Power generation-storage coordination management and control method of ship comprehensive electric propulsion system

Abstract

The invention discloses a power generation-storage coordination management and control method for a ship integrated electric propulsion system, and the method comprises the steps: state 1: when a single power generator supplies power, switching on a switch corresponding to a battery in a normal state when the voltage of a DC bus fluctuates; state 2: when one battery is connected with the generator in parallel, the discharge power of the battery is adjusted according to the states of the generator and the battery, and a switch corresponding to the other battery is closed or the load is adjusted; and state 3: when the two batteries and the generator are connected in parallel, whether the generator is in an operation state is determined according to whether the generator is normal or not, and switches of the two batteries are closed or loads are adjusted. Power generation-energy storage parallel operation is achieved, and energy storage meets the compensation requirement of the ship comprehensive electric propulsion system according to the monitoring state.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated power propulsion of ships, and mainly to a generation-storage coordinated control method of an integrated electric propulsion system of a ship. Background Art

[0002] The ship power system is a key component of the normal operation of the ship, and its stability and reliability are directly related to the safety and economic benefits of the ship. In the ship power system, generators and energy storage devices are two core elements, and their coordinated control is of great significance to the operation of the entire system.

[0003] Coordinated control of generators and energy storage devices can improve the stability and reliability of ship power systems. During navigation, ships are affected by a variety of factors, such as waves and wind speed, which may cause load fluctuations in ship power systems. If generators and energy storage devices cannot work well in coordination, it may cause voltage and frequency fluctuations in the power system, thus affecting the normal operation of the ship. Through coordinated control, generators and energy storage devices can complement each other when load fluctuates, maintaining the stability and reliability of the power system.

[0004] The coordinated control of generators and energy storage devices can improve the economic efficiency of ship power systems. The economic efficiency of ship power systems is mainly reflected in energy consumption and operating costs. Through coordinated control, the optimal operating state of generators and energy storage devices can be achieved, reducing energy consumption and operating costs.

[0005] The coordinated control of generators and energy storage devices can improve the environmental friendliness of ship power systems. With the improvement of global environmental awareness, the environmental friendliness of ship power systems has received more and more attention. Through coordinated control, the working time of generators can be reduced, the emission of exhaust gas can be reduced, and thus the pollution to the environment can be reduced.

[0006] The coordinated control of generators and energy storage devices can improve the safety of ship power systems. The safety of ship power systems is mainly reflected in preventing power system failures and accidents. Through coordinated control, the working status of generators and energy storage devices can be monitored in real time, potential failures and problems can be discovered and handled in a timely manner, and power system failures and accidents can be prevented. Therefore, when designing and operating ship power systems, full attention should be paid to the coordinated control of generators and energy storage devices to improve the overall performance and economic benefits of ship power systems.

[0007] However, although the existing generation-storage control methods have achieved certain results, most of them only adjust the power supply quality from the perspective of energy storage, and still face many challenges in practical applications. With the continuous development of ship electric propulsion systems, the complexity of ship electric propulsion systems is also increasing. How to achieve effective control of complex hybrid electric propulsion systems containing generation-storage, especially the control of the generation-storage system of AC-DC ship integrated electric propulsion containing distributed generation-storage, is an urgent problem to be solved. Summary of the invention

[0008] The present invention provides a generation-storage coordinated control method for a ship integrated electric propulsion system. By collecting information such as the voltage, current, energy storage SOC, grid connection status, bus voltage fluctuation, etc. of the distributed power supply, the distributed generation-storage system of the AC / DC ship electric propulsion system can be controlled to maintain system stability.

[0009] Specifically, the present invention proposes a generation-storage coordinated control method for a ship integrated electric propulsion system, wherein the ship integrated electric propulsion system includes a power generation system, a first battery, a second battery, a controllable load, a first parallel switch K1, and a second parallel switch K2, wherein the first parallel switch K1 is arranged between the first battery and a DC bus, and the second parallel switch K2 is arranged between the second battery and the DC bus, and the power generation system and the controllable load are both connected to the DC bus;

[0010] The generation-storage coordinated control method of the ship integrated electric propulsion system includes:

[0011] State 1: When the generator is used alone for power supply, if the DC bus voltage fluctuates, the switch corresponding to the battery in normal state is closed;

[0012] State 2: When a battery and a generator are connected in parallel, the discharge power of the battery is adjusted, the switch corresponding to the other battery is closed, or the load size is adjusted according to the status of the generator and the battery;

[0013] State 3: When two batteries and a generator are connected in parallel, the switches of the two batteries are closed or the load size is adjusted according to whether the generator is normal and whether it is in operation when it is normal.

[0014] Furthermore, in state 1, when it is detected that the DC bus voltage fluctuates by more than 2% and the time exceeds 5s, the first parallel switch K1 is closed if the state of the first battery is normal; if the first battery is abnormal, the state of the second battery is detected to be normal, and if it is normal, the second parallel switch K2 is closed; if both the first battery and the second battery are abnormal, the load is adjusted.

[0015] Furthermore, in the case of state 2, including when there is a fault in the generator, the second parallel switch K2 is controlled according to the bus voltage fluctuation:

[0016] When the DC voltage fluctuation is greater than 2%, if the first battery is normal, the second parallel switch K2 is closed; if the first battery is abnormal, the load size is adjusted.

[0017] Furthermore, in the case of state 2, including when the generator motor is normal and in operation, and the first parallel switch K1 is closed:

[0018] When it is detected that the SOC of the first battery is greater than 80%, the first battery is in a discharging state, and the DC voltage fluctuation is greater than 2%; if the state of the second battery is normal, the second parallel switch K2 is closed; when the state of the second battery is abnormal, and when the DC bus voltage exceeds the normal value by 2% or the discharge power of the first battery is 0, the load size is adjusted; when the DC bus voltage exceeds the normal value by 2% and the discharge power of the first battery is not zero, the first battery is discharged with 10% of the rated power reduced;

[0019] When it is detected that the SOC of the first battery is less than 30%, the first battery is in a charging state, and when the DC bus voltage fluctuation is greater than 2%, the second parallel switch K2 is closed if the state of the second battery is normal, and the load size is adjusted if the state of the second battery is abnormal;

[0020] When it is detected that the SOC of the first battery is between 30% and 80%, the first battery is in a charging and discharging state, and the bidirectional converter connected to the voltage and current control battery is used to realize the charging and discharging of the first battery according to the bus voltage fluctuation to meet the load power demand; when the DC bus voltage fluctuation is greater than 2%, the second parallel switch K2 is closed if the state of the second battery is normal, and the load size is adjusted if the state of the second battery is abnormal;

[0021] When the generator motor is normal and in operation, and the second parallel switch K2 is closed, it corresponds to the above situation.

[0022] Furthermore, in the case of state 2, including when the generator motor is normal and in a shutdown waiting state, and the first parallel switch K1 is closed:

[0023] When it is detected that the SOC of the first battery is greater than 80%, the first battery is in a discharging state, and when the DC bus voltage fluctuation is greater than 2%, if the state of the second battery is normal, the second parallel switch K2 is closed; if the state of the second battery is abnormal and the DC bus voltage exceeds the normal value by 2%, the generator set is started; when the DC bus voltage exceeds the normal value by 2% and the discharge power of the first battery is 0, the first battery is discharged at a reduced rated power of 10%; when the DC bus voltage exceeds the normal value by 2% and the discharge power of the first battery is 0, the load size is adjusted;

[0024] When it is detected that the SOC of the first battery is less than 30%, the generator set is started and the first battery is in a charging state; and when the DC voltage fluctuation is greater than 2%, the second parallel switch K2 is closed if the state of the second battery is normal, and if the state of the second battery is abnormal, it is determined whether the discharge power of the second battery is 0, and if it is 0, the load size is adjusted, and if it is not 0, the first battery is charged with 10% of the rated power reduction;

[0025] When it is detected that the SOC of the first battery is between 30% and 80%, if the load power demand is greater than 2 times the rated power of the battery, the generator set is started, otherwise the bidirectional converter connected to the voltage and current control battery is used to realize the charging and discharging of the first battery according to the bus voltage fluctuation to meet the load power demand, and when the DC bus voltage fluctuation is greater than 2%, the second parallel switch K2 is closed if the state of the second battery is normal, and if the state of the second battery is abnormal, it is determined whether the discharge power of the second battery is 0, if it is 0, the load size is adjusted, and if it is not 0, the first battery is charged with 10% of the rated power reduction;

[0026] When the generator motor is normal and in operation, and the second parallel switch K2 is closed, it corresponds to the above situation.

[0027] Furthermore, in the case of state 3, when there is an abnormality in the generator set and the system DC bus voltage fluctuation is greater than 2%, the load size is adjusted;

[0028] When the load fluctuation is no more than 2%, the output power of each battery and the output power size are determined according to the battery SOC.

[0029] Furthermore, in state 3, the output power of battery i is:

[0030]

[0031] Where i represents the i-th battery, and the value of i in this scheme can be 1 or 2; p i Indicates the output power of the ith battery, SOC i represents the i-th battery, and ∑SOC represents the sum of the battery SOCs.

[0032] Furthermore, in the case of state 3, when the generator set is normal and in normal operation:

[0033] When the SOC of both batteries is greater than 80%, both batteries are in the discharge working mode. If the DC bus voltage exceeds the normal control value by >2%, adjust the load size or generator output power, otherwise adjust at 10% of the rated power; when the battery discharge power is 0 and the DC bus voltage fluctuation still exceeds 2%, adjust the load size or generator output power, and exit the discharge working mode when the battery SOC is less than 70%;

[0034] When the SOC of both batteries is less than 30%, both batteries are in charging mode. If the DC bus voltage is lower than the normal control value>2%, adjust the load size or generator output power. Otherwise, adjust at 10% of the rated power. When the charging power is 0, if the bus voltage fluctuation still exceeds 2%, adjust the load size or generator output power. When the battery SOC is greater than 40%, exit the discharge mode.

[0035] When the SOC of the two batteries is between 30% and 80%, the two batteries are in the charge and discharge parallel working mode. The charge and discharge size is determined according to the bus voltage fluctuation. If the bus voltage fluctuation still exceeds 2%, the load size is adjusted.

[0036] When the SOC of one of the two batteries is greater than 80% and the SOC of the other battery is between 30% and 80%, when the battery is in a discharging state, the SOC greater than 80% is preferentially used for discharging. When the discharge power is greater than twice the rated power of the battery, the load size or the generator output power is adjusted. When the discharge power is between 1 and 2 times the rated power of the battery, the SOC greater than 80% is used for full power discharge, and the remaining power is compensated by the battery with an SOC between 30% and 80%. When the discharge power is less than 1 times the rated power of the battery, the battery with an SOC greater than 80% is used for compensation. When the SOC of the battery is greater than 80% and the SOC decreases to 70%, the discharge mode is exited and the switch is disconnected;

[0037] When the SOC of one of the two batteries is less than 30% and the SOC of the other battery is between 30% and 80%, when the battery is in a charging state, the battery with SOC less than 30% is preferentially used for charging. When the charging power is greater than twice the rated power of the battery, the load size or the generator output power is adjusted. When the charging power is between 1 and 2 times the rated power of the battery, the battery with SOC less than 30% is used for full power charging, and the remaining power is compensated by the battery with SOC between 30% and 80%. When the charging power is less than 1 times the rated power of the battery, the battery with SOC less than 30% is used for compensation. When the SOC of the battery with SOC less than 30% increases to 30%, the charging mode is exited and the switch is disconnected;

[0038] When the SOC of one of the two batteries is less than 30% and the SOC of the other battery is greater than 80%, the battery with SOC greater than 80% is in discharge mode, and the battery with SOC less than 30% is in charge mode. The de-charge and discharge modes are determined according to the battery SOC status; if the bus voltage fluctuation still exceeds 2%, the load size or generator output power is adjusted;

[0039] When the load power is within the energy storage rated power range for a long time, the generator will exit the operating state.

[0040] Furthermore, in state 3, when the generator set is normal and in a shutdown standby state, and the load power demand is not within the battery rated power range, the generation-storage control method is as follows:

[0041] When the SOC of both batteries is greater than 80%, both batteries are in discharge working mode. The discharge size is determined according to the bus voltage fluctuation. If the DC bus voltage exceeds the normal control value by >2%, adjust the load size or generator output power. Otherwise, adjust it at 10% of the rated power. When the discharge power is 0, if the bus voltage fluctuation still exceeds 2%, the output system is abnormal. The battery SOC is less than 70% and then exits the discharge working mode.

[0042] When the SOC of both batteries is less than 30%, both batteries are in charging mode, then the generator is started and the batteries are charged at rated power;

[0043] When the SOC of the two batteries is between 30% and 80%, the two batteries are in the charge-discharge parallel working mode. The charge-discharge size is determined according to the bus voltage fluctuation. If the bus voltage fluctuation still exceeds 2%, adjust the load size or start the generator to output power.

[0044] When the SOC of one of the two batteries is greater than 80% and the SOC of the other battery is between 30% and 80%, when the battery is in a discharging state, the SOC greater than 80% is preferentially used for discharging. When the discharge power is greater than twice the rated power of the battery, the load size is adjusted or the generator is started. When the discharge power is between 1 and 2 times the rated power of the battery, the SOC greater than 80% is used for full power discharge, and the remaining power is compensated by the battery with an SOC between 30% and 80%. When the discharge power is less than 1 times the rated power of the battery, the battery with an SOC greater than 80% is used for compensation. When the SOC of the battery is greater than 80% and the SOC decreases to 70%, the discharge mode is exited and the switch is disconnected;

[0045] When the SOC of one of the two batteries is less than 30% and the SOC of the other battery is between 30% and 80%, when the battery is in a charging state, the battery with SOC less than 30% is preferentially used for charging. When the charging power is greater than twice the rated power of the battery, the load size is adjusted. When the charging power is between 1 and 2 times the rated power of the battery, the battery with SOC less than 30% is used for full power charging, and the remaining power is compensated by the battery with SOC between 30% and 80%. When the charging power is less than 1 times the rated power of the battery, the battery with SOC less than 30% is used for compensation. When the SOC of the battery with SOC less than 30% increases to 30%, the charging mode is exited and the switch is disconnected;

[0046] When the SOC of one of the two batteries is less than 30% and the SOC of the other battery is greater than 80%, the battery with SOC greater than 80% is in discharge mode, and the battery with SOC less than 30% is in charge mode. The discharge and discharge modes are determined according to the battery SOC status. If the bus voltage fluctuation still exceeds 2%, adjust the load size or start the generator.

[0047] The beneficial effects achieved by the present invention are:

[0048] The present invention realizes the distributed generation-storage system control of the ship's integrated electric propulsion system.

[0049] The present invention realizes the parallel operation of generation and energy storage, and the energy storage meets the compensation demand of the ship's integrated electric propulsion system according to the monitoring status.

[0050] The present invention realizes the automatic switching of distributed generation and storage, and meets the power supply demand of the integrated electric propulsion system of the ship.

[0051] The distributed generation-storage system control of the ship integrated electric propulsion system provided by the present invention not only realizes the control of a single generation-storage system, but also realizes the control of multiple generation-storage systems, making it suitable for systems with larger capacity.

[0052] The present invention realizes the control of the distributed energy storage system when the marine diesel generator is operating normally, realizes the automatic switching of the distributed energy storage, and meets the power supply demand of the ship's integrated electric propulsion system.

[0053] The present invention realizes the energy storage power distribution of the ship's integrated electric propulsion system, and meets the power supply demand of the ship's integrated electric propulsion system according to the SOC state of the energy storage and the system power demand.

[0054] The present invention realizes the management and control of multiple state simulations of the source in the distributed generation-storage system, and provides theoretical guidance for the energy management of the integrated electric propulsion system of ships. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 A schematic diagram of a ship integrated electric propulsion system in a generation-storage coordinated control method of a ship integrated electric propulsion system provided by the present invention;

[0056] Figure 2 A schematic diagram of a method for coordinated control of generation and storage of a ship integrated electric propulsion system provided by the present invention, in which both the first parallel switch K1 and the second parallel switch K2 are disconnected;

[0057] Figure 3 A schematic diagram of the first parallel switch K1 or the second parallel switch K2 being closed and the generator being put into operation in a generation-storage coordinated control method of a ship integrated electric propulsion system provided by the present invention;

[0058] Figure 4 A schematic diagram of a method for coordinated control of generation and storage in a ship integrated electric propulsion system provided by the present invention, in which the first parallel switch K1 or the second parallel switch K2 is closed and the generator is not put into operation;

[0059] Figure 5 A schematic diagram of a generator set failure in a generation-storage coordinated control method for a ship integrated electric propulsion system provided by the present invention;

[0060] Figure 6 A schematic diagram of a method for coordinated control of generation and storage of a ship integrated electric propulsion system provided by the present invention, in which the first parallel switch K1 and the second parallel switch K2 are both closed and the generator is put into operation;

[0061] Figure 7 A schematic diagram of a generation-storage coordinated control method for a ship integrated electric propulsion system provided by the present invention in which the first parallel switch K1 and the second parallel switch K2 are both closed and the generator is not running. DETAILED DESCRIPTION

[0062] The technical solution of the present invention is described in more detail below in conjunction with the accompanying drawings. The present invention includes but is not limited to the following embodiments.

[0063] A method for energy storage control of a ship integrated electric propulsion system. The ship integrated electric propulsion system includes a power generation system, a first battery, a second battery, a controllable load, a first parallel switch K1, and a second parallel switch K2. The first parallel switch K1 is arranged between the first battery and the DC bus, and the second parallel switch K2 is arranged between the second battery and the DC bus. The power generation system and the controllable load are both connected to the DC bus. The structural diagram of the ship integrated electric propulsion system is shown in FIG. Figure 1 shown.

[0064] The generation and storage control of the ship's integrated electric propulsion system is mainly Figure 1 The distributed generation-storage equipment contained in the system is managed and controlled, including generation-storage management, which mainly includes three states: state 1: power supply by a single generator, state 2: one battery and generator in parallel, and state 3: two batteries and generators in parallel.

[0065] State 1: K1 and K2 are both disconnected. At this time, neither battery 1 nor the second battery is connected to the left 750V DC bus. The generator system supplies power to the load alone. When the DC bus voltage fluctuation is detected to exceed 2% and the time exceeds 5s, the switch K1 is closed according to whether the state of battery 1 is normal. If the first battery is abnormal, the state of the second battery is detected to be normal. If it is normal, the switch K2 is closed. If both the first battery and the second battery are abnormal, the load is adjusted. The working process is as follows: Figure 2 shown.

[0066] State 2: One of the switches K1 and K2 is closed. At this time, the first battery or the second battery is connected to the left 750V DC bus and supplies power to the load together with the generator. The control method of the battery is the same when one of the switches K1 and K2 is closed. The example of K1 closing is used for explanation.

[0067] In this state, the ship's generation and storage system is managed and controlled from three states: whether the generator set is normal and whether it is in operation during normal time.

[0068] (1) When the generator fails, only the first battery and the second battery need to be controlled, and the K2 switch is controlled according to the bus voltage fluctuation. When the DC voltage fluctuation is greater than 2%, K2 is controlled to close or the load size is adjusted according to the status of the first battery. If the first battery is normal, K2 is closed; if the first battery is abnormal, the load size is adjusted;

[0069] (2) When the generator motor is normal, the process is also divided into two processes, the generator is in shutdown or running state.

[0070] 1) When the generator is in operation:

[0071] When it is detected that the remaining battery capacity SOC of the first battery is greater than 80%, the first battery is in a discharging state, and K2 is controlled and the discharge power of the second battery is controlled according to the bus voltage fluctuation. When the DC voltage fluctuation is greater than 2%, the discharge power of the first battery is adjusted, K2 is controlled, or the load size is adjusted according to the state of the second battery; when the state of the second battery is normal, K2 is closed; when the state of the second battery is abnormal, and when the DC bus voltage exceeds the normal value by 2% or the discharge power of the first battery is 0, the load size is adjusted; when the DC bus voltage does not exceed the normal value by 2% and the discharge power of the first battery is not zero, the first battery is discharged at a reduced rated power of 10%.

[0072] When it is detected that the SOC of the first battery is less than 30%, the first battery is in a charging state, and the K2 switch and the charging power of the first battery are controlled according to the bus voltage fluctuation. When the DC voltage fluctuation is greater than 2%, the discharge power of the first battery, K2 or the load size are adjusted according to the state control of the second battery; if the state of the second battery is normal, K2 is closed, and if the state of the second battery is abnormal, the load size is adjusted.

[0073] When it is detected that the SOC of the first battery is between 30% and 80%, the first battery is in a charging and discharging state. According to the bus voltage fluctuation, the bidirectional converter connected to the voltage and current control battery is used to realize the charging and discharging of the first battery to meet the load power demand. When the DC bus voltage fluctuation is greater than 2%, the state of K2 is determined according to the state of the second battery. If the state of the second battery is normal, K2 is closed. If the state of the second battery is abnormal, the load size is adjusted. The workflow is as follows Figure 3 shown.

[0074] 2) When the generator is in shutdown and waiting state:

[0075] When it is detected that the SOC of the first battery is greater than 80%, the first battery is in a discharging state, and the K2 switch and the discharge power of the first battery are controlled according to the bus voltage fluctuation. When the DC voltage fluctuation is greater than 2%, if the state of the second battery is normal, K2 is closed; if the state of the second battery is abnormal and the DC bus voltage exceeds the normal value by 2%, the generator set is started; when the DC bus voltage does not exceed the normal value by 2% and the discharge power of the first battery is 0, the first battery is discharged at a reduced rated power of 10%; when the DC bus voltage does not exceed the normal value by 2% and the discharge power of the first battery is 0, the load size is adjusted.

[0076] When it is detected that the SOC of the first battery is less than 30%, the first battery is in a charging state, and K2 and the charging power of the first battery are controlled according to the bus voltage fluctuation. When the DC voltage fluctuation is greater than 2%, the generator set 1 is started, and the discharge power of the first battery is adjusted, K2 is closed, or the load size is adjusted according to the state of the second battery; if the state of the second battery is normal, K2 is closed; if the state of the second battery is abnormal, it is determined whether the discharge power of the second battery is 0, and if it is 0, the load size is adjusted; if it is not 0, the first battery is charged with 10% of the rated power reduced.

[0077] When it is detected that the SOC of the first battery is between 30% and 80%, the first battery is in a charging and discharging state. If the load power demand is greater than twice the rated power of the battery, the generator set 1 is started. Otherwise, the bidirectional converter connected to the battery is controlled by voltage and current according to the bus voltage fluctuation to realize the charging and discharging of the first battery to meet the load power demand. When the DC bus voltage fluctuation is greater than 2%, the state of K2 is determined according to the state of the second battery. If the state of the second battery is normal, K2 is closed. If the state of the second battery is abnormal, it is determined whether the discharge power of the second battery is 0. If it is 0, the load size is adjusted. If it is not 0, the first battery is charged with 10% of the rated power reduction. The workflow is as follows: Figure 4 shown.

[0078] The generation-storage control process when the second battery is connected to the busbar alone is the same as that when the first battery is connected to the busbar alone, and will not be described here.

[0079] State three: K1 and K2 are both closed. At this time, the first battery and the second battery are connected to the left 750V DC bus and are in parallel working state to supply power to the load together with the generator system.

[0080] In this state, the ship's generation and storage system is managed and controlled from three states: whether the generator set is normal and whether it is in operation during normal time.

[0081] (1) When there is an abnormality in generator set 1, only the energy storage battery needs to be controlled. When the system DC bus voltage fluctuation is greater than 2%, adjust the load size.

[0082] When the load fluctuation is no more than 2%, the two batteries are in parallel operation and control is implemented according to the SOC state. When the batteries are in parallel and current-sharing operation, the output power of each battery is determined according to the SOC of the stored power. The output power size is shown in the following formula.

[0083]

[0084] Where i represents battery i, and the value of i in this scheme can be 1 or 2; p i Indicates the output power of the ith battery, SOC i represents the i-th battery, and ∑SOC represents the sum of the battery SOCs.

[0085] (2) When the generator set 1 is normal, the process is also divided into two processes, the generator is in shutdown or running state.

[0086] 1) When the generator set is in normal operation:

[0087] When the SOC of both batteries is greater than 80%, both batteries are in discharge working mode. The discharge size is determined according to the bus voltage fluctuation. If the DC bus voltage exceeds the normal control value by >2%, adjust the load size or generator output power. Otherwise, adjust it at 10% of the rated power. When the discharge power is 0, if the bus voltage fluctuation still exceeds 2%, adjust the load size or generator output power. When the battery SOC is less than 70%, exit the discharge working mode.

[0088] When the SOC of both batteries is less than 30%, both batteries are in charging mode. The charging size is determined according to the bus voltage fluctuation. If the DC bus voltage is lower than the normal control value>2%, adjust the load size or generator output power. Otherwise, adjust it at 10% of the rated power. When the charging power is 0, if the bus voltage fluctuation still exceeds 2%, adjust the load size or generator output power. When the battery SOC is greater than 40%, exit the discharge mode.

[0089] When the SOC of the two batteries is between 30% and 80%, the two batteries are in the charge and discharge parallel working mode. The charge and discharge size is determined according to the bus voltage fluctuation. If the bus voltage fluctuation still exceeds 2%, the load size is adjusted.

[0090] When the SOC of one of the two batteries is greater than 80% and the SOC of the other battery is between 30% and 80%, when the battery is in a discharging state, the SOC greater than 80% is preferentially used for discharging. When the discharge power is greater than twice the rated power of the battery, the load size or the generator output power is adjusted. When the discharge power is between 1 and 2 times the rated power of the battery, the SOC greater than 80% is used for full power discharge, and the remaining power is compensated by the battery with an SOC between 30% and 80%. When the discharge power is less than 1 times the rated power of the battery, the battery with an SOC greater than 80% is used for compensation. When the SOC of the battery is greater than 80% and the SOC decreases to 70%, the discharge mode is exited and the switch is disconnected;

[0091] When the SOC of one of the two batteries is less than 30% and the SOC of the other battery is between 30% and 80%, when the battery is in a charging state, the battery with SOC less than 30% is preferentially used for charging. When the charging power is greater than twice the rated power of the battery, the load size or the generator output power is adjusted. When the charging power is between 1 and 2 times the rated power of the battery, the battery with SOC less than 30% is used for full power charging, and the remaining power is compensated by the battery with SOC between 30% and 80%. When the charging power is less than 1 times the rated power of the battery, the battery with SOC less than 30% is used for compensation. When the SOC of the battery with SOC less than 30% increases to 30%, the charging mode is exited and the switch is disconnected;

[0092] When the SOC of one of the two batteries is less than 30% and the SOC of the other battery is greater than 80%, the battery with SOC greater than 80% is in discharge mode, and the battery with SOC less than 30% is in charge mode. The discharge and discharge modes are determined according to the battery SOC status. If the bus voltage fluctuation still exceeds 2%, adjust the load size or generator output power.

[0093] When the load power is within the energy storage rated power range for a long time, the generator will exit the running state. The working process is as follows: Figure 6 shown.

[0094] 2) When the generator set is in shutdown and waiting state:

[0095] When the load power demand is within the rated power range of the battery, the working state is a model where two batteries are connected in parallel to supply power to the load. The generator can start to supply power to the load. This state is the same as the abnormal operation of the generator and the parallel operation of the energy storage, which will not be elaborated here. When the load power demand is not within the rated power range of the battery, the generation-storage control method is as follows:

[0096] When the SOC of both batteries is greater than 80%, both batteries are in discharge working mode. The discharge size is determined according to the bus voltage fluctuation. If the DC bus voltage exceeds the normal control value by >2%, adjust the load size or generator output power. Otherwise, adjust it at 10% of the rated power. When the discharge power is 0, if the bus voltage fluctuation still exceeds 2%, the output system is abnormal. The battery SOC is less than 70% and then exits the discharge working mode.

[0097] When the SOC of both batteries is less than 30%, both batteries are in charging mode, then the generator is started and the batteries are charged at rated power;

[0098] When the SOC of the two batteries is between 30% and 80%, the two batteries are in the charge-discharge parallel working mode. The charge-discharge size is determined according to the bus voltage fluctuation. If the bus voltage fluctuation still exceeds 2%, adjust the load size or start the generator to output power.

[0099] When the SOC of one of the two batteries is greater than 80% and the SOC of the other battery is between 30% and 80%, when the battery is in a discharging state, the SOC greater than 80% is preferentially used for discharging. When the discharge power is greater than twice the rated power of the battery, the load size is adjusted or the generator is started. When the discharge power is between 1 and 2 times the rated power of the battery, the SOC greater than 80% is used for full power discharge, and the remaining power is compensated by the battery with an SOC between 30% and 80%. When the discharge power is less than 1 times the rated power of the battery, the battery with an SOC greater than 80% is used for compensation. When the SOC of the battery is greater than 80% and the SOC decreases to 70%, the discharge mode is exited and the switch is disconnected;

[0100] When the SOC of one of the two batteries is less than 30% and the SOC of the other battery is between 30% and 80%, when the battery is in a charging state, the battery with SOC less than 30% is preferentially used for charging. When the charging power is greater than twice the rated power of the battery, the load size is adjusted. When the charging power is between 1 and 2 times the rated power of the battery, the battery with SOC less than 30% is used for full power charging, and the remaining power is compensated by the battery with SOC between 30% and 80%. When the charging power is less than 1 times the rated power of the battery, the battery with SOC less than 30% is used for compensation. When the SOC of the battery with SOC less than 30% increases to 30%, the charging mode is exited and the switch is disconnected;

[0101] When the SOC of one of the two batteries is less than 30% and the SOC of the other battery is greater than 80%, the battery with SOC greater than 80% is in discharge mode, and the battery with SOC less than 30% is in charge mode. The discharge and discharge modes are determined according to the battery SOC status. If the bus voltage fluctuation still exceeds 2%, adjust the load size or start the generator. The workflow is as follows Figure 7 shown.

[0102] The present invention is not limited to the above-mentioned specific implementation modes. A person skilled in the art may implement the present invention in various other specific implementation modes according to the embodiments and the disclosure of the drawings. Therefore, any design that adopts the design structure and concept of the present invention and makes some simple transformations or changes shall fall within the scope of protection of the present invention.

Claims

1. A generation-storage coordinated control method for a ship integrated electric propulsion system, the ship integrated electric propulsion system comprising a power generation system, a first battery, a second battery, a controllable load, a first parallel switch K1, and a second parallel switch K2, wherein the first parallel switch K1 is arranged between the first battery and a DC bus, the second parallel switch K2 is arranged between the second battery and the DC bus, and the power generation system and the controllable load are both connected to the DC bus; It is characterized in that The generation-storage coordinated control method of the ship integrated electric propulsion system includes: State 1: When the generator is used alone for power supply, if the DC bus voltage fluctuates, the switch corresponding to the battery in normal state is closed; State 2: When a battery and a generator are connected in parallel, the discharge power of the battery is adjusted, the switch corresponding to the other battery is closed, or the load size is adjusted according to the status of the generator and the battery; State 3: When two batteries and a generator are connected in parallel, the switches of the two batteries are closed or the load size is adjusted according to whether the generator is normal and whether it is in operation when it is normal.

2. The generation-storage coordinated control method of the ship integrated electric propulsion system according to claim 1 is characterized in that: In the case of state 1, when it is detected that the DC bus voltage fluctuates by more than 2% and the time exceeds 5s, the first parallel switch K1 is closed according to whether the state of the first battery is normal; If the first battery is abnormal, the state of the second battery is detected to see if it is normal. If it is normal, the second parallel switch K2 is closed; if both the first battery and the second battery are abnormal, the load is adjusted.

3. The generation-storage coordinated control method of the ship integrated electric propulsion system according to claim 1 is characterized in that: In the case of state 2, including when there is a generator fault, the second parallel switch K2 is controlled according to the bus voltage fluctuation: When the DC voltage fluctuation is greater than 2%, if the first battery is normal, the second parallel switch K2 is closed; if the first battery is abnormal, the load size is adjusted.

4. The generation-storage coordinated control method of a ship integrated electric propulsion system according to claim 1 is characterized in that: In the case of state 2, including when the generator motor is normal and in operation, and the first parallel switch K1 is closed: When it is detected that the SOC of the first battery is greater than 80%, the first battery is in a discharging state, and the DC voltage fluctuation is greater than 2%; if the state of the second battery is normal, the second parallel switch K2 is closed; when the state of the second battery is abnormal, and when the DC bus voltage exceeds the normal value by 2% or the discharge power of the first battery is 0, the load size is adjusted; when the DC bus voltage exceeds the normal value by 2% and the discharge power of the first battery is not zero, the first battery is discharged with 10% of the rated power reduced; When it is detected that the SOC of the first battery is less than 30%, the first battery is in a charging state, and when the DC bus voltage fluctuation is greater than 2%, the second parallel switch K2 is closed if the state of the second battery is normal, and the load size is adjusted if the state of the second battery is abnormal; When it is detected that the SOC of the first battery is between 30% and 80%, the first battery is in a charging and discharging state, and the bidirectional converter connected to the voltage and current control battery is used to realize the charging and discharging of the first battery according to the bus voltage fluctuation to meet the load power demand; when the DC bus voltage fluctuation is greater than 2%, the second parallel switch K2 is closed if the state of the second battery is normal, and the load size is adjusted if the state of the second battery is abnormal; When the generator motor is normal and in operation, and the second parallel switch K2 is closed, it corresponds to the above situation.

5. The generation-storage coordinated control method of a ship integrated electric propulsion system according to claim 1, characterized in that: In the case of state 2, including when the generator motor is normal and in a shutdown standby state, and the first parallel switch K1 is closed: When it is detected that the SOC of the first battery is greater than 80%, the first battery is in a discharging state, and when the DC bus voltage fluctuation is greater than 2%, if the state of the second battery is normal, the second parallel switch K2 is closed; if the state of the second battery is abnormal and the DC bus voltage exceeds the normal value by 2%, the generator set is started; when the DC bus voltage exceeds the normal value by 2% and the discharge power of the first battery is 0, the first battery is discharged at a reduced rated power of 10%; when the DC bus voltage exceeds the normal value by 2% and the discharge power of the first battery is 0, the load size is adjusted; When it is detected that the SOC of the first battery is less than 30%, the generator set is started and the first battery is in a charging state; and when the DC voltage fluctuation is greater than 2%, the second parallel switch K2 is closed if the state of the second battery is normal, and if the state of the second battery is abnormal, it is determined whether the discharge power of the second battery is 0, and if it is 0, the load size is adjusted, and if it is not 0, the first battery is charged with 10% of the rated power reduction; When it is detected that the SOC of the first battery is between 30% and 80%, if the load power demand is greater than 2 times the rated power of the battery, the generator set is started, otherwise the bidirectional converter connected to the voltage and current control battery is used to realize the charging and discharging of the first battery according to the bus voltage fluctuation to meet the load power demand, and when the DC bus voltage fluctuation is greater than 2%, the second parallel switch K2 is closed if the state of the second battery is normal, and if the state of the second battery is abnormal, it is determined whether the discharge power of the second battery is 0, if it is 0, the load size is adjusted, and if it is not 0, the first battery is charged with 10% of the rated power reduction; When the generator motor is normal and in operation, and the second parallel switch K2 is closed, it corresponds to the above situation.

6. The generation-storage coordinated control method of a ship integrated electric propulsion system according to claim 1, characterized in that: In the case of state 3, when there is an abnormality in the generator set and the system DC bus voltage fluctuation is greater than 2%, the load size is adjusted; When the load fluctuation is no more than 2%, the output power of each battery and the output power size are determined according to the battery SOC.

7. The generation-storage coordinated control method of a ship integrated electric propulsion system according to claim 6 is characterized in that: In the case of state 3, the output power of battery i is: Where i represents the i-th battery, and the value of i in this scheme can be 1 or 2; p i Indicates the output power of the ith battery, SOC i represents the i-th battery, and ∑SOC represents the sum of the battery SOCs.

8. The generation-storage coordinated control method of a ship integrated electric propulsion system according to claim 1, characterized in that: In case of state 3, when the generator set is normal and in normal operation: When the SOC of both batteries is greater than 80%, both batteries are in the discharge working mode. If the DC bus voltage exceeds the normal control value by >2%, adjust the load size or generator output power, otherwise adjust at 10% of the rated power; when the battery discharge power is 0 and the DC bus voltage fluctuation still exceeds 2%, adjust the load size or generator output power, and exit the discharge working mode when the battery SOC is less than 70%; When the SOC of both batteries is less than 30%, both batteries are in charging mode. If the DC bus voltage is lower than the normal control value>2%, adjust the load size or generator output power. Otherwise, adjust at 10% of the rated power. When the charging power is 0, if the bus voltage fluctuation still exceeds 2%, adjust the load size or generator output power. When the battery SOC is greater than 40%, exit the discharge mode. When the SOC of the two batteries is between 30% and 80%, the two batteries are in the charge and discharge parallel working mode. The charge and discharge size is determined according to the bus voltage fluctuation. If the bus voltage fluctuation still exceeds 2%, the load size is adjusted. When the SOC of one of the two batteries is greater than 80% and the SOC of the other battery is between 30% and 80%, when the battery is in a discharging state, the SOC greater than 80% is preferentially used for discharging. When the discharge power is greater than twice the rated power of the battery, the load size or the generator output power is adjusted. When the discharge power is between 1 and 2 times the rated power of the battery, the SOC greater than 80% is used for full power discharge, and the remaining power is compensated by the battery with an SOC between 30% and 80%. When the discharge power is less than 1 times the rated power of the battery, the battery with an SOC greater than 80% is used for compensation. When the SOC of the battery is greater than 80% and the SOC decreases to 70%, the discharge mode is exited and the switch is disconnected; When the SOC of one of the two batteries is less than 30% and the SOC of the other battery is between 30% and 80%, when the battery is in a charging state, the battery with SOC less than 30% is preferentially used for charging. When the charging power is greater than twice the rated power of the battery, the load size or the generator output power is adjusted. When the charging power is between 1 and 2 times the rated power of the battery, the battery with SOC less than 30% is used for full power charging, and the remaining power is compensated by the battery with SOC between 30% and 80%. When the charging power is less than 1 times the rated power of the battery, the battery with SOC less than 30% is used for compensation. When the SOC of the battery with SOC less than 30% increases to 30%, the charging mode is exited and the switch is disconnected; When the SOC of one of the two batteries is less than 30% and the SOC of the other battery is greater than 80%, the battery with SOC greater than 80% is in discharge mode, and the battery with SOC less than 30% is in charge mode. The de-charge and discharge modes are determined according to the battery SOC status; if the bus voltage fluctuation still exceeds 2%, the load size or generator output power is adjusted; When the load power is within the energy storage rated power range for a long time, the generator will exit the operating state.

9. The generation-storage coordinated control method of a ship integrated electric propulsion system according to claim 1, characterized in that: In the case of state 3, when the generator set is normal and in a shutdown standby state, and the load power demand is not within the rated power range of the battery, the generation-storage control method is as follows: When the SOC of both batteries is greater than 80%, both batteries are in discharge working mode. The discharge size is determined according to the bus voltage fluctuation. If the DC bus voltage exceeds the normal control value by >2%, adjust the load size or generator output power. Otherwise, adjust it at 10% of the rated power. When the discharge power is 0, if the bus voltage fluctuation still exceeds 2%, the output system is abnormal. The battery SOC is less than 70% and then exits the discharge working mode. When the SOC of both batteries is less than 30%, both batteries are in charging mode, then the generator is started and the batteries are charged at rated power; When the SOC of the two batteries is between 30% and 80%, the two batteries are in the charge-discharge parallel working mode. The charge-discharge size is determined according to the bus voltage fluctuation. If the bus voltage fluctuation still exceeds 2%, adjust the load size or start the generator to output power. When the SOC of one of the two batteries is greater than 80% and the SOC of the other battery is between 30% and 80%, when the battery is in a discharging state, the SOC greater than 80% is preferentially used for discharging. When the discharge power is greater than twice the rated power of the battery, the load size is adjusted or the generator is started. When the discharge power is between 1 and 2 times the rated power of the battery, the SOC greater than 80% is used for full power discharge, and the remaining power is compensated by the battery with an SOC between 30% and 80%. When the discharge power is less than 1 times the rated power of the battery, the battery with an SOC greater than 80% is used for compensation. When the SOC of the battery is greater than 80% and the SOC decreases to 70%, the discharge mode is exited and the switch is disconnected; When the SOC of one of the two batteries is less than 30% and the SOC of the other battery is between 30% and 80%, when the battery is in a charging state, the battery with SOC less than 30% is preferentially used for charging. When the charging power is greater than twice the rated power of the battery, the load size is adjusted. When the charging power is between 1 and 2 times the rated power of the battery, the battery with SOC less than 30% is used for full power charging, and the remaining power is compensated by the battery with SOC between 30% and 80%. When the charging power is less than 1 times the rated power of the battery, the battery with SOC less than 30% is used for compensation. When the SOC of the battery with SOC less than 30% increases to 30%, the charging mode is exited and the switch is disconnected; When the SOC of one of the two batteries is less than 30% and the SOC of the other battery is greater than 80%, the battery with SOC greater than 80% is in discharge mode, and the battery with SOC less than 30% is in charge mode. The discharge and discharge modes are determined according to the battery SOC status. If the bus voltage fluctuation still exceeds 2%, adjust the load size or start the generator.

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