A magnetic suspension flywheel system integrating roll stabilization and energy storage

Abstract

The application discloses a magnetic suspension flywheel system integrated with roll reduction and energy storage, and belongs to the cross technical field of ship motion control and shipborne integrated power system, comprising a magnetic suspension flywheel energy storage unit, a bidirectional power conversion module, a precession executing mechanism, a sensing and monitoring network and a cooperative controller. The magnetic suspension flywheel energy storage unit adopts a vertical structure, a gradient composite flywheel rotor supported by a driving magnetic suspension bearing and a permanent magnet synchronous motor coaxially connected with the flywheel are arranged in a vacuum cavity of the flywheel energy storage unit. The flywheel rotor adopts a gradient composite structure of an inner layer of high-strength alloy steel and an outer layer of carbon fiber composite material. The bidirectional power conversion module is connected with the permanent magnet synchronous motor and a ship power grid, and the cooperative controller performs coordinated control on the system according to the ship motion state, the flywheel operation state and the ship power grid information. The application realizes the integration and cooperation of the roll reduction, energy storage and ship power grid support functions, and can significantly improve the comprehensive performance of the ship.

Description

Technical Field

[0001] This invention relates to the interdisciplinary field of ship motion control and shipboard integrated power systems, specifically to a magnetic levitation flywheel system that integrates roll reduction and energy storage. Background Technology

[0002] With the rapid development of electric propulsion systems for new energy ships, ship power systems face challenges such as severe power fluctuations and insufficient inertia support. Introducing high-power-density energy storage devices has become a key path to improve the stability of ship power systems. Flywheel energy storage, due to its advantages such as high power density, long cycle life, and strong environmental adaptability, shows broad application prospects in the marine field. At the same time, the rolling motion of ships in complex sea conditions seriously affects navigation safety and crew comfort. Traditional anti-roll tanks or anti-roll fins have defects such as slow response and strong speed dependence. However, gyro-based anti-roll technology based on high-speed rotating flywheels has become an important development direction for anti-roll of high-performance ships due to its rapid response, controllable torque, and lack of speed limitations.

[0003] However, in existing technologies, energy storage flywheels and anti-roll gyroscopes are usually designed as independent systems or simply have their functions superimposed, making it difficult to achieve true physical integration and energy synergy. Most existing solutions involve spatial juxtaposition or functional splicing between energy storage devices and anti-roll devices, and have not yet formed a deeply integrated technical route based on a unified rotating body, a unified support structure, and a unified energy interface.

[0004] Existing marine flywheel anti-roll devices (such as CN105923118B) mostly employ a dual-flywheel structure with reversible rotation, generating inertial torque by controlling the acceleration and deceleration of the dual flywheels to achieve anti-roll. This type of solution relies on mechanical bearings for support, resulting in inherent drawbacks such as high frictional losses, limited speed, and high maintenance requirements. It struggles to simultaneously meet the dual requirements of high speed and high energy density for energy storage and large rotational inertia and high torque output for anti-roll. Furthermore, the generation of its anti-roll torque depends on changes in flywheel speed, deeply coupling the anti-roll function with the energy storage state: when the flywheel is at low speed and low energy storage, the anti-roll capability is significantly limited, and it is difficult to achieve continuously adjustable direction and stable, controllable torque output. Therefore, this type of solution essentially fails to overcome the structural contradiction between "high-speed energy storage" and "large inertia anti-roll."

[0005] Existing magnetic levitation flywheel energy storage systems (such as CN118432358A and CN111313600A) utilize magnetic bearings to eliminate mechanical friction. However, the former focuses on pure energy storage applications, reducing standby losses through a clutch mechanism but not on roll reduction. The latter uses hybrid magnetic levitation bearings to support a large-capacity flywheel, primarily addressing heat dissipation and long-term energy storage in a vacuum environment, similarly neglecting the roll reduction requirements of ships. While these systems offer advantages in high-speed and low-loss operation, they lack a mechanical actuator to actively deflect the flywheel's angular momentum vector, thus failing to generate the gyroscopic precession torque needed to counteract ship roll and therefore lack roll reduction capabilities. In other words, existing magnetic levitation flywheel technology primarily addresses the problem of "how the flywheel efficiently stores energy," but not the problem of "how the flywheel stably outputs roll-reducing torque while storing energy."

[0006] Furthermore, existing integrated flywheel systems typically switch flywheel speed and direction according to preset rules to achieve alternating operation between "energy storage mode" and "roll reduction mode." Essentially, this still involves function switching or phased reuse, rather than coordinated operation within the same flywheel unit. When the system performs roll reduction actions, the flywheel's acceleration and deceleration processes can easily disturb the ship's electrical grid power exchange; when the system responds to the ship's electrical grid power demands, it may introduce torque output fluctuations, adversely affecting the ship's attitude stability. Current technology has not yet achieved effective separation of roll reduction torque output and energy storage power exchange at the structural configuration and functional division level, thus making it difficult to simultaneously meet the ship's attitude stability requirements and the ship's electrical grid support requirements.

[0007] Furthermore, most existing flywheel devices are considered passive energy storage units or emergency power supplies, typically possessing only basic charging and discharging functions. They fail to fully leverage the advantages of flywheels, such as fast response speed and high power density, making it difficult for them to play a more proactive supporting role during shipboard electrical grid operation. Therefore, existing technologies not only fail to achieve deep integration of roll reduction and energy storage functions within the same flywheel unit, but also fail to fully demonstrate the multifunctional application value of flywheel systems in integrated shipboard energy scenarios.

[0008] In summary, existing technologies, limited by the physical limitations of mechanical bearings, the structural design with fragmented functions, or the excessive coupling between roll reduction and energy storage, have failed to achieve deep integration and synergy between roll reduction, energy storage, and grid support. Therefore, a novel system is urgently needed to overcome the contradiction between rotational speed and inertia at the physical level, achieving the organic unity of high-speed energy storage, stable roll reduction torque output, and shipboard grid support functions within a single flywheel unit, thus forming a new integrated technical solution for new energy ship applications. Summary of the Invention

[0009] To address the problems of existing marine flywheel anti-roll devices that rely on flywheel speed variations to generate inertial torque, the strong coupling between anti-roll function and energy storage, and traditional anti-roll gyroscopes that rely on constant speed operation and struggle to simultaneously perform energy storage functions, this invention provides a magnetic levitation flywheel system integrating anti-roll and energy storage. By integrating a high-speed rotating flywheel, magnetic levitation support structure, precession actuator, and bidirectional energy exchange interface within a single flywheel unit, it achieves coordinated and unified functions of ship anti-roll, flywheel energy storage, and shipboard power grid support. This invention shifts the primary adjustment mechanism for anti-roll torque from rapid flywheel speed changes to precession control. Flywheel speed regulation is mainly used for energy storage and power exchange with the grid, while precession control is primarily used for anti-roll torque output. Thus, even in energy storage operation with variable flywheel speed, the anti-roll torque output capability is maintained, and the anti-roll torque is continuously adjustable.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A magnetic levitation flywheel system integrating roll reduction and energy storage includes a magnetic levitation flywheel energy storage unit, a bidirectional power conversion module, a precession actuator, and a cooperative controller. The magnetic levitation flywheel energy storage unit adopts a vertical structure, including a vacuum chamber, a gradient composite flywheel rotor disposed within the vacuum chamber, a flywheel rotor shaft, a permanent magnet synchronous motor, and an active magnetic levitation bearing. The gradient composite flywheel rotor is sleeved on the flywheel rotor shaft and rigidly connected coaxially to the rotor of the permanent magnet synchronous motor. The flywheel rotor shaft is supported and suspended by the active magnetic levitation bearing. The permanent magnet synchronous motor is connected to the ship's electrical grid through the bidirectional power conversion module. The magnetic levitation flywheel energy storage unit is integrally mounted on the precession actuator, which drives the entire magnetic levitation flywheel energy storage unit to perform controlled deflection around an axis parallel to the ship's transverse axis, thereby changing the direction of the flywheel's angular momentum and generating a gyroscopic torque to resist the ship's roll. The cooperative controller is connected to the bidirectional power conversion module, the active magnetic levitation bearing, and the precession actuator.

[0012] Beneficial effects:

[0013] 1. This invention eliminates mechanical friction and speed limitations by using an active magnetic levitation bearing (five degrees of freedom fully active control) to replace mechanical bearings or hybrid bearings, enabling the flywheel to achieve high-speed and stable operation in a vacuum environment. At the same time, by using a gradient composite flywheel rotor (inner layer of high-strength alloy steel + outer layer of carbon fiber composite material), the stress during high-speed rotation tends to be uniform through the gradient distribution of material properties, giving full play to the material strength potential and achieving higher limiting speed and rotational inertia under the same safety margin. This helps to alleviate the structural contradiction between high energy storage density and large anti-rolling torque requirements.

[0014] 2. This invention introduces a precession actuator (precession bearing housing, precession shaft, and precession motor) to enable the flywheel unit to deflect in a controlled manner around an axis parallel to the ship's transverse axis. This system transforms the primary adjustment mechanism for the anti-roll torque from rapid changes in flywheel speed to precession control: flywheel speed is mainly used to regulate energy storage status and influence the system's output range of gyroscopic torque; precession angular velocity is mainly used to adjust the magnitude and direction of the gyroscopic torque output. The co-controller coordinates flywheel speed adjustment commands and precession control commands, reducing the mutual influence between energy storage power exchange and anti-roll torque output, thereby improving the flexibility and stability of the system's coordinated operation.

[0015] 3. This invention uses a collaborative controller to comprehensively judge the ship's motion state, flywheel operating state, and ship's power grid state, and coordinates the generation of flywheel speed adjustment commands and precession control commands. This enables the system to coordinate control between ship roll suppression, safe flywheel operation, and ship's power grid support, thereby reducing the conflict between roll reduction function and energy storage function and improving the overall operating performance under complex sea conditions and complex power consumption conditions.

[0016] 4. This invention configures a grid support control function in the cooperative controller or bidirectional power conversion module, which may include a virtual synchronous machine control function. When connected to the ship's AC grid, the system can adjust the active power output of the flywheel energy storage unit according to grid frequency changes, making it exhibit equivalent inertial response and damping support characteristics, and quickly inject active power to provide inertial support when the grid frequency drops. When connected to the ship's DC grid, the system can respond to DC bus voltage deviation and quickly adjust the charging and discharging power of the flywheel energy storage unit to provide voltage support. At the same time, the cooperative controller coordinates the flywheel power regulation and precession control actions to reduce the impact of the additional gyroscopic torque caused by power exchange on the ship's roll control, thereby achieving synergy between grid support and roll reduction control.

[0017] 5. By employing a configurable bidirectional power conversion module, the system can flexibly adapt to the topology (back-to-back bidirectional PWM or AC / DC bidirectional PWM) according to the ship's power grid type (AC or DC), and can be compatible with different ship power architectures without changing the mechanical structure, significantly improving the system's versatility and deployment flexibility.

[0018] In summary, this invention achieves a high degree of integration of mechanical structure, electrical interface and control strategy, enabling a single flywheel system to simultaneously possess the triple functions of a roll-damping gyroscope, a high-power-density energy storage unit and a shipboard electrical grid support unit. This is beneficial for improving the ship's navigation stability, energy utilization efficiency and the quality of shipboard electrical grid operation under complex operating conditions. Attached Figure Description

[0019] Figure 1This is a schematic diagram of a magnetic levitation flywheel system that integrates anti-sway and energy storage according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the gradient composite flywheel rotor used in this invention.

[0021] The attached figures are labeled as follows: 1-lower protective bearing; 2-lower radial magnetic levitation bearing; 3-gradient composite flywheel rotor; 4-vacuum cavity; 5-permanent magnet synchronous motor; 6-flywheel rotor shaft; 7-flywheel housing; 8-permanent magnet synchronous motor drive interface; 9-bidirectional converter; 10-grid connection interface; 11-ship electrical grid; 12-control and signal acquisition circuit; 13-precession shaft; 14-precession motor; 15-cooperative controller; 16-ship attitude sensor; 17-upper radial magnetic levitation bearing; 18-axial magnetic levitation bearing; 19-upper protective bearing; 20-precession bearing housing; 21-ship base; 31-flywheel rotor inner layer; 32-flywheel rotor outer layer. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0023] like Figure 1 As shown, this invention provides a magnetic levitation flywheel system integrating roll reduction and energy storage, physically installed inside the ship's hull. It achieves integrated coordination of ship roll reduction, flywheel energy storage, and ship electrical grid support functions. The system includes a magnetic levitation flywheel energy storage unit, a bidirectional power conversion module, a precession actuator, a sensing and monitoring network, and a coordination controller. This invention integrates the flywheel rotor, permanent magnet synchronous motor, active magnetic levitation bearing, precession actuator, and bidirectional power conversion interface into a single flywheel unit, achieving coordinated configuration of ship roll reduction, flywheel energy storage, and ship electrical grid support functions on a unified physical platform.

[0024] The magnetic levitation flywheel energy storage unit adopts a vertical structure, including a flywheel housing 7 mounted on a precession bearing seat 20, a vacuum chamber 4 disposed within the flywheel housing 7, and a gradient composite flywheel rotor 3, a flywheel rotor shaft 6, a permanent magnet synchronous motor 5, an active magnetic levitation bearing, and a protective bearing disposed within the vacuum chamber 4; the precession bearing seat 20 is mounted on a ship base 21. The gradient composite flywheel rotor 3 is sleeved on the flywheel rotor shaft 6 and preferably shares the same flywheel rotor shaft 6 with the rotor of the permanent magnet synchronous motor 5 to form a coaxial rigid connection, thereby constituting a coaxial integrated rotating structure, which helps to reduce the additional losses and structural complexity caused by intermediate transmission links, and improves the overall compactness and high-speed operation stability of the system.

[0025] The flywheel rotor shaft 6 is supported and suspended by active magnetic levitation bearings. These active magnetic levitation bearings are distributed along the axial direction of the flywheel rotor shaft 6 and include a lower radial magnetic levitation bearing 2 located at the lower part of the flywheel rotor shaft 6, an upper radial magnetic levitation bearing 17 located at the upper part of the shaft, and an axial magnetic levitation bearing 18 located in the axial direction. These bearings provide active radial and axial suspension support for the flywheel rotor shaft 6. The protective bearings include a lower protective bearing 1 and an upper protective bearing 19, which provide mechanical support in case of failure of the active magnetic levitation bearings or abnormal displacement of the flywheel rotor shaft 6. With this structure, the gradient composite flywheel rotor 3 can achieve low-resistance rotation within the vacuum chamber 4 and maintain stable operation under the support of the active magnetic levitation bearings.

[0026] Figure 1 The dashed line represents the control and signal acquisition circuit 12, which is used to acquire, condition and transmit signals from the ship attitude sensor 16, flywheel rotor displacement sensor, speed sensor, precession shaft angle and angular velocity sensor, permanent magnet synchronous motor electrical quantity sensor and ship power grid electrical measurement unit, and to realize control and signal interaction between the cooperative controller 15 and the bidirectional converter 9, active magnetic levitation bearing and precession motor 14.

[0027] Preferably, the active magnetic levitation bearing includes a set of upper radial magnetic levitation bearings 17, a set of lower radial magnetic levitation bearings 2, and an axial magnetic levitation bearing 18. The upper radial magnetic levitation bearings 17 and lower radial magnetic levitation bearings 2 are used to provide active levitation control in two radial directions, respectively, and the axial magnetic levitation bearing 18 is used to provide active levitation control in the axial direction, thereby constituting a five-degree-of-freedom active levitation control. Through the above-mentioned five-degree-of-freedom active levitation support, the flywheel rotor shaft 6 can maintain a stable levitation state during high-speed rotation, while the lower protective bearing 1 and the upper protective bearing 19 provide fault protection under abnormal working conditions.

[0028] Furthermore, in a specific embodiment, the upper and lower radial magnetic levitation bearings can adopt an 8-tooth structure, with a single-sided air gap of approximately 1 mm, an outer core diameter of approximately 300 mm, an inner core diameter of approximately 152 mm, and a stack thickness of approximately 120 mm; the rotor force-bearing surface diameter of the axial magnetic levitation bearing 18 can be approximately 130 mm, and the structural air gap can be approximately 2 mm; the bottom axial support can adopt a coil electromagnet structure, and the force-bearing plate diameter can be approximately 140 mm.

[0029] In one specific embodiment, when the rotor's self-weight is approximately 190 kg, the continuous support force provided by the axial magnetic levitation bearing 18 under normal levitation conditions can be approximately 2100 N, in order to meet the rotor's stable levitation requirements.

[0030] Furthermore, considering the requirements for marine impact, attitude disturbance, and engineering safety margin, the radial load capacity of the magnetic levitation bearing can be no less than 16,000 N, the axial short-time peak load capacity can be no less than 16,000 N, and the control current range can be 0 to 10 A.

[0031] The bidirectional power conversion module connects the permanent magnet synchronous motor 5 and the ship's electrical grid 11 to achieve bidirectional energy conversion. Preferably, the bidirectional power conversion module includes a bidirectional converter 9, a power drive unit, a voltage and current detection unit, a filtering unit, and an interface unit. The bidirectional converter 9 is used to convert electrical energy into its form, the power drive unit is used to drive power switching devices, the voltage and current detection unit is used to collect electrical quantities on the motor side and the power grid side, the filtering unit is used to suppress current harmonics and electromagnetic interference, and the interface unit is used to achieve electrical connection with the permanent magnet synchronous motor 5 and the ship's electrical grid 11.

[0032] In one specific embodiment, when connected to the ship's AC bus, the bidirectional power conversion module can adopt a back-to-back bidirectional pulse width modulation converter structure, including a grid-side converter, a machine-side converter, and a DC bus, to realize bidirectional energy transfer between the AC grid, the permanent magnet synchronous motor 5, and the DC bus. The power switching device can be an insulated gate bipolar transistor (IGBT) or a silicon carbide metal oxide semiconductor field-effect transistor (SiC MOSFET), with a switching frequency of 5kHz to 20kHz, and a bidirectional energy exchange power of, for example, 20 kW, or configured to 20 kW to 40 kW depending on the ship's grid requirements. When the system is in energy storage mode, the bidirectional converter 9 drives the permanent magnet synchronous motor 5 to operate in motor mode, causing the flywheel rotor 3 to accelerate and store energy; when the system is in energy release mode, the permanent magnet synchronous motor 5 operates in generator mode, outputting electrical energy to the ship's grid 11 via the bidirectional converter 9.

[0033] When connected to the ship's DC bus, the bidirectional power conversion module adopts an AC / DC bidirectional pulse width modulation converter structure to realize bidirectional energy exchange between the permanent magnet synchronous motor 5 and the ship's DC power grid. Through the above-mentioned bidirectional power conversion module, the flywheel energy storage unit can realize energy storage, energy release, and power exchange with the ship's power grid under the same electromechanical interface.

[0034] The stator of the permanent magnet synchronous motor 5 is connected to the bidirectional converter 9 via the permanent magnet synchronous motor drive interface 8, and the bidirectional converter 9 is then connected to the ship's power grid 11 via the grid connection interface 10. The bidirectional converter 9 is used to realize bidirectional energy conversion between the permanent magnet synchronous motor 5 and the ship's power grid 11: when the system is in energy storage mode, the bidirectional converter 9 controls the permanent magnet synchronous motor 5 to operate in motoring mode, causing the flywheel rotor 3 to accelerate and store energy; when the system is in energy release mode, the bidirectional converter 9 controls the permanent magnet synchronous motor 5 to operate in generating mode, converting the rotational mechanical energy of the flywheel rotor 3 into electrical energy and feeding it back to the ship's power grid 11. Preferably, the bidirectional power conversion module is configured for adaptability according to the ship's power grid type: when connected to the ship's AC bus, it is a back-to-back bidirectional pulse width modulation converter structure; when connected to the ship's DC bus, it is an AC / DC bidirectional pulse width modulation converter structure. Through the above methods, the present invention can realize bidirectional energy transmission between the permanent magnet synchronous motor 5 and different types of ship power grids. Through the aforementioned bidirectional power conversion module, the flywheel energy storage unit can realize energy storage, energy release, and power exchange with the ship's electrical grid under the same electromechanical interface, thus integrating it with the roll reduction function into the same flywheel system.

[0035] In one specific embodiment, the permanent magnet synchronous motor 5 can adopt a 24-slot, 4-pole structure, i.e., 2 pole pairs; the winding configuration can be Y-connected, and 4 parallel branches can be set, with 25 turns per winding and 7 parallel windings; the bare wire diameter is approximately 0.57 mm, and the cooling method can be water cooling. Its stator core outer diameter can be approximately 164 mm, stator core inner diameter approximately 85 mm, rotor core outer diameter approximately 79.4 mm, rotor core inner diameter approximately 40 mm, stator and rotor core lengths approximately 40 mm, and minimum air gap length approximately 2.8 mm. The magnet material can be N42EH. In one specific embodiment, the permanent magnet synchronous motor 5 can operate at 30,000 rpm and is suitable for high-speed drive / generation scenarios of 20 kW to 40 kW; its rated operating point can be located in the high-efficiency operating range, with an efficiency of over 98%, and a rated voltage level of 300 V to 800 V.

[0036] The precession actuator includes a precession bearing housing 20, at least one precession shaft 13, and a precession motor 14. The magnetic levitation flywheel energy storage unit is integrally mounted on the precession bearing housing 20. The precession bearing housing 20 is connected to the hull structure via the precession shaft 13 and is driven by the precession motor 14, causing the entire magnetic levitation flywheel energy storage unit to undergo controlled deflection around an axis parallel to the ship's transverse axis. This changes the direction of the flywheel's angular momentum and generates a gyroscopic torque to resist the ship's roll. Since the gradient composite flywheel rotor 3 is in a high-speed rotating state, when the precession motor 14 drives the precession bearing housing 20 to precess, causing the flywheel housing 7 and its internal magnetic levitation flywheel energy storage unit to precess, the direction of the gradient composite flywheel rotor 3 changes accordingly, thereby generating a gyroscopic torque to resist the ship's roll and achieving the ship's roll reduction function. Therefore, the flywheel speed regulation is mainly used to regulate the flywheel energy storage state and exchange power with the ship's electrical grid, while the precession actuator is mainly used to output the gyro torque required for roll reduction, so that the roll reduction function and the energy storage function can be divided and coordinated in the same flywheel unit.

[0037] Preferably, the precession motor 14 is a servo motor, torque motor or brushless DC motor, and is connected to the precession shaft 13 through a reduction mechanism or direct drive.

[0038] In one specific embodiment, the sensing and monitoring network includes a control and signal acquisition circuit 12 and a ship attitude sensor 16, which are used to acquire in real time ship motion status signals, flywheel rotor operating status signals, system electrical status signals, ship power grid status signals, and precession shaft angle and angular velocity signals.

[0039] Furthermore, the sensing and monitoring network may include:

[0040] Ship attitude sensor 16 or inertial measurement unit, installed on the hull or flywheel mounting base, is used to monitor the ship's roll angle and roll rate, and its measurement accuracy can be better than ±0.1°.

[0041] The displacement sensor installed at the corresponding measuring point on the flywheel rotor shaft 6 is used to monitor the radial and axial displacement of the flywheel rotor. It can be an eddy current displacement sensor.

[0042] A speed sensor installed at the end of the flywheel shaft or at a part that rotates synchronously with the shaft to monitor the speed of the flywheel rotor can be a photoelectric encoder or a magnetic encoder.

[0043] A sensor installed on the precession shaft 13 or the precession bearing housing 20 for monitoring the angle and angular velocity of the precession shaft, which may be an absolute encoder;

[0044] Sensors are installed on the 5th side of the permanent magnet synchronous motor to monitor the electrical quantities of the motor; and electrical measurement units are installed on the ship's power grid interface side to monitor the voltage, current, frequency or DC bus voltage of the ship's power grid.

[0045] The aforementioned signals are acquired, conditioned, and transmitted by the control and signal acquisition circuit 12 and then input to the collaborative controller 15, serving as the basis for the collaborative controller 15 to perform status judgment and operation control.

[0046] Preferably, the sampling frequency of the control and signal acquisition circuit 12 can be 1 kHz to 10 kHz, and includes an anti-aliasing filter unit and a digital filtering processing unit.

[0047] The collaborative controller 15 is connected to the control and signal acquisition circuit 12, the bidirectional converter 9, the active magnetic levitation bearing, and the precession motor 14. Preferably, the hardware core of the collaborative controller 15 can be a multi-core DSP or FPGA chip. Based on real-time signals collected by the sensing and monitoring network, the collaborative controller 15 comprehensively judges the flywheel operating status, the ship's attitude status, and the ship's electrical grid status, and generates flywheel speed adjustment commands and precession control commands. Among them, the flywheel speed adjustment command is executed by controlling the electromagnetic torque of the permanent magnet synchronous motor 5 through the bidirectional converter 9 to adjust the angular velocity of the gradient composite flywheel rotor 3, realizing power exchange between energy storage and the ship's electrical grid 11; the precession control command is executed by driving the precession motor 14 to control the precession bearing seat 20 to drive the flywheel shell 7 and its internal magnetic levitation flywheel energy storage unit to deflect around the precession shaft 13, so that the magnetic levitation flywheel energy storage unit outputs gyroscopic torque to resist the ship's roll. Therefore, in this invention, flywheel speed regulation is mainly used to achieve energy storage and power exchange with the power grid, while the precession actuator is mainly used to output the gyroscopic torque required for roll reduction. This allows the roll reduction function and energy storage function to work in a coordinated manner through physical mechanisms and control processes. Furthermore, the coordination controller 15 coordinates the flywheel speed regulation and precession control actions, enabling the flywheel energy storage unit to maintain its roll reduction torque output capability while exchanging energy, thereby improving the system's overall adaptability under complex sea conditions and complex power consumption conditions.

[0048] In one specific embodiment, the cooperative controller 15 or the bidirectional converter 9 is equipped with a grid support control function, which may include a virtual synchronous machine control function. When the ship's power grid 11 is an AC system and its frequency fluctuates, the system can adjust the active power output of the flywheel energy storage unit according to the grid frequency change, making it exhibit equivalent inertia response and damping support characteristics, and quickly inject active power when the grid frequency drops to provide inertia support. When the ship's power grid 11 is a DC system, the system can respond to the DC bus voltage deviation and quickly adjust the charging and discharging power of the flywheel energy storage unit to provide voltage support. At the same time, the cooperative controller 15 coordinates the flywheel power regulation and precession control actions to reduce the impact of the additional gyroscopic torque caused by power exchange on the ship's roll control. Through the above settings, the present invention can not only realize ship roll reduction and flywheel energy storage, but also achieve active support for the ship's power grid 11.

[0049] In one specific embodiment, the cooperative controller 15 has at least the following operating modes: a roll reduction mode primarily focused on suppressing ship roll, an energy storage mode primarily focused on achieving flywheel energy storage and ship power grid support, and a cooperative mode that coordinates roll reduction and ship power grid requirements. These modes can be switched automatically or manually depending on the operating conditions. In the roll reduction mode, the system primarily uses precession control, outputting the gyroscopic torque required for roll reduction through the precession actuator. In the energy storage mode, the system primarily uses flywheel speed regulation and power exchange to achieve energy storage and ship power grid support. In the cooperative mode, the cooperative controller 15 simultaneously coordinates flywheel speed regulation and precession control to balance roll reduction and ship power grid requirements.

[0050] like Figure 2 As shown, the gradient composite flywheel rotor 3 is mounted on the flywheel rotor shaft 6 and includes an inner flywheel rotor layer 31 and an outer flywheel rotor layer 32. The inner flywheel rotor layer 31 can be made of high-strength alloy steel to provide structural strength; the outer flywheel rotor layer 32 can be made of carbon fiber composite inertia ring to improve the flywheel rotor's angular momentum reserve. The inner flywheel rotor layer 31 and the outer flywheel rotor layer 32 form a discrete gradient structure through an interference fit. Here, "discrete gradient structure" refers to a composite rotor structure composed of layers of different materials, with each layer distributed radially according to its function, making the stress distribution of the flywheel rotor tend to be uniform under high-speed rotation conditions, thus balancing high-speed operation capability and large angular momentum output capability. The flywheel rotor shaft 6, the inner flywheel rotor layer 31, and the outer flywheel rotor layer 32 together constitute a unified flywheel rotating body.

[0051] In one specific embodiment, the integrated roll reduction and energy storage magnetic levitation flywheel system of the present invention is applicable to small surface vessels with a gross tonnage of approximately 50 tons. The typical dimensions of the vessels it is suited for are: length 18–22 m, beam 4.8–5.4 m, and draft 0.8–1.1 m. Addressing the application scenarios where such vessels are susceptible to significant roll due to cross waves during low-to-medium speed operations, near-shore operations, and navigation within harbors, the present invention achieves integrated roll reduction and energy storage functions through a vertically arranged magnetic levitation flywheel system. The overall height of the system can be 1.0–1.3 m, the bottom mounting width can be 0.9–1.0 m, and the flywheel body's outer diameter can be 0.9–1.0 m. In a specific structural design, the overall height can be approximately 1.26 m, the base width can be approximately 0.95 m, and the flywheel body's lateral dimension can be approximately 0.96 m. The applicable vessel roll period can be 4–8 s. The above-mentioned ship type compatibility range and structural dimensions indicate that the system described in this invention not only has the functional characteristics of integrated roll reduction and energy storage, but also has the structural feasibility for engineering applications in small and medium-sized new energy ships.

[0052] Under typical operating conditions, when the aforementioned 50-ton ship rolls in cross waves, the ship attitude sensor 16 detects that the roll angle amplitude has reached a preset range. The coordinating controller 15 drives the precession actuator to induce controlled precession of the magnetic levitation flywheel energy storage unit, outputting a gyroscopic torque opposite to the ship's roll direction, thereby reducing the ship's roll amplitude. Simultaneously, when the load on the ship's power grid 11 changes, the coordinating controller 15 controls the permanent magnet synchronous motor 5 to operate in either motoring or generating mode via the bidirectional converter 9, ensuring the flywheel maintains system stability while absorbing or releasing energy. This achieves coordinated unity of roll reduction, energy storage, and grid support within the same flywheel unit. Based on engineering design goals, the roll reduction amplitude attenuation can be no less than 60%. Therefore, it is evident that within the same flywheel unit, the roll reduction torque output, flywheel energy storage, and ship-grid power exchange can operate collaboratively under typical operating conditions, demonstrating the comprehensive application effect of the integrated roll reduction and energy storage system of this invention.

[0053] In one embodiment, the control process of the present invention may include: acquiring ship motion status signals, flywheel rotor operating status signals, system electrical status signals, ship power grid status signals, and precession shaft angle and angular velocity signals through a sensing and monitoring network; the cooperative controller 15 generates flywheel speed adjustment commands and precession control commands based on the acquired signals; controlling the electromagnetic torque of the permanent magnet synchronous motor 5 through a bidirectional power conversion module to execute the flywheel speed adjustment commands and realize energy exchange between the magnetic levitation flywheel energy storage unit and the ship power grid 11; simultaneously, by driving the precession motor 14 to execute the precession control commands, the magnetic levitation flywheel energy storage unit generates gyroscopic torque to resist ship roll; throughout the control process, flywheel speed adjustment is used to realize energy storage and power exchange with the power grid, and precession control is used to generate anti-roll gyroscopic torque.

[0054] In summary, in this embodiment, by combining a vertically structured magnetic levitation flywheel energy storage unit, a bidirectional power conversion module, a precession actuator, a sensing and monitoring network, and a cooperative controller, the same flywheel system simultaneously possesses the functions of ship roll reduction, flywheel energy storage, and ship power grid support. Specifically, by using flywheel speed regulation for energy storage and power grid exchange, and using precession control for roll reduction torque output, the roll reduction and energy storage functions are coordinated and integrated within the same flywheel unit, thereby improving the overall operational performance of the system under complex sea conditions and complex power consumption conditions.

Claims

1. A magnetic levitation flywheel system integrating anti-sway and energy storage, characterized in that, The system comprises a magnetic levitation flywheel energy storage unit, a bidirectional power conversion module, a precession actuator, and a cooperative controller. The magnetic levitation flywheel energy storage unit has a vertical structure, including a vacuum chamber, a gradient composite flywheel rotor housed within the vacuum chamber, a flywheel rotor shaft, a permanent magnet synchronous motor, and an active magnetic levitation bearing. The gradient composite flywheel rotor is mounted on the flywheel rotor shaft and rigidly connected coaxially to the rotor of the permanent magnet synchronous motor. The flywheel rotor shaft is supported and suspended by the active magnetic levitation bearing. The permanent magnet synchronous motor is connected to the ship's electrical grid via the bidirectional power conversion module. The magnetic levitation flywheel energy storage unit is mounted on the precession actuator, which drives the entire magnetic levitation flywheel energy storage unit to perform controlled deflection around an axis parallel to the ship's transverse axis, thereby changing the flywheel's angular momentum direction and generating a gyroscopic torque to resist the ship's roll. The cooperative controller is connected to the bidirectional power conversion module, the active magnetic levitation bearing, and the precession actuator. It also includes a sensing and monitoring network, which includes ship attitude sensors, flywheel rotor displacement sensors, speed sensors, precession shaft angle and angular velocity sensors, permanent magnet synchronous motor electrical quantity sensors, and ship electrical grid measurement units. Each sensor is connected to a co-controller. The cooperative controller has multiple operating modes, including at least a roll reduction mode primarily for suppressing ship roll, an energy storage mode primarily for achieving flywheel energy storage and ship power grid support, and a cooperative operating mode that balances ship roll reduction and flywheel energy storage. The cooperative controller is used to switch between different operating modes based on the ship's motion state, flywheel operating state, and ship power grid state signals, and to generate corresponding flywheel speed adjustment commands and precession control commands.

2. The magnetic levitation flywheel system integrating anti-sway and energy storage according to claim 1, characterized in that, The active magnetic levitation bearing includes a set of upper radial magnetic levitation bearings, a set of lower radial magnetic levitation bearings, and an axial magnetic levitation bearing. The upper and lower radial magnetic levitation bearings are used to provide active levitation control in two radial directions, respectively, and the axial magnetic levitation bearing is used to provide active levitation control in the axial direction, thereby constituting a five-degree-of-freedom active levitation control.

3. The magnetic levitation flywheel system integrating anti-sway and energy storage according to claim 1, characterized in that, The gradient composite flywheel rotor comprises an inner layer of high-strength alloy steel and an outer layer of carbon fiber composite material inertial ring, which are formed by interference fit to create a discrete gradient structure.

4. The magnetic levitation flywheel system integrating anti-sway and energy storage according to claim 1, characterized in that, The bidirectional power conversion module is a back-to-back bidirectional PWM converter used to connect to the ship's AC bus.

5. A magnetic levitation flywheel system integrating anti-sway and energy storage according to claim 1, characterized in that, The bidirectional power conversion module is an AC / DC bidirectional PWM converter used to connect to the ship's DC bus.

6. The magnetic levitation flywheel system integrating anti-sway and energy storage according to claim 1, characterized in that, The precession actuator includes a precession bearing housing, at least one precession shaft, and a precession motor; the magnetic levitation flywheel energy storage unit is integrally mounted on the precession bearing housing, which is connected to the hull structure via the precession shaft and driven by the precession motor.

7. A magnetic levitation flywheel system integrating anti-sway and energy storage according to claim 6, characterized in that, The precession motor is a servo motor, torque motor, or brushless DC motor, and is connected to the precession shaft through a reduction mechanism or direct drive.

8. The magnetic levitation flywheel system integrating anti-sway and energy storage according to claim 1, characterized in that, The cooperative controller or bidirectional power conversion module is equipped with a grid support control function. The grid support control function is used to adjust the active power output of the flywheel energy storage unit when the frequency of the ship's AC grid fluctuates, so that the system exhibits equivalent inertia response and damping support characteristics, or to adjust the charging and discharging power of the flywheel energy storage unit to provide voltage support when the voltage of the ship's DC grid deviates.

Images