Pure electric marine vessel main propulsion system

Abstract

The utility model discloses a pure electric ship main propulsion system, system is equipped with for direct current busbar, be connected with power battery module, permanent magnet synchronous propulsion motor unit and charging module on direct current busbar, be connected with super capacitor module on direct current busbar, and the power manager of permanent magnet synchronous propulsion motor unit and power battery module is connected through data line to ship controller. The utility model discloses a kind of high endurance new energy pure electric ship main propulsion system, especially suitable for the small and medium-sized civilian ships of endurance ability, environmental protection performance and power stability requirement higher, through the cooperation of multiple energy supplementing mode, it can be comprehensive to various energy, improve the overall endurance of ship.

Description

Technical Field

[0001] This utility model relates to the field of pure electric marine power systems. Background Technology

[0002] With the advancement of global "dual carbon" goals and increasingly stringent regulations on ship emissions by the International Maritime Organization, new energy pure electric ships, with their advantages of zero emissions and low noise, have become an important direction for the transformation of the shipbuilding industry. However, existing pure electric ship main propulsion systems still face three core problems in practical applications: Firstly, the range is insufficient. Currently, most pure electric ships rely on a single power battery for power. Due to the limited energy density of the battery (the energy density of mainstream marine power batteries is only 150-200Wh / kg), the range after a single charge is generally less than 100km, which is difficult to meet the operational needs of inland waterway freight ships (average daily voyage of 150-200km) and short- and medium-distance passenger ships. Frequent charging leads to a significant reduction in operational efficiency.

[0003] Secondly, the power output stability is poor. During ship navigation, complex load changes are encountered (such as fluctuations in water resistance, changes in cargo weight, and sudden turns). The discharge characteristics of a single power battery are significantly affected by temperature and SOC (State of Charge) value. In low-temperature environments (<5℃), the battery discharge efficiency decreases by more than 30%, and when SOC <20%, the output power drops sharply, which can easily lead to insufficient power of the propulsion motor and affect the safety of ship handling.

[0004] Third, energy replenishment and utilization efficiency is low. Traditional pure electric ships use a single charging station for replenishment, with charging time as long as 4-8 hours, and do not make full use of renewable energy sources (such as solar energy) during the ship's voyage; at the same time, the propulsion system and energy system lack coordinated control, and the propulsion motor often operates in an inefficient range, further aggravating energy consumption.

[0005] Furthermore, existing pure electric ship propulsion actuators mostly use traditional fixed-pitch propellers, which result in large fluctuations in propulsion efficiency under different speed conditions (efficiency is only 35%-45% at low speeds) and are easily affected by water flow, leading to power waste. Therefore, developing a pure electric ship main propulsion system that balances long endurance, stable power output, and efficient energy utilization has become the key to breaking through the bottleneck of new energy ship applications. Summary of the Invention

[0006] The technical problem to be solved by this utility model is to realize a system that can improve the endurance of electric ships.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a pure electric ship main propulsion system, the system is provided with a DC bus, on which a power battery module, a permanent magnet synchronous propulsion motor unit and a charging module are connected, and a supercapacitor module is connected to the DC bus. The ship controller is connected to the power manager of the permanent magnet synchronous propulsion motor unit and the power battery module through a data line.

[0008] The power battery module consists of two independent battery sub-modules. The two battery sub-modules are connected to the two output terminals of the switching mechanism via a power line. The input terminal of the switching mechanism is connected to the generator.

[0009] The ship controller is connected to the generator and switching structure via signal lines.

[0010] The charging module is connected to the DC bus.

[0011] A battery swapping auxiliary module is connected to the DC bus. The battery swapping auxiliary module is connected to the DC bus via a connector. The battery swapping auxiliary module is a power battery box that can be quickly replaced.

[0012] The pure electric vessel is equipped with photovoltaic panels, which are connected to a battery swapping auxiliary module via power lines.

[0013] The permanent magnet synchronous propulsion motor unit consists of two high-power-density permanent magnet synchronous propulsion motors, and the propulsion motors have a water-cooled heat dissipation structure.

[0014] This utility model is a high-endurance new energy pure electric ship main propulsion system, which is especially suitable for small and medium-sized civil ships with high requirements for endurance, environmental performance and power stability. Through the combination of various energy replenishment methods, it can comprehensively utilize various energy sources to improve the overall endurance of the ship. Attached Figure Description

[0015] The following is a brief explanation of the content represented by each of the accompanying drawings in this utility model specification: Figure 1 This is a schematic diagram of the main propulsion system for a pure electric ship. Detailed Implementation

[0016] The following description, with reference to the accompanying drawings, details the specific implementation of this utility model, including the shape and structure of each component, the relative positions and connections between the parts, the function and working principle of each part, the manufacturing process, and the operation and use methods. This will help those skilled in the art to have a more complete, accurate, and in-depth understanding of the inventive concept and technical solution of this utility model.

[0017] This invention relates to a high-endurance new energy pure electric ship main propulsion system. Addressing the problems of short range, unstable power output, and low energy replenishment efficiency in existing pure electric ships, this system achieves the dual goals of zero emissions and long range throughout the entire voyage through a synergistic design of "multi-source energy storage + high-efficiency propulsion + intelligent energy management." The system innovatively integrates photovoltaic energy storage modules, high-performance power battery packs, and marine supercapacitors, combined with a high-efficiency permanent magnet synchronous propulsion motor and an adjustable ducted propeller. Coupled with an intelligent energy allocation algorithm based on navigation condition prediction, it effectively improves energy utilization efficiency and propulsion performance. Actual measurements show that this system can increase ship range by 40%-55%, improve propulsion efficiency by 15%-20%, and increase charging efficiency by more than 30% compared to traditional pure electric ships. It is suitable for various pure electric ship types, including inland waterway cargo ships, sightseeing boats, and port vessels.

[0018] like Figure 1 As shown, the main propulsion system of a pure electric ship has a DC bus. The power battery module, permanent magnet synchronous propulsion motor unit, charging module, supercapacitor module and battery swapping module are all connected to the DC bus. The power battery module, supercapacitor module and battery swapping module supply power to the permanent magnet synchronous propulsion motor unit through the DC bus, and the charging module also charges the power battery module through the DC bus.

[0019] The power battery module uses marine-grade lithium iron phosphate square battery packs with a total capacity of 800-1500kWh and an energy density of 220-250Wh / kg. The battery pack is equipped with a liquid cooling temperature control system, which uses circulating coolant to control the battery operating temperature at 15-35℃, ensuring stable discharge efficiency (≥90%) under both low and high temperature environments. At the same time, a battery balancing management unit is set up to avoid overcharging and over-discharging of individual cells, extending the battery life to 8-10 years. To improve range, range extender technology can be used, which involves installing a generator on the ship to charge the power battery module. To maintain continuous charging during navigation and ensure battery monitoring status, the power battery module consists of two independent battery sub-modules. The two battery sub-modules are connected to the two output terminals of a switching mechanism via power lines. The input terminal of the switching mechanism is connected to the generator. The two independent battery sub-modules are also connected to the DC bus using independent switching elements, ensuring that at least one battery sub-module is supplying power to the DC bus. The ship controller is connected to the generator and the switching mechanism via signal lines and can control the switching. At the same time, the switching elements output by the power battery module are also controlled by the ship controller. When charging, one battery sub-module charges while the other battery module supplies power to the DC bus.

[0020] The permanent magnet synchronous propulsion motor unit employs two high-power-density permanent magnet synchronous propulsion motors (single unit power 300-600kW), with an efficiency range (90%-96%) covering commonly used ship speed conditions. The motors utilize a water-cooled heat dissipation structure, reducing volume by 25%-30% and weight by 20%-25% compared to traditional asynchronous motors, saving ship space. The motor speed adjustment range is 0-1800 r / min, supporting stepless speed regulation to adapt to different speed requirements. The propeller adopts a 3-4 blade scimitar design, equipped with an adjustable guide duct on the outer side. The inner wall of the duct is equipped with retractable guide vanes (4-6 blades), and the blade angle is adjusted via a hydraulic drive mechanism.

[0021] The permanent magnet synchronous propulsion motor unit has a propulsion control unit connected to the ship's controller. Based on ship maneuvering commands (such as rudder angle and throttle), this unit adjusts the propulsion motor speed and guide vane angle through a vector control algorithm to achieve a precise match between power output and navigation requirements. It also has a propeller cavitation monitoring function. When cavitation is detected, it automatically reduces the motor speed and adjusts the guide vane angle to suppress cavitation and reduce propeller wear.

[0022] The charging module is equipped with two 120kW DC fast charging piles, supports the CCS (Combined Charging System) standard interface, and has a charging current of 200-300A. It can charge the power battery from 20% SOC to 80% in just 1.5-2 hours, which is more than 30% more efficient than traditional charging. During the charging process, the charging current is controlled by the intelligent energy management module to avoid overcharging of the battery. At the same time, it can coordinate with the shore power grid to reduce electricity costs by charging during off-peak hours. The supercapacitor module uses a double-layer supercapacitor with a capacity of 50-100F and a rated voltage of 600-800V. The supercapacitor has a high-rate charge and discharge capability of over 10C, which is used to smooth the peak load of the power battery. When the ship accelerates, turns, or encounters sudden resistance, the supercapacitor quickly releases electrical energy to supplement power and avoids the lifespan degradation caused by high-current discharge of the power battery. When the ship decelerates, the supercapacitor prioritizes the recovery of braking kinetic energy (recovery efficiency ≥85%) to reduce energy loss. The battery swapping module is designed for short-haul, high-frequency vessels (such as harbor tugboats). It features a rapidly replaceable battery box (weighing 1.2-1.5 tons), achieved within 3-5 minutes via a hydraulic lifting device and guide rail structure on the ship's deck, meeting uninterrupted operation requirements. The battery box adopts a standardized design, supporting compatibility with different ship types and reducing operating costs. Simultaneously, the vessel is equipped with photovoltaic panels, flexible thin-film photovoltaic modules installed on the ship's deck and superstructure, covering a total area of ​​50-100㎡, with a conversion efficiency of 20%-22%. The photovoltaic modules are connected to the energy storage unit via an MPPT (maximum power point tracking) controller, dynamically adjusting output power according to sunlight intensity, generating an average of 15-30kWh per day to replenish the power battery and extend the cruising range. Furthermore, the photovoltaic module surface is coated with anti-salt spray and anti-UV coatings, adapting to the humid and highly corrosive marine environment. The photovoltaic panels only charge the battery swapping module, avoiding the impact of photovoltaic power generation fluctuations on the power battery module's lifespan.

[0023] The ship controller collects real-time ship operating parameters (speed, heading, load weight, remaining range), energy storage system parameters (power battery SOC value, supercapacitor voltage, photovoltaic output power), and environmental parameters (light intensity, water temperature, wind speed) at a sampling frequency of 15Hz. Based on an LSTM (Long Short-Term Memory) neural network, a condition prediction model is constructed, which, combined with route data (such as water flow speed in the channel and port location), predicts future navigation conditions (such as constant speed navigation, acceleration, and docking) 1-2 hours in advance, providing a basis for energy allocation.

[0024] The ship controller also has a fault diagnosis and protection unit, which monitors the status of the energy storage system and propulsion system in real time. When it detects that the power battery is overheated (>40℃), the supercapacitor is overvoltaged (>850V), or the photovoltaic module is short-circuited, it immediately cuts off the circuit of the faulty unit and switches to the backup power supply mode (such as power battery only). At the same time, it sends fault information to the shore-based monitoring center through audible and visual alarms and remote communication modules (4G / 5G) to ensure the safe operation of the system.

[0025] Before the ship starts, the intelligent energy management module detects the status of the multi-energy storage units (power battery SOC value, supercapacitor voltage, photovoltaic module performance). If the power battery SOC is ≥30%, the system enters standby mode; if the SOC is <20%, it automatically prompts for charging or battery swapping. During navigation, the data acquisition unit acquires parameters in real time, the operating condition prediction model predicts the future navigation state, and the dynamic energy distribution unit adjusts the power supply mode accordingly: photovoltaic + power battery power supply during constant speed navigation, power battery + supercapacitor power supply during acceleration, and supercapacitor recovers kinetic energy during deceleration. The propulsion actuator adjusts the propulsion motor speed and guide vane angle according to the control commands to ensure optimal propulsion efficiency; if propeller cavitation is detected, parameters are immediately adjusted to suppress cavitation. When a ship docks at a port, if resupply is required, it can choose DC fast charging (charges to 80% in 1.5-2 hours) or fast battery swapping (completes in 3-5 minutes); if no emergency resupply is required, the photovoltaic modules charge the power battery and simultaneously power the auxiliary system. During system operation, the fault diagnosis unit monitors the status in real time. If a fault occurs, it immediately cuts off the fault circuit, switches to standby mode, and issues an alarm to ensure ship safety.

[0026] This system utilizes a multi-energy storage unit (power battery + supercapacitor + photovoltaic) working in synergy. The photovoltaic system replenishes 15-30 kWh of electricity daily, and the supercapacitor has a kinetic energy recovery efficiency of ≥85%. The overall range is 40%-55% longer than that of traditional pure electric ships, meeting the daily navigation needs of inland waterway cargo ships of 150-200 km. Furthermore, the supercapacitor smooths out peak loads, avoids high-current discharge of the power battery, maintains a discharge efficiency of ≥90% in low-temperature environments (<5℃), and ensures stable ship handling and adaptability to complex navigation environments by ≤5% power fluctuation of the propulsion motor under different operating conditions. The intelligent energy distribution algorithm enables the multi-energy storage units to operate within the optimal range, and the propulsion mechanism improves the propulsion efficiency to 55%-65% through the adjustable duct propeller. The overall energy utilization efficiency is 20%-25% higher than that of traditional systems, reducing operating costs. DC fast charging can complete rapid energy replenishment in 1.5-2 hours, and battery swapping mode can replace batteries in 3-5 minutes, adapting to the needs of different operating scenarios. At the same time, photovoltaic energy storage reduces dependence on shore-based grids and lowers energy replenishment costs.

[0027] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A pure electric marine main propulsion system, the system comprising a DC busbar, wherein a power battery module, a permanent magnet synchronous propulsion motor unit, and a charging module are connected to the DC busbar, characterized in that: The DC busbar is connected to a supercapacitor module, and the ship controller is connected to the power manager of the permanent magnet synchronous propulsion motor unit and the power battery module via a data line.

2. The pure electric ship main propulsion system according to claim 1, characterized in that: The power battery module consists of two independent battery sub-modules. The two battery sub-modules are connected to the two output terminals of the switching structure via a power line. The input terminal of the switching structure is connected to the generator.

3. The pure electric ship main propulsion system according to claim 2, characterized in that: The ship controller is connected to the generator and switching structure via signal lines.

4. The pure electric ship main propulsion system according to claim 1, 2 or 3, characterized in that: The charging module is connected to the DC bus.

5. The pure electric ship main propulsion system according to claim 4, characterized in that: A battery swapping auxiliary module is connected to the DC bus. The battery swapping auxiliary module is connected to the DC bus via a connector. The battery swapping auxiliary module is a power battery box that can be quickly replaced.

6. The pure electric ship main propulsion system according to claim 5, characterized in that: The pure electric vessel is equipped with photovoltaic panels, which are connected to a battery swapping auxiliary module via power lines.

7. The pure electric ship main propulsion system according to claim 1 or 6, characterized in that: The permanent magnet synchronous propulsion motor unit consists of two high-power-density permanent magnet synchronous propulsion motors, and the propulsion motors have a water-cooled heat dissipation structure.

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