Propelling system of electric propulsion controllable-pitch propeller of breeding work ship

Abstract

The invention provides an electric propulsion controllable-pitch propeller propulsion system of a breeding work ship, which relates to the technical field of breeding work ships and comprises a main generator set, a main distribution board, a soft starter, a bypass contactor, a conversion cabinet, a propulsion motor and a propulsion propeller, a phase-shifting transformer, a high-power propulsion frequency converter and a brake resistor which are large in size and high in price in a conventional electric propulsion system are replaced with the low-power variable-frequency soft starter, a power distribution network is greatly simplified, fault points of a power system are reduced, and occupied space of a cabin is reduced. And the capacity of the variable-frequency soft starter is only about 1 / 3-1 / 4 of that of a conventional electric propulsion frequency converter, so that the equipment cost and the performance requirements are effectively reduced. A three-phase asynchronous motor without a speed regulation requirement is selected as a propulsion motor, so that the equipment purchase cost is remarkably reduced. And by adopting the bypass contactor for control, the harmonic interference influence of the power grid is reduced, and the service life of the variable-frequency soft starter is prolonged. The redundancy and reliability of the power system are greatly improved by reasonably designing the main distribution board and the conversion cabinet architecture.

Description

Technical Field

[0001] The present invention belongs to the technical field of aquaculture workboats, and more specifically, particularly relates to an electric propulsion controllable pitch propeller propulsion system for an aquaculture workboat. Background Art

[0002] At present, about 93% of the world's fishery resources are in a state of "fully exploited or overexploited", and the transformation of the marine fishery industrial structure is imminent. An aquaculture workboat is a new type of ship integrating ship technology and aquaculture technology, and has been successively applied to the production operations of marine pastures. At present, a major problem faced by deep-sea and far-sea aquaculture workboats is still the very high initial investment cost of the workboats, and it is difficult to find suitable operating enterprises, which has become a bottleneck factor restricting their rapid development.

[0003] The power system of an aquaculture workboat is an important indicator affecting the technical economy and ship cost of the whole ship. According to the production operation characteristics, an aquaculture workboat needs to be periodically and autonomously moored and cruise in the target sea area throughout the year for rotational production. Its main operating conditions include: navigation, entering and leaving the port, aquaculture, fish suction and processing, migration and transfer operations, etc. The workboat has the operating characteristics of long-term operation in the mooring aquaculture operation state throughout the year and very short navigation and transfer periods. If the conventional propulsion form is adopted for the power system of an aquaculture workboat, the installed power of the system is large and it is very uneconomical. Although the adoption of electric propulsion technology can reduce the total installed power of diesel engines, improve economy and fishery adaptability, there are still disadvantages for electrical devices such as high-power frequency converters, propulsion phase-shifting transformers, and braking resistors in the electric propulsion system, including high equipment parameter specifications, huge weight and size, much occupied engine room space, large equipment heat dissipation, high requirements for power grid harmonic suppression and power grid power quality, and complex distribution networks. At the same time, the core components such as the frequency conversion device in the electric propulsion system are also high-power electrical devices, and the overall cost of the power propulsion system is high. These disadvantages bring certain difficulties to the popularization of the aquaculture workboat industry.

[0004] Therefore, simplifying the distribution network, reducing the fault points of the power system, increasing the redundancy of the power propulsion system, ensuring the navigation safety of the aquaculture workboat, further improving the fishery adaptability and economy of the workboat, reducing the construction cost of the workboat, and achieving the goal of rapid popularization of the aquaculture workboat industry are technical problems that need to be broken through and solved for aquaculture workboats. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides an electric propulsion controllable pitch propeller propulsion system for an aquaculture workboat to solve the above problems.

[0006] An electric propulsion controllable pitch propeller propulsion system for an aquaculture workboat includes a main generating set, a main switchboard, a soft starter, a bypass contactor (and contactor switch), a conversion cabinet, a propulsion motor, and a propulsion propeller;

[0007] Main generating set: Fixedly installed in the engine room of the aquaculture workboat, providing AC power for the ship's power system;

[0008] Main switchboard: Used to control and monitor the operation of the main generating set, and supply the electric energy generated by the main generating set to the soft starter, propulsion motor, controllable pitch propeller and other loads through the main power grid. Corresponding power supply switches are provided in the main switchboard to supply corresponding electric energy and power protection to the propulsion motor;

[0009] Soft starter: Used to control the start of the non-speed-regulating propulsion motor in the "zero pitch" state, reduce the starting current of the propulsion motor, and avoid large impacts on the grid equipment;

[0010] Bypass contactor (and contactor switch): Used to switch the propulsion motor to bypass power supply after starting by the soft starter. The bypass contactor is provided with a corresponding bypass contactor switch, which supplies power electric energy to the propulsion motor and the controllable pitch propeller through the bypass contactor switch. The bypass contactor can extend the service life of the soft starter and reduce grid harmonic interference;

[0011] Transfer cabinet: Used to realize the mutual standby and redundant control of the power supply lines of the dual-machine and dual-propeller propulsion system, improve the safety and reliability of the propulsion system. Contactor switches are provided in the transfer cabinet;

[0012] Propulsion motor: A three-phase asynchronous motor without speed regulation requirements, used to provide thrust to the ship (propeller);

[0013] Propulsion propeller: A controllable pitch propeller is adopted, which is used to provide power to the ship. By adjusting the pitch, the torque, thrust and speed are changed, so as to realize the forward, backward, variable speed, stop and other actions of the ship without changing the rotation direction and speed of the propulsion motor.

[0014] Preferably, the electrical system of the main generating set is designed as AC690V or AC400V according to the capacity of the main generating set.

[0015] Preferably, the main switchboard is designed with 2 busbars, and the two-way propulsion loads are evenly distributed at both ends of the busbars. An independent power supply switch for the bypass power supply circuit is set in the main switchboard, providing power supply conditions for the mutual standby use of the two variable frequency soft starters of the propulsion system and the two-for-two redundant design.

[0016] Preferably, taking the variable frequency soft starter as an example, its capacity is about 1 / 3 - 1 / 4 of the capacity of the conventional electric propulsion frequency converter.

[0017] Preferably, the function of mutual standby and two-for-two redundant design of the two variable frequency soft starters is realized through the transfer cabinet. When any variable frequency soft starter fails, it does not affect the use of the two-way thrusters.

[0018] Preferably, after the propulsion motor reaches the rated speed, the soft starter withdraws, and the propulsion motor drives the propeller to continue running at the rated speed through the bypass contactor switch of the soft starter and the power supply switch in the main switchboard.

[0019] Preferably, after the propeller and the propulsion motor reach the rated speed, the power system of the aquaculture workboat changes to the pitch-adjusting operation mode. By adjusting the pitch, the torque, thrust, power of the propeller and the ship speed of the workboat are changed, and the propulsion motor always maintains the rated speed operation.

[0020] Preferably, when the ship speed is less than a certain value and meets the operating conditions of the soft starter and the propulsion motor with light load, the combined control of the speed, pitch ratio and low ship speed of the aquaculture workboat is realized.

[0021] Preferably, when a frequency conversion soft starter of one propulsion system fails, the other frequency conversion soft starter starts to operate after receiving the "allow start" command, maintains the normal operation of the propulsion motor and the propeller of the faulty path, and after the "zero pitch" start process is completed, the faulty path switches to the pitch-adjusting operation ship speed control mode.

[0022] Preferably, the frequency conversion soft starter, the propulsion motor, and the controllable pitch propeller are all equipped with corresponding control units at the control stations of the aquaculture workboat cab, the engine room centralized control station, and the local control station beside the machine, realizing the remote and local control of the power system.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] In the present invention, a small-power frequency conversion soft starter is used to replace the large-sized and expensive phase-shifting transformer, high-power propulsion frequency converter and braking resistor in the conventional electric propulsion system, greatly simplifying the power distribution network. The capacity of the frequency conversion soft starter is only about 1 / 3 - 1 / 4 of the capacity of the conventional electric propulsion frequency converter, effectively reducing the equipment cost and reducing the fault points of the power system.

[0025] In the present invention, a three-phase asynchronous motor without speed regulation requirement is selected for the propulsion motor. Compared with the more expensive frequency conversion propulsion motor in the conventional electric propulsion system, the equipment procurement cost is significantly reduced. At the same time, by reasonably designing the main switchboard and the system architecture, the occupancy of the engine room space is reduced, and the redundancy and reliability of the power system are improved.

[0026] In the present invention, a conversion cabinet is set in the system to realize the function of mutual backup and two-for-two redundancy design of two frequency conversion soft starters. When any one of the frequency conversion soft starters fails, the other soft starter can respond quickly, and through the conversion cabinet, the normal operation of the propulsion motor and the propeller of the faulty path is maintained, ensuring the continuous stability of the power system during navigation and operation, avoiding the loss of power of the ship due to equipment failure, and greatly improving the navigation safety of the aquaculture workboat in complex sea conditions.

[0027] In the present invention, the simplified power distribution network and equipment configuration reduce the number of devices and connection nodes, thereby reducing the probability of faults. At the same time, the application of the bypass contactor not only extends the service life of the soft starter, but also reduces the power grid harmonic interference, further ensuring the stable operation of the system.

[0028] In the present invention, the system adopts the combination of "AC electric propulsion controllable pitch propeller + non-speed-regulating propulsion motor + soft starter". Through the "zero pitch" starting and pitch-adjusting operation mode, it can accurately control actions such as the ship moving forward, backward, changing speed, and stopping without changing the rotation direction and speed of the propulsion motor, meeting the strict requirements for ship speed in various operating conditions such as the breeding workboat during navigation, entering and leaving ports, and migrating and transferring fields.

[0029] In the present invention, when the ship speed is less than a certain value and meets the light-load operating conditions of the soft starter and the propulsion motor, the system can achieve the combined control of speed, pitch ratio, and the low ship speed of the breeding workboat, providing a strong guarantee for the low-speed stable operation of the breeding workboat in light-load navigation, transfer and other operation scenarios, and improving the ship speed control efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of the electric propulsion controllable pitch propeller system of the breeding workboat in the present invention;

[0031] Figure 2 is a schematic diagram of a conventional electric propulsion system. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The following further describes in detail the embodiments of the present invention in conjunction with the drawings and examples. The following examples are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0033] Please refer to Figure 1 - Figure 2 , the present invention provides an electric propulsion controllable pitch propeller propulsion system for a breeding workboat, Figure 1 In the figure, reference numeral 1 is the main generating set, G1 - G4 provide power supply for the propulsion device, reference numeral 2 is the main switchboard (MSB), where 1QF - 4QF are the main switches of the three-phase AC main generating sets; 5QF - 8QF are the load switches; 9QF is the isolating switch of the main switchboard busbar; reference numeral 3 is the soft starter (VFSS1 - VFSS2), and the figure takes the variable-frequency soft starter as an example; reference numeral 4 is the conversion cabinet (CCB, where K4, K6, K7 are contactor switches); reference numeral 5 is the propulsion motor (M1 - M2); reference numeral 6 is the controllable pitch propeller (CPP1 - CPP2); K1, K2 are the bypass contactor switches; K3, K5 are the contactor switches; Figure 2 is a schematic diagram of a conventional electric propulsion system. The following combines Figure 1 , Figure 2The comparative design and the specific control process of this system are used to further illustrate the present invention. The configuration and installation of the system are as follows:

[0034] Main generating set: According to the power requirements of the whole ship propulsion system and other loads, determine the capacity and quantity of the main generating set. The main generating set is fixedly installed in the engine room of the aquaculture workboat. Its electrical system can be designed as AC690V or AC400V according to the capacity of the main generating set, providing AC power for the whole ship's power system.

[0035] Main switchboard: Adopt a two-busbar design, and evenly distribute the two-way propulsion loads at both ends of the busbars. Corresponding power supply switches are set in the main switchboard, which can not only control and monitor the operation of the main generating set, but also distribute electric energy to the soft starter, propulsion motor, controllable pitch propeller and other loads through the main power grid, and at the same time provide necessary electric energy and electrical protection for the propulsion motor. In particular, an independent power supply switch for the bypass power supply circuit should be set up to create power supply conditions for the mutual standby use of the two variable frequency soft starters of the propulsion system and the two-for-two redundancy design.

[0036] Soft starter: Select a variable frequency soft starter. According to the no-load current theory of the three-phase asynchronous motor and the working characteristics of the variable frequency soft starter for starting, determine its capacity, which is about 1 / 3 - 1 / 4 of the capacity of the conventional electric propulsion frequency converter. The soft starter is used to control the starting of the non-speed-regulating propulsion motor in the "zero pitch" state, reduce the starting current of the propulsion motor, and avoid causing a large impact on the grid equipment.

[0037] Bypass contactor: After the propulsion motor is started by the soft starter, the bypass contactor operates to switch the propulsion motor to the bypass power supply. The bypass contactor is equipped with a corresponding bypass contactor switch, which provides motive power electric energy to the propulsion motor and the controllable pitch propeller, extends the service life of the soft starter at the same time, and reduces the grid harmonic interference.

[0038] Conversion cabinet: A contactor switch is set in the conversion cabinet, and the conversion cabinet is used to realize the function of mutual standby of the two variable frequency soft starters and the two-for-two redundancy design, so as to improve the safety and reliability of the propulsion system.

[0039] Propulsion motor and propulsion propeller: Select a three-phase asynchronous motor without speed regulation requirements as the propulsion motor to provide thrust for the ship's propeller. Adopt a controllable pitch propeller, and change the torque, thrust and speed by adjusting the pitch, so as to realize the forward, backward, variable speed, stop and other actions of the ship without changing the rotation direction and speed of the propulsion motor.

[0040] System operation process:

[0041] "Zero Pitch" Starting Process: When the aquaculture workboat needs to switch from the moored state to the sailing state, first adjust the pitch of the propeller to the "zero pitch" state, at which time the ship speed is zero. Control the propulsion motor through the variable frequency soft starter to gradually increase the rotational speed of the propeller driven by the propulsion motor from zero to the rated speed. During the "zero pitch" starting stage, the propeller is in a light-load operating state, which is a zero-thrust pitch condition with low torque and power requirements. After the propulsion motor reaches the rated speed, the variable frequency soft starter exits the operation, and the propulsion motor drives the propeller to continue operating at the rated speed through the bypass contactor switch of the variable frequency soft starter and the power supply switch in the main switchboard.

[0042] Variable Pitch Operation Ship Speed Control Process: After both the propeller and the propulsion motor reach the rated speed, the power system of the aquaculture workboat enters the variable pitch operation mode. By adjusting the pitch of the propeller, the torque, thrust, and power of the propeller are changed, thereby controlling the ship speed of the workboat. During this process, the propulsion motor always maintains operation at the rated speed. At a small pitch, the torque and thrust of the propeller are small; if a large torque and high ship speed are required, the propulsion motor needs to increase the pitch of the propeller at the rated speed. When the torque and power of the propeller continue to increase by adjusting the pitch and the propulsion motor of the aquaculture workboat reaches the rated torque, the workboat finally realizes sailing at the rated ship speed. In addition, when the ship speed is less than a certain value and the conditions for light-load operation of the variable frequency soft starter and the propulsion motor are met, the combined control of the rotational speed, pitch ratio, and low ship speed of the aquaculture workboat can be achieved.

[0043] Redundant control process for mutually backup power propulsion systems: When a frequency conversion soft starter in one propulsion system fails, for example, the No. 1 frequency conversion soft starter (VFSS1) fails and cannot maintain the normal operation of the No. 1 propulsion motor (M1) and the left propeller (CPP1) of the left propulsion system, the propulsion system will detect the fault stop signal of the frequency conversion soft starter (VFSS1) and send a "start permission" request to the No. 2 propulsion frequency conversion soft starter (VFSS2) of the right propulsion system. When the No. 2 frequency conversion soft starter (VFSS2) is in the "idle mode" working state and receives the "start permission" instruction, it starts to run. At this time, the propulsion load switch (7QF) in the main switchboard (MSB), the bypass contactor switch (K5) of the right propulsion system, and the contactor switches (K4, K7) in the conversion cabinet (CCB) are all in the closed state to maintain the normal operation of the No. 1 propulsion motor (M1) and the left propeller (CPP1) of the left propulsion system. After the "zero pitch" starting process is completed, the No. 2 frequency conversion soft starter (VFSS2) exits the operation, and the left propulsion system switches to the pitch control ship speed control mode. At this time, the left propulsion system realizes the continuous independent ship speed control function of the No. 1 propulsion motor (M1) and the left propeller (CPP1) through the power-on and closing of the propulsion load switch (6QF) in the main switchboard (MSB), the bypass contactor switch (K1) of the left propulsion system, and the contactor switch (K4) in the conversion cabinet (CCB), and the open state of the contactor switch (K5) in the conversion cabinet (CCB), and then restores the full control of the propulsion and ship speed of the two propulsion systems. When the No. 2 frequency conversion soft starter (VFSS2) fails, the control process is similar.

[0044] Control operations of the power system: At the control stations in the cab, the machinery control room, and the local control station of the aquaculture workboat, there are corresponding control units for the frequency conversion soft starter, the propulsion motor, and the controllable pitch propeller. The crew can use these control units to achieve remote and local control of the power system to meet the operation requirements in different working scenarios.

[0045] The embodiments of the present invention are given for purposes of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are chosen and described in order to best explain the principles of the invention and its practical application, and to enable those of ordinary skill in the art to understand the invention and design various embodiments with various modifications suitable for specific purposes.

Claims

1. An electric propulsion controllable pitch propeller propulsion system for aquaculture vessels, characterized in that: The system includes main generator set, main switchboard, soft starter, bypass contactor, conversion cabinet, propulsion motor, propulsion propeller; Main generator set: fixedly installed in the engine room of the aquaculture vessel, providing AC power for the entire ship's power system; Main switchboard: controls and monitors the operation of the main generator set, and supplies the electric energy generated by the main generator set to the soft starter, propulsion motor, adjustable pitch propeller and other loads through the main power grid. The main switchboard is equipped with a power switch to provide the corresponding electric energy and power protection to the propulsion motor; Soft starter: controls the starting of the non-speed-regulated propulsion motor in the "zero pitch" state; Bypass contactor: After the propulsion motor is started by the soft starter, it switches to bypass power supply. The bypass contactor is equipped with a corresponding bypass contactor switch, which provides power energy to the propulsion motor and the propulsion controllable pitch propeller; Conversion cabinet: equipped with contactor switch; Propulsion motor: A three-phase asynchronous motor with no speed regulation requirement is used to provide thrust to the ship's propeller; Propulsion propeller: An adjustable pitch propeller is used to provide power to the ship. By adjusting the pitch, the torque, thrust and speed can be changed to achieve the ship's forward, backward, speed change, stop and other actions without changing the direction and speed of the propulsion motor.

2. The electric propulsion controllable pitch propeller propulsion system for aquaculture vessels according to claim 1, characterized in that: The power system of the main generator set is designed to be AC690V or AC400V according to the capacity of the main generator set.

3. The electric propulsion controllable pitch propeller propulsion system for aquaculture vessels according to claim 1, characterized in that: The main distribution board is designed as a two-section bus, and the two propulsion loads are evenly distributed at both ends of the bus. An independent power supply switch for the bypass power supply circuit is set in the main distribution board to provide power supply conditions for the mutual backup use of the two variable frequency soft starters in the propulsion system and the two-to-two redundant design.

4. The electric propulsion controllable pitch propeller propulsion system for aquaculture vessels according to claim 1, characterized in that: Taking the variable frequency soft starter as an example, its capacity is about 1 / 3-1 / 4 of the capacity of a conventional electric propulsion inverter.

5. The electric propulsion controllable pitch propeller propulsion system for aquaculture vessels as claimed in claim 1, characterized in that: The conversion cabinet is used to realize the function of two variable frequency soft starters serving as backup for each other and two-to-two redundant design. When any variable frequency soft starter fails, the use of the two thrusters is not affected.

6. The electric propulsion controllable pitch propeller propulsion system for aquaculture vessels as claimed in claim 1, characterized in that: After the propulsion motor reaches the rated speed, the soft starter exits, and the propulsion motor drives the propeller to continue running at the rated speed through the bypass contactor switch of the soft starter and the power supply switch in the main distribution board.

7. The electric propulsion controllable pitch propeller propulsion system for aquaculture vessels as claimed in claim 1, characterized in that: When the propeller and propulsion motor reach the rated speed, the power system of the aquaculture vessel is changed to the pitch adjustment operation mode. The torque, thrust, power of the propeller and the speed of the vessel are changed by adjusting the pitch, and the propulsion motor always maintains the rated speed.

8. The electric propulsion controllable pitch propeller propulsion system for aquaculture vessels as claimed in claim 1, characterized in that: When the speed is less than a certain value and meets the working conditions of the soft starter and propulsion motor running under light load, the joint control of the speed, pitch ratio and low speed of the aquaculture vessel is realized.

9. The electric propulsion controllable pitch propeller propulsion system for aquaculture vessels as claimed in claim 1, characterized in that: When one propulsion system variable frequency soft starter fails, the other variable frequency soft starter starts running after receiving the "start allowed" command, maintaining the normal operation of the faulty propulsion motor and propeller. After the "zero pitch" starting process is completed, the faulty path switches to the pitch adjustment ship speed control mode.

10. The electric propulsion controllable pitch propeller propulsion system for aquaculture vessels according to claim 1, characterized in that: The variable frequency soft starter, propulsion motor, and adjustable pitch propeller are equipped with corresponding control units in the aquaculture vessel's cab control station, engine room control room control station, and machine-side control station to achieve remote and local control of the power system.

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