A control system and control method for an unmanned surface vessel DC variable speed generator set

Abstract

This invention discloses a control system and method for an unmanned surface vessel (USV) DC variable speed generator set, belonging to the field of USV technology. The system includes a diesel engine, a rectifier generator, an energy-saving control unit, and an energy management unit. The diesel engine is connected to the generator to form a diesel generator set that supplies power to the load on the USV and is also signal-connected to the energy management unit. The energy management unit is signal-connected to the load and can obtain the load rate of the USV. The energy management unit is also signal-connected to the energy-saving control unit, enabling it to control the diesel generator set to start at a preset speed and preset output voltage, and to send the load rate and operating mode of the USV to the energy-saving control unit. The energy-saving control unit can set the diesel engine speed and the rectifier generator output voltage. This control system enables better matching of the generator set power and load rate on the USV, improving the operating economy of the USV.

Description

Technical Field

[0001] This invention belongs to the field of unmanned vessel technology, specifically relating to a control system and control method for an unmanned vessel DC variable speed generator set. Background Technology

[0002] Driven by the need for economic efficiency and energy efficiency, people are paying more and more attention to cost optimization in ship operation and have been trying to provide generator control technology solutions that can meet the specific needs of ships.

[0003] In recent years, there has been a growing interest in using variable-speed generator sets on ships. Variable-speed technology allows the generator set's speed and output voltage to be adjusted according to the connected electrical load, making its operation more economical. According to relevant research, compared to traditional constant-speed devices, variable-speed generator sets offer several advantages, such as fuel savings of up to 15%, increased overhaul intervals by up to 20%, lower noise, higher power density, and smaller installation space. However, current research in my country on the control of variable-speed generator sets for unmanned vessels is limited, and specific technical solutions for the speed and voltage control of DC variable-speed generator sets for unmanned vessels are lacking. This is detrimental to the future development of civilian and military unmanned vessels in my country. Summary of the Invention

[0004] In view of this, the present invention provides a control system and control method for an unmanned vessel DC variable speed generator set, which reduces fuel consumption, shortens overhaul time and reduces noise of the unmanned vessel through variable speed and voltage control.

[0005] A control system for an unmanned surface vessel DC variable speed generator set includes a diesel engine, a rectifier generator, an energy-saving control unit, and an energy management unit;

[0006] The diesel engine is connected to the generator to form a diesel generator set to supply power to the load on the unmanned vessel, and is also signal-connected to the energy management unit;

[0007] The energy management unit is connected to the load signal and can obtain the load's working / off status information, thereby obtaining the load rate of the unmanned vessel; the energy management unit is also connected to the energy-saving control unit and can control the diesel generator set to start to a preset speed and preset output voltage according to external input commands, and send the load rate and operating mode of the unmanned vessel to the energy-saving control unit.

[0008] The operating modes include low-noise operating mode, cruise operating mode, or high-speed navigation operating mode, and each operating mode corresponds to a different power range;

[0009] The energy-saving control unit can set the diesel engine speed and the rectifier generator output voltage after receiving the load rate and the unmanned vessel's operating mode. The set diesel engine speed and rectifier generator output voltage are then sent to the energy management unit, which controls the diesel engine speed and the rectifier generator output voltage.

[0010] Furthermore, it also includes seawater pumps and cooling pipes;

[0011] The seawater pump is signal-connected to the energy management unit and is connected to the diesel generator set through the cooling pipe to form the seawater cooling system of the diesel generator set.

[0012] A temperature sensor is installed at the cooling water outlet of the seawater cooling system, and the energy management unit can collect the cooling water outlet temperature through the temperature sensor.

[0013] The energy-saving control unit, upon receiving the load rate and operating mode of the unmanned vessel, sets the seawater pump speed according to a preset seawater pump speed control logic, and sends the set seawater pump speed to the energy management unit, which then sends it to the seawater pump to control its speed.

[0014] Furthermore, the energy-saving control unit includes a digital input module, a digital output module, a communication module, a control module, and a power supply module;

[0015] The digital input module, the digital output module, and the communication module are respectively connected to the control module via signals.

[0016] The control module has functions for downloading and debugging programs, resetting, logic control, and processing.

[0017] The power module provides power to the digital output module and the control module;

[0018] The communication module uses dual Ethernet communication / dual CAN communication for its external communication interface.

[0019] Furthermore, the diesel engine uses two ECU control systems, which serve as backups for each other.

[0020] Furthermore, this invention also provides a control method for an unmanned surface vessel (USV) DC variable speed generator set, which employs the aforementioned control system for the USV variable speed generator set and includes the following steps:

[0021] Step S1: The energy management unit sends a start command to the diesel generator set, and the diesel generator set starts to the preset speed. At the same time, the energy management unit sends the unmanned vessel operation mode to the energy-saving control unit.

[0022] Step S2: After receiving the unmanned vessel operation mode, the energy-saving control unit sets the speed of the diesel engine and the output voltage of the rectifier generator, and sends the set diesel engine speed and the set rectifier generator output voltage to the energy management unit. The energy management unit then sends these settings to the diesel engine and the rectifier generator respectively. The diesel engine operates at the set speed, and the rectifier generator operates at the set output voltage. Different output voltages can meet the power requirements of the load in the corresponding unmanned vessel operation mode.

[0023] The diesel engine speed is set according to a stepped control setting: each unmanned vessel operating mode corresponds to a fixed speed.

[0024] Furthermore, the fixed rotational speed in the stepped control is set according to the following steps:

[0025] Step 1: Calculate the power required by the diesel engine for the unmanned vessel under different operating modes;

[0026] Step 2: Add a set power reserve to the power required by the diesel engine to obtain the power range of the unmanned vessel under different operating modes;

[0027] Step 3: Determine the fixed speed for each of the operating modes based on the power range and the universal characteristic fuel consumption curve of the diesel engine, wherein the maximum power corresponding to the fixed speed can cover the power range of the corresponding operating mode.

[0028] Furthermore, the seawater pump speed control logic is as follows: based on the cooling water flow requirements of the diesel generator set under different load rates, and combined with the flow provided by the seawater pump at different speeds, the seawater pump speed is determined; or the seawater pump speed is increased or decreased based on the cooling water outlet temperature.

[0029] Furthermore, when the energy-saving control unit malfunctions, the energy management unit sends the operating mode to the diesel engine, the diesel engine operates at the fixed speed corresponding to the operating mode, and the rectifier generator outputs voltage according to the fixed output voltage corresponding to the operating mode.

[0030] Furthermore, when both the energy-saving control unit and the energy management unit fail, the diesel engine automatically accelerates to its rated speed, and the rectifier generator outputs its rated voltage.

[0031] Beneficial effects:

[0032] (1) In the control system of the unmanned ship DC variable speed generator set, the diesel engine is connected to the rectifier generator to form a diesel generator set to supply power to the load on the unmanned ship, and is also connected to the energy management unit. The energy management unit is connected to the load signal and can obtain the load working / shutdown status information, thereby obtaining the load rate of the unmanned ship. The energy management unit is also connected to the energy-saving control unit and can control the diesel generator set to start up to the preset speed and output the preset voltage according to the external input command, and send the load rate of the unmanned ship and the unmanned ship operation mode (including low noise mode, cruise mode and high speed navigation mode with the speed increasing in sequence, each operation mode corresponding to a different power range) to the energy-saving control unit. After receiving the load rate of the unmanned ship and the unmanned ship operation mode, the energy-saving control unit can set the diesel engine speed and the rectifier generator output voltage, and send the set diesel engine speed and rectifier generator output voltage to the energy management unit, which then sends them to the diesel engine governor and the rectifier generator voltage regulator to control the diesel engine speed and the rectifier generator output voltage. This control system enables variable speed and voltage control of the generator set of the unmanned vessel under different operating modes and load rates, so that the generator set power of the unmanned vessel is better matched with the load rate, improving the operating economy of the unmanned vessel, increasing the endurance of the unmanned vessel, reducing emissions, reducing operating noise, enhancing the stealth of the unmanned vessel, and improving the reliability, adaptability to shipyard environment, and maintainability of the unmanned vessel.

[0033] (2) The seawater pump is signal-connected to the energy management unit and the energy-saving control unit, and is connected to the diesel generator set through cooling pipes to form a seawater cooling system for the diesel generator set. A temperature sensor is installed at the cooling water outlet of the seawater cooling system, and the energy management unit can collect the cooling water outlet temperature through the temperature sensor. After receiving the load rate and operating mode of the unmanned vessel, the energy-saving control unit can set the seawater pump speed according to the preset seawater pump speed control logic, and send the set seawater pump speed to the energy management unit, which then sends it to the seawater pump to control the speed of the seawater pump. By controlling the speed of the seawater pump, the energy consumption of the unmanned vessel can be reduced while ensuring the cooling requirements of the diesel generator set, thus improving the operating economy of the unmanned vessel.

[0034] (3) The energy-saving control unit includes a digital input module, a digital output module, a communication module, a control module, and a power supply module. The digital input module, digital output module, and communication module are connected to the control module via signals. The control module has functions for program download and debugging, reset, logic control, and processing. The power supply module provides power to the digital output module and the control module. The communication module uses dual Ethernet / dual CAN communication for its external communication interface. This energy-saving control unit has a simple structure, and each module can use mature microcontroller chips, ensuring the reliability of the speed control of the unmanned vessel's variable-speed generator set. Moreover, since the external communication interface uses dual Ethernet / dual CAN communication, it has good redundancy. When the energy-saving control unit fails, the diesel engine will receive the operating mode from the energy management unit to control the speed, and the unmanned vessel can still continue to operate, improving the reliability of the unmanned vessel's operation.

[0035] (4) Two ECU control systems are used on each diesel engine for redundancy, which further improves the reliability of diesel engine speed control and rectifier generator output voltage control in the unmanned ship DC variable speed generator set.

[0036] (5) Hierarchical control of diesel engine speed control logic: Each unmanned vessel operating mode corresponds to a fixed speed. Thus, with the speed set, the diesel engine operates at a fixed speed in each operating mode. Moreover, by controlling the generator output voltage, each fixed speed of the diesel engine has a corresponding generator output voltage, making the control logic relatively simple.

[0037] (6) In the stepped control of diesel engine speed, the setting of fixed speed takes into account a certain power reserve. At the same time, the output voltage control of rectifier generator also takes into account a certain power reserve, so that changes in external load of unmanned vessel will not cause diesel engine overload.

[0038] (7) Seawater pump speed control includes two methods: one is to determine the seawater pump speed based on the cooling water flow requirements of the diesel generator set under different load rates, combined with the flow provided by the seawater pump at different speeds; the other is to increase or decrease the seawater pump speed based on the cooling water outlet temperature. Both control methods can be flexibly selected according to the working conditions, and both can make the energy on the unmanned vessel more efficient while ensuring the cooling requirements of the diesel generator set.

[0039] (8) When the energy-saving control unit fails, the energy management unit sends the operating mode to the diesel engine and rectifier generator. The diesel engine and rectifier generator operate at the preset speed and preset output voltage corresponding to different operating modes, which improves the reliability of the unmanned ship's navigation.

[0040] (9) When both the energy-saving control unit and the energy management unit fail, the diesel generator set automatically speeds up to the rated speed and the rectifier generator outputs the rated voltage, which further ensures the reliability of the unmanned ship during unmanned navigation. Attached Figure Description

[0041] Figure 1 A schematic diagram of the unmanned vessel DC variable speed generator control system provided in an embodiment of the present invention;

[0042] Figure 2 for Figure 1 A schematic diagram of the composition of the energy-saving control unit;

[0043] Figure 3 The universal characteristic fuel consumption curve of a diesel engine provided in the embodiments of the present invention;

[0044] Figure 4 According to the embodiments of the present invention Figure 3 The optimal power curve is formed;

[0045] Figure 5 for Figure 1 A schematic diagram of the control flow of the energy-saving control unit. Detailed Implementation

[0046] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0047] Example 1:

[0048] This embodiment provides a speed control system for an unmanned surface vessel variable speed generator set, such as... Figure 1 As shown, the system includes a diesel engine, a rectifier generator, an energy-saving control unit, and an energy management unit, wherein:

[0049] A diesel engine and a rectifier generator are connected to form a diesel generator set to supply power to the load on the unmanned surface vessel (USV), and the set is also connected to the energy management unit (EMU). The EMU is connected to the load and can obtain the load's on / off status information, thus determining the USV's load rate. The EMU is also connected to the energy-saving control unit (EVU) and can control the diesel generator set to start at a preset speed and output a preset voltage based on external input commands. The EMU sends the USV's load rate and operating mode (including low-noise, cruising, and high-speed navigation modes, each corresponding to a different power range) to the EMU. Upon receiving the load rate and operating mode signals, the EMU sets the diesel engine speed and the rectifier generator output voltage, and sends these settings to the EMU. The EMU then controls the diesel engine speed and rectifier generator output voltage; each diesel engine speed setting corresponds to a specific generator output voltage setting. The USV speed increases sequentially from low-noise to cruising to high-speed navigation, with the low-noise mode having the most stringent requirements for vibration and noise control.

[0050] Furthermore, the control system of the unmanned vessel's DC variable speed generator set also includes a seawater pump and cooling pipes. The seawater pump is signal-connected to the energy management unit and is connected to the diesel generator set through the cooling pipes to form a seawater cooling system for the diesel generator set. A temperature sensor is installed at the cooling water outlet of the seawater cooling system, and the energy management unit can collect the cooling water outlet temperature through the temperature sensor. After receiving the load rate and operating mode of the unmanned vessel, the energy-saving control unit can set the seawater pump speed according to the preset seawater pump speed control logic and send the set seawater pump speed to the energy management unit, which then sends it to the seawater pump to control the seawater pump speed.

[0051] Specifically, in this embodiment, the diesel engine is a four-stroke, water-cooled, turbocharged, intercooled diesel engine, mainly composed of a crankcase, moving parts, cylinder head, valve control mechanism, speed control system, lubrication system, fuel system, cooling water system, intake / exhaust system, starting / stop system, monitoring system, and other equipment and systems, including accessories such as a pre-fuel pump, starter motor, and rectifier generator. Furthermore, in this embodiment, the unmanned surface vessel is equipped with three diesel generator sets, primarily operating in an alternating, backup configuration. Each diesel generator set uses two ECU control systems (master + slave), a single common rail pump, and each diesel generator set meets the following specifications:

[0052]

[0053] In this embodiment, the rectifier generator is a 1000KW permanent magnet generator, which includes a composite excitation generator body, a twelve-phase rectifier device, an excitation regulating device, an air cooler, monitoring sensors, and other components.

[0054] like Figure 2 As shown, in this embodiment, the energy-saving control unit consists of a control module, a power supply module, a digital input module, a digital output module, and a communication module. The power supply module, with a power conversion module and a power isolation module at its core, converts the external 24V DC to 5V DC and 3.3V DC, respectively supplying power to the digital output module and the control module. Both the digital input module and the digital output module are based on optocouplers, enabling complete isolation between the control module and the external power supply. The digital input module has 8 channels, and the digital output module has 4 channels. The communication module has CAN isolation and CAN transmission functions. More specifically, the communication module's external communication interface uses dual Ethernet communication / dual CAN communication, with each serving as a backup.

[0055] The energy-saving control unit and the energy management unit communicate via two CAN networks, CAN1 and CAN2 are redundant; 250kbps, adaptive, shielded twisted pair cable.

[0056] In this embodiment, the power required by the diesel engine for the aforementioned low-noise operation mode, cruise operation mode, and high-speed navigation operation mode is shown in the table below:

[0057]

[0058] Example 2:

[0059] Based on Embodiment 1 above, this embodiment provides a control method for an unmanned vessel DC variable speed generator set, including the following steps:

[0060] Step S1: The energy management unit sends a start command to the diesel generator set, which starts at the preset speed and outputs the preset voltage; at the same time, the energy management unit sends the unmanned vessel operation mode to the energy-saving control unit.

[0061] Step S2: After receiving the unmanned vessel operation mode, the energy-saving control unit sets the speed of the diesel engine and the output voltage of the rectifier generator, and sends the set diesel engine speed and the set rectifier generator output voltage to the energy management unit. The energy management unit then sends these settings to the diesel engine and the rectifier generator. The diesel engine operates at the set speed, causing the rectifier generator to output the set voltage. The output voltage control of the rectifier generator takes into account a certain power reserve, and different output voltages can meet the power requirements of the load in the corresponding unmanned vessel operation mode.

[0062] The diesel engine speed is set according to the stepped control setting: each unmanned vessel operating mode corresponds to a fixed speed.

[0063] Specifically, stepped control refers to dividing the load rate into several intervals within a variable speed range, based on the actual optimal speed at each load rate. Each interval has a defined target speed, and the target speed remains unchanged when the load changes within a certain interval. More specifically, the fixed speed in the stepped control described above is set according to the following steps:

[0064] Step 1: Calculate the power required by the diesel engine for the unmanned vessel under different operating modes;

[0065] According to Example 1, the diesel engine needs to provide approximately 260kW, 540kW and 980kW in low-noise operation mode, cruise operation mode and high-speed navigation operation mode, respectively.

[0066] Step 2: Add a set power reserve to the power required by the diesel engine to obtain the power range of the unmanned vessel under different operating modes. In this embodiment, the load fluctuation in each operating mode is temporarily considered to be 15%. Therefore, in the low-noise operating mode, cruise operating mode, and high-speed navigation operating mode, the power range of the diesel engine is approximately 220.0-300kW, 460-625kW, and 830-1125kW, respectively. The maximum power corresponding to the selected diesel engine speed for each operating condition must be able to cover the above power range.

[0067] Step 3: Determine the fixed speed for each operating mode based on the power range and the universal characteristic fuel consumption curve of the diesel engine. The maximum power corresponding to this fixed speed should be able to cover the power range of the corresponding operating mode.

[0068] Reference Figure 3 The following suggestions are made for setting the fixed speed in low-noise operation mode, cruise operation mode, and high-speed operation mode:

[0069] Low-noise operation mode (260kW, 220.0-300kW): The universal characteristic fuel consumption curve of a diesel engine shows that at a power output of 260kW, a lower fuel consumption value can be achieved around 1000rpm. Lower speeds would be detrimental to the long-term stable operation of the diesel engine. Simultaneously, the maximum power that a diesel engine can provide at 1000rpm exceeds 297kW. Considering these factors, setting the fixed speed at 1000rpm is more reasonable for low-noise operation mode.

[0070] Cruise operation mode (543kW, 460-625kW): Fuel consumption is relatively low at 1300rpm, but vibration and noise are higher than at 1200rpm.

[0071] High-speed navigation mode (977kW, 830-1125kW): Since the power of the diesel engine in the high-speed navigation mode is close to the rated power of the diesel engine, and the power range of the diesel engine considering load fluctuations even exceeds the rated power of the diesel engine, the fixed speed of the diesel engine in the high-speed navigation mode is considered to be the rated speed of 1500rpm.

[0072] like Figure 4 As shown, the optimal power curve of a diesel engine basically exhibits the following characteristics: at the same power, a lower fuel consumption rate can be achieved at a slightly higher speed. However, at higher speeds, vibration and noise will also be greater.

[0073] The above-mentioned energy-saving control unit controls the speed of the seawater pump as follows: Based on the cooling water flow requirements of the diesel generator set under different load rates, and combined with the flow provided by the seawater pump at different speeds, the speed of the seawater pump is determined; or the speed of the seawater pump is increased or decreased based on the cooling water outlet temperature in the seawater cooling system of the diesel generator set.

[0074] like Figure 5 As shown in the diagram, the workflow of the diesel generator set during operation reveals that when the ship needs to enter a low-noise operation mode, cruising operation mode, or high-speed navigation operation mode, the energy management unit controls the diesel generator set to start. The generator set starts at the set speed according to the operating mode (e.g., 1000 rpm for low-noise operation mode, 1200 rpm for cruising operation mode, and 1500 rpm for high-speed navigation operation mode). After the mode is established, the energy management unit sends the operating mode to the energy-saving control unit via CAN communication. The energy-saving control unit sets the speed of the diesel engine and seawater pump, as well as the output voltage of the rectifier generator, and sends the set diesel engine speed, seawater pump speed, and rectifier generator output voltage to the energy management unit. The energy management unit then transmits these settings to the governor of the diesel engine, the frequency converter of the seawater pump, and the voltage regulator of the rectifier generator, respectively. When the energy-saving control unit malfunctions, such as due to power failure, module failure, or communication failure, the energy management unit sends the operating mode signal to the diesel engine and rectifier generator. The diesel engine operates at the fixed speed corresponding to the different operating modes, and the rectifier generator outputs voltage according to the fixed output voltage corresponding to the operating mode. When both the energy-saving control unit and the energy management unit fail (the energy-saving control unit and the energy management unit have fault self-checking functions), the diesel engine automatically accelerates to the rated speed and the rectifier generator outputs the rated voltage.

[0075] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., 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 system for an unmanned surface vessel DC variable speed generator set, characterized in that, Includes a diesel engine, rectifier generator, energy-saving control unit, and energy management unit; The diesel engine and the rectifier generator together form a diesel generator set to supply power to the load of the unmanned vessel, and are also connected to the energy management unit via signal. The energy management unit is connected to the load signal and can obtain the load's working / off status information, thereby obtaining the load rate of the unmanned vessel; the energy management unit is also connected to the energy-saving control unit and can control the diesel generator set to start to a preset speed and preset output voltage according to external input commands, and send the load rate and operating mode of the unmanned vessel to the energy-saving control unit. The energy-saving control unit can set the diesel engine speed and the rectifier generator output voltage after receiving the load rate and the unmanned vessel's operating mode. The set diesel engine speed and rectifier generator output voltage are sent to the energy management unit, which then controls the diesel engine speed and the rectifier generator output voltage. The diesel engine speed setting is based on stepped control, with each unmanned surface vessel (USV) operating mode corresponding to a fixed speed. Specifically, the power required by the diesel engine for the USV under different operating modes is calculated. A set power reserve is added to the required power to obtain the power range of the USV under different operating modes. Based on the power range and the universal characteristic fuel consumption curve of the diesel engine, the fixed speed for each operating mode is determined. The maximum power corresponding to the fixed speed can cover the power range of the corresponding operating mode. Each speed setting of the diesel engine has a corresponding rectifier generator output voltage setting. Different output voltages can meet the power requirements of the load in the corresponding USV operating mode. The operating modes include low-noise operating mode, cruising operating mode, or high-speed navigation operating mode, each corresponding to a different power range.

2. The control system of the unmanned vessel DC variable speed generator set as described in claim 1, characterized in that, It also includes seawater pumps and cooling pipes; The seawater pump is signal-connected to the energy management unit and is connected to the diesel generator set through the cooling pipe to form the seawater cooling system of the diesel generator set. A temperature sensor is installed at the cooling water outlet of the seawater cooling system, and the energy management unit can collect the cooling water outlet temperature through the temperature sensor. The energy-saving control unit, upon receiving the load rate and operating mode of the unmanned vessel, sets the seawater pump speed according to a preset seawater pump speed control logic, and sends the set seawater pump speed to the energy management unit, which then sends it to the seawater pump to control its speed.

3. The control system of the unmanned vessel DC variable speed generator set as described in claim 2, characterized in that, The energy-saving control unit includes a digital input module, a digital output module, a communication module, a control module, and a power supply module; The digital input module, the digital output module, and the communication module are respectively connected to the control module via signals. The control module has functions for downloading and debugging programs, resetting, logic control, and processing. The power module provides power to the digital output module and the control module; The communication module uses dual Ethernet communication / dual CAN communication for its external communication interface.

4. The control system of the unmanned vessel DC variable speed generator set as described in claim 2 or 3, characterized in that, The diesel engine uses two ECU control systems, which serve as backups for each other.

5. A control method for an unmanned surface vessel DC variable speed generator set, characterized in that, The control system of the unmanned vessel DC variable speed generator set according to any one of claims 2-4 includes the following steps: Step S1: The energy management unit sends a start command to the diesel generator set, the diesel generator set starts to the preset speed, and at the same time the energy management unit sends the unmanned vessel operation mode to the energy saving control unit; Step S2: After receiving the unmanned vessel operation mode, the energy-saving control unit sets the speed of the diesel engine and the output voltage of the rectifier generator, and sends the set diesel engine speed and the set rectifier generator output voltage to the energy management unit. The energy management unit then sends the set values ​​to the diesel engine and the rectifier generator respectively. The diesel engine operates at the set diesel engine speed, and the rectifier generator operates at the set output voltage.

6. The control method for the unmanned surface vessel DC variable speed generator set as described in claim 5, characterized in that, The seawater pump speed control logic is as follows: based on the cooling water flow requirements of the diesel generator set under different load rates, and combined with the flow provided by the seawater pump at different speeds, the seawater pump speed is determined; or the seawater pump speed is increased or decreased based on the cooling water outlet temperature.

7. The control method for the unmanned surface vessel DC variable speed generator set as described in claim 5, characterized in that, When the energy-saving control unit fails, the energy management unit sends the operating mode to the diesel engine, the diesel engine operates at the fixed speed corresponding to the operating mode, and the rectifier generator outputs voltage according to the fixed output voltage corresponding to the operating mode.

8. The control method for the unmanned surface vessel DC variable speed generator set as described in claim 5, characterized in that, When both the energy-saving control unit and the energy management unit fail, the diesel engine automatically accelerates to the rated speed, and the rectifier generator outputs the rated voltage.

Images