Ship parallel mechanical hybrid driving system and driving method

Abstract

The invention relates to the technical field of ship propulsion, and particularly discloses a ship parallel mechanical hybrid driving system and a driving method.The system comprises a gearbox, an engine, a reversible motor, a braking structure and a battery pack; a planetary gear set is arranged in the gearbox, the engine is connected with the sun gear, the reversible motor is connected with the gear ring, and the planet carrier is connected with the propeller. A sun wheel brake part and a gear ring brake part are arranged, and the sun wheel brake part adopts a normally-closed electromagnetic brake and is used for selecting an engine or a motor as a main power source; the gear ring braking part adopts an electromagnetic eddy current brake, and the braking torque can be continuously controlled by adjusting the exciting current; by coordinating and controlling the states of the two brake parts, the system can achieve clutch-free switching of four working modes of mechanical propulsion, electric propulsion, hybrid propulsion and advancing power generation. The problems that a traditional clutch system is large in abrasion, low in efficiency and uncontrollable in generated power are solved, and the comprehensive performance of a ship power system is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of ship propulsion technology, specifically to a parallel mechanical hybrid drive system and drive method for ships. Background Technology

[0002] Hybrid propulsion technology for ships is a crucial development direction for green shipping. By combining traditional heat engines with electric propulsion systems, it significantly improves a vessel's energy efficiency, maneuverability, and environmental friendliness. Among these, the parallel hybrid power architecture, due to its compact structure, diverse modes, and ability to fully utilize existing diesel engine technology, has become one of the mainstream choices for medium and large-sized vessels. This technological field continuously pursues higher system efficiency, lower operating costs, and better space utilization, driving ongoing innovation in power coupling technologies and energy management strategies.

[0003] Currently, existing technical solutions in this field mainly revolve around several typical structures. One widely adopted approach is a clutch-based power coupling system, which achieves switching and combination between different power sources by controlling the engagement and disengagement of multiple clutches. Another approach uses a planetary gear mechanism for power distribution, forming different transmission paths by fixing specific elements of the planetary gear set. These technical solutions offer different approaches to achieving hybrid propulsion in ships.

[0004] However, the aforementioned existing technical solutions still have significant limitations. Clutch-based systems suffer from poor mode switching smoothness, significant transmission efficiency loss, and high wear and maintenance costs of the clutch itself. While existing planetary gear mechanisms can achieve power splitting, their power generation mode typically simply couples the generator speed with the engine speed, resulting in the inability to independently adjust the generated power according to grid demand, posing a potential safety hazard when there is excess power generation. Summary of the Invention

[0005] To address the technical problems in the prior art, this invention provides a parallel mechanical hybrid drive system and driving method for ships, aiming to solve the problems of uneven mode switching, low transmission efficiency, and system safety risks caused by the reliance on clutches in the prior art, as well as the strong coupling between power generation and engine speed, which cannot be independently adjusted.

[0006] A parallel mechanical hybrid drive system for ships includes a gearbox, an engine, a reversible motor, a braking structure, a propulsion unit, and a battery pack, wherein... The gearbox includes a housing and a planetary gear set consisting of a sun gear, planet gears, a planet carrier, and a ring gear, housed within the housing. The output end of the engine is connected to the sun gear drive; The output end of the reversible motor is connected to the gear ring drive; The braking structure includes a sun gear brake and a gear ring brake; The planetary carrier is connected to the thruster as a power output end; The battery pack is electrically connected to the reversible motor to form a charging and discharging circuit; when the reversible motor is running as a generator, it charges the battery pack, and when it is running as a motor, it is powered by the battery pack. The sun gear brake is located inside the housing at the corresponding sun gear, and can switch the sun gear between a locked state and a released state to select whether to use an engine or a reversible motor as the main power source. The gear ring brake is located inside the housing at the gear ring and can be continuously adjusted between three states: locked, released, and controllable slip. When the engine is the main power source, it controls the rotational speed of the gear ring, thereby controlling the power of the reversible motor driven by the gear ring to generate electricity.

[0007] Optionally, the sun gear brake includes a normally closed electromagnetic brake, which is located in the housing at the location corresponding to the sun gear shaft and connected to the ship control system. It is used to control the power-off locking or power-on release to select the use of an engine or a reversible motor as the main power source.

[0008] Optionally, the gear ring brake includes a transmission gear and an electromagnetic eddy current brake, wherein, The transmission gear is rotatably connected to the housing and meshes with the outer periphery of the gear ring; the output end of the reversible motor is driven by the axle of the transmission gear. The electromagnetic eddy current brake is located at the axle of the corresponding transmission gear inside the housing. The braking torque is continuously adjusted by adjusting the magnitude of the excitation current. When the engine is used as the main power source, the speed of the gear ring is controlled, thereby controlling the power of the reversible motor driven by the gear ring to rotate in reverse to generate electricity.

[0009] Optionally, the gear ring brake also includes a cooling fan, which is located in the housing corresponding to the electromagnetic eddy current brake and is used to dissipate heat from the surface of the electromagnetic eddy current brake.

[0010] Optionally, a parallel mechanical hybrid drive system for ships also includes a bidirectional converter and a DC bus, wherein, The battery pack is electrically connected to the DC bus via the bidirectional converter to store and release electrical energy.

[0011] Optionally, a parallel mechanical hybrid drive system for ships further includes a bidirectional inverter, through which the reversible motor is electrically connected to the DC bus; When the reversible motor is running as a motor, it inverts the DC power from the DC bus into AC power to drive the reversible motor; when the reversible motor is running as a generator, it rectifies the AC power it outputs into DC power and supplies it to the DC bus and the battery pack for storage.

[0012] Optionally, it also includes backup power generation equipment and a first rectifier, wherein, The output of the backup power generation equipment is electrically connected to the DC bus via a first rectifier, and is used to supply power to the DC bus when the battery pack is below a set threshold or the engine fails, so as to ensure continuous power supply and propulsion for the ship.

[0013] Optionally, a parallel mechanical hybrid propulsion system for ships further includes a shore power tank and a second rectifier, wherein, The shore power box has an input terminal for connecting to shore power at the dock, and an output terminal that is electrically connected to the DC bus via a second rectifier to charge the battery pack with shore power during berthing, while simultaneously shutting down the engine and backup power generation equipment to achieve zero-emission berthing.

[0014] This invention also provides a parallel mechanical hybrid drive method for ships, characterized in that it combines the above-mentioned parallel mechanical hybrid drive system for ships to perform hybrid drive, and the drive method includes: S1: Real-time acquisition of the ship's speed requirement command and the real-time state of charge value of the battery pack; the system simultaneously coordinates the locking or releasing state of the sun gear brake and the operating mode of the reversible motor to select the engine or the reversible motor as the main power source. S2: When the engine is selected as the main power source, the sun gear brake is released, and the propulsion power and power generation power are adjusted in real time by continuously adjusting the gear ring brake in three states: locked, released, or controllable slip. When the reversible motor is selected as the main power source, the gear ring brake is fully released, the sun gear brake is locked, and the reversible motor drives the propeller independently through the gear ring, planetary gears, and planetary carrier. The engine has zero drag, and the system enters the pure electric propulsion state. S3: When the real-time state of charge of the battery pack is lower than the set threshold and cannot be replenished by on-the-go power generation, the backup power generation equipment is started, and power is supplied to the DC bus through the first rectifier to ensure continuous navigation; S4: During berthing, the ship connects to the shore power structure, and the DC bus and battery pack are charged through the second rectifier. At the same time, all prime movers are shut down to achieve zero-emission berthing.

[0015] Optionally, there are four operating modes, and the specific operating methods of the four driving modes are as follows: Mechanical propulsion mode: The gear ring brake is locked, while the sun gear brake is released; the engine is started, and its output power is transmitted to the planet carrier through the sun gear and planet gears to drive the propeller. At this time, the reversible motor is in standby or idle state. Electric propulsion mode: The sun gear brake is locked, and the ring gear brake is released. The battery pack supplies power to the reversible motor, which operates as an electric motor. The output power is transmitted to the planet carrier through the ring gear and planetary gears to drive the propeller. At this time, the engine is off. Hybrid propulsion mode: Both the sun gear brake and the ring gear brake are in the released state; at the same time, the engine is started and the battery pack is controlled to supply power to the reversible motor, so that the power output by the engine and the reversible motor is input through the sun gear and the ring gear respectively, and after the planetary gear system converges, it is transmitted to the planet carrier to jointly drive the thruster. In the driving power generation mode: the sun gear brake is controlled to be in the released state, while the ring gear brake is controlled to be in the controllable slip state; the engine is started, and most of its power is transmitted to the planet carrier via the sun gear and planet gears to drive the propeller, while a small portion of its power is transmitted to the reversible motor via the planet gears and ring gear to drive it to operate as a generator to generate electricity; by continuously adjusting the braking torque of the ring gear brake, the follow-up speed of the ring gear is controlled, thereby precisely controlling the power generation of the reversible motor.

[0016] Compared with the prior art, the parallel mechanical hybrid drive system and drive method for ships provided by the present invention have the following advantages: (1) By innovatively setting sun gear brake and ring gear brake at the sun gear and ring gear respectively, the traditional friction clutch is completely eliminated; the power source switching and power distribution are realized by the combination of the states of the two brakes, which fundamentally eliminates the impact, wear and energy loss caused by clutch engagement and disengagement, significantly improves the transmission efficiency, reliability and durability of the system, and greatly reduces the maintenance cost in the later stage.

[0017] (2) The speed of the gear ring is infinitely adjustable by the gear ring brake, thereby precisely controlling the power generation of the reversible motor. This makes the power generation process no longer strongly coupled with the engine speed, and can be intelligently and independently adjusted according to the battery pack state of charge and DC bus voltage requirements. This completely solves the safety risks of battery overcharging, bus voltage rise, and generator overload caused by uncontrollable power generation in the existing technology. At the same time, it can ensure that the engine always works in the high-efficiency range, optimize the energy management of the whole ship, and improve the economy.

[0018] (3) Based on the coordinated control of dual brake components, the system can switch flexibly and smoothly between four modes: mechanical propulsion, electric propulsion, hybrid propulsion and power generation while in motion. It can meet the high power requirements of the ship when sailing at high speed, achieve zero-emission and quiet navigation when entering and leaving the port, and efficiently charge the battery during cruise, which greatly enhances the ship's adaptability and maneuverability to different navigation conditions.

[0019] (4) Combining backup power generation equipment with shore power interface, it forms a multi-energy integrated system; it can generate electricity by utilizing the spare power of the main engine while the engine is running, and can also start the backup power supply when necessary. It can also use shore power to achieve zero emissions when berthing, which comprehensively improves energy utilization efficiency, reduces fuel consumption and pollutant emissions, and is in line with the development trend of green shipping. Attached Figure Description

[0020] Figure 1 This is an overall structural block diagram of a parallel mechanical hybrid drive system for ships according to the present invention; Figure 2 This is a schematic diagram of the internal structure of the gearbox of a parallel mechanical hybrid drive system for ships according to the present invention; Figure 3 This is a schematic diagram of the internal disassembled structure of the gearbox of a ship parallel mechanical hybrid drive system according to the present invention; Figure 4 This is a flowchart of the steps of a parallel mechanical hybrid drive method for ships according to the present invention.

[0021] In the diagram: 1. Gearbox; 11. Housing; 121. Sun gear; 122. Planetary gears; 123. Planetary carrier; 124. Ring gear; 12. Planetary gear set; 2. Engine; 3. Reversible motor; 4. Braking structure; 41. Sun gear brake; 411. Normally closed electromagnetic brake; 42. Ring gear brake; 421. Transmission gear; 422. Electromagnetic eddy current brake; 423. Cooling fan; 5. Propeller; 6. Battery pack; 7. Bidirectional converter; 8. DC bus; 9. Bidirectional inverter; 100. Backup power generation equipment; 101. First rectifier; 110. Shore power box; 111. Second rectifier. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0024] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0028] Please see Figure 1-3The present application proposes a parallel mechanical hybrid drive system for ships, including a gearbox 1, an engine 2, a reversible motor 3, a braking structure 4, a thruster 5, and a battery pack 6.

[0029] like Figure 1-3 As shown, the gearbox 1 includes a housing 11 and a planetary gear set 12 disposed within the housing 11, consisting of a sun gear 121, planet gears 122, a planet carrier 123, and a ring gear 124. The planetary gear set 12 is the core mechanism for power distribution and coupling in this invention. Its basic operating principle is as follows: when any one of the three basic components—sun gear 121, planet carrier 123, and ring gear 124—is fixed, power will be input from one of the other two components and output from the other, forming a fixed transmission ratio. When all three components rotate freely, the coupling input of two power sources or the power splitting is realized.

[0030] The output end of engine 2 is driven to connect to sun gear 121 via flange or spline, etc. Engine 2 can be any type of marine internal combustion engine such as diesel engine, natural gas engine, methanol engine, etc.; the output end of reversible motor 3 is driven to connect to gear ring 124. Reversible motor 3 is usually a permanent magnet synchronous motor or an electrically excited synchronous motor, which can output torque as a motor and output electricity as a generator; braking structure 4 includes sun gear brake 41 and gear ring brake 42, and planetary carrier 123 is connected to propeller 5 via output shaft as power output end; battery pack 6 is electrically connected to reversible motor 3 to form a charging and discharging circuit; when reversible motor 3 is running as a generator, it supplies power to battery pack 6. Charging is performed by the battery pack 6, which is typically a lithium-ion battery pack or other types of power battery packs. The sun gear brake 41 is located inside the housing 11 corresponding to the sun gear 121 and can switch the sun gear 121 between locked and released states to select whether to use the engine 2 or the reversible motor 3 as the main power source. The gear ring brake 42 is located inside the housing 11 corresponding to the gear ring 124 and can continuously adjust the gear ring 124 between locked, released, and controllable slip states. When the engine 2 is used as the main power source, the gear ring 124 is controlled to rotate and generate electricity.

[0031] Specifically, by using planetary gear set 12 in conjunction with two braking components, a clutchless, purely mechanical power coupling and distribution is creatively achieved. The sun gear brake 41 is responsible for mode switching and selecting the power source, while the ring gear brake 42 is responsible for fine power adjustment, thereby controlling the power generation. The two have clear division of labor and work together. This fundamentally eliminates the problems of transmission efficiency loss, impact wear, and high maintenance costs caused by traditional clutches, greatly improving the reliability and durability of the system. More importantly, through the "controllable slip" state of the ring gear brake 42, continuous and precise control of the power generation is achieved independently of the engine speed. This solves the safety hazards of overcharging and overload caused by the non-adjustable power generation in existing technologies, making the energy management of the entire ship intelligent, efficient, and safe.

[0032] The specific implementation of the controllable slip state is as follows: The ship control system calculates the target power generation based on the real-time state of charge of the battery pack 6 and the voltage requirements of the DC bus 8, and then calculates the target rotational speed of the gear ring 124 or the target braking torque of the electromagnetic eddy current brake 422. Subsequently, the control system adjusts the excitation current of the electromagnetic eddy current brake 422 to form a closed-loop control circuit, making its actual braking torque approach the target value, thereby stabilizing the power generation within the required range. In this way, the power generation is decoupled from the engine speed 2, enabling independent, smooth, and precise control, ensuring that the engine always operates in the high-efficiency fuel consumption range, while avoiding battery overcharging or excessive bus voltage. At the same time, the control method here is a conventional control method in the prior art.

[0033] In some embodiments, such as Figure 2-3 As shown, the sun gear brake 41 includes a normally closed electromagnetic brake 411, which is located inside the housing 11 at the shaft corresponding to the sun gear 121 and is connected to the ship control system. It is used to control the power-off locking or power-on release to select the use of the engine 2 or the reversible motor 3 as the main power source.

[0034] Specifically, this embodiment optimizes the sun gear brake 41; it adopts a normally closed electromagnetic brake 411, which works by locking when power is off and releasing when power is on; this "power-off safety" mode ensures that the sun gear 121 can be reliably locked in the event of system failure or power failure, thus enhancing safety; its control logic is simple and reliable, requiring only power on or off, and has a fast response speed, perfectly meeting the requirements of the "mode switching" function for high reliability and fast response, and its own structure is simple with extremely low maintenance costs.

[0035] In some embodiments, such as Figure 2-3As shown, the gear ring brake 42 includes a transmission gear 421 and an electromagnetic eddy current brake 422. The transmission gear 421 is rotatably connected inside the housing 11 and meshes with the outer periphery of the gear ring 124. The output end of the reversible motor 3 is driven and connected to the axle of the transmission gear 421. The electromagnetic eddy current brake 422 is located inside the housing 11 at the axle corresponding to the transmission gear 421. By adjusting the magnitude of the excitation current, the braking torque is continuously adjusted. When the engine 2 is used as the active power source, the rotational speed of the gear ring 124 is controlled, thereby controlling the power of the reversible motor 3 driven by the gear ring 124 to rotate in reverse and generate electricity.

[0036] Specifically, this embodiment provides a preferred implementation of the gear ring brake 42; an electromagnetic eddy current brake 422 is used and meshes with the gear ring 124 through a transmission gear 421. Its braking torque has a good linear relationship with the excitation current. Only by changing the current value can the continuous stepless torque adjustment with millisecond-level response be achieved, thereby realizing precise control of the power generation. This non-contact braking method avoids friction and wear, has a long service life, and high reliability. It is a key technical guarantee for the system to achieve the core beneficial effect of safe and controllable power generation.

[0037] In some embodiments, such as Figure 2-3 As shown, the gear ring brake 42 also includes a cooling fan 423, which is located on the housing 11 corresponding to the electromagnetic eddy current brake 422 and is used to dissipate heat from the surface of the electromagnetic eddy current brake 422.

[0038] Specifically, this embodiment is a further improvement on the gear ring brake 42; a cooling fan 423 is added to force-cool the electromagnetic eddy current brake 422. Since the electromagnetic eddy current brake 422 is in a long-term sliding friction condition during the driving power generation mode, it will generate a lot of heat. Forced air cooling can effectively remove the heat and prevent it from decaying or being damaged due to overheating, thus ensuring the stability of the braking torque and the reliability of the brake operation, thereby ensuring the continuity and stability of the power generation control function.

[0039] In some embodiments, such as Figure 1 As shown, a parallel mechanical hybrid drive system for ships also includes a bidirectional converter 7 and a DC bus 8. The battery pack 6 is electrically connected to the DC bus 8 through the bidirectional converter 7 to store and release electrical energy.

[0040] Specifically, this embodiment introduces a core architecture for power management; the DC bus 8 serves as the common power platform for the entire system, and the bidirectional converter 7 is an intelligent portal for managing battery charging and discharging. It can boost or step down the fluctuating voltage of the battery pack 6 to the stable voltage level required by the DC bus 8, realizing bidirectional and efficient energy flow. It is a necessary foundation for realizing efficient and controllable energy exchange between the reversible motor 3 and the battery pack 6, thereby improving the energy management efficiency of the entire system.

[0041] In some embodiments, such as Figure 1 As shown, a parallel mechanical hybrid drive system for ships also includes a bidirectional inverter 9, and the reversible motor 3 is electrically connected to the DC bus 8 through the bidirectional inverter 9; when the reversible motor 3 is running as a motor, the DC power of the DC bus 8 is inverted into AC power to drive the reversible motor 3; when the reversible motor 3 is running as a generator, the AC power output is rectified into DC power and sent to the DC bus 8 and the battery pack 6 for storage.

[0042] Specifically, this embodiment improves the power conversion chain; the bidirectional inverter 9 is the "translator" between the reversible motor 3 and the DC bus 8, realizing efficient bidirectional conversion between DC and AC power; it works in conjunction with the bidirectional converter 7 to form a complete and efficient "charging and discharging circuit", which enables the two core functions of "reversible motor generating electricity to charge the battery" and "battery discharging to drive the motor" to be perfectly realized, and is the electrical foundation for the system to have multiple working modes.

[0043] In some embodiments, such as Figure 1 As shown, a parallel mechanical hybrid drive system for ships also includes a backup power generation device 100 and a first rectifier 101. The output of the backup power generation device 100 is electrically connected to the DC bus 8 via the first rectifier 101, and is used to supply power to the DC bus 8 when the battery pack 6 is below a set threshold or the engine 2 fails, so as to ensure continuous power supply and propulsion for the ship.

[0044] Specifically, this embodiment increases the redundancy and reliability of the system; the backup power generation equipment 100 can be a small-power diesel generator set as an emergency power source. When the main power generation is insufficient or fails, it can automatically start and supply power to the DC bus 8 through the first rectifier 101. It can supply power for the ship's daily load and provide auxiliary power for the propulsion system when necessary, which greatly enhances the safety redundancy and endurance reliability of the ship's operation.

[0045] In some embodiments, such as Figure 1 As shown, a parallel mechanical hybrid drive system for ships also includes a shore power box 110 and a second rectifier 111. The input end of the shore power box 110 is used to connect to the shore power at the dock, and the output end is electrically connected to the DC bus 8 via the second rectifier 111 to charge the battery pack 6 with shore power during berthing, while shutting down the engine 2 and the backup power generation equipment 100 to achieve zero-emission berthing.

[0046] Specifically, this embodiment expands the system's energy sources; through the shore power box 12 and the second rectifier 121, the ship can use the port's mains power to charge the battery pack 6 and supply the entire ship's load when berthing. This can completely shut down the engine 2 and the backup power generation equipment 100, achieving absolute zero emissions and zero noise during berthing, meeting the most stringent port environmental protection regulations, while reducing the main engine's operating hours and maintenance costs, and has significant environmental and economic value.

[0047] This invention also provides a parallel mechanical hybrid drive method for ships, such as... Figure 4 As shown, in conjunction with the above-mentioned parallel mechanical hybrid drive system for ships, the ship is driven by hybrid propulsion, and the drive method includes: S1: Real-time acquisition of the ship's speed requirement command and the real-time state of charge value of the battery pack; the system simultaneously coordinates the locking or releasing state of the sun gear brake and the operating mode of the reversible motor to select the engine or the reversible motor as the main power source. S2: When the engine is selected as the main power source, the sun gear brake is released, and the propulsion power and power generation power are adjusted in real time by continuously adjusting the gear ring brake in three states: locked, released, or controllable slip. When the reversible motor is selected as the main power source, the gear ring brake is fully released, the sun gear brake is locked, and the reversible motor drives the propeller independently through the gear ring, planetary gears, and planetary carrier. The engine has zero drag, and the system enters the pure electric propulsion state. S3: When the real-time state of charge of the battery pack is lower than the set threshold and cannot be replenished by on-the-go power generation, the backup power generation equipment is started, and power is supplied to the DC bus through the first rectifier to ensure continuous navigation; S4: During berthing, the ship connects to the shore power structure, and the DC bus and battery pack are charged through the second rectifier. At the same time, all prime movers are shut down to achieve zero-emission berthing.

[0048] There are four operating modes, and the specific operating methods of the four driving modes are as follows: Mechanical propulsion mode: The gear ring brake is locked, while the sun gear brake is released; the engine is started, and its output power is transmitted to the planet carrier through the sun gear and planet gears to drive the propeller. At this time, the reversible motor is in standby or idle state. Electric propulsion mode: The sun gear brake is locked, and the ring gear brake is released. The battery pack supplies power to the reversible motor, which operates as an electric motor. The output power is transmitted to the planet carrier through the ring gear and planetary gears to drive the propeller. At this time, the engine is off. Hybrid propulsion mode: Both the sun gear brake and the ring gear brake are in the released state; at the same time, the engine is started and the battery pack is controlled to supply power to the reversible motor, so that the power output by the engine and the reversible motor is input through the sun gear and the ring gear respectively, and after the planetary gear system converges, it is transmitted to the planet carrier to jointly drive the thruster. In the driving power generation mode: the sun gear brake is controlled to be in the released state, while the ring gear brake is controlled to be in the controllable slip state; the engine is started, and most of its power is transmitted to the planet carrier via the sun gear and planet gears to drive the propeller, while a small portion of its power is transmitted to the reversible motor via the planet gears and ring gear to drive it to operate as a generator to generate electricity; by continuously adjusting the braking torque of the ring gear brake, the follow-up speed of the ring gear is controlled, thereby precisely controlling the power generation of the reversible motor.

[0049] The beneficial effects of this method are consistent with those of the system; by intelligently sensing speed and power demand and coordinating the control of two braking components, it achieves automatic, smooth, and intelligent switching of four working modes; ultimately, it makes the system of this invention not only a hardware innovation, but also a "smart brain" that can automatically select the optimal working mode according to the actual situation, thereby comprehensively improving the ship's power, economy, safety, and environmental protection.

[0050] The ship control system mentioned above is the control center of the entire propulsion system. Its control connection method and control method are all conventional operations in the existing technology, and will not be described in detail here.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A parallel mechanical hybrid drive system for ships, characterized in that, It includes a gearbox (1), an engine (2), a reversible motor (3), a braking structure (4), a thruster (5), and a battery pack (6), among which, The gearbox (1) includes a housing (11) and a planetary gear set (12) consisting of a sun gear (121), planet gears (122), a planet carrier (123) and a ring gear (124) disposed in the housing (11). The output end of the engine (2) is driven by the sun gear (121); The output end of the reversible motor (3) is drivenly connected to the gear ring (124); The braking structure (4) includes a sun gear brake (41) and a gear ring brake (42). The planetary carrier (123) is connected to the thruster (5) as a power output end; The battery pack (6) is electrically connected to the reversible motor (3) to form a charging and discharging circuit; the reversible motor (3) charges the battery pack (6) when it is running as a generator, and is powered by the battery pack (6) when it is running as a motor. The sun gear brake (41) is located inside the housing (11) at the sun gear (121), and can switch the sun gear (121) between the locked state and the released state, so as to select the engine (2) or the reversible motor (3) as the main power source; The gear ring brake (42) is located inside the housing (11) at the gear ring (124), and can continuously adjust the gear ring (124) between the locked state, the released state and the controllable slip state. It is used to control the rotation speed of the gear ring (124) when the engine (2) is the active power source, thereby controlling the power of the reversible motor (3) driven by the gear ring (124) to generate electricity.

2. The parallel mechanical hybrid drive system for ships according to claim 1, characterized in that, The sun gear brake (41) includes a normally closed electromagnetic brake (411), which is located inside the housing (11) at the shaft of the sun gear (121) and connected to the ship control system. It is used to control the power-off locking or power-on release to select the use of the engine (2) or the reversible motor (3) as the main power source.

3. The parallel mechanical hybrid drive system for ships according to claim 1, characterized in that, The gear ring brake (42) includes a transmission gear (421) and an electromagnetic eddy current brake (422), wherein, The transmission gear (421) is rotatably connected inside the housing (11) and meshes with the outer periphery of the gear ring (124). The output end of the reversible motor (3) is driven by the wheel shaft of the transmission gear (421). The electromagnetic eddy current brake (422) is located in the housing (11) at the axle of the corresponding transmission gear (421). The braking torque is continuously adjusted by adjusting the magnitude of the excitation current. When the engine (2) is used as the active power source, the speed of the gear ring (124) is controlled, thereby controlling the power of the reversible motor (3) driven by the gear ring (124) to rotate in the reverse direction to generate electricity.

4. A ship parallel mechanical hybrid drive system according to claim 3, characterized in that, The gear ring brake (42) also includes a cooling fan (423), which is located on the housing (11) corresponding to the electromagnetic eddy current brake (422) for heat dissipation of the surface of the electromagnetic eddy current brake (422).

5. A parallel mechanical hybrid drive system for ships according to claim 1, characterized in that, It also includes a bidirectional converter (7) and a DC bus (8), wherein, The battery pack (6) is electrically connected to the DC bus (8) through the bidirectional converter (7) to store and release electrical energy.

6. A parallel mechanical hybrid drive system for ships according to claim 5, characterized in that, It also includes a bidirectional inverter (9), through which the reversible motor (3) is electrically connected to the DC bus (8); When the reversible motor (3) is running as a motor, it converts the DC power of the DC bus (8) into AC power to drive the reversible motor (3); when the reversible motor (3) is running as a generator, it rectifies the AC power output into DC power and sends it to the DC bus (8) and the battery pack (6) for storage.

7. A parallel mechanical hybrid drive system for ships according to claim 5, characterized in that, It also includes a backup power generation unit (100) and a first rectifier (101), wherein, The output of the backup power generation equipment (100) is electrically connected to the DC bus (8) via the first rectifier (101) to supply power to the DC bus (8) when the battery pack (6) is below the set threshold or the engine (2) fails, so as to ensure continuous power supply and propulsion of the ship.

8. A parallel mechanical hybrid drive system for ships according to claim 5, characterized in that, It also includes a shore power box (110) and a second rectifier (111), wherein, The input end of the shore power box (110) is used to connect to the shore power of the dock, and the output end is electrically connected to the DC bus (8) via the second rectifier (111) to charge the battery pack (6) with shore power during berthing, while shutting down the engine (2) and the backup power generation equipment (100) to achieve zero-emission berthing.

9. A parallel mechanical hybrid drive method for ships, characterized in that, In conjunction with the ship parallel mechanical hybrid drive system as described in any one of claims 1-8, the ship is driven in a hybrid manner, the drive method comprising: S1: Real-time acquisition of the ship's speed requirement command and the real-time state of charge value of the battery pack; the system simultaneously coordinates the locking or releasing state of the sun gear brake and the operating mode of the reversible motor to select the engine or the reversible motor as the main power source. S2: When the engine is selected as the main power source, the sun gear brake is released, and the propulsion power and power generation power are adjusted in real time by continuously adjusting the gear ring brake in three states: locked, released, or controllable slip. When the reversible motor is selected as the main power source, the gear ring brake is fully released, the sun gear brake is locked, and the reversible motor drives the propeller independently through the gear ring, planetary gears, and planetary carrier. The engine has zero drag, and the system enters the pure electric propulsion state. S3: When the real-time state of charge of the battery pack is lower than the set threshold and cannot be replenished by on-the-go power generation, the backup power generation equipment is started, and power is supplied to the DC bus through the first rectifier to ensure continuous navigation; S4: During berthing, the ship connects to the shore power structure, and the DC bus and battery pack are charged through the second rectifier. At the same time, all prime movers are shut down to achieve zero-emission berthing.

10. A parallel mechanical hybrid drive method for ships according to claim 9, characterized in that, There are four operating modes, and the specific operating methods of the four driving modes are as follows: Mechanical propulsion mode: The gear ring brake is locked, while the sun gear brake is released; the engine is started, and its output power is transmitted to the planet carrier through the sun gear and planet gears to drive the propeller. At this time, the reversible motor is in standby or idle state. Electric propulsion mode: The sun gear brake is locked, and the ring gear brake is released. The battery pack supplies power to the reversible motor, which operates as an electric motor. The output power is transmitted to the planet carrier through the ring gear and planetary gears to drive the propeller. At this time, the engine is off. Hybrid propulsion mode: Both the sun gear brake and the ring gear brake are in the released state; at the same time, the engine is started and the battery pack is controlled to supply power to the reversible motor, so that the power output by the engine and the reversible motor is input through the sun gear and the ring gear respectively, and after the planetary gear system converges, it is transmitted to the planet carrier to jointly drive the thruster. Traveling power generation mode: Control the sun gear brake to be in the released state, and simultaneously control the gear ring brake to be in a controllable slip state; When the engine is started, most of its power is transmitted to the planetary carrier via the sun gear and planetary gears to drive the propeller, and a small portion of its power is transmitted to the reversible motor via the planetary gears and ring gear to drive it to operate as a generator to generate electricity. By continuously adjusting the braking torque of the ring gear brake, the follow-up speed of the ring gear is controlled, thereby precisely controlling the power generation of the reversible motor.

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