Full-link energy management method and system of wave energy independent power supply system

Abstract

The invention discloses a full-link energy management method and system of a wave energy independent power supply system. The method comprises the steps that when the built-in vibration body type wave energy power generation device captures wave energy, a reference signal of generator acting force generated in real time in the running state of the built-in vibration body type wave energy power generation device is obtained; converting the reference signal of the acting force of the generator into a reference signal of the dq-axis voltage of the generator, and outputting the reference signal of the dq-axis voltage of the generator into an SVPWM signal corresponding to the reference signal of the dq-axis voltage of the generator through space vector pulse width modulation; controlling an AC / DC converter to convert alternating current into direct current through an SVPWM signal; and when the direct current output by the AC / DC converter is transmitted to the direct current bus, performing voltage stabilization control on the voltage of the direct current bus by adopting a controller based on the Lyapunov theorem. The technical problems that in the prior art, a wave energy power supply device is low in power generation efficiency, unstable in output power and uncertain in energy flow are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy management of renewable energy, and in particular to a full-link energy management method and system for a wave energy independent power supply system. Background Art

[0002] Ocean observation equipment represented by buoys is an important means of obtaining ocean information and is widely used in the field of global ocean observation. The new generation of ocean observation equipment for "transparent ocean, smart ocean" has higher requirements for power supply due to observation needs such as high sampling rate and multiple sensors. As a widely distributed and huge marine renewable energy source, wave energy has outstanding advantages such as high energy flow density, high energy grade and long duration. Wave energy power generation technology is naturally suitable for powering ocean observation equipment and solving the problem of deep-sea energy replenishment for ocean observation equipment. In order to ensure observation performance, ocean observation equipment has high reliability and long endurance requirements for electricity. However, the strong randomness, large volatility and high intermittency of wave energy lead to problems such as large fluctuations in wave energy power generation and large peak-to-average power ratio, making it difficult to directly supply power to ocean observation equipment.

[0003] Current research on wave energy generation technology, especially energy management technology, mainly focuses on the optimal control of wave energy capture at the front end and energy storage management at the back end. There is no complete and comprehensive system-level modeling solution for the design and research of a complete set of wave energy generation devices. The present invention proposes a full-link energy management method from waves to the power supply end for energy conversion in each link of the wave energy generation process, including optimal control of wave energy capture, AC / DC conversion control, hybrid energy storage control and energy management, so as to fully meet the requirements of marine observation equipment for power consumption and power quality, and provide guidance for the design and development of independent wave energy power supply devices. Summary of the invention

[0004] The embodiments of the present invention provide a full-link energy management method and system based on independent power supply of wave energy, so as to at least solve the technical problems of low power generation efficiency, unstable output power and uncertain energy flow of wave energy power supply devices in the prior art.

[0005] According to one aspect of an embodiment of the present invention, a full-link energy management method based on independent power supply of wave energy is provided. The method may include: when the built-in impact-vibration body wave energy power generation device captures wave energy, obtaining the reference signal of the generator force generated in real time by the operation state of the built-in impact-vibration body wave energy power generation device; converting the reference signal of the generator force into a reference signal of the generator dq axis voltage, and outputting the reference signal of the generator dq axis voltage through space vector pulse width modulation. The SVPWM signal corresponding to the reference signal of the generator dq axis voltage; controlling the AC / DC converter to convert AC power into DC power through the SVPWM signal; when the DC power output by the AC / DC converter is transmitted to the DC bus, the voltage of the DC bus is stabilized by using a controller based on the Lyapunov theorem, wherein the DC bus end is connected in parallel with the battery and the supercapacitor through a buck-boost DC / DC converter, and the battery, the supercapacitor, and the buck-boost DC / DC converter together form a hybrid energy storage system.

[0006] Optionally, the expression of the reference signal of the generator force is: (1) in, represents the power of the wave energy captured by the built-in vibration wave energy generator at the i-th moment, is the penalty term, which represents the power consumed. is the weight factor, represents the number of steps to be predicted, is the current discrete moment, represents the constraint boundary of the relative displacement between the built-in vibrating body and the external floating body, The constraint boundary representing the force of the built-in impact vibrator wave energy power generation device, The reference signal representing the generator force at time i under discrete conditions, Indicates the relative displacement between the built-in vibration body and the external floating body. Indicates the force of the built-in impact vibration wave energy power generation device.

[0007] Optionally, the voltage stabilization control of the DC bus by using a controller based on the Lyapunov theorem includes: obtaining an actual voltage and a target voltage output by the DC bus; based on the actual voltage and the target voltage output by the DC bus, outputting a current reference signal for the hybrid energy storage system, wherein the current reference signal of the hybrid energy storage system is divided into a high-frequency current reference signal and a low-frequency current reference signal; Based on the current reference signal of the hybrid energy storage system, the voltage of the DC bus is stabilized and controlled.

[0008] Optionally, the process of outputting a current reference signal for the hybrid energy storage system based on the actual voltage and target voltage output by the DC bus is as follows: an expression defining an error between the actual voltage and the target voltage is: (2) in, is the actual voltage, is the target voltage, is the error between the actual voltage and the target voltage; When the error between the actual voltage and the target voltage approaches 0, the derivative of the error between the actual voltage and the target voltage should satisfy: (3) in, is the derivative of the error between the actual voltage and the target voltage, is the parameter; The dynamic equation for the actual voltage is: (4) in, is the filter capacitor, They are respectively the current from the built-in vibrating wave energy generator, the current of the supercapacitor, the current of the battery and the current flowing from the DC bus to the DC load.

[0009] Based on formulas (2), (3) and (4), the expression of the current reference signal of the hybrid energy storage system is obtained as follows: (5) in, is the current reference signal of the hybrid energy storage system, is the high frequency current reference signal, It is the current reference signal of the low frequency part.

[0010] Optionally, the voltage stabilization control of the DC bus based on the current reference signal of the hybrid energy storage system includes: obtaining a first error signal based on the low-frequency current reference signal and the measured current of the battery; obtaining a first control signal after the first error signal passes through a PI controller; obtaining a first pulse width modulation signal based on the first control signal and a sawtooth wave signal, wherein the first pulse width modulation signal is used to control the charging and discharging of the battery; and controlling the voltage of the DC bus based on the first pulse width modulation signal.

[0011] Optionally, the voltage stabilization control of the DC bus based on the current reference signal of the hybrid energy storage system also includes: obtaining a second error signal based on the high-frequency current reference signal and the measured current of the supercapacitor; when the second error signal passes through the PI controller, a second control signal is obtained; based on the second control signal and the sawtooth wave signal, a second pulse width modulation signal is obtained, wherein the second pulse width modulation signal is used to control the charging and discharging of the supercapacitor.

[0012] Beneficial effects of the present invention: The present invention proposes a full-link energy management method and system based on independent power supply of wave energy, and the beneficial effects are reflected in the following three aspects: (1) The present invention comprehensively considers all aspects of the power conversion of the wave energy power supply device, including the interaction between waves and the floating body, the interaction between the floating body and the generator, and the AC / DC conversion of the generator output power, which can better reflect the power conversion characteristics of the wave energy power supply device.

[0013] (2) Based on the concept of a built-in impact-vibration body wave energy device, the present invention proposes a nonlinear model predictive control method and uses a Lyapunov controller and SVPWM technology to control the AC / DC conversion module to achieve optimal capture of wave energy. This method can not only significantly improve the wave energy conversion efficiency of the device, but also has operability in terms of technical implementation.

[0014] (3) The present invention connects a hybrid energy storage system consisting of a battery and a supercapacitor in parallel to the terminal DC bus of the wave energy power generation device, adopts a Lyapunov controller, a low-pass filter and a PI controller to generate a PWM signal, controls the DC / DC conversion module of the hybrid energy storage system in real time, switches the charge and discharge states of the battery and the supercapacitor, and realizes a continuous and stable DC voltage output, thereby solving the problem of large power fluctuations in the wave energy power supply device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 is a flow chart of a full-link energy management method based on independent power supply of wave energy according to an embodiment of the present invention; Figure 2 is a schematic diagram of a built-in vibration body type wave energy power supply device according to an embodiment of the present invention; Figure 3 is a schematic diagram of a full-link energy management method based on independent power supply by wave energy according to an embodiment of the present invention; Figure 4 is a block diagram of a full-link energy management system according to an embodiment of the present invention; Figure 5 is a schematic diagram of a simulation model of a full-link energy management method according to an embodiment of the present invention; Figure 6 is a comparison diagram of a reference signal and a measurement signal of a generator force according to an embodiment of the present invention; Figure 7 is a comparison diagram of a reference signal and a measurement signal of a battery current according to an embodiment of the present invention; Figure 8 is a comparison diagram of a reference signal and a measurement signal of a supercapacitor current according to an embodiment of the present invention; Fig. 9 is a comparison diagram of a reference signal and a measurement signal of a DC bus voltage according to an embodiment of the present invention; Fig.10 is a timing diagram of average power and instantaneous power of a built-in vibration-body wave energy power supply device according to an embodiment of the present invention; Fig.11 is a schematic diagram of a full-link energy management system based on independent power supply of wave energy according to an embodiment of the present invention. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0017] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0018] Example 1 According to an embodiment of the present invention, a full-link energy management method for independent power supply based on wave energy is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system containing at least one set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in an order different from that shown here.

[0019] Figure 1 is a flow chart of a full-link energy management method based on independent power supply of wave energy according to an embodiment of the present invention, such as Figure 1 As shown, the method may include the following steps: Step S101, when the built-in impact-vibration body type wave energy power generation device captures wave energy, a reference signal of the generator force generated in real time by the operation state of the built-in impact-vibration body type wave energy power generation device is obtained.

[0020] In the technical solution provided in the above step S101 of the present invention, Figure 2 is a schematic diagram of a built-in vibration body type wave energy power supply device according to an embodiment of the present invention, Figure 2 (a) is a schematic diagram of a built-in vibration wave energy power supply device. Figure 2 (b) is a rendering of a built-in impact-vibration wave power supply device, in which the cylindrical floating body of the wave power device only considers the movement in the vertical direction. According to Newton's second law of motion, the expression of its hydrodynamic model is: (6) in, and They represent the mass of the floating body, heave acceleration, hydrostatic restoring force, radiation force, wave excitation force, floating body-oscillator interaction force and generator force respectively.

[0021] The expression of the hydrostatic restoring force of a cylindrical floating body is: (7) in, and are the fluid density, gravitational acceleration, float radius and float displacement respectively.

[0022] The expression of radiation force is: (8) in, represents the additional mass of the floating body at infinite frequency, is the unit impulse response of the radiation force, Indicates the heave speed of the floating body.

[0023] The wave excitation force is expressed in the time domain as: (9) in, represents the unit impulse response function of the excitation force, represents the incident wave height. Considering The non-causal characteristics of , need to be subjected to a certain time shift, t and Represents a time series variable, rewritten as follows: (10) in represents the length of the time shift, represents the predicted wave height, Represents the unit impulse response function of the causalized excitation force.

[0024] Since the convolution term is time-consuming in calculation, system identification can be used to approximate the convolution terms in the radiation force and excitation force by a finite-order state space equation. The expression of the approximated state space model is: (11) in, and are the system state vectors for radiation force and excitation force, respectively, represents the convolution term in the radiation force, , , , , , , is the system matrix, and the order can be calculated according to and The degree of fit is determined by To excite the waves.

[0025] The dynamic model of the internal oscillator is expressed by the following equation: (12) in, and denote the mass and displacement of the oscillator respectively, The interaction force between the oscillator and the floating body is Depends on the relative displacement between the two , can be summarized as follows: (13) in, Represent the stiffness coefficients of the support spring, upper impact spring and lower impact spring respectively, and Represents the upper and lower vibration distance.

[0026] For the cylindrical linear permanent magnet generator used in the wave energy device, The expression of the mathematical model in axis coordinates is: (14) in, and Represents the generator Shaft voltage and current, represents the magnetic flux linkage, represents the electrical angular velocity, and is the equivalent resistance and Axis inductance. Electrical angular velocity and pickup capacity can be expressed as: (15) in, is the magnetic pole pitch, The relative speed between the internal impact body and the external floating body.

[0027] Step S102, converting the reference signal of the generator force into the reference signal of the generator dq axis voltage, and outputting the reference signal of the generator dq axis voltage into an SVPWM signal corresponding to the reference signal of the generator dq axis voltage through space vector pulse width modulation.

[0028] In the technical solution provided in the above step S102 of the present invention, Figure 3 is a schematic diagram of a full-link energy management method based on independent power supply by wave energy according to an embodiment of the present invention, Figure 4 is a block diagram of a full-link energy management system according to an embodiment of the present invention, such as Figure 3 and Figure 4 As shown, the reference signal of the generator force is converted into the reference signal of the generator dq axis voltage, and the reference signal of the generator dq axis voltage is output through space vector pulse width modulation (Space Vector Pulse Width Modulation, referred to as SVPWM) to output the SVPWM signal corresponding to the reference signal of the generator dq axis voltage. Directly with Shaft current and related, so the control signal The tracking can be done by and Here we set Reference current of the axis , has two advantages: (1) it maximizes the ratio of force to current, which can produce a larger generator force with a smaller current; (2) it can offset the nonlinear term in the generator equation Therefore, the generator The expression of the shaft current reference signal is: (16) in, For generator Shaft current reference signal.

[0029] for The shaft current is controlled using a controller based on Lyapunov's theorem, defining The error between the shaft current and its reference signal is: (17) in, for The error of the shaft current from its reference signal, for The error of the shaft current from its reference signal, For generator Shaft current reference signal.

[0030] To allow error and tend to 0, their derivatives should satisfy (18) in, for The derivative of the error of the shaft current from its reference signal, for The derivative of the error of the shaft current from its reference signal, and is a positive control parameter. Combining the above equations, we can get the generator The expression of the control law of the shaft voltage is: (19) in, for The reference signal of the shaft voltage, for The reference signal of the shaft voltage, and The tracking is achieved by controlling the AC / DC conversion module through SVPWM technology.

[0031] Step S103, controlling the AC / DC converter to convert the alternating current into direct current through the SVPWM signal.

[0032] In the technical solution provided in step S103 of the present invention, if Figure 3 and Figure 4 As shown, the conversion of the current in the AC / DC converter is controlled by the SVPWM signal to achieve tracking control of the generator force control signal.

[0033] Step S104, when the DC power output by the AC / DC converter is transmitted to the DC bus, the voltage of the DC bus is stabilized and controlled by using a controller based on the Lyapunov theorem, wherein the DC bus end is connected in parallel with the battery and the supercapacitor through the buck-boost DC / DC converter, and the battery, the supercapacitor, and the buck-boost DC / DC converter together constitute a hybrid energy storage system.

[0034] In the technical solution provided in step S104 of the present invention, if Figure 3 and Figure 4 As shown, the DC power output end (DC bus) is connected in parallel with a hybrid energy storage system consisting of a supercapacitor and a battery, and a controller based on the Lyapunov theorem is used to stabilize the DC bus voltage.

[0035] The above method of this embodiment is further introduced below.

[0036] As an optional embodiment, in step S101, the expression of the reference signal of the generator force is: (1) Among them, among them, represents the power of the wave energy captured by the built-in vibration wave energy generator at the i-th moment, is the penalty term, which represents the power consumed. is the weight factor, represents the number of steps to be predicted, is the current discrete moment, represents the constraint boundary of the relative displacement between the built-in vibrating body and the external floating body, The constraint boundary representing the force of the built-in impact vibrator wave energy power generation device, The reference signal representing the generator force at time i under discrete conditions, Indicates the relative displacement between the built-in vibration body and the external floating body. Indicates the force of the built-in impact vibration wave energy power generation device.

[0037] As an optional implementation method, step S104, the use of a controller based on Lyapunov's theorem to perform voltage stabilization control on the DC bus voltage includes: obtaining the actual voltage and target voltage output by the DC bus; based on the actual voltage and target voltage output by the DC bus, outputting a current reference signal for the hybrid energy storage system, wherein the current reference signal of the hybrid energy storage system is divided into a high-frequency current reference signal and a low-frequency current reference signal; based on the current reference signal of the hybrid energy storage system, the voltage of the DC bus is stabilized.

[0038] In this embodiment, the Lyapunov controller outputs a current reference signal to the hybrid energy storage system based on the error signal between the actual voltage and the reference voltage, and performs voltage stabilization control on the DC bus according to the current reference signal of the hybrid energy storage system. When the wave energy generation power is greater than the load power demand, the hybrid energy storage system is mainly charged; when the wave energy generation power is insufficient to meet the load power demand, the hybrid energy storage system is mainly discharged; by switching the charge and discharge of the battery and the supercapacitor, the output power of the wave energy device is smoothed to achieve stable and continuous DC power output.

[0039] As an optional embodiment, the process of outputting a current reference signal for the hybrid energy storage system based on the actual voltage and target voltage output by the DC bus is as follows: The expression that defines the error between the actual voltage and the target voltage is: (2) in, is the actual voltage, is the target voltage, is the error between the actual voltage and the target voltage; When the error between the actual voltage and the target voltage approaches 0, the derivative of the error between the actual voltage and the target voltage should satisfy: (3) in, is the derivative of the error between the actual voltage and the target voltage, is the parameter; The dynamic equation for the actual voltage is: (4) in, is the filter capacitor, They are respectively the current from the built-in vibrating wave energy generator, the current of the supercapacitor, the current of the battery and the current flowing from the DC bus to the DC load.

[0040] Based on formulas (2), (3) and (4), the expression of the current reference signal of the hybrid energy storage system is obtained as follows: (5) in, is the current reference signal of the hybrid energy storage system, is the high frequency current reference signal, It is the current reference signal of the low frequency part.

[0041] As an optional implementation method, the voltage of the DC bus is stabilized and controlled based on the current reference signal of the hybrid energy storage system, including: obtaining a first error signal based on the low-frequency current reference signal and the measured current of the battery; when the first error signal passes through a PI controller, a first control signal is obtained; based on the first control signal and a sawtooth wave signal, a first pulse width modulation signal is obtained, wherein the first pulse width modulation signal is used to control the charging and discharging of the battery; based on the first pulse width modulation signal, the voltage of the DC bus is stabilized and controlled.

[0042] In this embodiment, if Figure 4 As shown, the low-frequency current reference signal is compared with the measured current of the battery to obtain a first error signal; when the first error signal passes through the PI controller, a first control signal is obtained; according to the first control signal and the sawtooth wave signal, a first pulse width modulation signal is obtained, wherein the first pulse width modulation signal is used to control the charging and discharging of the battery; according to the first pulse width modulation signal, the voltage of the DC bus is stabilized and controlled.

[0043] As an optional implementation method, the voltage of the DC bus is stabilized and controlled based on the current reference signal of the hybrid energy storage system, and also includes: obtaining a second error signal based on the high-frequency current reference signal and the measured current of the supercapacitor; when the second error signal passes through the PI controller, a second control signal is obtained; based on the second control signal and the sawtooth wave signal, a second pulse width modulation signal is obtained, wherein the second pulse width modulation signal is used to control the charging and discharging of the supercapacitor; based on the second pulse width modulation signal, the voltage of the DC bus is stabilized and controlled.

[0044] In this embodiment, if Figure 4 As shown, the high-frequency current reference signal is compared with the measured current of the supercapacitor to obtain a second error signal; when the second error signal passes through the PI controller, a second control signal is obtained; according to the second control signal and the sawtooth wave signal, a second pulse width modulation signal is obtained, wherein the second pulse width modulation signal is used to control the charging and discharging of the supercapacitor; according to the second pulse width modulation signal, the voltage of the DC bus is stabilized and controlled.

[0045] Experimental part: Figure 5 is a schematic diagram of a simulation model of a full-link energy management method according to an embodiment of the present invention.

[0046] Figure 6 3 is a comparison diagram between a reference signal and a measurement signal of a generator force according to an embodiment of the present invention.

[0047] Figure 7 4 is a comparison diagram of a reference signal and a measurement signal of a battery current according to an embodiment of the present invention.

[0048] Figure 8 3 is a comparison diagram of a reference signal and a measurement signal of a supercapacitor current according to an embodiment of the present invention.

[0049] Fig. 9 3 is a comparison diagram of a reference signal and a measurement signal of a DC bus voltage according to an embodiment of the present invention.

[0050] Fig.10 It is a timing diagram of average power and instantaneous power of a built-in vibration body type wave energy power supply device according to an embodiment of the present invention.

[0051] like Figure 5 As shown in Figure 1, in order to verify the full-link energy management system based on wave energy generation proposed in this invention, a corresponding simulation model was built in the MATLAB / SIMULINK simulation environment. Taking the average wave conditions of Island A over 2 years (significant wave height 1.10 m, average period 5.93 s) as an example, the output results of the simulation model under irregular waves are shown in Figure 1. Figure 6~Figure 10 shown. Figure 6 The comparison between the reference signal and the measured signal of the generator force is shown. The measured signal of the generator can track the reference signal well, which verifies the effectiveness of nonlinear model predictive control in optimal power generation control. Figure 7 and Figure 8 The current tracking control performance of the battery and supercapacitor in the hybrid energy storage system is demonstrated respectively. It can be seen that the currents of the battery and supercapacitor have different change rates, and the measured signals are generally consistent with the reference signals, which proves the effectiveness of the high- and low-frequency shunting strategy and DC / DC conversion module control adopted in the present invention. Fig. 9 The variation of the DC bus voltage is demonstrated, and the actual voltage tracks the reference voltage of 150 V very well, with a voltage fluctuation of less than 3% throughout the entire process, which proves the effectiveness of the proposed hybrid energy storage and energy management method to achieve stable and continuous DC voltage output. Fig.10 The output power of the generator was demonstrated. The average power of the wave energy independent power supply device exceeded 300W, which can meet the power requirements of conventional ocean observation equipment.

[0052] In the embodiment of the present invention, when the built-in impact-vibration wave energy power generation device captures wave energy, the operating state of the built-in impact-vibration wave energy power generation device is obtained to generate a reference signal of the generator force in real time; the reference signal of the generator force is converted into a reference signal of the dq axis voltage of the generator, and the reference signal of the dq axis voltage of the generator is output through space vector pulse width modulation to obtain an SVPWM signal corresponding to the reference signal of the dq axis voltage of the generator; the AC / DC converter is controlled by the SVPWM signal to convert alternating current into direct current; when the direct current output by the AC / DC converter is transmitted to the DC bus, the DC bus is connected to the DC bus by adopting a Lyapunov-based The controller of the theorem performs voltage stabilization control on the DC bus voltage, wherein the DC bus end is connected in parallel with the battery and supercapacitor through a buck-boost DC / DC converter, and the battery, supercapacitor, and buck-boost DC / DC converter together form a hybrid energy storage system, which solves the technical problems of low power generation efficiency, unstable output power, and uncertain energy flow of wave energy power supply devices in the prior art, and achieves the technical effect of fully meeting the requirements of marine observation equipment for power consumption and power quality through optimal control of wave energy capture, AC / DC conversion control, hybrid energy storage control, and energy management, providing guidance for the design and development of independent wave energy power supply devices.

[0053] Example 2 According to an embodiment of the present invention, a full-link energy management system based on independent power supply of wave energy is also provided. It should be noted that the full-link energy management system based on independent power supply of wave energy can be used to execute the full-link energy management method based on independent power supply of wave energy in Example 1.

[0054] Fig.11 is a schematic diagram of a full-link energy management system based on independent power supply of wave energy according to an embodiment of the present invention. Fig.11 As shown, a full-link energy management system based on independent power supply of wave energy may include: an acquisition unit, a first processing unit, a second processing unit and a third processing unit.

[0055] The acquisition unit is used to acquire a reference signal of the generator force generated in real time by the operation state of the built-in impact-vibration body type wave energy power generation device when the built-in impact-vibration body type wave energy power generation device captures wave energy.

[0056] The first processing unit is used to convert the reference signal of the generator force into the reference signal of the generator dq axis voltage, and output the SVPWM signal corresponding to the reference signal of the generator dq axis voltage through space vector pulse width modulation.

[0057] The second processing unit is used to control the AC / DC converter to convert the alternating current into direct current through the SVPWM signal.

[0058] The third processing unit is used for stabilizing the voltage of the DC bus by adopting a controller based on Lyapunov's theorem when the DC power output by the AC / DC converter is transmitted to the DC bus, wherein the DC bus end is connected in parallel with the battery and the supercapacitor through the buck-boost DC / DC converter, and the battery, the supercapacitor and the buck-boost DC / DC converter together constitute a hybrid energy storage system.

[0059] Optionally, the acquisition unit further includes: an expression of a reference signal of the generator force is: (1) in, represents the power of the wave energy captured by the built-in vibration wave energy generator at the i-th moment, is the penalty term, which represents the power consumed. is the weight factor, represents the number of steps to be predicted, is the current discrete moment, represents the constraint boundary of the relative displacement between the built-in vibrating body and the external floating body, The constraint boundary representing the force of the built-in impact vibrator wave energy power generation device, The reference signal representing the generator force at time i under discrete conditions, Indicates the relative displacement between the built-in vibration body and the external floating body. Indicates the force of the built-in impact vibration wave energy power generation device.

[0060] Optionally, the third processing unit also includes: an acquisition module, used to acquire the actual voltage and target voltage of the DC bus output; an output module, used to output a current reference signal for the hybrid energy storage system based on the actual voltage and target voltage of the DC bus output, wherein the current reference signal of the hybrid energy storage system is divided into a high-frequency current reference signal and a low-frequency current reference signal; a control module, used to perform voltage stabilization control on the DC bus voltage based on the current reference signal of the hybrid energy storage system.

[0061] Optionally, the output module further includes: an expression defining the error between the actual voltage and the target voltage as: (2) in, is the actual voltage, is the target voltage, is the error between the actual voltage and the target voltage; When the error between the actual voltage and the target voltage approaches 0, the derivative of the error between the actual voltage and the target voltage should satisfy: (3) in, is the derivative of the error between the actual voltage and the target voltage, is the parameter; The dynamic equation for the actual voltage is: (4) in, is the filter capacitor, They are respectively the current from the built-in vibrating wave energy generator, the current of the supercapacitor, the current of the battery and the current flowing from the DC bus to the DC load.

[0062] Based on formulas (2), (3) and (4), the expression of the current reference signal of the hybrid energy storage system is obtained as follows: (5) in, is the current reference signal of the hybrid energy storage system, is the high frequency current reference signal, It is the current reference signal of the low frequency part.

[0063] Optionally, the control module also includes: a first obtaining submodule, used to obtain a first error signal based on a low-frequency current reference signal and a measured current of the battery; a first processing submodule, used to obtain a first control signal after the first error signal passes through a PI controller; a second obtaining submodule, used to obtain a first pulse width modulation signal based on the first control signal and a sawtooth wave signal, wherein the first pulse width modulation signal is used to control the charging and discharging of the battery; and a first control submodule, used to perform voltage stabilization control on the voltage of the DC bus based on the first pulse width modulation signal.

[0064] Optionally, the control module also includes: a third obtaining submodule, used to obtain a second error signal based on the high-frequency partial current reference signal and the measured current of the supercapacitor; a second processing submodule, used to obtain a second control signal after the second error signal passes through the PI controller; a fourth obtaining submodule, used to obtain a second pulse width modulation signal based on the second control signal and the sawtooth wave signal, wherein the second pulse width modulation signal is used to control the charging and discharging of the supercapacitor; and a second control submodule, used to perform voltage stabilization control on the voltage of the DC bus based on the second pulse width modulation signal.

[0065] In this embodiment, an acquisition unit is used to obtain a reference signal of a generator force generated in real time by the operation state of the built-in vibration wave energy power generation device when the built-in vibration wave energy power generation device captures wave energy; a first processing unit is used to convert the reference signal of the generator force into a reference signal of the dq axis voltage of the generator, and output the reference signal of the dq axis voltage of the generator through space vector pulse width modulation to obtain an SVPWM signal corresponding to the reference signal of the dq axis voltage of the generator; a second processing unit is used to control the AC / DC converter to convert alternating current into direct current through the SVPWM signal; a third processing unit is used to convert the direct current output by the AC / DC converter to the When the DC bus is connected, the voltage of the DC bus is stabilized by adopting a controller based on Lyapunov's theorem, wherein the DC bus end is connected in parallel with the battery and the supercapacitor through a buck-boost DC / DC converter, and the battery, the supercapacitor, and the buck-boost DC / DC converter together form a hybrid energy storage system, which solves the technical problems of low power generation efficiency, unstable output power, and uncertain energy flow of wave energy power supply devices in the prior art, and achieves the technical effect of fully meeting the requirements of marine observation equipment for power consumption and power quality through optimal control of wave energy capture, AC / DC conversion control, hybrid energy storage control and energy management, and providing guidance for the design and development of independent wave energy power supply devices.

[0066] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0067] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0068] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0069] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed over multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0070] In addition, each functional unit in each embodiment of the present invention may be integrated into a first processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0071] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A full-link energy management method based on independent power supply of wave energy, characterized in that: include: When the built-in impact-vibration wave energy power generation device captures wave energy, a reference signal of the generator force generated in real time by the operation status of the built-in impact-vibration wave energy power generation device is obtained; The reference signal of the generator force is converted into the reference signal of the generator dq axis voltage, and the reference signal of the generator dq axis voltage is modulated by space vector pulse width to output the SVPWM signal corresponding to the reference signal of the generator dq axis voltage; The AC / DC converter is controlled by the SVPWM signal to convert AC power into DC power; When the DC power output by the AC / DC converter is transmitted to the DC bus, the voltage of the DC bus is stabilized by using a controller based on Lyapunov's theorem, wherein the DC bus end is connected in parallel with the battery and supercapacitor through a buck-boost DC / DC converter, and the battery, supercapacitor, and buck-boost DC / DC converter together form a hybrid energy storage system.

2. The method according to claim 1, characterized in that The expression of the reference signal of the generator force is: （1） in, represents the power of the wave energy captured by the built-in vibration wave energy generator at the i-th moment, is the penalty term, which represents the power consumed. is the weight factor, represents the number of steps to be predicted, is the current discrete moment, represents the constraint boundary of the relative displacement between the built-in vibrating body and the external floating body, The constraint boundary representing the force of the built-in impact vibrator wave energy power generation device, The reference signal representing the generator force at time i under discrete conditions, Indicates the relative displacement between the built-in vibration body and the external floating body. Indicates the force of the built-in impact vibration wave energy power generation device.

3. The method according to claim 1, characterized in that The controller based on Lyapunov's theorem is used to control the voltage of the DC bus, including: Get the actual voltage and target voltage of the DC bus output; Based on the actual voltage and target voltage output by the DC bus, a current reference signal for the hybrid energy storage system is output, wherein the current reference signal of the hybrid energy storage system is divided into a high-frequency current reference signal and a low-frequency current reference signal; Based on the current reference signal of the hybrid energy storage system, the voltage of the DC bus is stabilized and controlled.

4. The method according to claim 3, characterized in that The process of outputting a current reference signal for the hybrid energy storage system based on the actual voltage and target voltage output by the DC bus is as follows: The expression that defines the error between the actual voltage and the target voltage is: （2） in, is the actual voltage, is the target voltage, is the error between the actual voltage and the target voltage; When the error between the actual voltage and the target voltage approaches 0, the derivative of the error between the actual voltage and the target voltage should satisfy: （3） in, is the derivative of the error between the actual voltage and the target voltage, is the parameter; The dynamic equation for the actual voltage is: （4） in, is the filter capacitor, They are respectively the current from the built-in vibrating wave energy generator, the current of the supercapacitor, the current of the battery and the current flowing from the DC bus to the DC load. Based on formulas (2), (3) and (4), the expression of the current reference signal of the hybrid energy storage system is obtained as follows: （5） in, is the current reference signal of the hybrid energy storage system, is the high frequency current reference signal, It is the current reference signal of the low frequency part.

5. The method according to claim 3, characterized in that: The voltage stabilization control of the DC bus based on the current reference signal of the hybrid energy storage system includes: Obtaining a first error signal based on a low-frequency current reference signal and a measured current of the battery; When the first error signal passes through the PI controller, a first control signal is obtained; Based on the first control signal and the sawtooth wave signal, a first pulse width modulation signal is obtained, wherein the first pulse width modulation signal is used to control the charging and discharging of the battery; Based on the first pulse width modulation signal, the voltage of the DC bus is stabilized and controlled.

6. The method according to claim 3, characterized in that The voltage stabilization control of the DC bus based on the current reference signal of the hybrid energy storage system also includes: A second error signal is obtained based on the high-frequency current reference signal and the measured current of the supercapacitor; When the second error signal passes through the PI controller, a second control signal is obtained; Based on the second control signal and the sawtooth wave signal, a second pulse width modulation signal is obtained, wherein the second pulse width modulation signal is used to control the charging and discharging of the supercapacitor; Based on the second pulse width modulation signal, the voltage of the DC bus is stabilized and controlled.

7. A full-link energy management system based on independent power supply of wave energy, characterized in that: include: An acquisition unit, used for acquiring a reference signal of a generator force generated in real time by the operation state of the built-in impact-vibration-body wave energy power generation device when the built-in impact-vibration-body wave energy power generation device captures wave energy; A first processing unit is used to convert the reference signal of the generator force into a reference signal of the generator dq axis voltage, and output the reference signal of the generator dq axis voltage into an SVPWM signal corresponding to the reference signal of the generator dq axis voltage through space vector pulse width modulation; a second processing unit, for controlling an AC / DC converter to convert alternating current into direct current through an SVPWM signal; The third processing unit is used for stabilizing the voltage of the DC bus by adopting a controller based on Lyapunov's theorem when the DC power output by the AC / DC converter is transmitted to the DC bus, wherein the DC bus end is connected in parallel with the battery and the supercapacitor through the buck-boost DC / DC converter, and the battery, the supercapacitor and the buck-boost DC / DC converter together constitute a hybrid energy storage system.

8. A computer system, characterized in that include: One or more processors, and a computer-readable storage medium for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors are enabled to implement the method of claim 1.

9. A computer-readable storage medium, characterized in that Computer executable instructions are stored, and when the instructions are executed, they are used to implement the method of claim 1.

10. A computer program product, characterized in that The invention comprises computer executable instructions, which are used to implement the method of claim 1 when being executed.

Images