Rapid power limiting system and method for propulsion system of electric propulsion ship

Abstract

The invention discloses a fast power limiting system of an electric propulsion ship propulsion system. The fast power limiting system comprises an MCU; an electrical parameter acquisition module; a switching value input module; a switching value output module; an analog quantity output module; the system samples the output power of the on-grid power generation equipment in real time, and when the average power of the on-grid power generation equipment exceeds the percentage limit, the MCU judges the power limit and outputs an analog quantity signal to the DCS controller; when the power generation equipment loop switch generates displacement information and detects that the load of the power supply loop drops rapidly, the MCU judges that the power drops suddenly and outputs a switching value signal to the DCS controller. The invention further discloses a rapid power limiting method of the electric propulsion ship propulsion system. Compared with the prior art, the problem that a power management system of an existing electric propulsion ship cannot quickly respond to emergency situations of an electric propulsion system is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric propulsion ships, and particularly to a rapid power limitation system and method for an electric propulsion ship propulsion system. Background Art

[0002] Compared with the propulsion power management system of traditional rudder and propeller devices, electric propulsion ships have higher requirements for the reliability of the power management system, faster dynamic response capabilities, and stronger fault tolerance capabilities to ensure the continuity and maneuverability of the propulsion load.

[0003] During the normal operation of electric propulsion ships, situations may occur where the remaining power of the power grid is insufficient, or most of the power is lost instantaneously due to sudden power source failures. In such cases, the power management system needs to respond quickly, send power limitation instructions to the propulsion system, and ensure the safe and stable operation of the entire system.

[0004] Currently, the overall coordination ability of the power management system of ship power stations cannot meet the rapid response requirements in case of emergencies in electric propulsion systems, resulting in the inability of electric propulsion ships to operate safely and stably. Summary of the Invention

[0005] The purpose of the present invention is to provide a rapid power limitation system and method for an electric propulsion ship propulsion system to solve the problem that the power management system of existing electric propulsion ships cannot respond quickly to emergencies in electric propulsion systems.

[0006] To achieve the above purpose, on the one hand, the present invention provides a rapid power limitation system for an electric propulsion ship propulsion system, including:

[0007] MCU;

[0008] An electrical parameter acquisition module that exchanges data with the MCU through SPI communication. The electrical parameter acquisition module includes several electrical parameter acquisition units, with one electrical parameter acquisition unit corresponding to one power generation device. After sampling and calculation, the electrical parameter acquisition module obtains sampling parameters and outputs them to the MCU. The sampling parameters include voltage, current, phase, and frequency;

[0009] A digital input module that includes several digital input interfaces, and the digital input interfaces are connected to the IO pins of the MCU through optocouplers;

[0010] A digital output module that includes several digital output interfaces. The digital output interfaces include at least one DO action switch interface, and the DO action switch interface is used to output digital signals to the DCS controller;

[0011] An analog output module exchanges data with the MCU through SPI communication. The MCU calculates the remaining power percentage of the on-grid devices in real time according to the power protection criterion, and obtains the calculation result. The analog output module outputs an analog signal to the DCS controller through the analog output interface. If the remaining power of the power grid is less than the set value, the DCS controller limits the output power of the thruster to the preset load power;

[0012] Among them, the digital input interface includes a bus tie switch interface and several power generation equipment loop switch interfaces. The bus tie switch interface is used to collect the status of the bus tie switch in the power management system, and the power generation equipment loop switch interface is used to collect the status of the power generation equipment loop switch in the power management system;

[0013] The system samples the output power of the on-grid power generation equipment in real time. When the average power of the on-grid power supply equipment exceeds the percentage limit, the MCU determines it as power limit and outputs an analog signal to the DCS controller; when the power generation equipment loop switch generates a position change information and it is detected that the load of the power supply loop drops rapidly, the MCU determines it as power sudden drop and outputs a digital signal to the DCS controller.

[0014] On the other hand, the present invention also discloses a method for quickly limiting the power of a propulsion system of a power propulsion ship, including the following steps:

[0015] S1. Parameter sampling: The electrical parameter acquisition module acquires electrical parameters of the power generation equipment, obtains the sampling parameters and outputs them to the MCU;

[0016] S2. Digital input: The MCU obtains the status of the bus tie switch and the power generation equipment loop switch through the digital input interface;

[0017] S3. Power limit: The system samples the output power of the on-grid power generation equipment in real time. When the average power of the on-grid power supply equipment exceeds the percentage limit, the MCU determines it as power limit and outputs an analog signal to the DCS controller;

[0018] S4. Sudden drop limit: When the power generation equipment loop switch generates a position change information and it is detected that the load of the power supply loop drops rapidly, the MCU determines it as power sudden drop and outputs a digital signal to the DCS controller. After receiving the signal, the DCS reduces the propulsion load to the preset low power, and at the same time waits for the power management system to enable the standby generator set. After the power supply returns to normal, the sudden drop limit is cancelled.

[0019] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are:

[0020] 1. In the present invention, for the power management system of existing electric propulsion ships, an independent power source electrical parameter acquisition and transmission system under emergency conditions is constructed to meet the power limitation during the operation of the propulsion ship and the rapid power limitation of the propulsion system in case of sudden drop of the power supply load, ensuring the safety, stability and reliability of the ship during navigation.

[0021] 2. In the present invention, the electrical parameter acquisition module exchanges data with the MCU through SPI communication, with high data transmission rate and reliability. When it is judged by the digital input module that there is a sudden power drop, with the sampling single point time of the electrical parameter acquisition module remaining unchanged, the power drop protection response time of the MCU is shortened by reducing the number of sampling calculation points, and a digital signal is output to the DCS controller faster.

[0022] 3. In the present invention, in the digital input module, the optocoupler electrically isolates the input signal and the output signal through the optical isolation principle, effectively preventing the input signal from generating voltage interference, current interference or ground interference on the IO pins of the MCU, realizing a more reliable and stable input signal, reducing the mutual influence between circuits, and having strong anti-interference ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0024] Figure 1 It is the architecture diagram of the power management system of existing electric propulsion ships.

[0025] Figure 2 It is the system architecture diagram of a rapid power limitation system for the propulsion system of an electric propulsion ship.

[0026] Figure 3 It is the schematic diagram of the system interface of a rapid power limitation system for the propulsion system of an electric propulsion ship.

[0027] Figure 4 It is the schematic diagram of the power supply circuit in a rapid power limitation system for the propulsion system of an electric propulsion ship.

[0028] Figure 5 It is the schematic diagram of the digital input circuit in a rapid power limitation system for the propulsion system of an electric propulsion ship.

[0029] Figure 6 It is the schematic diagram of the digital output circuit in a rapid power limitation system for the propulsion system of an electric propulsion ship. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0032] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0033] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "upper", "inner", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0034] In the description of the present invention, it should also be noted that unless otherwise clearly defined and limited, the terms "arranged", "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Embodiment 1

[0036] Please refer to Figure 1-6 , on the one hand, the present invention provides a rapid power limitation system for a power propulsion ship propulsion system, including:

[0037] MCU;

[0038] The electrical parameter acquisition module exchanges data with the MCU through SPI communication. The electrical parameter acquisition module includes several electrical parameter acquisition units, and one electrical parameter acquisition unit corresponds to one power generation device. After sampling and calculation by the electrical parameter acquisition module, sampling parameters are obtained and output to the MCU. The sampling parameters include voltage, current, phase, and frequency;

[0039] The digital input module includes several digital input interfaces, and the digital input interfaces are connected to the IO pins of the MCU through optocouplers;

[0040] The digital output module includes several digital output interfaces. The digital output interfaces include at least one DO action switch interface, and the DO action switch interface is used to output digital signals to the DCS controller;

[0041] The analog output module exchanges data with the MCU through SPI communication. The MCU calculates the remaining power percentage of the on-grid equipment in real time according to the power protection criterion to obtain the calculation result. The analog output module outputs analog signals to the DCS controller through the analog output interface. If the remaining power of the power grid is less than the set value, the DCS controller limits the output power of the thruster to the preset load power, and the default value of the limit power is 70%, and the specific set value is adjustable;

[0042] Among them, the digital input interfaces include the bus tie switch interface and several power generation equipment loop switch interfaces. The bus tie switch interface is used to collect the status of the bus tie switch in the power management system, and the power generation equipment loop switch interface is used to collect the status of the power generation equipment loop switch in the power management system;

[0043] The system samples the output power of the on-grid power generation equipment in real time. When the average power of the on-grid power supply equipment exceeds the percentage limit, the MICU judges it as power limit and outputs an analog signal to the DCS controller; when the power generation equipment loop switch generates a change information and it is detected that the load of the power supply loop drops rapidly, the MCU judges it as power sudden drop and outputs a digital signal to the DCS controller.

[0044] In addition, in order to improve the response speed during power sudden drop, when the MCU judges it as power limit, the sampling calculation points during sampling calculation by the MCU are n1, and an analog signal is output to the DCS controller; when the power generation equipment loop switch generates a change information and it is detected that the load of the power supply loop drops rapidly, the MCU judges it as power sudden drop and outputs a digital signal to the DCS controller.

[0045] The circuit of the digital output module includes MOS transistors, optocouplers and relays, which are driven by the IO pins of the MCU. When the IO pin outputs a high level to trigger the N-channel MOS transistor, a conduction path is formed between M1 and GND, thereby driving the light-emitting diode inside the optocoupler to emit light. The output pin of the optocoupler converts the optical signal into an electrical signal, enabling the negative electrode of the relay coil to receive current supply, and the normally open and normally closed points of the relay to switch, and the D01 pin to conduct with the common terminal com. For details, please refer to the appendix Figure 6 。

[0046] For the existing power management system of electric propulsion ships, an independent power source electrical parameter acquisition and transmission system under emergency conditions is constructed to meet the power limitation during the operation of the propulsion ship and the rapid power limitation of the propulsion system under the sudden drop of the power supply load, ensuring the safety, stability and reliability of the ship during navigation.

[0047] On the other hand, the present invention also discloses a method for rapid power limitation of an electric propulsion ship propulsion system, including the following steps:

[0048] S1. Parameter sampling: The electrical parameter acquisition module acquires electrical parameters of the power generation equipment, obtains the sampling parameters and outputs them to the MCU;

[0049] S2. Digital input: The MCU obtains the states of the bus tie switch and the power generation equipment loop switch through the digital input interface;

[0050] S3. Power limitation: The system samples the output power of the on-grid power generation equipment in real time. When the average power of the on-grid power supply equipment exceeds the percentage limit, the MCU determines it as power limitation and outputs an analog signal to the DCS controller;

[0051] S4. Sudden drop limitation: When the power generation equipment loop switch generates displacement information and it is detected that the load of the power supply loop drops rapidly, the MCU determines it as a power sudden drop, outputs a digital signal to the DCS controller. After receiving the signal, the DCS reduces the propulsion load to a preset low power, and the default setting value is generally 30%, which can be adjusted according to the usage situation. At the same time, it waits for the power management system (PMS) to enable the standby generator set. After the power supply returns to normal, the sudden drop limitation is cancelled.

[0052] The MCU realizes communication with the upper computer software through the RS485 communication interface. The system is provided with 1 RS485 communication interface as the human-machine interaction interface, and the setting parameters can be read and the system parameters can be configured through the setting software.

[0053] A DAC chip is arranged between the MCU and the analog output interface. The DAC chip is used to convert the digital signal into an analog output signal with a high conversion rate

[0054] The MCU is connected to an operating status switch, which is used to provide real-time feedback on the operating status of the fast power limit system. The operating status switch disconnects when a fault occurs in the fast power limit system, cutting off the power supply to indicating devices such as indicator lights it controls to give a fault indication.

[0055] Working principle: The electrical parameter acquisition module exchanges data with the MCU through SPI communication, featuring high data transmission rate and reliability. When the switch input module determines that a sudden power drop has occurred, and assuming the sampling single-point time of the electrical parameter acquisition module remains unchanged, the MCU's power drop protection response time is shortened by reducing the number of sampling calculation points, and a digital output signal is sent to the DCS controller more quickly.

[0056] In the switch input module, the optocoupler electrically isolates the input and output signals based on the optical isolation principle, effectively preventing voltage interference, current interference, or ground interference from the input signal to the MCU's IO pins, achieving a more reliable and stable input signal, reducing the mutual influence between circuits, and having strong anti-interference ability. For the specific working principle, please refer to the appendix Figure 5 When DI1 is conducting with -24V, it drives the internal light-emitting diode of the optocoupler, causing IN1 connected to the IO pin to change from a 3.3V high level to a low level, thereby identifying the external input signal.

[0057] Embodiment 2

[0058] Based on the above embodiment, the following further improved technical solutions are made in this embodiment: The electrical parameter acquisition unit includes an electricity metering chip, a current sampling circuit, and a voltage sampling circuit. The current sampling circuit is arranged between the two-phase current acquisition interface and the electricity metering chip, and the two-phase current acquisition interface is used to connect to a power generation device. The voltage sampling circuit is arranged between the three-phase voltage acquisition interface and the electricity metering chip, and the three-phase voltage acquisition interface is used to connect to a power generation device. The electricity metering chip calculates sampling parameters including voltage, current, active power, reactive power, power factor, and frequency based on the sampled voltage and sampled current.

[0059] Referring to the attached drawings, the power generation device includes a generator set or a battery pack. The sampling calculation period of the electrical parameter acquisition module ≤ 100ms. The electricity metering chip independently calculates the active power, reactive power, power factor, phase, frequency, and harmonic distortion of all phases of each harmonic, reducing the calculation burden on the MCU during electrical parameter acquisition and achieving fast and reliable data transmission.

[0060] When the generator set is overloaded, the engine speed will decrease. Therefore, when the power supply frequency in the sampling parameters drops below the set value, the MCU calculates and outputs an analog signal to the DCS controller of the electric propulsion system (DCS), and the DCS controller limits the output power of the thruster.

[0061] Embodiment 3

[0062] On the basis of the above embodiment, the following technical solutions are further made as improvements: The power supply circuit of the MCU adopts dual - power redundancy power supply. The power supply circuit includes a DC24V input circuit, a 5V power supply circuit, and a 3.3V power supply circuit.

[0063] For the DC24V input power supply, reverse - connection protection, over - current protection, over - voltage protection, EMC improvement, and current filtering are performed. Independent dual - path power supply is adopted, one main and one auxiliary. Among them, in the 5V power supply circuit, 24V is converted to 5V through the DC - DC isolated power supply module WRB2405S - 3WR2, and in the 3.3V power supply circuit, 5V is converted to 3.3V through the 5V - to - 3.3 LDO linear voltage regulator AMS1117 - 3.3. 3.3V is the power supply for the core of the MCU and the VCCIO (I / O voltage) of the FPGA. For details, please refer to the appendix Figure 4 。

[0064] Embodiment 4

[0065] On the basis of the above embodiment, the following technical solutions are further made as improvements: In step S3, the MCU calculates grid discrimination data including total power, total current, and remaining power according to the sampling parameters, and outputs the remaining power of the current grid to the DCS controller.

[0066] In step S3, when the bus - tie switch is closed, all on - grid power supplies will be included in the load calculation; when the bus - tie switch is open, the main power supplies on both sides of the switch perform load calculations respectively. The calculation results are output through different analog interfaces, that is, the calculation results are output through 2 - way analog output interfaces according to the on - off state of the bus - tie switch. The system automatically judges the operating partition state of the main power supply according to the bus - tie switch state, and the power - limit logic also adopts different control logics according to the partition working conditions.

[0067] The above - mentioned are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent replacements or changes, and all should be covered by the protection scope of the present invention.

Claims

1. A rapid power limiting system for an electric propulsion ship propulsion system, characterized in that: include: MCU; An electrical parameter acquisition module, which exchanges data with the MCU through SPI communication. The electrical parameter acquisition module includes several electrical parameter acquisition units, one electrical parameter acquisition unit corresponds to one power generation device. After sampling and calculation, the electrical parameter acquisition module obtains the sampled parameters and outputs them to the MCU; The switch quantity input module includes a plurality of switch quantity input interfaces, and the switch quantity input interfaces are connected to the IO pins of the MCU through optical couplers; A switch quantity output module, comprising a plurality of switch quantity output interfaces, wherein the switch quantity output interfaces include at least one DO action switch interface, and the DO action switch interface is used to output a switch quantity signal to a DCS controller; The analog output module exchanges data with the MCU through SPI communication. The MCU calculates the residual power percentage of the networked equipment in real time according to the power protection criterion and obtains the calculation result. The analog output module outputs the analog signal to the DCS controller through the analog output interface. If the residual power of the power grid is less than the set value, the DCS controller limits the output power of the thruster to the preset load power. Among them, the switch quantity input interface includes a bus tie switch interface and several power generation equipment loop switch interfaces. The bus tie switch interface is used to collect the status of the bus tie switch in the power management system, and the power generation equipment loop switch interface is used to collect the status of the power generation equipment loop switch in the power management system; The system samples the output power of the grid-connected power generation equipment in real time. When the average power of the grid-connected power supply equipment exceeds the percentage limit, the MCU determines it as power limitation and outputs an analog signal to the DCS controller. When the circuit switch of the power generation equipment generates displacement information and detects that the load of the power supply circuit drops rapidly, the MCU determines it as a sudden power drop and outputs a switch signal to the DCS controller.

2. The electric propulsion ship propulsion system rapid power limitation system according to claim 1, characterized in that: The electrical parameter acquisition unit includes an electricity metering chip, a current sampling circuit and a voltage sampling circuit. The current sampling circuit is arranged between a two-phase current acquisition interface and the electricity metering chip. The two-phase current acquisition interface is used to connect the power generation equipment. The voltage sampling circuit is arranged between a three-phase voltage acquisition interface and the electricity metering chip. The three-phase voltage acquisition interface is used to connect the power generation equipment. The electricity metering chip calculates sampling parameters including voltage, current, active power, reactive power, power factor and frequency according to the sampled voltage and sampled current.

3. The electric propulsion ship propulsion system rapid power limitation system according to claim 1, characterized in that: MCU communicates with the host computer software through the RS485 communication interface.

4. The electric propulsion ship propulsion system rapid power limitation system according to claim 1, characterized in that: The power supply circuit of the MCU adopts dual power supply redundancy.

5. The electric propulsion ship propulsion system rapid power limitation system according to claim 4, characterized in that: The power supply circuit includes a DC24V input circuit, a 5V power supply circuit and a 3.3V power supply circuit.

6. The electric propulsion ship propulsion system rapid power limitation system according to claim 1, characterized in that: A DAC chip is provided between the MCU and the analog output interface, and the DAC chip is used to convert digital signals into analog output signals.

7. The electric propulsion ship propulsion system rapid power limitation system according to claim 1, characterized in that: The MCU is connected to an operation status switch, and the operation status switch is used to feed back the operation status of the fast power limiting system in real time.

8. A method for rapid power limitation of an electric propulsion ship propulsion system, characterized in that: The following steps are involved: S1. Parameter sampling: The electrical parameter acquisition module collects electrical parameters of the power generation equipment, obtains the sampled parameters and outputs them to the MCU; S2, switch input: MCU obtains the status of the bus tie switch and the power generation equipment loop switch through the switch input interface; S3, power limit: The system samples the output power of the grid-connected power generation equipment in real time. When the average power of the grid-connected power supply equipment exceeds the percentage limit, the MCU determines that it is power limited and outputs an analog signal to the DCS controller; S4, sudden drop limit: When the power generation equipment circuit switch generates position change information and detects that the load of the power supply circuit drops rapidly, the MCU determines it as a power sudden drop and outputs a switch signal to the DCS controller. After receiving the signal, the DCS will reduce the load to the preset low power and wait for the power management system to enable the standby generator set. After the power supply returns to normal, the sudden drop limit is cancelled.

9. A method for rapid power limitation of an electric propulsion ship propulsion system according to claim 8, characterized in that: In step S3, the MCU calculates the grid identification data including the total power, the total current and the residual power according to the sampling parameters, and outputs the residual power of the current grid to the DCS controller.

10. The method for rapid power limitation of an electric propulsion ship propulsion system according to claim 8, characterized in that: In step S3, when the bus tie switch is closed, all grid power sources will be included in the load calculation; and when the bus tie switch is open, the main power sources on both sides of the switch will be subject to load calculation respectively.

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