Mechanical-electrical hybrid propulsion ship power system and control method thereof

Abstract

The application relates to the technical field of ship power system control, in particular to a mechanical-electrical hybrid propulsion ship power system and a control method thereof. The application uses a bidirectional motor as a mechanical energy and electrical energy conversion node, and cooperates with a control and switching device to make the propulsion system and the power system communicate in the form of electrical energy, realizes power mutual conversion and application between the two systems, and effectively improves the power utilization efficiency of the ship power system by combining the corresponding control method. The application realizes the communication between the propulsion system and the power system, that is, the relative independence of the two systems is maintained, the propulsion system and the power system can be backed up for each other, and the vitality of the propulsion system and the power system is greatly improved. The application improves the low noise of the ship under low-speed working conditions, the power crossover makes the arrangement of the propulsion system more flexible, and helps to improve the overall space utilization efficiency of the ship.

Description

Technical Field

[0001] This invention relates to the field of ship propulsion system control technology, specifically to a ship propulsion system with electromechanical hybrid propulsion and its control method. Background Technology

[0002] The propulsion system has always been a top priority in ship design. Due to the wide range of ship speeds and various operating conditions, the determination of the propulsion system design needs to consider the following factors:

[0003] (a) The ratio of maximum propulsion power to total shipboard power; (b) The ease of obtaining the equipment; (c) The maintainability and reliability of the system; (d) The economics of life-cycle operation; (e) The system's survivability (damage resistance); (f) Other (special operating conditions, such as low-noise operating conditions);

[0004] In existing marine propulsion system designs, the ship's electrical system and propulsion system typically operate independently. In recent years, with the development and application of marine electric propulsion technology, marine propulsion systems have also evolved into various combinations and operating modes to meet the diverse operational needs of ship navigation. However, even with existing technologies that combine the electric and propulsion systems, problems such as insufficient power utilization and high system noise persist. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a ship propulsion system with electromechanical hybrid propulsion and its control method, which can effectively improve the power utilization efficiency of the ship propulsion system and enhance the fuel economy and low noise performance of the ship.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] I. A ship propulsion system with electromechanical hybrid propulsion

[0008] This invention provides a ship propulsion system with electromechanical hybrid propulsion, including separately installed gas turbine 1 and gas turbine 2. Gas turbine 1 and gas turbine 2 are respectively connected to propulsion shaft 5 and propulsion shaft 6 via gearbox 3 and gearbox 4. Propeller 7 and propeller 8 are respectively connected to the ends of propulsion shaft 5 and propulsion shaft 6. Bidirectional shaft-driven motor 9 and bidirectional shaft-driven motor 10 are respectively provided in the middle of propulsion shaft 5 and propulsion shaft 6. Bidirectional shaft-driven motor 9 and bidirectional shaft-driven motor 10 are electrically connected to control and conversion device 11 via connecting cables. Control and conversion device 11 is electrically connected to ship electrical system 12.

[0009] Preferably, both the bidirectional shaft-driven motor 9 and the bidirectional shaft-driven motor 10 have both generator mode and motor mode, used to convert the mechanical energy of the corresponding propulsion shaft into electrical energy and transmit it to the control and transfer device 11, or to convert the electrical energy transmitted by the control and transfer device 11 into mechanical energy to drive the corresponding propulsion shaft to operate.

[0010] Preferably, the control and transfer device 11 is used to control the speed of the bidirectional shaft motor 9 and the bidirectional shaft motor 10 in motor mode. At the same time, the control and transfer device 11 is also used to transmit the electrical energy transmitted in the shaft motor generator mode to the ship's power system 12, or to transmit the electrical energy stored in the ship's power system 12 to the shaft motor in motor mode.

[0011] II. A Control Method for Ship Propulsion Systems

[0012] Based on the same inventive concept, the present invention also provides a control method for the ship propulsion system as described above, specifically including the following steps:

[0013] S1 determines the current operating condition of the ship;

[0014] S2, when the ship is operating at high speed, it adopts a dual gas turbine propulsion system plus an electric power system for auxiliary propulsion;

[0015] S3, when the ship is operating at cruising speed; uses a single gas turbine propulsion system plus a single electric motor propulsion system.

[0016] S4, when the ship is operating at low speed, it adopts a single gas turbine propulsion plus electric system auxiliary propulsion.

[0017] S5: When the ship is in a fault-resistant operating condition, it switches to the corresponding backup propulsion mode according to the location of the fault.

[0018] Preferably, in step S2, the high-speed operating condition specifically refers to a ship speed that is higher than a preset maximum ship cruising speed.

[0019] The aforementioned dual gas turbine propulsion plus electric system assisted propulsion mode specifically involves both gas turbines operating at a preset power level; simultaneously, both bidirectional shaft-driven motors are in electric motor mode, with power supplied by the ship's electrical system to assist in driving the corresponding propulsion shafts.

[0020] Preferably, in step S3, the cruising speed operating condition specifically refers to a ship speed that is not higher than a preset maximum cruising speed and not lower than a preset minimum cruising speed.

[0021] The single gas turbine propulsion plus single motor propulsion configuration specifically involves any one gas turbine operating at a preset power level, with its corresponding bidirectional shaft motor in generator mode, transmitting the electrical energy generated by the generator to another bidirectional shaft motor for use. The other bidirectional shaft motor is in motor mode, used to drive the propulsion shaft of the other gas turbine.

[0022] Part of the electrical energy generated by the generator is transmitted to the other bidirectional shaft motor, and the other part is transmitted to the load of the ship's power system.

[0023] Preferably, in step S4, the low-speed operating condition specifically refers to the ship's speed being lower than a preset minimum cruising speed.

[0024] The single gas turbine propulsion plus electric system assisted propulsion mode specifically involves any one gas turbine operating at a preset power level, with the corresponding bidirectional shaft motor on its propulsion shaft in motor mode, and the gas turbine and the corresponding bidirectional shaft motor jointly driving the corresponding propulsion shaft to rotate.

[0025] Preferably, in step S5, when the ship's gas turbine malfunctions, both bidirectional shaft motors are in motor mode, and the ship's electrical system provides power to drive the corresponding propulsion shafts.

[0026] Preferably, in step S5, when the ship's electrical system fails, both gas turbines operate at a preset power of 4, and both bidirectional shaft-driven motors are in generator mode, transmitting the electrical energy generated by the generators to the loads of the ship's electrical system.

[0027] Compared with the prior art, the present invention has the following main advantages:

[0028] 1. This invention uses a bidirectional motor as a node for converting mechanical energy into electrical energy, and in conjunction with control and transfer devices, connects the propulsion system and the power system in the form of electrical energy, realizing the mutual conversion of power between the two systems. Combined with the corresponding control method, it can effectively improve the power utilization efficiency of the ship's power system.

[0029] 2. This invention uses a hybrid propulsion system combining mechanical and electric propulsion, which maintains the maturity and reliability of traditional propulsion systems while possessing the advanced features of electric propulsion, and further improves the economy of the ship's life cycle and the stability of its operation.

[0030] 3. This invention enables the connection between the propulsion system and the power system, thus maintaining the relative independence of the two systems while allowing the propulsion system and the power system to serve as backups for each other, greatly improving the survivability of the propulsion system and the power system;

[0031] 4. This invention improves the low noise performance of ships under low-speed conditions, and the electric jumper makes the layout of the propulsion system more flexible, which helps to improve the overall space utilization efficiency of the ship. Attached Figure Description

[0032] Figure 1 This is an overall schematic diagram of the ship's propulsion system in an embodiment of the present invention;

[0033] Figure 2 This is a flowchart of the control method in an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of the ship's propulsion system under high-speed operating conditions in an embodiment of the present invention. Figure 1 ;

[0035] Figure 4 This is a schematic diagram of the ship's propulsion system under high-speed operating conditions in an embodiment of the present invention. Figure 2 ;

[0036] Figure 5 This is a schematic diagram of the ship's propulsion system operating at cruising speed in an embodiment of the present invention. Figure 1 ;

[0037] Figure 6 This is a schematic diagram of the ship's propulsion system operating at cruising speed in an embodiment of the present invention. Figure 2 ;

[0038] Figure 7 This is a schematic diagram of the ship's power system operating under low-speed conditions in an embodiment of the present invention.

[0039] In the diagram: 1-Gas turbine one; 2-Gas turbine two; 3-Gearbox one; 4-Gearbox two; 5-Propulsion shaft one; 6-Propulsion shaft two; 7-Propeller one; 8-Propeller two; 9-Bidirectional shaft-driven motor one; 10-Bidirectional shaft-driven motor two; 11-Control and switching device; 12-Ship electrical system. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0041] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0042] Example 1: This example provides a ship propulsion system with electromechanical hybrid propulsion, such as... Figure 1 As shown, it mainly includes: a separately installed gas turbine 1 and a gas turbine 2. The gas turbine 1 and the gas turbine 2 are respectively connected to the propulsion shaft 5 and the propulsion shaft 6 through gearbox 3 and gearbox 4. The ends of the propulsion shaft 5 and the propulsion shaft 6 are respectively connected to the propeller 7 and the propeller 8. The middle parts of the propulsion shaft 5 and the propulsion shaft 6 are respectively provided with a bidirectional shaft-driven motor 9 and a bidirectional shaft-driven motor 10. The bidirectional shaft-driven motor 9 and the bidirectional shaft-driven motor 10 are electrically connected to the control and transfer device 11 through connecting cables. The control and transfer device 11 is electrically connected to the ship's electrical system 12.

[0043] Furthermore, both the bidirectional shaft-driven motor 9 and the bidirectional shaft-driven motor 10 have both generator mode and motor mode, used to convert the mechanical energy of the corresponding propulsion shaft into electrical energy and transmit it to the control and transfer device 11, or to convert the electrical energy transmitted by the control and transfer device 11 into mechanical energy to drive the corresponding propulsion shaft to operate.

[0044] Furthermore, the control and transfer device 11 is used to control the speed of the bidirectional shaft motor 9 and the bidirectional shaft motor 10 in motor mode. At the same time, the control and transfer device 11 is also used to transmit the electrical energy transmitted in the shaft motor generator mode to the ship's power system 12, or to transmit the electrical energy stored in the ship's power system 12 to the shaft motor in motor mode.

[0045] Example 2: Based on the same inventive concept, this example also provides a control method for the ship propulsion system as described above, such as... Figure 2 As shown, the specific steps include the following:

[0046] S1 determines the current operating condition of the ship;

[0047] S2, when the ship is operating at high speed, it adopts a dual gas turbine propulsion system plus an electric power system for auxiliary propulsion;

[0048] S3, when the ship is operating at cruising speed; uses a single gas turbine propulsion system plus a single electric motor propulsion system.

[0049] S4, when the ship is operating at low speed, it adopts a single gas turbine propulsion plus electric system auxiliary propulsion.

[0050] S5: When the ship is in a fault-resistant operating condition, it switches to the corresponding backup propulsion mode according to the location of the fault.

[0051] Furthermore, in step S2, the high-speed operating condition specifically refers to the ship's speed being higher than the preset maximum cruise speed.

[0052] The aforementioned dual gas turbine propulsion plus electric system assisted propulsion mode specifically involves both gas turbines operating at a preset power level; simultaneously, both bidirectional shaft-driven motors are in electric motor mode, with power supplied by the ship's electrical system to assist in driving the corresponding propulsion shafts.

[0053] Furthermore, in step S3, the cruise speed operating condition specifically refers to the ship's speed not exceeding the preset maximum cruise speed and not falling below the preset minimum cruise speed.

[0054] The single gas turbine propulsion plus single motor propulsion configuration specifically involves any one gas turbine operating at a preset power level, with its corresponding bidirectional shaft motor in generator mode, transmitting the electrical energy generated by the generator to another bidirectional shaft motor for use. The other bidirectional shaft motor is in motor mode, used to drive the propulsion shaft of the other gas turbine.

[0055] Part of the electrical energy generated by the generator is transmitted to the other bidirectional shaft motor, and the other part is transmitted to the load of the ship's power system.

[0056] Furthermore, in step S4, the low-speed operating condition specifically refers to the ship's speed being lower than the preset minimum cruising speed.

[0057] The single gas turbine propulsion plus electric system assisted propulsion mode specifically involves any one gas turbine operating at a preset power level, with the corresponding bidirectional shaft motor on its propulsion shaft in motor mode, and the gas turbine and the corresponding bidirectional shaft motor jointly driving the corresponding propulsion shaft to rotate.

[0058] Furthermore, in step S5, when the ship's gas turbine malfunctions, both bidirectional shaft motors are in motor mode, and the ship's electrical system provides power to drive the corresponding propulsion shafts.

[0059] Furthermore, in step S5, when the ship's electrical system malfunctions, both gas turbines operate at a preset power of 4, and both bidirectional shaft-driven motors are in generator mode, transmitting the electrical energy generated by the generators to the loads of the ship's electrical system.

[0060] Example 3: This example provides a control method for a ship's propulsion system, including:

[0061] 1) High-speed operation conditions

[0062] When the ship is running at high speed, similar to a combined gas turbine and diesel propulsion system, the two propulsion systems operate independently, with each gas turbine driving a shaft propeller. Figure 3 As shown, the propulsion scheme for this working condition ensures the maturity and reliability of mechanical propulsion, and can reduce the development risks of high-speed electric propulsion and high-power electric propulsion related equipment.

[0063] Under this operating condition, the ship operates in mechanical propulsion mode; simultaneously, the remaining power reserve of the electrical system can be used as reserve power for the propulsion system, such as... Figure 4 As shown, when necessary, surplus power from the electrical system can be used to drive motors and add power to the propulsion system, making the ship's power more abundant.

[0064] 2) Cruise speed operating condition

[0065] At cruising speed, propulsion power requirements are significantly reduced, allowing propulsion to be achieved through either main engine. Its shaft motor acts as a generator, converting some of the power into electrical energy. This electrical energy is then transmitted to the other shaft motor via a switching control device. At this time, the other shaft motor functions as an electric motor, as detailed below. Figure 5 As shown.

[0066] In this operating condition, the ship operates in a hybrid propulsion mode. To increase the main engine's operating power under this condition, the power generated by the shaft-driven motor can be supplied to the load of the electrical system while simultaneously supporting the propulsion of the other shaft. Figure 6 As shown.

[0067] 3) Low-speed operation conditions

[0068] Below cruising speed, the main engine power has ample surplus for propulsion, and the main engine operates at low power. Under these conditions, the main engine efficiency is low, and operational stability is poor. This application proposes that, in addition to using the main engine for propulsion (operating as in cruising mode), electric propulsion can also be achieved using the reserve power of the electrical system. In this case, the electrical system operates at a relatively high power level, resulting in better operational stability and reduced gearbox vibration, thus lowering overall ship vibration and noise radiation. An operational diagram is shown below. Figure 7 As shown.

[0069] The power output of the electric system can be adjusted according to the load, thus enabling high-efficiency operation at low speeds. In addition to its good economic advantages, it is also suitable for low-noise operating conditions, improving the ship's special performance characteristics. Under this condition, the ship as a whole is equivalent to a fully electric vessel.

[0070] 4) Special operating conditions

[0071] a) Fault-resistant operating conditions

[0072] As a ship, it is essential to consider the special operating modes of systems under failure conditions, namely, failure operation conditions. As the two most important systems providing power and electricity, the survivability of the propulsion system and the electrical system should be an important consideration in ship design.

[0073] This technical solution eliminates the need for a bridging gearbox in the propulsion system, reducing the layout constraints of the two main engines. This helps reduce the risk of simultaneous failure of both main engines. The cable-connected shaft-driven motors also offer greater layout flexibility than those with bridging gearboxes, allowing them to be distributed across different compartments. Furthermore, the integration of the electrical and propulsion systems further enhances the survivability of both systems. The propulsion system can then serve as a backup for the electrical system, and vice versa, significantly improving the overall survivability of the ship's propulsion and electrical systems.

[0074] The operating mode after a power system failure is similar to that of cruise operation. Figure 6 The operating mode after a propulsion system failure is similar to that under low-speed conditions. Figure 7 .

[0075] b) Low-noise operating conditions

[0076] Low-speed electric propulsion system operating condition (refer to low-speed operating condition) Figure 7 The mechanical noise originates solely from the diesel generator, reducing vibration noise from three gearboxes compared to a combined diesel and gas turbine (COG) system. This results in superior low-noise mechanical performance. Furthermore, the lower infrared radiation from the diesel engine contributes to reduced infrared radiation and improved infrared characteristics of the ship.

[0077] Furthermore, all parts of this application that are not described in detail are the same as or implemented using existing technology.

[0078] In summary:

[0079] 1. This invention uses a bidirectional motor as a node for converting mechanical energy into electrical energy, and in conjunction with control and transfer devices, connects the propulsion system and the power system in the form of electrical energy, realizing the mutual conversion of power between the two systems. Combined with the corresponding control method, it can effectively improve the power utilization efficiency of the ship's power system.

[0080] 2. This invention uses a hybrid propulsion system combining mechanical and electric propulsion, which maintains the maturity and reliability of traditional propulsion systems while possessing the advanced features of electric propulsion, and further improves the economy of the ship's life cycle and the stability of its operation.

[0081] 3. This invention enables the connection between the propulsion system and the power system, thus maintaining the relative independence of the two systems while allowing the propulsion system and the power system to serve as backups for each other, greatly improving the survivability of the propulsion system and the power system;

[0082] 4. This invention improves the low noise performance of ships under low-speed conditions, and the electric jumper makes the layout of the propulsion system more flexible, which helps to improve the overall space utilization efficiency of the ship.

[0083] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for a ship propulsion system with electromechanical hybrid propulsion, characterized in that, The ship's propulsion system includes a separately installed gas turbine one (1) and a gas turbine two (2). The gas turbine one (1) and the gas turbine two (2) are connected to the propulsion shaft one (5) and the propulsion shaft two (6) respectively through gearbox one (3) and gearbox two (4). The ends of the propulsion shaft one (5) and the propulsion shaft two (6) are respectively connected to propeller one (7) and propeller two (8). The middle part of the propulsion shaft one (5) and the propulsion shaft two (6) is respectively provided with a bidirectional shaft-driven motor one (9) and a bidirectional shaft-driven motor two (10). The bidirectional shaft-driven motor one (9) and the bidirectional shaft-driven motor two (10) are electrically connected to the control and transfer device (11) through connecting cables. The control and transfer device (11) is electrically connected to the ship's power system (12). The control method includes the following steps: S1 determines the current operating condition of the ship; S2, when the ship is operating at high speed, it adopts a dual gas turbine propulsion system plus an electric power system for auxiliary propulsion; The high-speed operating condition specifically refers to a ship speed that is higher than the preset maximum cruising speed. The aforementioned dual gas turbine propulsion plus electric system assisted propulsion mode specifically involves both gas turbines operating at a preset power level; simultaneously, both bidirectional shaft-driven motors are in electric motor mode, with power supplied by the ship's electrical system to assist in driving the corresponding propulsion shafts. S3, when the ship is operating at cruising speed; uses a single gas turbine propulsion system plus a single electric motor propulsion system. The cruise speed operating condition is specifically defined as the ship's speed not exceeding the preset maximum cruise speed and not falling below the preset minimum cruise speed. The single gas turbine propulsion plus single motor propulsion configuration specifically involves any one gas turbine operating at a preset power level, with the corresponding bidirectional shaft motor on its propulsion shaft in generator mode, transmitting the electrical energy generated by the generator to another bidirectional shaft motor for use. The other bidirectional shaft motor is in motor mode, used to drive the propulsion shaft corresponding to the other gas turbine. Part of the electrical energy generated by the generator is transmitted to the other bidirectional shaft motor, and the other part is transmitted to the load of the ship's electrical system. S4, when the ship is operating at low speed, it adopts a single gas turbine propulsion plus electric system auxiliary propulsion. The low-speed operating condition specifically refers to a ship's speed being lower than the preset minimum cruising speed. The single gas turbine propulsion plus electric system auxiliary propulsion mode is specifically that any gas turbine operates at a preset power of 3, and the corresponding bidirectional shaft motor on its propulsion shaft is in motor mode, and the gas turbine and the corresponding bidirectional shaft motor jointly drive the corresponding propulsion shaft to rotate. S5: When the ship is in a fault-resistant operating condition, it switches to the corresponding backup propulsion mode according to the location of the fault.

2. The control method for a ship propulsion system with electromechanical hybrid propulsion according to claim 1, characterized in that: Both the bidirectional shaft-driven motor 1 (9) and the bidirectional shaft-driven motor 2 (10) have both generator mode and motor mode, which are used to convert the mechanical energy of the corresponding propulsion shaft into electrical energy and transmit it to the control and transfer device (11), or to convert the electrical energy transmitted by the control and transfer device (11) into mechanical energy to drive the corresponding propulsion shaft to operate.

3. The control method for a ship propulsion system with electromechanical hybrid propulsion according to claim 2, characterized in that: The control and transfer device (11) is used to control the rotational speed of the bidirectional shaft motor one (9) and the bidirectional shaft motor two (10) in motor mode. At the same time, the control and transfer device (11) is also used to transmit the electrical energy transmitted in the shaft motor generator mode to the ship's power system (12), or to transmit the electrical energy stored in the ship's power system (12) to the shaft motor in motor mode.

4. The control method for a ship propulsion system with electromechanical hybrid propulsion according to claim 1, characterized in that... In step S5, when the ship's gas turbine malfunctions, both bidirectional shaft motors are in motor mode, and the ship's electrical system provides power to drive the corresponding propulsion shafts.

5. The control method for a ship propulsion system with electromechanical hybrid propulsion according to claim 4, characterized in that... In step S5, when the ship's electrical system fails, both gas turbines operate at the preset power level, and both bidirectional shaft motors are in generator mode, transmitting the electrical energy generated by the generators to the loads of the ship's electrical system.

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