Driving system for improving dynamic response performance of rotary drum sail and control method

Abstract

The invention relates to the technical field of ship energy conservation and electrical control, in particular to a driving system and a control method for improving the dynamic response performance of a rotary drum sail, the driving system takes a direct current bus as a hub, is connected with a main driving loop, an energy adjusting loop and a safe energy consumption loop in parallel, and shares a ship power grid and a rectification unit; and a storage battery pack energy storage unit and a bidirectional DC / DC converter are matched, so that integration of power supply, energy recovery and overvoltage protection is realized. According to the control method, the logic of'monitoring start-mode decision-state check-dynamic regulation-closed loop 'is adopted, and through accurate judgment of charge capacity and direct-current bus voltage, combined power supply of the power grid and the energy storage unit and braking kinetic energy recovery and reuse are achieved. According to the method, the problem of dynamic response hysteresis of the large-inertia rotating cylinder caused by ship power grid power limitation is effectively solved, the wind energy capturing efficiency and the overall energy efficiency of the system are remarkably improved, and meanwhile the equipment cost and the operation energy consumption are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ship energy saving and electrical control, in particular to a driving system and control method for improving dynamic response performance of a rotating cylinder wind sail. BACKGROUND

[0002] As a wind energy auxiliary propulsion device that utilizes the Magnus Effect to generate propulsion force, the rotating cylinder wind sail (Flettner Rotor) has received widespread attention in the field of ship energy saving and emission reduction in recent years. The basic principle is that when a cylindrical rotor rotates at high speed around the axis, a pressure difference is generated due to the surface speed difference under the action of airflow, forming a lift force perpendicular to the incoming flow direction. The component of this lift force along the ship's heading can assist the main propulsion system, thereby achieving fuel saving. The increasingly stringent requirements of the International Maritime Organization (IMO) on ship carbon emissions, as well as the continuous rise in fuel costs, have further promoted the commercial application of rotating cylinder wind sail technology. It has been proven that the installation of a rotating cylinder wind sail system on an ocean-going cargo ship can achieve an average fuel saving effect of 5% to 30%, with significant economic and environmental benefits.

[0003] However, the actual operational efficiency of the rotating cylinder wind sail is highly dependent on its dynamic response performance, i.e., the ability to quickly adjust the rotor speed according to real-time changes in wind speed and direction. In an ideal state, the system should be able to quickly increase the speed to capture peak wind energy when a gust arrives, and quickly reduce the speed to avoid energy waste when the wind condition weakens. However, there is a fundamental contradiction in practical applications: to generate sufficient thrust, commercial rotating cylinder wind sails are usually designed to be very large, with the rotating parts (rotors) having very high rotational inertia. According to the principles of mechanics, driving a large inertia load to achieve high angular acceleration requires extremely large instantaneous torque, which in turn requires the driving motor to output peak power several times its rated power. As an independent running limited capacity power grid, the design capacity of the ship power system mainly meets the needs of conventional loads, and it is usually difficult to withstand the huge power impact caused by the simultaneous rapid acceleration of multiple rotating cylinder wind sails. Therefore, the existing rotating cylinder wind sail driving systems generally have serious dynamic response lag, and it often takes several minutes or even more than ten minutes to accelerate from static to rated speed. This slow response makes the system unable to effectively track ocean gusts with a duration of several minutes, resulting in a large amount of wind energy not being captured in time, causing wind energy loss and severely restricting the fuel saving potential of the rotating cylinder wind sail.

[0004] Furthermore, insufficient dynamic response also brings the risk of mechanical resonance and challenges in energy recovery. Large rotating drums need to pass through one or more structural resonance speed points during acceleration. If they remain in the resonance zone for too long, even minor imbalances can be amplified, causing severe tower vibrations and threatening equipment safety. Ideally, they should quickly pass through the resonance zone with sufficiently high angular acceleration, but this is precisely limited by the instantaneous power output capability of the drive system. On the other hand, during deceleration or braking, the enormous rotational kinetic energy stored in the drum is usually dissipated as heat through energy-consuming braking resistors. This not only wastes energy but also requires a large cooling system, increasing equipment size, weight, safety hazards, and maintenance costs.

[0005] To optimize the operating efficiency of rotary sails, existing patent CN117864366A discloses a marine rotary sail system based on an energy storage device. This system acquires navigation information such as wind speed, wind direction, ship speed, and rotary sail rotation speed through a data acquisition unit, and an analysis unit determines whether to adjust engine power or the rotation speed of each rotary sail based on preset judgment logic, aiming to improve wind energy utilization. The core of this patent lies in optimizing and adjusting the system under steady-state or quasi-steady-state conditions through logical judgment and feedback control. However, this solution has significant limitations: First, its energy storage unit is only used to store the electrical energy used to drive the power unit, and it does not design an acceleration power compensation mechanism for the large inertia characteristics of the rotary sail, thus failing to overcome the instantaneous power limit of the ship's electrical grid and failing to solve the core pain point of dynamic response lag. Second, the solution does not consider the mechanical resonance characteristics of the rotary sail and does not design a control strategy for rapid passage through the resonance zone, thus failing to avoid the equipment safety risks caused by vibration accumulation. Third, its braking energy recovery is only simple storage and does not form a closed-loop utilization mechanism of "energy storage-acceleration-recovery". The recovered energy cannot be efficiently reused in the rotary start-up or acceleration process, resulting in limited energy utilization efficiency. Fourth, the solution does not address the impact suppression of the instantaneous high power on the ship's electrical grid during rotary acceleration, lacks corresponding power buffer design, and is difficult to adapt to the actual application scenarios of multi-rotor configurations.

[0006] Existing patent CN110544971A discloses a control system and method for regenerative braking energy of ships. It employs a hybrid energy storage architecture of supercapacitors and batteries, connecting to a DC bus via two bidirectional DC / DC converters. Utilizing an energy distribution module with a low-pass filter, it allocates the high-frequency and low-frequency components of braking energy based on the remaining charge of the energy storage unit, achieving full absorption and storage of braking energy and solving the problem of insufficient utilization of ship braking energy. However, this solution differs fundamentally from the core requirements of a rotary sail propulsion system: First, its application scenario is the overall recovery of ship braking energy, not the dynamic response optimization of a rotary sail propulsion system. It lacks a power compensation mechanism designed for the large inertia acceleration requirements of the rotary sail, failing to meet the rapid speed adjustment needs in gust winds. Second, its energy distribution logic only addresses the decomposition and storage of braking energy; the recovered energy cannot be efficiently reused for rotary sail startup or resonance zone crossing processes. Finally, this solution does not consider the mechanical resonance characteristics of the rotary sail, lacks a targeted rapid crossing control strategy, cannot guarantee the safe operation of the rotary sail, and does not address the issue of grid impact suppression.

[0007] Therefore, a completely new system architecture and control method is urgently needed to achieve rapid dynamic response of small-capacity grids driving large-inertia loads, while solving problems such as safe crossing of the resonance zone, grid impact suppression and closed-loop utilization of braking energy, thereby improving wind energy capture efficiency, reducing equipment costs and operating energy consumption, ensuring long-term stable operation of equipment, further releasing the energy-saving potential of rotary sail technology, and promoting its large-scale and efficient application in the shipping industry. Summary of the Invention

[0008] In view of this, the present invention aims to propose a drive system and control method to improve the dynamic response performance of rotary sails, so as to solve the problems in the prior art of low wind energy capture efficiency caused by the sluggish dynamic response of large inertia rotary sails, equipment safety hazards caused by difficulty in crossing the resonance zone, impact on the ship's power grid caused by high power start-up, and serious waste of braking energy.

[0009] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0010] This invention discloses a drive system for improving the dynamic response performance of a rotary sail, comprising:

[0011] Main drive circuit: It consists of the ship's electrical grid, rectifier unit, DC bus, inverter unit and drive unit connected together;

[0012] Energy regulation circuit: It consists of a shipboard electrical grid, a rectifier unit, a DC bus, a bidirectional power conversion unit, and an energy storage unit.

[0013] Safety energy consumption circuit: It consists of the ship's electrical grid, rectifier unit, DC bus, control components and energy consumption unit connected together.

[0014] Furthermore, the main drive circuit, energy regulation circuit, and safety energy consumption circuit are connected in parallel with the DC bus as the common coupling point, and share the ship's power grid and rectifier unit.

[0015] Furthermore, the drive unit in the drive system is a drive motor; the bidirectional power conversion unit is a bidirectional DC / DC converter; the energy storage unit is a battery pack; the control component is a braking resistor switch; and the energy dissipation unit is a braking resistor.

[0016] Furthermore, the drive system also includes a controller, which is communicatively connected to the main drive circuit, the energy regulation circuit, and the safety energy dissipation circuit.

[0017] Furthermore, the controller can control the operating mode of the bidirectional DC / DC converter.

[0018] This invention also discloses a control method for improving the dynamic response performance of a rotary sail, applied to the aforementioned drive system. The control method includes:

[0019] S1 rotary drum start command listening and initial flow splitting:

[0020] The controller continuously listens for the rotary drum start command;

[0021] S2 Startup Mode Decision:

[0022] The controller determines whether a rapid start-up is needed based on real-time operating conditions;

[0023] S3 Battery Pack Status Check and Joint Start-up Determination:

[0024] If a fast start is required and the battery pack's charge capacity is greater than or equal to the first threshold, the bidirectional DC / DC converter is switched to discharge mode, allowing the battery pack and the ship's electrical grid to jointly supply power to the DC bus; if a fast start is not required or the battery pack's charge capacity is less than the first threshold, the ship's electrical grid supplies power to the DC bus only through the rectifier unit.

[0025] S4 Steady-State Operation and Dynamic Energy Management:

[0026] Monitoring DC bus 3 voltage V bus When V bus Exceeding the recycling threshold V 回收阈值 If the battery pack's charge capacity is less than the second threshold, the bidirectional DC / DC converter is switched to charging mode for energy recovery; if the battery pack's charge capacity is greater than or equal to the second threshold, then V is compared. bus and braking threshold V 制动阈值， Determine whether to connect to a safe energy consumption circuit;

[0027] S5 Standby / Charging Mode Management:

[0028] When the drive system is in standby mode, if the battery pack charge capacity is less than or equal to the second threshold, the bidirectional DC / DC converter is controlled to switch to charging mode to charge the battery using the surplus power of the ship's power grid.

[0029] S6 closed-loop control.

[0030] Furthermore, in step S1, if the controller does not receive a start command, it will directly jump to step S5 to enter standby / charging mode management; if it receives a start command, it will enter step S2 to make a detailed decision on the start mode.

[0031] Furthermore, in step S2, the actual operating conditions include, but are not limited to, the rate of change of wind speed, the rate of change of wind direction, and the actual rotational speed of the vortex drum.

[0032] Furthermore, in step S4, V bus Greater than or equal to the braking threshold V 制动阈值 The controller immediately activates the braking resistor switch, connecting the safety energy dissipation circuit to the drive system; if V bus Less than or equal to V 制动阈值 If so, no intervention is needed.

[0033] Furthermore, in step S6, after completing the control flow under any working condition, the drive system returns to the initial state and restarts the rotary drum start command listening and initial diversion in step S1.

[0034] Compared with existing technologies, the drive system and control method for improving the dynamic response performance of rotary sails described in this invention have the following advantages:

[0035] (1) Significantly improved dynamic response performance: With the help of the combined power supply mode of "ship power grid + hybrid energy storage", the instantaneous peak power required for the start-up, acceleration and resonance crossing of the large inertia rotary drum can be quickly replenished, the start-up time of the rotary drum is greatly shortened, and it can quickly cross the resonance zone with high angular acceleration, effectively capturing the energy of short-term ocean gusts and fully releasing the energy-saving potential of the rotary drum sail.

[0036] (2) Closed-loop and efficient energy utilization: The drive system recovers the rotational kinetic energy generated during the deceleration and braking of the drum into the battery pack through a bidirectional DC / DC converter, and releases it again for driving when needed. This forms an energy closed loop of "recovery-storage-reuse", which significantly reduces the energy waste caused by traditional energy-consuming braking and improves the overall energy efficiency;

[0037] (3) Reduce equipment cost and weight: Since the peak power of the ship's power grid is assisted by the battery pack, the rated capacity of the rectifier and the cable can be appropriately reduced during the design and selection, so as to achieve "small horse pulling a big cart" and reduce the initial investment cost; and the three circuits share the ship's power grid and rectifier unit with the DC bus as the common hub, reducing redundant structure and saving equipment volume, weight and cost.

[0038] (4) High reliability and redundancy: A dual overvoltage protection mechanism of "battery absorption as the main method and resistance dissipation as the auxiliary method" is formed, which greatly improves the safety of the system under extreme conditions. Attached Figure Description

[0039] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0040] Figure 1 This is a schematic diagram of the circuit topology of the drive system described in this invention;

[0041] Figure 2 This is a logic flowchart of the control method described in this invention.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1. Shipboard electrical grid; 2. Rectifier unit; 3. DC bus; 4. Inverter unit; 5. Bidirectional DC / DC converter; 6. Braking resistor switch; 7. Drive motor; 8. Battery pack; 9. Braking resistor; 10. Controller. Detailed Implementation

[0044] This invention provides a drive system for improving the dynamic response performance of a rotary sail, comprising:

[0045] Main drive circuit: It consists of the ship's electrical grid 1, rectifier unit 2, DC bus 3, inverter unit 4 and drive unit connected together;

[0046] Energy regulation circuit: It consists of a shipboard power grid 1, a rectifier unit 2, a DC bus 3, a bidirectional power conversion unit, and an energy storage unit.

[0047] Safety energy consumption circuit: It consists of ship electrical grid 1, rectifier unit 2, DC bus 3, control components and energy consumption unit connected together.

[0048] More specifically, in the main drive circuit, the initial AC power is provided by the ship's electrical grid 1, which is converted into DC power by the rectifier unit 2 and then collected on the DC bus 3. The input terminal of the inverter unit 4 is connected to the DC bus 3, which inverts the DC power into AC power with adjustable voltage and frequency to drive the drive unit located inside the rotating drum, thereby controlling the rotation speed of the rotating drum. The core components of the energy regulation circuit are the bidirectional power conversion unit and the energy storage unit, which are connected in series. Their core function is to realize the bidirectional and controllable flow of energy. When the rotating drum needs to accelerate rapidly, the bidirectional power conversion unit switches the discharge mode. The energy stored in the energy storage unit is quickly injected into the DC bus 3 to provide instantaneous power compensation. When the drum brakes or there is excess energy, the bidirectional power conversion unit switches the charging mode to store the feedback energy on the DC bus 3 into the energy storage unit to achieve energy recovery. In the safety energy dissipation circuit, the energy dissipation unit is connected in parallel to the DC bus 3 through the control component. When the voltage of the DC bus 3 exceeds the safety threshold due to abnormal conditions, the controller 10 will quickly connect the safety energy dissipation circuit to the drive system through the control component to guide the excess energy to dissipate in other forms through the energy dissipation unit, preventing the drive system from being damaged by overvoltage.

[0049] The drive system of this invention constructs an integrated solution for energy supply, dynamic adjustment and safety protection through the parallel architecture and coordinated control of three loops. It effectively solves the core problem of dynamic response hysteresis of large inertia rotary sails, while taking into account energy recovery and system safety.

[0050] Specifically, the main drive circuit, energy regulation circuit, and safety energy consumption circuit are connected in parallel with DC bus 3 as the common coupling point, and share the ship's power grid 1 and rectifier unit 2.

[0051] More specifically, the ship's electrical grid 1 is connected to the input of rectifier unit 2, supplying AC power to it. It serves as the main AC power source for the drive system, providing initial AC power for the entire system and also acting as the charging power source for the energy storage unit in standby / charging mode. Rectifier unit 2 is an AC / DC converter interface, with its input connected to ship's electrical grid 1 and its output connected to DC bus 3. Its core function is to convert the AC power from ship's electrical grid 1 into stable DC power, providing continuous DC power support to DC bus 3. DC bus 3 is the DC common coupling point and energy hub of the drive system. It is connected in parallel with the input of inverter unit 4, one end of the bidirectional power conversion unit, and one end of the control components. DC bus 3 is responsible for collecting the output power of rectifier unit 2 and distributing it to components such as inverter unit 4 and the bidirectional power conversion unit, while also carrying feedback energy during braking / regeneration operations.

[0052] It should be noted that the inverter unit 4 is the core of the DC / AC conversion. Its input end is connected to the DC bus 3, and its output end is connected to the drive unit. The inverter unit 4 converts the DC power from the DC bus 3 into AC power with adjustable voltage and frequency, and applies it to the drive unit to achieve precise control of the rotation speed and torque of the rotating drum, adapting to the power requirements of different working conditions of the rotating drum.

[0053] Preferably, the rectifier unit 2 adopts a three-phase bridge uncontrolled rectifier or a thyristor rectifier capable of high-precision voltage regulation; the DC bus 3 adopts a low-impedance copper bus or a high-voltage insulated cable, and the surface is treated with anti-salt spray and anti-vibration insulation protection; the inverter unit 4 adopts an IGBT three-phase bridge inverter, and the output waveform is adjusted by pulse width modulation technology.

[0054] The three major circuits—main drive circuit, energy regulation circuit, and safety energy consumption circuit—share the ship's power grid 1 and rectifier unit 2, which greatly simplifies the system structure, reduces the configuration of redundant power supplies and conversion components, and lowers the size, weight, and manufacturing cost of the equipment. The DC bus 3 serves as a common energy hub, realizing the centralized distribution and flow of energy, improving energy transmission efficiency, and avoiding energy loss and coordination conflicts caused by multiple independent power supplies.

[0055] Specifically, the drive unit in the drive system is the drive motor 7; the bidirectional power conversion unit is the bidirectional DC / DC converter 5; the energy storage unit is the battery pack 8; the control component is the braking resistor switch 6; and the energy dissipation unit is the braking resistor 9.

[0056] More specifically, the input end of the drive motor 7 is connected to the output end of the inverter unit 4, and the output shaft is mechanically fixed to the central shaft of the rotary drum via a coupling. It converts the electrical energy input from the inverter unit 4 into mechanical energy, directly driving the rotary drum sail to rotate at high speed, serving as the power actuator for achieving Magnus effect propulsion. The bidirectional DC / DC converter 5 is a bidirectional power flow controller, with one end connected in parallel to the DC bus 3 and the other end connected to the battery pack 8. It has two basic operating modes: discharge mode and charging mode. The battery pack 8 is a high-power-density energy storage unit, i.e., a supercapacitor, connected only to the other end of the bidirectional DC / DC converter 5. The battery pack 8 can efficiently recover and store kinetic energy during rotary drum braking; it can also release energy during rapid rotary drum start-up and resonance crossing to supplement the instantaneous power of the DC bus 3 and mitigate the impact of high-power loads on the ship's electrical grid 1. The braking resistor 9 is a redundant overvoltage protection component of the drive system. It is directly connected in parallel to the DC bus 3 through the braking resistor switch 6. When the voltage of the DC bus 3 exceeds the safety threshold due to excessive regenerative energy that the battery pack 8 cannot fully absorb, the braking resistor switch 6 closes quickly, guiding the excess energy to the braking resistor 9 to be dissipated as heat. This is a hardware protection barrier to prevent overvoltage damage to the drive system.

[0057] Preferably, the drive motor 7 is a permanent magnet synchronous motor with high power density and high efficiency; the bidirectional DC / DC converter 5 adopts a Buck / Boost bidirectional topology circuit, which can switch between "Boost discharge" and "Buck charge" modes; the battery pack 8 adopts a hybrid structure of "lithium iron phosphate battery pack + supercapacitor", with the lithium battery responsible for continuous power output and long-term energy storage, and the supercapacitor responsible for instantaneous high power compensation; the braking resistor switch 6 adopts an IGBT chopper or thyristor switch with high voltage resistance and fast response characteristics; and is normally in the open state.

[0058] The drive motor 7 is a permanent magnet synchronous motor, which improves power conversion efficiency and reduces operating energy consumption. At the same time, its high torque density characteristics can quickly respond to speed adjustment needs. The bidirectional topology design of the bidirectional DC / DC converter 5 realizes efficient bidirectional energy flow, quickly replenishing instantaneous power during discharge and precisely matching the needs of the battery pack 8 during charging. The hybrid structure of the battery pack 8 has complementary advantages, meeting long-term energy storage needs while providing millisecond-level instantaneous high-power compensation, effectively mitigating the impact of the ship's power grid 1. The high response characteristics of the braking resistor switch 6 provide reliable redundancy protection for system overvoltage, reducing the risk of equipment damage.

[0059] Specifically, the drive system also includes a controller 10, which is communicatively connected to the main drive circuit, the energy regulation circuit, and the safety energy consumption circuit.

[0060] It should be noted that the controller 10, as the control center of the drive system, is connected to the rectifier unit 2, inverter unit 4, bidirectional DC / DC converter 5, braking resistor switch 6 and battery management system of battery pack 8 through various communication interfaces. It can collect key parameters such as DC bus 3 voltage, battery charge capacity, motor speed and grid status in real time, and make decisions based on preset control methods to coordinate the work of each unit.

[0061] The centralized and coordinated control of controller 10 avoids response delays and conflicts caused by the independent operation of each loop, and improves the overall dynamic response speed of the drive system. By collecting multi-dimensional parameters in real time, it enables accurate judgment of operating conditions and coordinated scheduling of components, ensuring the stable operation of the drive system in complex navigation environments.

[0062] Specifically, the controller 10 can control the operating mode of the bidirectional DC / DC converter 5.

[0063] It should be noted that when the rotary sail needs to start, accelerate, or cross the resonance zone quickly, the drive system's demand for instantaneous peak power exceeds the immediate supply capacity of the ship's electrical grid 1, requiring the battery pack 8 to provide instantaneous peak power compensation. At this time, the controller 10 instructs the bidirectional DC / DC converter 5 to switch to discharge mode, boosting the lower voltage output from the battery pack 8 to a voltage level matching that of the DC bus 3, thereby rapidly injecting the high power density energy pre-stored in the battery pack 8 into the DC bus 3 to supplement the insufficient power of the ship's electrical grid 1. When the rotary sail is decelerating or braking, or when changes in wind conditions cause the drive motor 7 to regenerate energy, resulting in excess energy and a higher voltage on the DC bus 3, the controller 10 instructs the bidirectional DC / DC converter 5 to switch to charging mode. At this time, the bidirectional DC / DC converter 5 will charge the higher DC bus 3 voltage V. bus By stepping down the voltage, the voltage is adjusted to a range suitable for safe and efficient charging of the battery pack, thereby storing the excess kinetic energy or regenerative energy of the drive system and realizing energy recovery and utilization.

[0064] The controller 10 provides precise control over the working mode of the bidirectional DC / DC converter 5, enabling a closed-loop utilization of "power replenishment-energy recovery". This allows the drive system to overcome the instantaneous power limitation of the ship's electrical grid 1, solve the power requirements for rapid start-up and resonance crossing of the large inertia rotary drum, and efficiently recover the rotational kinetic energy during braking, reducing energy waste and lowering the ship's operating energy consumption.

[0065] The present invention also provides a control method for improving the dynamic response performance of a rotary sail, applied to the above-mentioned drive system, the control method comprising:

[0066] S1 rotary drum start command listening and initial flow splitting:

[0067] Controller 10 continuously listens for the start command of the rotary drum;

[0068] S2 Startup Mode Decision:

[0069] The controller 10 determines whether a rapid start-up is needed based on real-time operating conditions;

[0070] Status check and joint start-up determination of S3 battery pack 8:

[0071] If a fast start is required and the battery pack 8 has a charge capacity greater than or equal to the first threshold, the bidirectional DC / DC converter 5 is switched to discharge mode so that the battery pack 8 and the ship's electrical grid 1 supply power to the DC bus 3 together; if a fast start is not required or the battery pack 8 has a charge capacity less than the first threshold, the ship's electrical grid 1 supplies power to the DC bus 3 only through the rectifier unit 2.

[0072] S4 Steady-State Operation and Dynamic Energy Management:

[0073] Monitoring DC bus 3 voltage V bus When V bus Exceeding the recycling threshold V 回收阈值 If the battery pack 8's charge capacity is less than the second threshold, the bidirectional DC / DC converter 5 is controlled to switch to charging mode for energy recovery; if the battery pack 8's charge capacity is greater than or equal to the second threshold, then V is compared. bus and braking threshold V 制动阈值， Determine whether to connect to a safe energy consumption circuit;

[0074] S5 Standby / Charging Mode Management:

[0075] When the drive system is in standby mode, if the battery pack 8 has a charge capacity less than or equal to the second threshold, the bidirectional DC / DC converter 5 is controlled to switch to charging mode to charge it using the surplus power of the ship's power grid 1.

[0076] S6 closed-loop control.

[0077] It should be noted that the first threshold refers to the minimum charged capacity at which the battery pack 8 can stably provide instantaneous power assistance and avoid deep discharge damage; the recovery threshold refers to the minimum voltage value on the DC bus 3 that triggers energy recovery, when V bus When the value is higher than this, it indicates that there is excess energy that can be recovered in the drive system; the second threshold refers to the upper limit of the charge capacity of the battery pack 8 for safe charging; the braking threshold refers to the overvoltage protection threshold on the DC bus 3 when the safe energy dissipation circuit needs to be activated.

[0078] More specifically, before executing the control method, the drive system needs to be initialized and self-tested. Then, the controller 10 executes the control method cyclically according to the received instructions and the drive system status.

[0079] More specifically, in step S2, the controller 10 determines whether a rapid start-up response is needed based on real-time operating conditions. If a rapid start-up is not required, the controller only connects the main drive circuit to the drive system, activating the "grid power supply" mode. In this mode, the controller 10 mainly controls the rectifier unit 2 and the inverter unit 4, supplying power from the ship's grid 1 to the DC bus 3 via the rectifier unit 2, thereby driving the motor 7 to smoothly accelerate the rotary drum to the target speed. If a rapid start-up is required, the process proceeds to step S3, where the status of the battery pack 8 is checked to determine whether hybrid acceleration should be activated.

[0080] More specifically, in step S3, after determining that the rotating drum needs to be started quickly, the controller 10 immediately reads the battery management system data of the battery pack 8, obtains the current charge capacity of the battery pack 8, and determines whether the charge capacity of the battery pack 8 is ≥20%. When the charge capacity of the battery pack 8 is ≥20%, it indicates that the battery pack 8 has the ability to provide instantaneous power assistance. The controller 10 then connects the main drive circuit and the energy regulation circuit to the drive system and starts the joint power supply mode of "grid + DC / DC discharge". In this mode, the controller 10 simultaneously issues commands. On the one hand, the rectifier unit 2 draws power from the ship's grid 1. On the other hand, it controls the bidirectional DC / DC converter 5 to switch to the discharge mode, injecting the energy stored in the battery pack 8 into the DC bus 3 with high power density. The two energy sources converge at the DC bus 3, providing the inverter unit 4 and the drive motor 7 with instantaneous high power far exceeding the power supply capacity of a single grid, thereby realizing the rapid acceleration of the rotating drum and ensuring that it can quickly and safely pass through the mechanical resonance speed zone with a high angular acceleration. When the charge capacity of the battery pack 8 is less than 20%, in order to protect the battery from deep discharge damage, the controller 10 will not connect the energy regulation circuit to the drive system, nor will it enable the DC / DC discharge mode, and will use the "grid power supply" mode for power supply.

[0081] More specifically, in step S4, after the rotating drum reaches the target speed and enters steady-state operation, the controller 10 shifts its focus to real-time monitoring and dynamic energy allocation, handling any feedback energy that may occur during operation, specifically including:

[0082] S41 DC Bus 3 Voltage Monitoring: Controller 10 collects the voltage V of DC Bus 3 in real time. bus and the recycling threshold V 回收阈值 Compare; when V bus >V 回收阈值 This indicates that there is excess energy in DC bus 3. At this time, controller 10 will then determine whether battery pack 8 is in a rechargeable state.

[0083] S42 Energy recovery judgment: If the battery pack 8 is not full and is in good condition, start the DC / DC energy recovery mode and recover the excess energy on the DC bus 3 to the battery pack 8 through the bidirectional DC / DC converter 5; if the battery is full or cannot be charged, proceed to the braking resistor 9 protection judgment process in step S43.

[0084] S43 Braking Resistor 9 Protection: Compare V bus With V 制动阈值 If V bus >V 制动阈值This indicates that the feedback energy is too large or too fast, and the battery pack 8 can no longer fully absorb it, posing a risk of overvoltage damage to the DC bus 3. At this time, the controller 10 immediately forces the brake resistor switch 6 to close, activating the brake resistor 9 energy dissipation mode, allowing excess energy to be rapidly discharged as heat through the brake resistor 9, ensuring the safety of the drive system voltage. If V bus ≤V 制动阈值 Then the drive system does not require additional intervention.

[0085] More specifically, in step S5, when the system does not receive a start command, the controller 10 focuses on the energy state management of the battery pack 8. If the charge capacity of the battery pack 8 is less than or equal to the second threshold, the drive system enters the "DC / DC charging" mode, using the surplus power of the ship's electrical grid 1 to charge the battery pack 8 through the rectifier unit 2 and the bidirectional DC / DC converter 5 until it reaches the second threshold, at which point charging stops. If the charge capacity of the battery pack 8 is greater than the second threshold, the drive system enters the standby mode, maintaining a low power consumption state and waiting for the next start command.

[0086] The control method provided by this invention achieves precise control of the rotary drum under all operating conditions through graded threshold judgment and multi-loop coordinated scheduling. Specifically, the control method solves the power bottleneck of rapid start-up and resonance crossing of the large inertia rotary drum through a joint power supply mode, achieves efficient recovery of braking energy and overvoltage protection of the drive system through dynamic energy management, and ensures that the battery pack 8 is always ready through a standby charging mode, thereby improving the overall wind energy capture efficiency, equipment safety and energy utilization efficiency.

[0087] Specifically, in step S1, if the controller 10 does not receive a start command, it will directly jump to step S5 and enter standby / charging mode management; if it receives a start command, it will enter step S2 to make a detailed decision on the start mode.

[0088] More specifically, the controller 10 continuously listens for the rotary drum start command from the ship's drive system or operating interface. If no start command is received, it indicates that the rotary drum does not need to run at the moment, and the drive system directly jumps to step S5 to enter standby / charging mode management. If a start command is received, it indicates that the rotary drum needs to be started, and the process enters step S2 to make a detailed decision on the start mode.

[0089] The initial power distribution mechanism based on the startup command enables the drive system to intelligently distinguish between running and standby states, reduce unnecessary power consumption, and prioritize the charging and maintenance of battery pack 8 to ensure that it is always available.

[0090] Specifically, in step S2, the actual operating conditions include, but are not limited to, the rate of change of wind speed, the rate of change of wind direction, and the actual rotational speed of the vortex drum.

[0091] The comprehensive consideration of multi-dimensional operating parameters makes the decision on the start-up mode more accurate, which not only avoids the impact of unnecessary rapid start-up on the power grid, but also enables the timely start-up of the "grid + DC / DC discharge" joint power supply mode under critical operating conditions, ensuring wind energy capture efficiency and equipment safety.

[0092] Specifically, in step S6, after completing the control process under any working condition, the drive system returns to the initial state and restarts the rotary drum start command listening and initial diversion in step S1.

[0093] More specifically, after completing the control process for any of the above operating conditions, the control cycle ends, but the control logic of the drive system does not stop. Instead, it returns to the "system initialization & self-test" state and restarts the loop of listening and judging from step S1. This cycle repeats continuously, forming a complete closed-loop energy management and dynamic control process of "energy storage standby - power injection - steady-state cruise - energy recovery," enabling the drive system to continuously and intelligently adapt to changing navigation conditions.

[0094] The closed-loop control architecture ensures the continuity and adaptability of the drive system control, enabling the drive system to seamlessly cope with continuously changing navigation environments and operating commands, realizing intelligent management throughout the entire cycle and all operating conditions, and greatly improving the reliability and overall energy efficiency of the drive system.

[0095] Example 1

[0096] This embodiment applies a drive system and control method for improving the dynamic response performance of rotary sails to a 180,000-ton large bulk carrier equipped with four rotary sails, and verifies its effectiveness through specific parameters and scenarios.

[0097] The core hardware configuration of this large bulk carrier is as follows:

[0098] Rotary drum drive motor 7: stable operating power 60kW, starting power 150kW, rated voltage 380VAC; DC bus 3: rated voltage 540VDC; Battery pack 8: uses lithium iron phosphate battery pack, total capacity 20kWh, rated voltage 300V; Bidirectional DC / DC converter 5: rated power 60kW, with Buck / Boost bidirectional conversion function.

[0099] Specific parameter settings: V of DC bus 3 回收阈值 650V; V of DC bus 3 制动阈值 The voltage is 720V; the charging cut-off capacity of battery pack 8 is 95%; and the discharging cut-off capacity is 20%.

[0100] Typical operating condition demonstration:

[0101] Scenario A: A ship encounters a sudden strong wind during navigation, with the wind speed rising sharply to 25 m / s, which exceeds the safe operating range of the rotary drum. The rotary drum needs to be stopped immediately and reduced from 180 rpm to 0 rpm.

[0102] At this time, after the controller 10 receives the emergency stop command, the drive motor 7 immediately switches to the generator state. The rotational kinetic energy of the drum is converted into electrical energy by the motor, which is then rectified by the inverter unit 4 and fed back to the DC bus 3, resulting in the bus voltage V. bus Rapidly rises to 670V; controller 10 detects V bus 670V, V bus >V 回收阈值 The energy recovery conditions were met, and the current charge capacity of battery pack 8 was monitored to be 75%. Controller 10 immediately activated the DC / DC energy recovery mode, and the bidirectional DC / DC converter 5 switched to charging mode, absorbing the feedback energy from DC bus 3 at a power of 50kW to charge battery pack 8. During the charging process, the bus voltage V... bus It stabilizes at around 680V, ​​the braking resistor 9 does not engage, and it does not generate heat.

[0103] Scenario B: After an emergency stop of 1 hour, the wind direction improves and the apparent wind speed stabilizes at 12 m / s, meeting the operating conditions of the rotary drum. The rotary drum needs to be started quickly, accelerating from 0 rpm to 180 rpm within 180 seconds.

[0104] At this time, the controller 10 determines that a rapid start is required and detects that the battery pack 8 has a charge capacity of 80%, and starts the grid + DC / DC discharge joint start mode; the ship's grid 1 provides 60kW steady-state power to the DC bus 3 through the rectifier unit 2, and the bidirectional DC / DC converter 5 switches the discharge mode and outputs 50kW power to the DC bus 3 in reverse. The two work together to power the inverter unit 4, with a total instantaneous power of 110kW; the inverter unit 4 outputs the appropriate voltage and frequency, drives the motor 7 to generate peak torque, and the drum accelerates from a standstill. When the speed approaches the lower limit of the resonance range, the controller 10 controls the bidirectional DC / DC converter 5 to briefly increase the output power to 60kW, helping the drum to quickly pass through the resonance zone within 8 seconds;

[0105] The entire startup process took only 180 seconds, and the rotating drum successfully reached its rated speed of 180 rpm. The startup time of a traditional non-energy storage auxiliary drive system is about 450 seconds. The drive system of this invention reduces the startup time of the rotating drum by 60%, and the instantaneous load of the ship's power grid 1 is only 60kW, with voltage fluctuations of less than 5%, which does not affect other electrical equipment on the ship.

[0106] In summary, the drive system of this invention uses DC bus 3 as a hub, connecting the main drive, energy regulation, and safety protection circuits in parallel. It achieves the collection and intelligent scheduling of shipboard electrical energy, energy storage unit energy, and braking feedback energy. The control method of this invention, based on real-time monitoring of the battery pack 8's charge capacity and DC bus 3's voltage, realizes dynamic on-demand allocation of the rotary drum drive power and closed-loop energy management, effectively solving the response hysteresis problem of large-inertia rotary drums, enabling them to quickly track wind condition changes and improve wind energy capture efficiency. Simultaneously, the drive system forms an energy closed loop through braking energy recovery and reuse, significantly improving the overall energy efficiency of the drive system.

[0107] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A drive system for improving the dynamic response performance of a rotary sail, the drive system comprising: The main drive circuit consists of the ship's electrical grid (1), rectifier unit (2), DC bus (3), inverter unit (4) connected to the drive unit; Energy regulation circuit: It consists of a ship power grid (1), a rectifier unit (2), a DC bus (3), a bidirectional power conversion unit, and an energy storage unit. Safety energy consumption circuit: It consists of a ship power grid (1), a rectifier unit (2), a DC bus (3), control components, and energy consumption units.

2. The drive system according to claim 1, characterized in that, The main drive circuit, energy regulation circuit and safety energy consumption circuit are connected in parallel with the DC bus (3) as the common coupling point, and share the ship power grid (1) and the rectifier unit (2).

3. The drive system according to claim 1, characterized in that, The drive unit in the drive system is a drive motor (7); the bidirectional power conversion unit is a bidirectional DC / DC converter (5); the energy storage unit is a battery pack (8); the control component is a braking resistor switch (6); and the energy dissipation unit is a braking resistor (9).

4. The drive system according to claim 1, characterized in that, The drive system also includes a controller (10), which is communicatively connected to the main drive circuit, the energy regulation circuit and the safety energy consumption circuit.

5. The drive system according to claim 4, characterized in that, The controller (10) can control the operating mode of the bidirectional DC / DC converter (5).

6. A control method for improving the dynamic response performance of a rotary sail, applied to the drive system of any one of claims 1 to 5, the control method comprising: S1 rotary drum start command listening and initial flow splitting: Controller 10 continuously listens for the start command of the rotary drum; S2 Startup Mode Decision: The controller (10) determines whether a rapid start-up is required based on the real-time operating conditions; Status check and joint start-up determination of S3 battery pack (8): If a fast start is required and the battery pack (8) has a charge capacity greater than or equal to the first threshold, then control the bidirectional DC / DC converter (5) to switch to discharge mode so that the battery pack (8) and the ship's power grid (1) supply power to the DC bus (3). If fast start-up is not required or the battery pack (8) has a charge capacity less than the first threshold, then power is supplied to the DC bus (3) only by the ship's electrical grid (1) through the rectifier unit (2); S4 Steady-State Operation and Dynamic Energy Management: Monitoring DC bus (3) voltage V bus When V bus Exceeding the recycling threshold V 回收阈值 When the charge capacity of the battery pack (8) is less than the second threshold, the bidirectional DC / DC converter (5) is controlled to switch to charging mode to perform energy recovery; if the charge capacity of the battery pack (8) is greater than or equal to the second threshold, then V is compared. bus and braking threshold V 制动阈值， Determine whether to connect to a safe energy consumption circuit; S5 Standby / Charging Mode Management: When the drive system is in standby mode, if the battery pack (8) has a charge capacity less than or equal to the second threshold, the bidirectional DC / DC converter (5) is controlled to switch to charging mode and the surplus power of the ship's power grid (1) is used to charge it. S6 closed-loop control.

7. The control method according to claim 6, characterized in that, In step S1, if the controller (10) does not receive a start command, it will directly jump to step S5 and enter standby / charging mode management; if it receives a start command, it will enter step S2 to make a detailed decision on the start mode.

8. The control method according to claim 6, characterized in that, In step S2, the actual operating conditions include, but are not limited to, the rate of change of wind speed, the rate of change of wind direction, and the actual rotational speed of the rotary drum.

9. The control method according to claim 6, characterized in that, In step S4, the V bus Greater than or equal to the braking threshold V 制动阈值 The controller (10) immediately activates the braking resistor switch (6) to connect the safety energy dissipation circuit to the drive system; if V bus Less than or equal to V 制动阈值 If so, no intervention is needed.

10. The control method according to claim 6, characterized in that, In step S6, after completing the control process under any working condition, the drive system returns to the initial state and restarts the rotary drum start command listening and initial diversion in step S1.

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