable at time k, and P be the output current value of the rechargeable battery assembly. float (k) represents the power required for continuous buoy operation at sea state k, U b (k) represents the output voltage of the rechargeable battery assembly at time k;

[0062] The constraints of the model predictive controller include: SOC constraints, rechargeable battery component output current constraints, and control constraints.

[0063] The SOC constraint is as follows:

[0064] SOC min <SOC(k+i|k)<SOC max i = 1, 2, ..., N;

[0065] Among them, SOC min The first preset power threshold, SOC max The second preset power threshold is defined as N, which is the maximum prediction period, and i is the number of moments to be extrapolated from the current moment.

[0066] The output current constraint condition of the rechargeable battery assembly is:

[0067]

[0068] Among them, P float (k) represents the power required for continuous buoy operation at sea state k, T load (k+i|k) represents the operating time of the monitoring component of the buoy within each working cycle at the i-th future time, r(k+i|k) represents the wave power generation value at the i-th future time, and T float For the buoy's working cycle, U b (k) represents the output voltage of the rechargeable battery module at time k, I b max I is the battery's maximum output current. b min This is the maximum current absorbed by the battery;

[0069] The control constraints are as follows:

[0070] 0≤T load (k+i|k)≤T float i = 0, 1, ..., N-1;

[0071] Among them, T load (k+i|k) represents the working time of the monitoring component within each working cycle of the buoy at the i-th time in the future.

[0072] The above-described technical solutions of the embodiments of the present invention have the following beneficial technical effects:

[0073] By adopting an integrated buoy with fully enclosed oscillating wave power generation, no major modifications to the buoy are required. The buoy equipment can be continuously powered, allowing the buoy to maintain normal operation to the greatest extent and reducing the dormancy time caused by insufficient power. Attached Figure Description

[0074] Figure 1 This is a schematic diagram of the wave energy power supply system for marine buoy equipment provided in an embodiment of the present invention;

[0075] Figure 2 This is a schematic diagram of the Thevenin model circuit structure provided in an embodiment of the present invention;

[0076] Figure 3 This is a schematic diagram of the control principle of the model predictive controller provided in an embodiment of the present invention;

[0077] Figure 4 This is a flowchart of the wave energy power supply system control method for marine buoy equipment provided in an embodiment of the present invention.

[0078] Figure label:

[0079] 1. Monitoring component, 2. First spring, 3. Directional rod, 4. Linear motor stator, 5. Linear motor mover, 6. Control component, 7. Rechargeable battery component. Detailed Implementation

[0080] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0081] Please refer to Figure 1The first aspect of this invention provides a wave energy power supply system for a marine buoy device. The marine buoy device includes: a buoy shell and a monitoring component 1 disposed on the outer surface of the buoy shell. The wave energy power supply system includes: a rechargeable battery component 7, a power generation component, and a control component 6. The buoy shell is a fully enclosed structure. The power generation component is disposed inside the buoy shell and adopts an oscillating wave power generation structure based on a linear motor. When the buoy shell is impacted by waves, it drives the power generation component to generate electricity and supply power to the monitoring component 1 and the rechargeable battery component 7. The control component 6 acquires the real-time power generation of the power generation component and the real-time SOC status information of the rechargeable battery component 7, controls the rechargeable battery component 7 to charge and discharge, and controls the operating status of the monitoring component 1.

[0082] The marine buoy equipment (hereinafter referred to as the buoy) consists of: a buoy shell, a monitoring component 1, a spring, a linear motor, a limit switch, and a controller. The buoy, serving as the carrier for the monitoring equipment and wave power generation device, moves up and down with the waves. As the buoy moves with the waves, the spring deforms, driving the linear motor's mover 5 to move. At this time, relative motion occurs between the linear motor's mover 5 and the stator, thus continuously supplying power to the buoy equipment.

[0083] Optionally, the monitoring component 1 is disposed on the top upper surface of the buoy housing; the rechargeable battery component 7 is disposed on the bottom of the buoy housing; and the power generation component is disposed between the top of the buoy housing and the rechargeable battery component 7.

[0084] Specifically, the power generation component includes: a linear motor stator 4, a linear motor mover 5, a first spring 2, and a second spring; the two ends of the linear motor stator 4 are respectively connected to the top wall of the buoy housing and the top of the rechargeable battery; the first spring 2, the linear motor mover 5, and the second spring are sequentially sleeved on the linear motor stator 4; the two ends of the first spring 2 are respectively connected to the top wall of the buoy housing and one side of the linear motor mover 5; and the two ends of the second spring are respectively connected to the top of the rechargeable battery and the other side of the linear motor mover 5.

[0085] The power generation component is located inside the buoy and integrated with the buoy shell. It mainly comprises a linear motor mover 5, a linear motor stator 4, a first spring 2, and a second spring. Since the power generation component is located inside the buoy, no significant modifications to the buoy shell's shape are required; it can be installed inside the buoy shell using a flange fixing device. The linear motor stator 4 is mainly composed of permanent magnets, magnetically conductive silicon steel sheets, and stainless steel sleeves. The permanent magnets are axially magnetized. The linear motor mover 5 consists of a three-phase armature winding, a winding frame, and a shell. The winding frame uses a hollow disc coil design, directly wound within the winding frame slots, resulting in high slot fill factor, no end caps, high copper utilization, low copper loss, and better energy-saving performance.

[0086] Furthermore, when the SOC of the rechargeable battery component 7 is less than the first preset power threshold, the control component 6 controls the power generation component to supply power only to the rechargeable battery component 7 and puts the monitoring component 1 into a sleep state; when the SOC of the rechargeable battery component 7 is greater than or equal to the first preset power threshold and less than the second preset power threshold, the control component 6 controls the monitoring component 1 to be in a continuous operation state or an intermittent operation state according to the power generation value of the power generation component; when the SOC of the rechargeable battery component 7 is greater than or equal to the second preset power threshold, the control component 6 controls the monitoring component 1 to be in a continuous operation state.

[0087] Optionally, the rechargeable battery assembly 7 is located at the bottom of the floating body shell.

[0088] When the battery SOC is less than a first preset power threshold, SOC <SOC min At this time, all the wave power generated is used to charge the battery, with the aim of restoring it to a safe SOC range as quickly as possible, i.e., [SOC]. min SOC max Among them, SOC min and SOC max These are pre-set constants, such as 20% and 80%.

[0089] When the battery SOC is greater than or equal to the second preset power threshold, i.e., SOC≥SOC max It undertakes the functions of energy storage and peak shaving compensation to ensure that the buoy is in continuous working mode. Its specific principle is as follows: when the wave conditions are good, the power generation is higher than the power load required for the buoy to work continuously, and the battery absorbs the power generation minus the load and the remaining power; when the wave conditions are average, the power generation is lower than the power required for the buoy to work continuously, and the battery releases the load minus the power generation and the remaining power to provide power to the buoy.

[0090] When the battery SOC is greater than or equal to the first preset capacity threshold and less than the second preset capacity threshold, that is, when the SOC... min ≤SOC <SOC max The buoy operates in an intermittent mode, with its sleep interval determined by a real-time rolling optimized model predictive control (MPC) unit, designed to maximize buoy operating time and battery life.

[0091] Furthermore, when the SOC of the rechargeable battery component 7 is greater than or equal to the first preset power threshold and less than the second preset power threshold, if the real-time power generation of the power generation component is less than the load power threshold, the control component 6 controls the monitoring component 1 to operate in an intermittent state; if the real-time power generation of the power generation component is greater than or equal to the load power threshold required for continuous operation of the monitoring component 1, the control component 6 controls the monitoring component 1 to operate in a continuous state.

[0092] Please refer to Figure 2The control component 6 includes: a model predictive controller based on the Thevenin model; the Thevenin model includes: an equivalent power source, a first resistor, a parallel resistor, and a parallel capacitor. The positive terminal of the equivalent power source is connected to the first resistor, the parallel resistor, and the positive terminal of the load in sequence, and the negative terminal of the equivalent power source is connected to the negative terminal of the load. The parallel capacitor and the parallel resistor are connected in parallel. When the monitoring component 1 is in an intermittent operation state, the model predictive controller obtains the working time of the monitoring component 1 in each buoy working cycle based on its state equation, objective function, and constraints. The buoy working cycle can be one wave cycle. The objective function aims to maximize the buoy working time in the prediction cycle and minimize battery energy loss.

[0093] Please refer to Figure 3 Specifically, let x = [U1, SOC] T As a state variable, U1 represents the voltage of the RC parallel circuit inside the battery module; the voltage is taken as T for each buoy's working cycle. float Working hours T load As a control variable, i.e., u = T load The working cycle T of the buoy float The value is equal to 0.1 to 0.2 wave peak periods, which can be obtained through actual ocean observations; the output power P of the wave generator is taken as... WEC The disturbance variable is r = P WEC Let the state variable, control variable, and disturbance variable at time k be x(k), u(k), and r(k), respectively. The discretized state equation is obtained using the forward Euler method.

[0094] The optimal operating time of the monitoring components within the buoy's working cycle is determined in real time by a model predictive controller. The model predictive controller solves a quadratic programming problem using the interior point method to obtain the optimal operating time of the monitoring components within the buoy's working cycle.

[0095] The state equation of the model predictive controller is:

[0096]

[0097] Where x(k+1) and x(k) are the state variables at times k+1 and k, u(k) is the control variable at time k, and r(k) is the disturbance variable at time k. The control variable u(k) at time k adopts the corresponding buoy working period T. float Operating time T of the internal monitoring component load The disturbance variable r(k) at time k is the real-time power generation P of the power generation component. WEC Δt is the sampling time interval, P float (k) represents the power required for continuous buoy operation at sea state k, U b(k) represents the output voltage of the rechargeable battery component 7 at time k, η and Q N R represents the charge / discharge efficiency coefficient and capacity of the rechargeable battery assembly 7. c1 C1 is the parallel resistance value, C2 is the parallel capacitance value, and T is the parallel capacitance value. float R1 is the working cycle duration of the buoy, and R1 is the first resistor.

[0098] The control objectives of the model predictive controller are: ① to maximize the buoy's operating time within the prediction period N; ② to minimize the positive correlation between battery energy loss and battery life loss. The objective function J of the model predictive controller is:

[0099]

[0100] Where w1 and w2 represent positive weighting coefficients, N is the maximum prediction period, i is the number of time steps forward from the current time, and T... load The working period T of the buoy float Operating time of internal monitoring components, I b Let R0 be the output current value of the rechargeable battery assembly 7, R0 be the first resistance value, u(k) be the control variable at time k, r(k) be the disturbance variable at time k (i.e., the wave power generation value, generated by the power generation assembly), and P be the output current value of the rechargeable battery assembly 7. float (k) represents the power required for continuous buoy operation at sea state k, U b (k) represents the output voltage of the rechargeable battery component 7 at time k.

[0101] Furthermore, considering the objective function It only relates to the perturbation variable and can be ignored. Meanwhile, U(k) is defined as follows: The objective function is then minimized by taking the negative value of the model.

[0102] The above formula can be:

[0103]

[0104] To obtain the standard quadratic programming model shown in the above equation, this invention employs two approximations: ① In the control-guided model, only the energy loss on resistor R0 is considered, which is a reasonable approximation based on the fact that "energy loss on resistor R0 dominates in the battery model"; ② It is assumed that B1(k+i|k) and B2(k+i|k) are only related to P at the current time. float (k) and U b (k) related, i.e., B 1,2 (k+i|k)=B 1,2(k|k) is a reasonable approximation based on the fact that "the wave conditions are basically stable in a short period of time, and the battery voltage can be approximated as constant". In the rolling optimization process with a very limited prediction time domain, the error caused by the above approximation can be ignored, which greatly reduces the complexity of the calculation process.

[0105] Furthermore, since the vector f is related to the perturbation variable at future times, this invention uses an AR model to predict the perturbation variable at N future times, i.e., r(k+i|k). The following quadratic programming problem is solved using the interior-point method to obtain the control sequence U(k). * ,Right now:

[0106]

[0107] After each rolling optimization, only the first term is used for real-time control; the solution process for the quadratic programming problem is as follows:

[0108]

[0109] Specifically, the constraints of the model predictive controller include: SOC constraints, output current constraints of the rechargeable battery module 7, and control constraints.

[0110] The SOC constraint is:

[0111] SOC min <SOC(k+i|k)<SOC max i = 1, 2, ..., N;

[0112] Among them, SOC min The minimum SOC (first preset capacity threshold) of the battery. max Where SOC is the maximum value of the battery (second preset power threshold), N is the maximum prediction period, and i is the number of moments to be predicted from the current moment.

[0113] The output current constraint condition for rechargeable battery assembly 7 is:

[0114]

[0115] Among them, P float (k) represents the power required for continuous buoy operation at sea state k, T load (k+i|k) represents the operating time of the monitoring component of the buoy within each working cycle at the i-th future time, r(k+i|k) represents the wave power generation value at the i-th future time, and T float For the buoy's working cycle, U b (k) represents the output voltage of the rechargeable battery component 7 at time k, I b max I is the battery's maximum output current. b minI is the maximum current absorbed by the battery (with the output direction as positive). b min (If it is a negative value);

[0116] The control constraints are:

[0117] 0≤T load (k+i|k)≤T float i = 0, 1, ..., N-1;

[0118] Among them, T load (k+i|k) represents the working time of the monitoring component within each working cycle of the buoy at the i-th time in the future.

[0119] Furthermore, the objective function J of the model predictive controller is:

[0120]

[0121] Wherein, U(k) is the control sequence starting from the current time k, r(k|k) is the wave power generation value at the current time k, and r(k+N-1|k) is the wave power generation value at the N-1th time after the current time k.

[0122] Accordingly, please refer to Figure 4 The second aspect of this invention provides a control method for a wave energy power supply system of a marine buoy device, used to control the wave energy power supply system of the aforementioned marine buoy device, comprising the following steps:

[0123] Step S100: Obtain the SOC of the rechargeable battery component 7 based on the control component 6.

[0124] In step S200, when the SOC of the rechargeable battery component 7 is less than the first preset power threshold, the control component 6 controls the power generation component to supply power only to the rechargeable battery component 7 and puts the monitoring component 1 into a sleep state.

[0125] In step S300, when the SOC of the charging battery component 7 is greater than or equal to the first preset power threshold and less than the second preset power threshold, the control component 6 controls the monitoring component 1 to be in continuous operation or intermittent operation state according to the power generation value of the power generation component.

[0126] In step S400, when the SOC of the rechargeable battery component 7 is greater than or equal to the second preset power threshold, the control component 6 controls the monitoring component 1 to be in continuous operation.

[0127] Specifically, in step S300, when the SOC of the charging battery component 7 is greater than or equal to the first preset energy threshold and less than the second preset energy threshold, the control component 6 controls the monitoring component 1 to be in continuous operation or intermittent operation state according to the power generation value of the power generation component, including:

[0128] In step S310, if the real-time power generation of the power generation component is less than the load power threshold, the control component 6 controls the monitoring component 1 to operate in an intermittent state.

[0129] In step S320, if the real-time power generation of the power generation component is greater than or equal to the load power threshold required for continuous operation of the monitoring component 1, the control component 6 controls the monitoring component 1 to be in continuous operation.

[0130] Furthermore, the control component 6 includes: a model predictive controller based on the Thevenin model, which includes: an equivalent power source, a first resistor, a parallel resistor, and a parallel capacitor. The positive terminal of the equivalent power source is connected in sequence to the first resistor, the parallel resistor, and the positive terminal of the load. The negative terminal of the equivalent power source is connected to the negative terminal of the load. The parallel capacitor and the parallel resistor are connected in parallel.

[0131] Specifically, when using the aforementioned Thevenin model, in step S310, if the real-time power generation of the power generation component is less than the load power threshold, the control component 6 controls the monitoring component 1 to operate in an intermittent state, including:

[0132] When monitoring component 1 is in the interval operation state, the model predictive controller obtains the working time of monitoring component 1 in each buoy working cycle based on its state equation, objective function and constraints.

[0133] The objective function aims to maximize the buoy's operating time within the prediction period and minimize battery energy loss.

[0134] In one specific embodiment of the present invention, the state equation of the model prediction controller is:

[0135]

[0136] Where x(k+1) and x(k) are the state variables at times k+1 and k, u(k) is the control variable at time k, and r(k) is the disturbance variable at time k. The control variable u(k) at time k adopts the corresponding buoy working period T. float Operating time T of the internal monitoring component load The disturbance variable r(k) at time k is the real-time power generation P of the power generation component. WEC Δt is the sampling time interval, P float (k) represents the power required for continuous buoy operation at sea state k, U b (k) represents the output voltage of the rechargeable battery component 7 at time k, η and Q N R represents the charge / discharge efficiency coefficient and capacity of the rechargeable battery assembly 7. c1 C1 is the parallel resistance value, C2 is the parallel capacitance value, and T is the parallel capacitance value.float R1 is the first resistor, representing the buoy's working cycle duration.

[0137] The objective function J of the model predictive controller is:

[0138]

[0139] Where w1 and w2 represent positive weighting coefficients, N is the maximum prediction period, i is the number of time steps forward from the current time, and T... load The working period T of the buoy float Operating time of internal monitoring components, I b Let R0 be the output current value of the rechargeable battery assembly 7, R0 be the first resistance value, u(k) be the control variable at time k, r(k) be the disturbance variable at time k (i.e., the wave power generation value, generated by the power generation assembly), and P be the output current value of the rechargeable battery assembly 7. float (k) represents the power required for continuous buoy operation at sea state k, U b (k) represents the output voltage of the rechargeable battery component 7 at time k.

[0140] The constraints of the model predictive controller include: SOC constraints, output current constraints of rechargeable battery module 7, and control constraints.

[0141] The SOC constraint is:

[0142] SOC min <SOC(k+i|k)<SOC max i = 1, 2, ..., N;

[0143] Among them, SOC min The minimum SOC (first preset capacity threshold) of the battery. max Where SOC is the maximum value of the battery (second preset power threshold), N is the maximum prediction period, and i is the number of moments to be predicted from the current moment.

[0144] The output current constraint condition for rechargeable battery assembly 7 is:

[0145]

[0146] Among them, P float (k) represents the power required for continuous buoy operation at sea state k, T load (k+i|k) represents the operating time of the monitoring component of the buoy within each working cycle at the i-th future time, r(k+i|k) represents the wave power generation value at the i-th future time, and T float For the buoy's working cycle, U b (k) represents the output voltage of the rechargeable battery component 7 at time k, I b max I is the battery's maximum output current.b min I is the maximum current absorbed by the battery (with the output direction as positive). b min (If it is a negative value);

[0147] The control constraints are:

[0148] 0≤T load (k+i|k)≤T float i = 0, 1, ..., N-1;

[0149] Among them, T load (k+i|k) represents the working time of the monitoring component within each working cycle of the buoy at the i-th time in the future.

[0150] This invention aims to protect a wave energy power supply system and its control method for a marine buoy device. The marine buoy device includes a buoy shell and a monitoring component disposed on the outer surface of the buoy shell. The wave energy power supply system includes a rechargeable battery assembly, a power generation assembly, and a control assembly. The buoy shell is a fully enclosed structure. The power generation assembly is disposed inside the buoy shell. When the buoy shell is impacted by waves, it drives the power generation assembly to generate electricity, supplying power to the monitoring assembly and the rechargeable battery assembly. The control assembly acquires the real-time power generation of the power generation assembly and the real-time SOC status information of the rechargeable battery assembly, controls the charging and discharging of the rechargeable battery assembly, and controls the operating status of the monitoring assembly. The above technical solution has the following effects:

[0151] By adopting a wave energy power supply system, no major modifications to the existing buoy structure are required. The buoy equipment can be continuously powered, allowing the buoy to maintain normal operation to the greatest extent and reducing the dormancy time caused by insufficient power.

[0152] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A wave energy power supply system for a marine buoy device, characterised in that, The offshore buoy device comprises a buoy shell and a monitoring assembly (1) arranged on the outer surface of the buoy shell, and the wave energy power supply system comprises a charging battery assembly (7), a power generation assembly and a control assembly (6); The buoy shell is a fully enclosed structure; The power generation assembly is arranged inside the buoy shell and adopts an oscillating body type wave power generation structure based on a linear motor; When the buoy shell is impacted by waves, the power generation assembly is driven to generate power to supply power to the monitoring assembly (1) and the charging battery assembly (7); The control assembly (6) acquires real-time power generation power of the power generation assembly and real-time SOC state information of the charging battery assembly (7), controls the charging battery assembly (7) to charge and discharge, and controls the running state of the monitoring assembly (1); When the SOC of the charging battery assembly (7) is less than a first preset power threshold, the control assembly (6) controls the power generation assembly to supply power only to the charging battery assembly (7), and makes the monitoring assembly (1) in a dormant state; When the SOC of the charging battery assembly (7) is greater than or equal to the first preset power threshold and less than a second preset power threshold, the control assembly (6) controls the monitoring assembly (1) to be in a continuous running state or an interval running state according to the power generation power value of the power generation assembly; When the SOC of the charging battery assembly (7) is greater than or equal to the second preset power threshold, the control assembly (6) controls the monitoring assembly (1) to be in a continuous running state; When the SOC of the charging battery assembly (7) is greater than or equal to the first preset power threshold and less than a second preset power threshold, the control assembly (6) controls the monitoring assembly (1) to be in a continuous running state or an interval running state according to the power generation power value of the power generation assembly, comprising: When the SOC of the charging battery assembly (7) is greater than or equal to the first preset power threshold and less than a second preset power threshold, If the real-time power generation power of the power generation assembly is less than a load power threshold, the control assembly (6) controls the monitoring assembly (1) to be in an interval running state; If the real-time power generation power of the power generation assembly is greater than or equal to the load power threshold required for the continuous running of the monitoring assembly (1), the control assembly (6) controls the monitoring assembly (1) to be in a continuous running state.

2. The wave energy power supply system of the offshore buoy device according to claim 1, wherein The monitoring assembly (1) is arranged on the upper surface of the top of the buoy shell; The charging battery assembly (7) is arranged at the bottom of the buoy shell; The power generation assembly is arranged between the top of the buoy shell and the charging battery assembly (7).

3. The wave energy power supply system of the offshore buoy device according to claim 2, wherein The power generation assembly comprises a linear motor stator (4), a linear motor rotor (5), a first spring (2) and a second spring. The two ends of the linear motor stator (4) are respectively connected to the top wall of the buoy housing and the top of the rechargeable battery. The first spring (2), the linear motor mover (5) and the second spring are sequentially sleeved on the linear motor stator (4). The two ends of the first spring (2) are respectively connected to the top wall of the buoy housing and one side of the linear motor mover (5). The two ends of the second spring are respectively connected to the top of the rechargeable battery and the other side of the linear motor mover (5).

4. The wave energy power supply system for marine buoy equipment according to claim 1, characterized in that, The control component (6) includes: a model prediction controller based on the Thevenin model; The Thevenin model includes: an equivalent power source, a first resistor, a parallel resistor, and a parallel capacitor. The positive terminal of the equivalent power source is connected in sequence to the first resistor, the parallel resistor, and the positive terminal of the load. The negative terminal of the equivalent power source is connected to the negative terminal of the load. The parallel capacitor and the parallel resistor are connected in parallel. When the monitoring component (1) is in the interval operation state, the model prediction controller obtains the working time of the monitoring component (1) in each buoy working cycle based on its state equation, objective function and constraints; The objective function aims to maximize the buoy's operating time within the prediction period and minimize battery energy loss.

5. The wave energy power supply system for marine buoy equipment according to claim 4, characterized in that, The state equation of the model predictive controller is: Where x(k+1) and x(k) are the state variables at times k+1 and k, u(k) is the control variable at time k, and r(k) is the disturbance variable at time k. The control variable u(k) at time k adopts the corresponding buoy working period T. float Operating time T of the internal monitoring component load The disturbance variable r(k) at time k is the real-time power generation P of the power generation component. WEC Δt is the sampling time interval, P float (k) represents the power required for continuous buoy operation at sea state k, U b (k) represents the output voltage of the rechargeable battery assembly (7) at time k, η and Q N R represents the charge / discharge efficiency coefficient and capacity of the rechargeable battery assembly (7). c1 C1 is the parallel resistance value, C1 is the parallel capacitance value, and T is the parallel capacitance value. float R1 is the first resistor, representing the buoy's working cycle duration. The objective function J of the model predictive controller is: ； wherein w1 and w2 represent positive weight coefficients, N is a maximum prediction period, i is a time number recursively from a current time, T load is the working period of the buoy float is the working time length of the internal monitoring component, I b is an output current value of the charging battery component (7), R0 is the first resistance value, u(k) is a control variable at time k, r(k) is a disturbance variable at time k, P float (k) represents the power required by the continuous operation mode of the buoy under sea conditions at time k, U b (k) represents the output voltage of the charging battery component (7) at time k; The constraints of the model predictive controller include: SOC constraints, rechargeable battery assembly (7) output current constraints, and control constraints. The SOC constraint is as follows: ； Wherein, SOC min is the first preset power threshold, SOC max is the second preset power threshold, N is the maximum prediction period, and i is the number of times from the current time. The output current constraint condition of the rechargeable battery assembly (7) is: where P float (k) is the power required for the buoy to run in continuous mode under sea state at time k, T load (k+i|k) is the working time of the monitoring component per working cycle of the buoy at the future i-th time, r (k+i|k) is the wave power value at the future i-th time, T float is the working cycle of the buoy, U b (k) represents the output voltage of the charging battery component (7) at time k, is the maximum output current of the battery, is the maximum absorption current of the battery; The control constraints are as follows: ； wherein T load (k+i|k) is the working time length of the monitoring component of the buoy in each working cycle at the future i th time.

6. The wave energy power supply system for marine buoy equipment according to claim 5, characterized in that, In neglecting the target function J in ; and defining U(k) as: and taking the negative of the minimization model, the target function J of the model predictive controller is transformed into: wherein U(k) is the control sequence with the current time k as the starting point, r(k|k) is the wave power value at the current time k, and r(k+N-1|k) is the wave power value at the N-1th time after the current time k.

7. A method of controlling a wave energy power supply system for a marine buoyant installation, c h a r a c t e r i s e d i n that Wave energy power supply system for controlling the marine buoy equipment as described in any one of claims 1-6.

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