A hybrid power ship energy efficiency control system and method

Abstract

The present invention provides a hybrid ship energy efficiency control system and method, the control system includes a first diesel generator set, a second diesel generator set, a shore power supply, an AC bus, an energy storage unit, a DC bus, a left motor, a left clutch, a left main engine, a right motor, a right clutch and a right main engine; the first diesel generator set, the second diesel generator set and the shore power supply AC bus are connected; the AC bus is connected to the DC bus; the energy storage unit is connected to the DC bus in sequence; the DC bus connects the left motor and the right motor; the left motor is connected to the left propeller and the left main engine; the right motor is connected to the right propeller and the right main engine. The advantages are: the propeller can be driven by the main engine alone, the motor alone or the main engine and the motor in combination of diesel-electric drive; the motor can work in a propulsion state or in a power generation state, and the reliability is high; an optimal gray prediction control method for hybrid ship energy efficiency is proposed, which fundamentally solves the problem of diesel engine running at the lowest fuel consumption rate SFOC.

Description

Technical Field

[0001] The present invention relates to the field of energy conservation, emission reduction and hybrid power technology for ships, marine engineering engineering ships, tugboats, etc., and in particular to a hybrid power ship energy efficiency control system and method. Background Art

[0002] At present, fuel is still the dominant energy source for ships, and fuel saving is the fundamental task of ships. Diesel engine manufacturers have developed perfect fuel-saving technology around in-cylinder combustion. The minimum fuel consumption rate (SFOC) of marine medium-speed engines is (191±5%) g / (kw〃h), and the corresponding optimal load of medium-speed engines is 100%; the minimum fuel consumption rate (SFOC) of low-speed engines is (162~165) g / (kw〃h), and the corresponding optimal load of low-speed engines is (75~80)%; but it is difficult to maintain the minimum fuel consumption rate in the actual operation of diesel engines. Changes in ship conditions and sea conditions result in the inability to meet the operating conditions required by diesel engines, which is a problem that restricts the optimal energy efficiency of diesel engines. Therefore, it is difficult to further reduce the minimum fuel consumption rate (SFOC) of diesel engines, and it is difficult to maintain the optimal working conditions of diesel engines in actual operation to achieve the minimum fuel consumption rate.

[0003] The main engine power is proportional to the cube of the speed. If the speed is appropriately reduced, the main engine power and fuel consumption rate SFOC will decrease in a cubic relationship, which can significantly reduce fuel consumption. There is an optimal economic speed for ships, which is the basis for ship design and the best matching point of ship-engine-propeller. However, considering the ship's route and operating requirements, it is difficult for ships to maintain the optimal economic speed. This requires choosing the correct calculation and evaluation method, analyzing the scientific and reasonable economic speed for different ship types and ages, and seeking the best balance between diesel engine fuel consumption and speed. Considering the actual operating conditions of ship diesel engines, when power and speed change, its fuel consumption rate SFOC is affected by the injection volume, ventilation quality, speed, etc., and is not a fixed value. The influence of the ship's operating speed makes it difficult to operate diesel engines to save fuel. However, green energy such as wind energy, solar energy, and wave energy are not effective enough on ships and the cost is too high.

[0004] Focusing on the energy saving of waste heat from ship main engine, the current waste gas boilers, waste gas turbines, and water generators have successfully utilized the waste heat from the main engine, and directly utilized the waste heat energy from the low-speed main engine. Converting the waste heat from the main engine into electrical energy has become a hot topic, including shaft belt motors, waste gas turbine power generation, waste gas boiler steam power generation, main engine exhaust ORC power generation, exhaust and ambient temperature difference power generation, etc. The cost is too high and the efficiency is poor. Only shaft belt motors have application prospects, but the application of shaft belt motors on ships is to reduce the work done by diesel generators, ignoring the problem of the ship's main engine and generator diesel engine running at the lowest fuel consumption rate SFOC.

[0005] Oil-gas hybrid power and oil-electric-gas hybrid power are one of the hot directions of ship development. Oil-electric hybrid power ships have become a research hotspot and have begun to be implemented, while oil-electric-gas hybrid power ship research has not yet been carried out. However, it only solves the emission and pollution problems such as SOx and NOx. If battery energy storage technology is not added to the hybrid power, it will be difficult to ensure the optimal energy efficiency of hybrid ships.

[0006] At present, the research on oil-electric hybrid power focuses on electric propulsion, ignoring that the fundamental way to save fuel for ships is to save fuel for diesel engines, and the fundamental way to save fuel for diesel engines is to operate at the lowest fuel consumption rate SFOC. Therefore, electric propulsion ships may not be fuel-efficient. Some ships use wind and solar energy to reduce the work done by power generation diesel engines, but not to save fuel by running diesel engines at the lowest fuel consumption rate SFOC.

[0007] The current status of technologies to improve ship energy efficiency is as follows:

[0008] 1. Ships use economical speed to achieve the goal of saving fuel, but the economical speed is affected by routes, cargo operations, etc. In order to meet the ship's schedule, operational needs, loading and unloading requirements, port tides, and avoid severe sea conditions, ships always sail at a variable speed, far away from the economical speed. This is a common problem and difficulty.

[0009] 2. The main engine shaft belt generator in the hybrid power system partially replaces the diesel generator set to supply power to the ship, reducing the output power of the generator diesel engine.

[0010] 3. The wind and solar power generation in the hybrid power system is stored in the battery pack and then inverted and connected to the ship's power grid, reducing the output power of the diesel engine.

[0011] 4. The shore power in the hybrid power is stored in the battery pack and then inverter-connected to the ship's power grid, replacing the power supply of the diesel generator.

[0012] 5. The battery energy storage or supercapacitor energy storage in the hybrid power system is connected to the ship's DC power grid through DC / DC (chopper) or connected to the ship's AC power grid through DC / AC (rectifier / inverter module), which plays a "peak-filling" role in the ship's power station, preventing the diesel generator set from changing too much load and improving the stability of the ship's power station.

[0013] Therefore, the existing solution for hybrid ships is to reduce the output power of the power generation diesel engine to achieve the goal of fuel saving, but there is still a blank in ship operation to achieve fuel saving by optimal control of the diesel engine's minimum fuel consumption rate SFOC.

[0014] The technical problems caused by the above technical status are as follows

[0015] 1. The working conditions of tugboats, engineering ships and other types of ships are changeable and the load is unstable. There are light load and heavy load in the berthing condition, anchoring condition, cruising condition, towing or construction condition. However, their power configuration is designed according to the full load condition, which causes waste of power reserve and is uneconomical.

[0016] 2. Tugboats, engineering vessels and other types of ships rarely operate at full load for a long period of time, but the thermal efficiency of the diesel engine is designed and configured according to the rated operating conditions, which causes the diesel engine to deviate from the minimum fuel consumption rate SFOC operating range, resulting in a worse fuel consumption rate for the diesel engine and a loss of fuel efficiency.

[0017] 3. Existing hybrid ships achieve the goal of fuel saving by reducing the work done by ship diesel engines, ignoring the fuel saving goal of taking the minimum fuel consumption rate SFOC of ship diesel engines as the optimal control.

[0018] 4. Existing hybrid ships are either diesel-powered or electric-powered, but not mutually exclusive. This is a technical difficulty that restricts the improvement of ship energy efficiency.

[0019] 5. The ship's operating conditions and environment are changeable and uncertain. When the power and speed change, its fuel consumption rate SFOC is affected by the injection volume, ventilation quality, speed, etc. The exact point of the best fuel consumption rate SFOC in the actual operation of the ship's diesel engine is difficult to determine, and it belongs to the gray system. This is the difficulty in achieving ship fuel saving by controlling the best fuel consumption rate SFOC of the diesel engine. Summary of the invention

[0020] The object of the present invention is to provide a hybrid power ship energy efficiency control system and method, so as to solve the above-mentioned problems existing in the prior art.

[0021] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0022] A hybrid ship energy efficiency control system, the ship includes a left propeller and a right propeller; the control system includes a first diesel generator set, a second diesel generator set, a shore power supply, an AC bus, an energy storage unit, a DC bus, a left motor, a left clutch, a left main engine, a right motor, a right clutch and a right main engine; the first diesel generator set and the second diesel generator set are connected to the AC bus through a first AC circuit breaker and a second AC circuit breaker respectively; the shore power supply is connected to the AC bus through a vacuum circuit breaker, a transformer group and a third AC circuit breaker in sequence; the AC bus is respectively connected to a first rectifier / inverter module, a second rectifier / inverter module and a third rectifier / inverter module through a fourth AC circuit breaker, a fifth AC circuit breaker, a sixth AC circuit breaker and a seventh AC circuit breaker and the fourth rectifier / inverter module, and then respectively connected to the DC bus through the corresponding first DC circuit breaker, the second DC circuit breaker, the third DC circuit breaker and the fourth DC circuit breaker; the energy storage unit is connected to the DC bus through the fifth DC circuit breaker, the chopper and the sixth DC circuit breaker in sequence; an eighth AC circuit breaker is arranged on the AC bus between the fourth AC circuit breaker and the fifth AC circuit breaker; a ninth AC circuit breaker is arranged on the AC bus between the sixth AC circuit breaker and the seventh AC circuit breaker; the DC bus is respectively connected to the tenth AC circuit breaker and the eleventh AC circuit breaker through the fifth rectifier / inverter module and the sixth rectifier / inverter module, and then respectively connected to the left motor and the right motor; the left motor is connected to the left propeller and the left main engine; the right motor is connected to the right propeller and the right main engine.

[0023] Preferably, the first diesel generator set and the second diesel generator set are of the same model but different capacities, and the power of the second diesel generator set is half of that of the first diesel generator set.

[0024] Preferably, the energy storage unit includes a battery group and a supercapacitor; the battery group includes a first lithium battery group, a second lithium battery group, a third lithium battery group and a fourth lithium battery group, the capacity of the first lithium battery group and the second lithium battery group are equal and are the capacity of the second diesel generator set; the capacity of the third lithium battery group and the fourth lithium battery group are equal and are half of the capacity of the second diesel generator set.

[0025] Preferably, when the left propeller and the right propeller are variable pitch propellers, the left motor and the right motor are connected to the left main engine and the right main engine respectively; when the left propeller and the right propeller are fixed pitch propellers, the left motor is connected to the left main engine through the left clutch; the right motor is connected to the right main engine through the right clutch.

[0026] The present invention also aims to provide a hybrid ship energy efficiency control method, which is implemented using any of the above control systems; the control method specifically adopts different power supply modes according to the working conditions of the ship to ensure the optimal energy efficiency of the hybrid ship; the working conditions of the ship include

[0027] Berth condition: shore power supply is used to fully charge the energy storage unit;

[0028] Anchoring condition: The energy storage unit supplies power. When the anchoring time is too long, causing the energy storage unit to discharge to 30% of its rated capacity, the second diesel generator set will be used first to fully charge the energy storage unit. When the whole ship is out of power, the second diesel generator set will start automatically to restore the ship's power supply to normal. The second diesel generator set has an emergency power generation function.

[0029] Shutdown condition: the first diesel generator set, the second diesel generator set, the left main engine, the right main engine, the left motor and the right motor are shut down;

[0030] Waiting condition; the ship is in the standby state and can depart immediately upon receiving the order to sail; the standby state includes berthing standby, anchoring standby and drifting standby; berthing standby and anchoring standby require the second diesel generator set to be started first to charge the energy storage unit. When there is no abnormality in the ship's operating system, the whole ship is ready to start at any time. If the waiting condition time is too long, the second diesel generator set will be shut down and the energy storage unit will be used for power supply; when drifting standby, the left or right propeller runs slowly. When the energy storage unit is powered for too long and causes the energy storage unit to discharge to 30% of its rated capacity, the second diesel generator set will be started for power supply; when drifting standby, at least one propeller needs to be running, and the motor corresponding to the propeller is in PTI electric mode;

[0031] Port entry and exit conditions; the energy storage unit is selected for power supply, and the two motors are in PTI electric mode to drive the corresponding propellers respectively, and the main engine and the motor are ready to start at any time; when the energy storage unit is powered for too long, causing the energy storage unit to discharge to 30% of its rated capacity, the second diesel generator set is put into operation and maintained at full load and minimum SFOC, and both motors are in PTI electric mode, and the ship is in electric propulsion mode;

[0032] The ship is in low-speed or medium-speed working condition; the energy storage unit is preferably used for power supply, and the two motors are in PTI electric working mode to drive the corresponding propellers respectively. When the energy storage unit is powered for too long, causing the energy storage unit to discharge to 30% of its rated capacity, one main engine is put into operation to drive the corresponding propeller, and the main engine is put into operation and maintained at full load and minimum SFOC, and the motor connected to the main engine is in PTO power generation mode; the other main engine is not running, and the motor connected to it is in PTI electric mode. At this time, the ship enters dual-shaft hybrid propulsion mode;

[0033] The energy storage unit supplies power, and two motors drive the corresponding propellers respectively. One main engine is put into operation and maintained at full load and minimum SFOC; and the other main engine and two diesel generator sets are ready to start at any time;

[0034] Ship high-speed operation; two main engines are put into operation and maintained at full load and minimum SFOC, two motors are in PTO power generation mode, and the energy storage unit is fully charged;

[0035] Maximum towing condition; preferably, both main engines are put into operation and maintained at full load and minimum SFOC, the left and right motors are in PTI electric mode, and the energy storage unit supplies power to the motors and drives the propellers together with the main engines; when the energy storage unit is discharged to 30% of its rated capacity, the two diesel generator sets are put into operation and maintained at full load and minimum SFOC; when the ship's pushing or towing load changes, the two motors automatically switch to PTI electric mode or PTO power generation mode to balance the sudden increase or decrease in load, and the energy storage unit cooperates with the two motors to charge or discharge to balance the sudden increase or decrease in electrical load.

[0036] Preferably, the two motors automatically switch between PTI electric mode and PTO power generation mode, including three situations, namely, the motor is in PTI electric mode and the main engine is shut down; the motor is in PTI electric mode and the main engine is working; the motor is in PTO power generation mode and the main engine is working; when the propulsion load increases, resulting in an increase in the main engine power, the motor generates a propulsion effect in PTI electric mode to compensate for the increase in propulsion load; when the propulsion load decreases, resulting in a decrease in the main engine power, the motor generates a resistance effect in PTO power generation mode to compensate for the decrease in propulsion load, so that the main engine power does not fluctuate with the change of the propulsion load, so that it is always operating at full load and minimum SFOC.

[0037] Preferably, the energy storage unit cooperates with two motors to charge or discharge, including three situations, namely, the energy storage unit supplies power and the diesel generator set is shut down; the energy storage unit is charged or discharged, and a single diesel generator set is working; the energy storage unit supplies power and two diesel generator sets are working; when the power station load increases, resulting in an increase in the power of the diesel generator set, the energy storage unit discharges; when the power station load decreases, resulting in a decrease in the power of the diesel generator set, the energy storage unit charges, so that the power of the diesel generator set does not fluctuate with the change of the power station load, so that it is always at full load and minimum SFOC operation.

[0038] Preferably, the AC / DC hybrid bus and energy storage unit are used to realize the minimum SFOC operation of the diesel generator set at full load and the minimum SFOC operation of the main engine at full load, which together constitute the minimum control of the diesel engine fuel consumption rate SFOC. The diesel engine fuel consumption rate SFOC is affected by the injection amount, ventilation quality, speed, and load rather than a fixed value. The diesel engine fuel consumption rate SFOC is calculated as follows:

[0039]

[0040]

[0041] Where, λ is the correction coefficient; MFO To detect the fuel consumption quality of diesel generator sets and main engines in real time; s is the continuous sampling interval of the system; P shaft is the shaft power of the diesel generator set and the main engine; P a is the atmospheric pressure of the working environment; T te is the working environment atmospheric temperature; T cx The inlet temperature of the main engine scavenging air cooler under working conditions;

[0042] The EEOI energy efficiency fuel index formula is as follows:

[0043]

[0044] Where CF is the conversion factor between fuel consumption and CO2; D corresponds to the distance of work done; t D The time required for the ship's voyage D;

[0045] Since the best fuel consumption rate of diesel engine in actual operation is difficult to determine, it belongs to the grey system. Therefore, the grey model is used for quantitative prediction. The best fuel consumption rate range of diesel engine bench test is the prediction boundary. s The EEOI raw data obtained in sequence are accumulated to generate the EEOI series as follows

[0046]

[0047] EEOI (r) (k) = EEOI (r) (k-1)+EEOI (r-1) (k)

[0048] The original EEOI data collected in chronological order during the operation of the diesel generator set, the first EEOI data remains unchanged, the second EEOI data is the original first EEOI data plus the original second EEOI data, the third EEOI data is the original first, second and third EEOI data added together, the algorithm is carried out in sequence, and a new EEOI series is accumulated and generated, which has a strong regularity and is close to a certain function as the EEOI generation function, which can be used for energy efficiency change trend analysis;

[0049] Then the SFOC sequence generated by cumulative subtraction is as follows

[0050]

[0051] Right now

[0052]

[0053] Among them, i, k and r are all natural numbers, corresponding to the time series of sequential sampling of the diesel engine unit operation. The SFOC series is generated by subtracting the two SFOC data before and after the SFOC original data collected according to the time series; this obtains incremental information in the SFOC modeling process, which is used for energy efficiency comparison and analysis of the hybrid system to capture the SFOC minimum value range.

[0054] Preferably, the ship energy efficiency is a composite nonlinear uncertain energy efficiency system consisting of 10 nonlinear uncertain modes, which is approximately

[0055]

[0056] Γ(x,t)=V1x1+V2x2+…+V n x n +γ(t)

[0057] Then the formula Discrete

[0058]

[0059] Where x = EEIO or SFOC, x∈R n , u∈R, G is an n×n dimensional matrix, Ω is an n-dimensional matrix; Γ(x,k)∈R, ΩΓ(x,t) is the uncertain part of the energy efficiency system such as parameter uncertainty and external interference, V i and γ(t) is the time variable; u is the diesel engine injection quantity control; t = kT s , T s is the sampling time;

[0060] Then the grey prediction of EEOI is

[0061] First establish EEOI (0) (k) Original discrete number series, calculation of EEOI (1) (k) Accumulate the discrete series and calculate the E matrix as follows

[0062]

[0063] Among them, E T E must be reversible. If it is not reversible, increase n appropriately until E T E reversible;

[0064] Calculating EEOI (0) (k) discrete sequence and EEOI (1) (k) cumulative discrete series Right now

[0065]

[0066] The EEOI uncertainty parameter estimate is calculated as

[0067]

[0068] in,

[0069] The EEOI grey model is

[0070]

[0071] Among them, the subscript E represents EEOI;

[0072] SFOC grey prediction is

[0073] First, establish SFOC (0) (k) Original discrete sequence, calculation of SFOC (1) (k) Subtract the discrete series and calculate the S matrix as follows

[0074]

[0075] Among them, S T S must be reversible. If it is not reversible, increase n appropriately until S T S is reversible;

[0076] Calculation of SFOC (0) (k) discrete sequence and SFOC (1) (k) cumulative discrete series Right now

[0077]

[0078] The estimated value of the SFOC uncertainty parameter is calculated as

[0079]

[0080] in,

[0081] The SFOC gray model is

[0082]

[0083] Wherein, the subscript S represents SFOC.

[0084] Preferably, the EEOI grey prediction optimizes the energy efficiency of the ship as a whole, controls the ship speed by adjusting the propeller speed, and thus controls the time required to reach the voyage D; the EEOI grey prediction results are used for route planning and voyage design, which requires comprehensive optimization and analysis of the voyage D and the time required from the departure point to the destination. D 、Fuel consumption M FOand the capacity of the energy storage unit, determine the reasonable ship speed to minimize the EEOI; the EEOI grey prediction control algorithm is:

[0085]

[0086]

[0087] SFOC grey prediction takes diesel engine energy efficiency as optimization target and realizes minimum fuel consumption SFOC control by adjusting diesel engine fuel injection amount. The SFOC grey prediction control algorithm is:

[0088]

[0089]

[0090] The beneficial effects of the present invention are: 1. The present invention has a flexible ship propulsion mode, and the propeller can be driven by the main engine alone, the motor alone, or the main engine and the motor in combination with diesel-electric drive; the left and right motors have flexible working conditions, can work in the propulsion state, and can also work in the power generation state, with high reliability. 2. In view of the operational uncertainty, variable ship conditions, working conditions and sea conditions, unstable loads and large impacts of ships such as tugboats and engineering ships, the present invention proposes an optimal gray prediction control method for the energy efficiency of hybrid ships, which fundamentally solves the problem of diesel engines running at the lowest fuel consumption rate SFOC. 3. The present invention is suitable for hybrid ships with oil-electric hybrid power, oil-electric-gas hybrid capabilities, and the use of green energy such as wind energy and solar energy, filling the gap in the optimal control technology and method for the lowest fuel consumption rate SFOC of medium-speed engines of tugboats, engineering ships, etc., and has strategic significance for promoting ship environmental protection, energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0091] Figure 1 is a schematic diagram of the structure of a control system in an embodiment of the present invention;

[0092] Figure 2 is a principle block diagram of a control method in an embodiment of the present invention;

[0093] Figure 3 is a control logic diagram of each working condition in an embodiment of the present invention;

[0094] Figure 4 is a flow chart of the coordinated control of the energy storage unit and the motor in an embodiment of the present invention;

[0095] Figure 5 It is a flow chart of gray control in the control method in an embodiment of the present invention. DETAILED DESCRIPTION

[0096] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation methods described herein are only used to explain the present invention and are not used to limit the present invention.

[0097] Embodiment 1

[0098] like Figure 1 As shown, in this embodiment, a hybrid ship energy efficiency control system is provided, the ship includes a left propeller and a right propeller; the control system includes a first diesel generator set, a second diesel generator set, a shore power supply, an AC bus, an energy storage unit, a DC bus, a left motor, a left clutch, a left main engine, a right motor, a right clutch and a right main engine; the first diesel generator set and the second diesel generator set are connected to the AC bus through a first AC circuit breaker (ACB1) and a second AC circuit breaker (ACB2) respectively; the shore power supply is connected to the AC bus through a vacuum circuit breaker (VCB), a transformer group and a third AC circuit breaker in sequence; the AC bus is connected to a first rectifier / inverter module through a fourth AC circuit breaker (ACB4), a fifth AC circuit breaker (ACB5), a sixth AC circuit breaker (ACB6) and a seventh AC circuit breaker (ACB7) respectively. Second rectifier / inverter module The third rectifier / inverter module and the fourth rectifier / inverter module The energy storage unit is connected to the DC bus through the corresponding first DC circuit breaker (DCB1), the second DC circuit breaker (DCB2), the third DC circuit breaker (DCB3) and the fourth DC circuit breaker (DCB4); the energy storage unit is connected to the DC bus through the fifth DC circuit breaker (DCB5), the chopper (DC / DC) and the sixth DC circuit breaker (DCB6) in sequence; an eighth AC circuit breaker (ACB8) is arranged on the AC bus between the fourth AC circuit breaker (ACB4) and the fifth AC circuit breaker (ACB5); a ninth AC circuit breaker (ACB9) is arranged on the AC bus between the sixth AC circuit breaker (ACB6) and the seventh AC circuit breaker (ACB7); the DC bus is connected to the DC bus through the fifth rectifier / inverter module and the sixth rectifier / inverter module The tenth AC circuit breaker (ACB10) and the eleventh AC circuit breaker (ACB11) are connected respectively, and then the left motor and the right motor are connected respectively; the left motor is connected to the left propeller and the left main engine; the right motor is connected to the right propeller and the right main engine.

[0099] The first diesel generator set and the second diesel generator set are connected to the AC bus through the first AC circuit breaker and the second AC circuit breaker respectively and are incorporated into the AC grid. The two are of the same model but different capacities. The power of the second diesel generator set is half of that of the first diesel generator set. When the ship is berthed, it is connected to shore power. After the shore power is adjusted to the ship voltage level by the vacuum circuit breaker and the transformer group, it is connected to the AC bus through the third AC circuit breaker and incorporated into the AC grid. The AC grid supplies power to the AC loads of the entire ship. After the AC grid is connected to the corresponding four rectifier modules (the first rectifier / inverter module, the second rectifier / inverter module, the third rectifier / inverter module and the fourth rectifier / inverter module) through the fourth AC circuit breaker, the fifth AC circuit breaker, the sixth AC circuit breaker and the seventh AC circuit breaker, it is connected to the DC bus through the corresponding first DC circuit breaker, the second DC circuit breaker, the third DC circuit breaker and the fourth DC circuit breaker and incorporated into the DC grid. The DC grid supplies power to the uninterruptible power supply and battery packs of the communication, navigation and other equipment of the entire ship. There are connecting switches, an eighth AC circuit breaker and a ninth AC circuit breaker, between the first diesel generator set and the second diesel generator set, which can supply power either individually or jointly, and have a flexible topological structure.

[0100] In this embodiment, the energy storage unit includes a battery group and a supercapacitor; the battery group includes a first lithium battery group, a second lithium battery group, a third lithium battery group and a fourth lithium battery group, the capacity of the first lithium battery group and the second lithium battery group is equal and is the capacity of the second diesel generator set; the capacity of the third lithium battery group and the fourth lithium battery group is equal and is half of the capacity of the second diesel generator set. The energy storage unit can store energy and discharge energy, playing the role of "peak filling valley" and "optimizing energy efficiency". The supercapacitor compensates for the transient interference caused by the impact load on the power grid.

[0101] In this embodiment, when the left propeller and the right propeller are variable pitch propellers, the left motor and the right motor are connected to the left main engine and the right main engine respectively; when the left propeller and the right propeller are fixed pitch propellers, the left motor is connected to the left main engine through the left clutch; the right motor is connected to the right main engine through the right clutch.

[0102] Both the left and right main engines are medium-speed engines. The main engine power output shaft is connected to the rotor shaft of the shaft-belted permanent magnet variable frequency synchronous motor through a stepless speed-adjustable clutch. The motor M / G rotor shaft is the intermediate shaft of the ship's shaft system. The motor rotor shaft is rigidly connected to the clutch output end and the tail shaft through flanges at both ends. The tail shaft directly drives the fixed-pitch propeller. If the clutch is not selected, a variable-pitch propeller is required.

[0103] After the clutch is engaged, the main engine drives the shaft belt motor and propeller to rotate, which not only propels the ship but also drives the motor to generate electricity to supply the ship's power grid; or the motor is in electric state, and the motor and the main engine jointly drive the propeller to rotate. After the clutch is disengaged, the main engine stops, and the shaft belt motor is a propulsion motor, driving the propeller to rotate. It has a flexible ship propulsion mode. The propeller can be driven by the main engine alone, the motor alone, or the main engine and the motor in a diesel-electric drive; the left and right motors have flexible working conditions and can work in the propulsion state or the power generation state, with high reliability.

[0104] In this embodiment, the control system includes a host computer, which can control the opening and closing of each circuit breaker in the control system, and control the start and stop of the first diesel generator set, the second diesel generator set, the shore power supply, the energy storage unit, the left motor, the left clutch, the left main engine, the right motor, the right clutch and the right main engine, so that the ship adopts different power supply methods to ensure the optimal energy efficiency of the hybrid ship.

[0105] Embodiment 2

[0106] like Figures 2 to 5 As shown, in this embodiment, a hybrid ship energy efficiency control method is provided, and the control method is implemented using a control system; the control method is specifically, according to the working conditions of the ship, different power supply modes are adopted to ensure the optimal energy efficiency of the hybrid ship; the working conditions of the ship include

[0107] Berthing condition; the shore power supply is used to supply power and the energy storage unit is fully charged; (at this time, the first AC circuit breaker and the second AC circuit breaker are disconnected, the tenth AC circuit breaker and the eleventh AC circuit breaker are disconnected, and the remaining circuit breakers are all closed);

[0108] Anchoring condition; the energy storage unit supplies power. When the anchoring time is too long, causing the energy storage unit to discharge to 30% of its rated capacity, the second diesel generator set is used for power supply first and fully charges the energy storage unit. When the whole ship is out of power, the second diesel generator set starts automatically to restore the ship's power supply to normal. The second diesel generator set has an emergency power generation function. (At this time, first the first AC circuit breaker, the second AC circuit breaker and the third AC circuit breaker are disconnected, the tenth AC circuit breaker and the eleventh AC circuit breaker are disconnected, and the remaining circuit breakers are closed. When the anchoring time is too long, the first AC circuit breaker and the third AC circuit breaker are disconnected, the tenth AC circuit breaker and the eleventh AC circuit breaker are disconnected, and the remaining circuit breakers are all closed).

[0109] Shutdown condition: the first diesel generator set, the second diesel generator set, the left main engine, the right main engine, the left motor and the right motor are shut down; (at this time, all circuit breakers are disconnected);

[0110] Waiting condition; the ship is in the standby state and can depart immediately upon receiving the order to sail; the standby state includes berthing standby, anchoring standby and drifting standby; berthing standby and anchoring standby require the second diesel generator set to be started first to charge the energy storage unit. When there is no abnormality in the ship's operating system, the whole ship is ready to start at any time. If the waiting condition time is too long, the second diesel generator set will be shut down and the energy storage unit will be used for power supply; when drifting standby, the left or right propeller runs slowly. When the energy storage unit is powered for too long and causes the energy storage unit to discharge to 30% of its rated capacity, the second diesel generator set will be started for power supply; when drifting standby, at least one propeller needs to be running, and the motor corresponding to the propeller is in PTI electric mode; ( When the vehicle is in the parking standby and anchored standby states, first the first AC circuit breaker, the second AC circuit breaker, the third AC circuit breaker, the tenth AC circuit breaker and the eleventh AC circuit breaker are disconnected, and the remaining circuit breakers are all closed; when the waiting time for the working condition is too long, the second AC circuit breaker is closed, and the remaining circuit breakers remain unchanged) (When the vehicle is in the drifting standby state, first one of the tenth AC circuit breaker and the eleventh AC circuit breaker is closed, the first AC circuit breaker, the second AC circuit breaker and the third AC circuit breaker are disconnected, and the remaining circuit breakers are closed; when the energy storage unit supplies power for too long, causing the energy storage unit to discharge to 30% of its rated capacity, the second AC circuit breaker is closed, the second diesel generator set is started to supply power, and the remaining circuit breakers remain unchanged);

[0111] Port entry and exit conditions (maneuvering and slow-speed navigation, diesel generator sets and energy storage units operate in coordination); the energy storage unit is preferably used for power supply, and the two motors are in PTI electric mode to drive the corresponding propellers respectively, and the main engine and the motor are in a state of starting at any time; when the energy storage unit is powered for too long, causing the energy storage unit to discharge to 30% of its rated capacity, the second diesel generator set is put into operation and maintained at full load and minimum SFOC operation, both motors are in PTI electric mode, and the ship is in electric propulsion mode; (In this process, the first AC circuit breaker, the second AC circuit breaker and the third AC circuit breaker are first disconnected, and the remaining circuit breakers are all closed; when the energy storage unit is powered for too long, causing the energy storage unit to discharge to 30% of its rated capacity, the second AC circuit breaker is closed, the second diesel generator set is started, and the states of the remaining circuit breakers remain unchanged)

[0112] The ship is in low or medium speed condition (diesel-electric unit is not working); preferably, the energy storage unit is used for power supply, and the two motors are in PTI electric working mode to drive the corresponding propellers respectively. When the energy storage unit is powered for too long, causing the energy storage unit to discharge to 30% of its rated capacity, one main engine is put into operation to drive the corresponding propeller, and the main engine is put into operation and maintained at full load minimum SFOC, and the motor connected to the main engine is in PTO power generation mode; the other main engine is not running, and the motor connected to it is in PTI electric mode, at this time the ship enters the dual-axis hybrid propulsion mode; (in this process, first the first AC circuit breaker, the second AC circuit breaker and the third AC circuit breaker are disconnected, and they are all closed with the circuit breaker; when the energy storage unit is powered for too long, causing the energy storage unit to discharge to 30% of its rated capacity, the main engine is put into operation)

[0113] Ship high-speed operation; two main engines are put into operation and maintained at full load and minimum SFOC, two motors are in PTO power generation mode, and the energy storage unit is fully charged; (during this process, the first AC circuit breaker, the second AC circuit breaker and the third AC circuit breaker are disconnected, and the remaining circuit breakers are all closed)

[0114] Maximum towing force condition; preferably, both main engines are put into operation and maintained at full load and minimum SFOC, the left and right motors are in PTI electric mode, and the energy storage unit supplies power to the motors and drives the propellers together with the main engines; when the energy storage unit is discharged to 30% of its rated capacity, the two diesel generator sets are put into operation and maintained at full load and minimum SFOC; when the ship's pushing or towing load changes, the two motors automatically switch to PTI electric mode or PTO power generation mode to balance the sudden increase or decrease in load, and the energy storage unit cooperates with the two motors to charge or discharge to balance the sudden increase or decrease in electrical load, achieving a "peak-filling" effect. The maximum towing force condition of tugboats and engineering ships only accounts for about 5% of the entire service life of tugboats and engineering ships. Therefore, the main engine power of the present invention can be selected to be small to prevent a large amount of fuel waste and environmental pollution. (During this process, the first AC circuit breaker, the second AC circuit breaker and the third AC circuit breaker are disconnected, and the remaining circuit breakers are all closed; when the energy storage unit is discharged to 30% of its rated capacity, the first AC circuit breaker and the second AC circuit breaker are closed, and the remaining circuit breakers remain in the same state).

[0115] In order to achieve the optimal energy efficiency control of the main engine and the generator diesel engine based on the minimum SFOC, the motor coaxial with the main engine uses PTI (generator) or PTO (electric) to balance the sudden increase or decrease of the propulsion load, and the energy storage unit discharges or charges to balance the sudden increase or decrease of the power station load. Load changes do not affect the operation of the main engine and the generator diesel engine at the minimum SFOC.

[0116] In this embodiment, the coordinated control principle of the hybrid ship energy storage unit and the motor is as follows: Figure 4 As shown; specifically as follows:

[0117] The four lithium battery packs of the energy storage unit are charged and discharged in groups to improve reliability and efficiency. Supercapacitors are used to compensate for the instantaneous energy when a large load is put into use, to prevent the lithium battery pack from charging and discharging too quickly and affecting its life, and to prevent the diesel generator set from swinging the throttle sharply. The energy storage unit optimizes the energy efficiency of the power generation diesel engine through the ship power station. The energy storage unit coordinates the load effect of the power station and plays a role of "smoothing the peak and filling the valley", ensuring that the power generation diesel engine operates stably at the rated load state of the lowest SFOC.

[0118] The motor is coaxially connected to the main engine through a clutch, which increases the flexibility of the motor and the main engine working together. Through the coordination of the propulsion load effect of the motor PTI (electric mode) and PTO (power generation mode), the motor plays a "peak-filling" role in the mechanical load, compensating for the propeller load changes, thereby maintaining the main engine stable operation at the rated load state of the lowest SFOC.

[0119] The hybrid ship energy efficiency optimization control system includes power station load optimization and regulation effect functions and mechanical load optimization and regulation effect functions. The control system analyzes and calculates the ship load and energy storage unit capacity in real time, performs logical control according to the ship operating conditions, and coordinates the charging / discharging state of the energy storage unit and the generating / electrical mode of the motor. Once the generator diesel engine or propulsion main engine is started and put into operation, it operates at the rated load state with the lowest fuel consumption SFOC and must be stable. This is achieved through the combined action of the energy storage unit and the motor.

[0120] There are three situations in which the two motors automatically switch between PTI electric mode and PTO power generation mode, namely, the motor is in PTI electric mode and the main engine is stopped; the motor is in PTI electric mode and the main engine is working; the motor is in PTO power generation mode and the main engine is working; when the propulsion load increases, causing the main engine power to increase, the motor is in PTI electric mode to produce a propulsion effect to compensate for the increase in propulsion load; when the propulsion load decreases, causing the main engine power to decrease, the motor is in PTO power generation mode to produce a resistance effect to compensate for the decrease in propulsion load, so that the main engine power does not fluctuate with the change of propulsion load, so that it is always operating at full load and minimum SFOC.

[0121] The energy storage unit cooperates with two motors to charge or discharge in three situations, namely, the energy storage unit is powered and the diesel generator set is shut down; the energy storage unit is charged or discharged and a single diesel generator set is working; the energy storage unit is powered and two diesel generator sets are working; when the power station load increases, causing the diesel generator set power to increase, the energy storage unit discharges; when the power station load decreases, causing the diesel generator set power to decrease, the energy storage unit charges, so that the diesel generator set power does not fluctuate with the power station load changes, so that it is always at full load and minimum SFOC operation.

[0122] The regulating effect of the energy storage unit and the PTI / PTO function of the motor are linked through the ship power station. The ship power station management system PMS of the present invention is different from the PMS currently used on board. The PMS of the present invention minimizes the working time of the power generation diesel engine and the main engine, maintains the rated load stability of the diesel engine and the main engine and the lowest SFOC value.

[0123] The hybrid ship energy efficiency system optimizes the configuration of the generator diesel engine and the main engine. The power of the diesel generator set + main engine meets the heavy-load maximum load condition, which solves the problem that the generator diesel engine cannot be used for propulsion and solves the problem of large and wasteful power selection of the propulsion main engine.

[0124] In this embodiment, in order to achieve optimal control, the control system should first initialize and assign values ​​to the system parameters; the initial values ​​of system parameters of different types of ships are different. The initial values ​​of system parameters are design values ​​and rated values. As reference values, they mainly include the voltage, current, power, and power factor of the power grid; the output speed, torque power, temperature, and fuel consumption rate SFOC of the generator diesel engine and the main engine; the ship's speed, propeller speed, torque and power, etc.

[0125] The diesel engine bench power-fuel consumption SFOC curve determines the minimum fuel consumption range. The optimal fuel consumption rate of the diesel engine bench test is within the rated speed and rated power range, and the actual operating conditions always deviate from the bench test environment. Through the AC / DC hybrid bus and energy storage unit, the full-load minimum SFOC operation of the diesel generator set and the full-load minimum SFOC operation of the main engine are achieved, which together constitute the minimum control of the diesel engine fuel consumption rate SFOC. The diesel engine fuel consumption rate SFOC is affected by the injection volume, ventilation quality, speed, and load rather than a fixed value. The diesel engine fuel consumption rate SFOC is calculated as follows:

[0126]

[0127]

[0128] Where, λ is the correction coefficient; M FO To detect the fuel consumption mass (kg) of diesel generator sets and main engine in real time, mass flow meter is used for detection; T s P is the continuous sampling interval of the system, which is set by software; shaft P is the shaft power (kW) of the diesel generator set and the main engine, and the power detector collects the power signal; a is the atmospheric pressure of the working environment, detected by the ship's cabin pressure gauge; T te is the working environment atmospheric temperature, detected by the ship's engine room thermometer; T cx It is the inlet temperature of the main engine scavenging air cooler under working environment, which is directly detected by the thermometer on the air cooler;

[0129] The EEOI energy efficiency fuel index formula is as follows:

[0130]

[0131] Where CF is the conversion coefficient between fuel consumption and CO2, see Table 1; D corresponds to the distance of work done; t D The time required for the ship's voyage D.

[0132] Table 1 Dimensionless conversion factor CF between fuel consumption (unit: g) and CO2 emissions based on carbon content (unit: g)

[0133]

[0134]

[0135] Since the best fuel consumption rate of diesel engine in actual operation is difficult to determine, it belongs to the grey system. Therefore, the grey model is used for quantitative prediction. The best fuel consumption rate range of diesel engine bench test is the prediction boundary. s The EEOI raw data obtained in sequence are accumulated to generate the EEOI series as follows

[0136]

[0137] EEOI (r) (k) = EEOI (r) (k-1)+EEOI (r-1) (k)

[0138] The original EEOI data collected in chronological order during the operation of the diesel generator set, the first EEOI data remains unchanged, the second EEOI data is the original first EEOI plus the original second EEOI data, the third EEOI data is the original first, second and third EEOI added together, the algorithm is carried out in sequence, and a new EEOI series is generated by accumulation, which has a strong regularity and is close to a certain function as the EEOI generation function, which can be used for energy efficiency change trend analysis; then the SFOC series generated by accumulation and subtraction is as follows

[0139]

[0140] Right now

[0141]

[0142] Among them, i, k and r are all natural numbers, corresponding to the time series of diesel engine group operation and sampling in sequence. The SFOC series generated by cumulative subtraction is obtained by subtracting the two SFOC data before and after the SFOC original data collected in the time series. This obtains incremental information in the SFOC modeling process, which is used for energy efficiency comparison analysis of hybrid power systems and captures the minimum SFOC range.

[0143] The grey SFOC model uses residual size (or average value, or the residual value of the most recent SFOC data) and point test, energy efficiency correlation test, and posterior difference residual distribution statistical characteristic test. The grey SFOC model is essentially different from the general multiple linear regression model. The general multiple linear regression model is based on the original SFOC data sequence, while the grey SFOC model is based on the cumulative or cumulative subtraction sequence of the original SFOC data, which is the characteristic of the present invention.

[0144] In this embodiment, the optimal grey prediction control principle of hybrid ship energy efficiency is as follows: Figure 5 The specific contents are as follows:

[0145] Due to the uncertainty of the load of hybrid ships, the randomness of sea conditions, and the uncertainty of diesel engine SFOC changes, in order to reduce the impact of the uncertain part of the hybrid energy efficiency system, improve the energy efficiency optimization control performance, and improve the robustness, in the energy efficiency optimization control process, the gray prediction is first used to estimate the uncertain part parameters and compensate for the optimization control. Since the gray prediction does not need to be carried out continuously in real time, there is no data divergence problem in real-time identification. The uncertain part cannot be measured directly and must be indirectly calculated and predicted by the measured data.

[0146] The signals that need to be collected by the present invention include the fuel consumption mass MFO of the diesel generator set and the main engine detected in real time by the mass flow meter, the shaft power Pshaft of the diesel generator set and the main engine detected in real time by the power detector, the ambient atmospheric pressure Pa detected in real time by the ship's engine room pressure gauge, the ambient atmospheric temperature Tte detected in real time by the ship's engine room thermometer, the main engine scavenging air inlet temperature Tcx directly detected in real time by the air cooler thermometer, and the ship's sailing distance D measured by the bridge odometer.

[0147] In this embodiment, the ship energy efficiency is a composite nonlinear uncertain energy efficiency system consisting of 10 nonlinear uncertain modes, which is approximately

[0148]

[0149] Γ(x,t)=V1x1+V2x2+…+V n x n +γ(t)

[0150] Then the formula Discrete

[0151]

[0152] Where x = EEIO or SFOC, x∈R n , u∈R, G is an n×n dimensional matrix, Ω is an n-dimensional matrix; Γ(x,k)∈R, ΩΓ(x,t) is the uncertain part of the energy efficiency system such as parameter uncertainty and external interference, V i and γ(t) is the time variable; u is the diesel engine injection quantity control; t = kT s , T s is the sampling time;

[0153] 1. EEOI grey prediction

[0154] First establish EEOI (0) (k) Original discrete number series, calculation of EEOI (1) (k) Accumulate the discrete series and calculate the E matrix as follows

[0155]

[0156] Among them, E T E must be reversible. If it is not reversible, increase n appropriately until E T E reversible;

[0157] Calculating EEOI (0) (k) discrete sequence and EEOI (1) (k) cumulative discrete series Right now

[0158]

[0159] The EEOI uncertainty parameter estimate is calculated as

[0160]

[0161] in,

[0162] The EEOI grey model is

[0163]

[0164] Among them, the subscript E represents EEOI; the EEOI gray model is an energy efficiency model based on the ship as a whole, reflecting the navigation efficiency of the ship. When the ship is moored, including berthing, anchoring and drifting, the generator diesel engine and the propulsion main engine are shut down, the energy storage unit supplies power to the entire ship, the voyage D=0 and EEOI=0; when the ship is sailing, the generator diesel engine and the propulsion main engine are shut down, the energy storage unit supplies power to the entire ship, at this time the ship energy efficiency is optimal, D≠0 and EEOI=0; as long as the generator diesel engine or the propulsion main engine is running, EEOI≠0, in this case the energy efficiency of the ship at anchor is the worst. In more cases, the generator diesel engine or the propulsion main engine is running during the ship's navigation, D≠0 and EEOI≠0, the ship energy efficiency control target of the present invention is D→+∞ and EEOI→0, which is achieved through Figure 1 This is achieved through flexible topology system design of hybrid ships, EEOI grey prediction, EEOI feature analysis, and coordinated operation of energy storage units and shaft motors.

[0165] 2. SFOC grey prediction is

[0166] First, establish SFOC (0) (k) Original discrete sequence, calculation of SFOC (1) (k) Subtract the discrete series and calculate the S matrix as follows

[0167]

[0168] Among them, S T S must be reversible. If it is not reversible, increase n appropriately until S T S is reversible;

[0169] Calculation of SFOC (0) (k) discrete sequence and SFOC (1) (k) cumulative discrete series Right now

[0170]

[0171] The estimated value of the SFOC uncertainty parameter is calculated as

[0172]

[0173] in,

[0174] The SFOC gray model is

[0175]

[0176] Among them, the subscript S represents SFOC; the SFOC gray model is a diesel engine energy efficiency model, which reflects the fuel utilization rate of the diesel engine (generator diesel engine and propulsion main engine). The minimum fuel consumption rate SFOC of the medium-speed diesel engine is designed at the rated operating conditions of rated speed and rated load. SFOC is affected by the injection volume, ventilation quality, speed, load, etc. rather than a fixed value. In actual operation, SFOC is affected by many uncertain factors. The actual operating conditions cause SFOC to always deviate from the minimum operating point, resulting in a large fuel consumption rate. The feature of the present invention is that no matter how the actual operating conditions change, the diesel engine set is controlled to operate at the minimum SFOC operating point. Therefore, the control target of the diesel engine set of the present invention is either to shut down SFOC=0, or once the diesel engine is started, it will enter the optimal operating condition (rated speed, rated power) with the minimum SFOC and operate stably, which is not affected by the actual load. This goal is achieved through Figure 1 This is achieved through flexible topology system design of hybrid ships, SFOC grey prediction, SFOC characteristic analysis, and coordinated operation of energy storage units and shaft belt motors.

[0177] In this embodiment, the EEOI grey prediction method of the present invention is different from the SFOC grey prediction method. EEOI adopts an accumulation generation method to convert EEOI non-negative time series and swinging data into incremental data, weakening randomness, having a strong regularity, and close to the soaring function; SFOC adopts a cumulative reduction generation method to obtain the negative increment information of SFOC. When the SFOC increment changes from a negative value to a positive value, the SFOC minimum value point is captured, and the increment on the minimum SFOC is maintained at 0. The optimal energy efficiency of a ship is when the power-generating diesel engine and the main engine of the ship are both shut down when the ship is not in a full ship power-off or paralyzed state. At this time, the energy storage unit supplies power to the entire ship, the shaft belt motor is shut down or in PTI electric state, the ship fuel consumption rate SFOC is 0, and the fuel consumption is 0.

[0178] One of the innovative points of the present invention is that the control of the fuel injection amount of the propulsion main engine and the fuel injection amount u of the generator diesel engine is the simplest. Either the fuel injection amount in the shutdown state is controlled to 0, or once started and put into operation, the fuel injection amount is controlled to a fixed value under the minimum SFOC of the rated load and rated speed and maintained unchanged. The fuel injection amount u of the propulsion main engine and the generator diesel engine is 0 and the throttle scale is controlled to a fixed value, which eliminates the need for complex fuel injection amount control strategies.

[0179] The feature extraction methods of the energy efficiency EEOI and SFOC of the present invention include three types: time domain features, frequency domain features, and time-frequency domain features. The time domain features of the energy efficiency EEOI and SFOC include statistical features of time signals, standard deviation changes, mean value changes, signal skewness and kurtosis, thresholds, mutation values, etc. The frequency domain features of the energy efficiency EEOI and SFOC include peak values ​​and peak frequencies, FFT analysis, spectrum analysis, Hilbert-Huang (HHT) analysis, etc. The time-frequency domain features of the energy efficiency EEOI and SFOC include spectral kurtosis, spectral quotient analysis, etc. The energy efficiency features extracted by the present invention are used to analyze the energy efficiency level of ships, predict changing trends, find the optimal energy efficiency working space, and capture the neighborhood of the lowest working point of SFOC.

[0180] In this embodiment, the control effects of EEOI grey prediction and SFOC grey prediction in ship energy efficiency optimization are:

[0181] 1. EEOI grey prediction optimizes the energy efficiency of the ship as a whole, and controls the ship speed by adjusting the propeller speed, thereby controlling the time required to reach the voyage D; EEOI grey prediction results are used for route planning and voyage design, which requires comprehensive optimization and analysis of the voyage D and the time required from the departure point to the destination. D 、Fuel consumption M FO and the capacity of the energy storage unit, determine the reasonable ship speed to minimize the EEOI; the EEOI grey prediction control algorithm is:

[0182]

[0183]

[0184] 2. SFOC grey prediction takes diesel engine energy efficiency as optimization target and realizes minimum fuel consumption SFOC control by adjusting diesel engine fuel injection amount; the SFOC grey prediction control algorithm is:

[0185]

[0186]

[0187] SFOC grey prediction controls the diesel engine throttle opening (fuel injection amount) and takes effect when searching for the lowest fuel consumption rate SFOC. Once the SFOC minimum operating point and its range are determined, it automatically switches to throttle scale (fuel injection amount) fixed value control.

[0188] Embodiment 3

[0189] In this embodiment, by combining the contents of the first embodiment and the second embodiment, the following control can be achieved by adopting a control system and a control method:

[0190] 1. Hybrid power system logic control program: including diesel-electric unit start-stop, parallel and decoupling control, main engine start-stop control, shaft motor switching control, shore power switching control and energy storage unit switching control; closing and opening control of circuit breakers VCB, ACB and DCB.

[0191] 2. Hybrid AC / DC power station automation control program: Diesel engine fuel consumption rate SFOC minimum control includes optimal SFOC control of the generator diesel engine and optimal SFOC control of the main engine. The SFOC minimum control corresponds to 10 hybrid operating modes, the combined and coordinated work of shore power supply, energy storage unit power supply, main engine propulsion, shaft motor power generation and electric state to achieve the best fuel-saving mode for ships.

[0192] 3. Energy efficiency optimal control program: The goal of the energy efficiency optimal control of the present invention is to achieve the minimum fuel consumption rate SFOC control of the generator diesel engine and the minimum fuel consumption rate SFOC control of the ship's main engine. There are eight working conditions of the ship, including berthing, anchoring, parking, standby stop, entering and leaving the port, low speed and high speed, and maximum towing. The corresponding working combinations of the main engine, diesel-electric unit, shore power, energy storage unit, and shaft belt motor are as follows: as long as the generator diesel engine and the main engine are started, they will enter the minimum fuel consumption rate SFOC point of the rated load, and the load change of the ship will be compensated by the energy storage unit, thereby achieving the purpose of ship fuel saving.

[0193] 4. Comprehensive analysis of hybrid power system ship energy efficiency EEOI: including analysis of ship energy efficiency change trend; comparative analysis of energy efficiency under different ship working conditions and hybrid power working modes; correlation analysis between energy efficiency of ships under non-operating conditions. The analysis results evaluate the ship energy efficiency level and adjust the different working modes of the ship hybrid power, providing decision-making for optimal control of ship energy efficiency.

[0194] By adopting the above technical solution disclosed in the present invention, the following beneficial effects are obtained:

[0195] The present invention provides a hybrid ship energy efficiency control method and system. The present invention has a flexible ship propulsion mode. The propeller can be driven by the main engine alone, the motor alone, or the main engine and the motor in combination with diesel-electric drive; the left and right motors have flexible working conditions and can work in a propulsion state or a power generation state, with high reliability. Aiming at the problems of uncertainty in operation, changeable ship conditions, working conditions and sea conditions, unstable loads and large impacts of ships such as tugboats and engineering ships, the present invention proposes an optimal gray prediction control method for hybrid ship energy efficiency, which fundamentally solves the problem of diesel engines running at the lowest fuel consumption rate SFOC. The present invention is suitable for hybrid ships with oil-electric hybrid power, oil-electric-gas hybrid capacity and green energy such as wind energy and solar energy, filling the gap in the optimal control technology and method of the lowest fuel consumption rate SFOC of medium-speed engines of tugboats, engineering ships, etc., and has strategic significance for promoting ship environmental protection, energy conservation and emission reduction.

[0196] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be considered as the scope of protection of the present invention.

Claims

1. A hybrid ship energy efficiency control system, the ship includes a left propeller and a right propeller; characterized in that: The control system includes a first diesel generator set, a second diesel generator set, a shore power supply, an AC bus, an energy storage unit, a DC bus, a left motor, a left clutch, a left host, a right motor, a right clutch and a right host; the first diesel generator set and the second diesel generator set are connected to the AC bus through a first AC circuit breaker and a second AC circuit breaker respectively; the shore power supply is connected to the AC bus through a vacuum circuit breaker, a transformer group and a third AC circuit breaker in sequence; the AC bus is connected to a first rectifier / inverter module, a second rectifier / inverter module, a third rectifier / inverter module and a fourth rectifier / inverter module respectively through a fourth AC circuit breaker, a fifth AC circuit breaker, a sixth AC circuit breaker and a seventh AC circuit breaker. The inverter module is connected to the DC bus through the corresponding first DC circuit breaker, the second DC circuit breaker, the third DC circuit breaker and the fourth DC circuit breaker; the energy storage unit is connected to the DC bus through the fifth DC circuit breaker, the chopper and the sixth DC circuit breaker in sequence; an eighth AC circuit breaker is arranged on the AC bus between the fourth AC circuit breaker and the fifth AC circuit breaker; a ninth AC circuit breaker is arranged on the AC bus between the sixth AC circuit breaker and the seventh AC circuit breaker; the DC bus is connected to the tenth AC circuit breaker and the eleventh AC circuit breaker respectively through the fifth rectifier / inverter module and the sixth rectifier / inverter module, and then connected to the left motor and the right motor respectively; the left motor is connected to the left propeller and the left main engine; The right motor is connected to the right propeller and the right main engine; The first diesel generator set and the second diesel generator set have the same model but different capacities, and the power of the second diesel generator set is half of that of the first diesel generator set; When the left propeller and the right propeller are variable pitch propellers, the left motor and the right motor are connected to the left main engine and the right main engine respectively; when the left propeller and the right propeller are fixed pitch propellers, the left motor is connected to the left main engine through the left clutch; The right motor is connected to the right host through the right clutch.

2. The hybrid ship energy efficiency control system according to claim 1, characterized in that: The energy storage unit includes a battery group and a supercapacitor; the battery group includes a first lithium battery group, a second lithium battery group, a third lithium battery group and a fourth lithium battery group, the capacity of the first lithium battery group and the second lithium battery group are equal and are the capacity of the second diesel generator set; the capacity of the third lithium battery group and the fourth lithium battery group are equal and are half of the capacity of the second diesel generator set.

3. A hybrid ship energy efficiency control method, characterized in that: The control method is implemented using the control system described in any one of claims 1 to 2 above; the control method is specifically, according to the working conditions of the ship, different power supply modes are adopted to ensure the optimal energy efficiency of the hybrid ship; the working conditions of the ship include Berth condition: shore power supply is used to fully charge the energy storage unit; Anchoring condition: The energy storage unit supplies power. When the anchoring time is too long, causing the energy storage unit to discharge to 30% of its rated capacity, the second diesel generator set will be used first to fully charge the energy storage unit. When the whole ship is out of power, the second diesel generator set will start automatically to restore the ship's power supply to normal. The second diesel generator set has an emergency power generation function. Shutdown condition: the first diesel generator set, the second diesel generator set, the left main engine, the right main engine, the left motor and the right motor are shut down; Waiting condition; The ship is in standby state and can depart immediately upon receiving the order to sail; the standby state includes berthing standby, anchoring standby and drifting standby; berthing standby and anchoring standby require the second diesel generator set to be started first to charge the energy storage unit. When there is no abnormality in the ship's operating system, the whole ship is ready to start at any time. If the waiting time is too long, the second diesel generator set will be shut down and the energy storage unit will be used for power supply; when drifting standby, the left or right propeller runs slowly. When the energy storage unit is powered for too long and causes the energy storage unit to discharge to 30% of its rated capacity, the second diesel generator set will be started for power supply; when drifting standby, at least one propeller needs to be running, and the motor corresponding to the propeller is in PTI electric mode; Port entry and exit conditions; The energy storage unit supplies power, and the two motors are in PTI electric mode to drive the corresponding propellers respectively, and the main engine and the motor are ready to start at any time; when the energy storage unit supplies power for too long, causing the energy storage unit to discharge to 30% of its rated capacity, the second diesel generator set is put into operation and maintained at full load and minimum SFOC, and both motors are in PTI electric mode, and the ship is in electric propulsion mode; The ship is in low or medium speed condition; the energy storage unit is powered, and the two motors are in PTI electric working mode to drive the corresponding propellers respectively. When the energy storage unit is powered for too long, causing the energy storage unit to discharge to 30% of its rated capacity, one main engine is put into operation to drive the corresponding propeller, and the main engine is put into operation and maintained at full load minimum SFOC, and the motor connected to the main engine is in PTO power generation mode; the other main engine is not running, and the motor connected to it is in PTI electric mode. At this time, the ship enters dual-shaft hybrid propulsion mode; The energy storage unit supplies power, and two motors drive the corresponding propellers respectively. One main engine is put into operation and maintained at full load and minimum SFOC; and the other main engine and two diesel generator sets are ready to start at any time; Ship high-speed operation; two main engines are put into operation and maintained at full load and minimum SFOC, two motors are in PTO power generation mode, and the energy storage unit is fully charged; Maximum traction condition; Both main engines are put into operation and maintained at full load and minimum SFOC. The left and right motors are in PTI electric mode. The energy storage unit supplies power to the motors and drives the propellers together with the main engines. When the energy storage unit is discharged to 30% of its rated capacity, the two diesel generator sets are put into operation and maintained at full load and minimum SFOC. When the ship's pushing or towing load changes, the two motors automatically switch to PTI electric mode or PTO power generation mode to balance the sudden increase or decrease in load. The energy storage unit cooperates with the two motors to charge or discharge to balance the sudden increase or decrease in electrical load.

4. The hybrid ship energy efficiency control method according to claim 3 is characterized by: There are three situations in which the two motors automatically switch between PTI electric mode and PTO power generation mode, namely, the motor is in PTI electric mode and the main engine is stopped; the motor is in PTI electric mode and the main engine is working; the motor is in PTO power generation mode and the main engine is working; when the propulsion load increases, causing the main engine power to increase, the motor is in PTI electric mode to produce a propulsion effect to compensate for the increase in propulsion load; when the propulsion load decreases, causing the main engine power to decrease, the motor is in PTO power generation mode to produce a resistance effect to compensate for the decrease in propulsion load, so that the main engine power does not fluctuate with the change of propulsion load, so that it is always operating at full load and minimum SFOC.

5. The hybrid ship energy efficiency control method according to claim 4 is characterized in that: The energy storage unit cooperates with two motors to charge or discharge in three situations, namely, the energy storage unit is powered and the diesel generator set is shut down; the energy storage unit is charged or discharged and a single diesel generator set is working; the energy storage unit is powered and two diesel generator sets are working; when the power station load increases, causing the diesel generator set power to increase, the energy storage unit discharges; when the power station load decreases, causing the diesel generator set power to decrease, the energy storage unit charges, so that the diesel generator set power does not fluctuate with the power station load changes, so that it is always at full load and minimum SFOC operation.

6. The hybrid ship energy efficiency control method according to claim 5, characterized in that: Through the AC / DC hybrid bus and energy storage unit, the minimum SFOC operation of the diesel generator set at full load and the minimum SFOC operation of the main engine at full load together constitute the minimum control of the diesel engine fuel consumption rate SFOC. The diesel engine fuel consumption rate SFOC is affected by the injection amount, ventilation quality, speed, and load rather than a fixed value. The diesel engine fuel consumption rate SFOC is calculated as follows: Where, λ is the correction coefficient; M FO To detect the fuel consumption quality of diesel generator sets and main engines in real time; s is the continuous sampling interval of the system; P shaft is the shaft power of the diesel generator set and the main engine; P a is the atmospheric pressure of the working environment; T te is the working environment atmospheric temperature; T cx The inlet temperature of the main engine scavenging air cooler under working conditions; The EEOI energy efficiency fuel index formula is as follows: Where CF is the conversion factor between fuel consumption and CO2; D corresponds to the distance of work done; t D The time required for the ship's voyage D; Since the best fuel consumption rate of diesel engine in actual operation is difficult to determine, it belongs to the grey system. Therefore, the grey model is used for quantitative prediction. The best fuel consumption rate range of diesel engine bench test is the prediction boundary. s The EEO I raw data obtained in sequence are accumulated to generate the EEOI series as follows EEOI (r) (k)=EEOI (r) (k-1)+EEOI (r-1) (k) The original EEOI data collected in chronological order during the operation of the diesel generator set, the first EEOI data remains unchanged, the second EEOI data is the original first EEOI data plus the original second EEOI data, the third EEOI data is the original first, second and third EEOI data added together, the algorithm is carried out in sequence, and a new EEOI series is accumulated and generated, which has a strong regularity and is close to a certain function as the EEOI generation function, which can be used for energy efficiency change trend analysis; Then the SFOC sequence generated by cumulative subtraction is as follows Right now Among them, i, k and r are all natural numbers, corresponding to the time series of sequential sampling of the diesel engine unit operation. The SFOC series is generated by subtracting the two SFOC data before and after the SFOC original data collected according to the time series; this obtains incremental information in the SFOC modeling process, which is used for energy efficiency comparison and analysis of the hybrid system to capture the SFOC minimum value range.

7. The hybrid ship energy efficiency control method according to claim 6, characterized in that: The ship energy efficiency is a composite nonlinear uncertain energy efficiency system consisting of 10 nonlinear uncertain modes, which can be approximated as Γ(x,t)=V1x1+V2x2+…+V n x n +γ(t) Then the formula Discrete Where x = EEIO or SFOC, x∈R n , u∈R, G is an n×n dimensional matrix, Ω is an n-dimensional matrix; Γ(x,k)∈R, ΩΓ(x,t) is the uncertain part of the energy efficiency system such as parameter uncertainty and external interference, V i and γ(t) is the time variable; u is the diesel engine injection quantity control; t = kT s , T s is the sampling time; The EEOI grey prediction is to first establish the EEOI (0) (k) Original discrete number series, calculation of EEOI (1) (k) Accumulate the discrete series and calculate the E matrix as follows Among them, E T E must be reversible. If it is not reversible, increase n appropriately until E T E reversible; Calculating EEOI (0) (k) discrete sequence and EEOI (1) (k) cumulative discrete series Right now The EEOI uncertainty parameter estimate is calculated as in, The EEOI grey model is Among them, the subscript E represents EEOI; SFOC grey prediction is to first establish SFOC (0) (k) Original discrete sequence, calculation of SFOC (1) (k) Subtract the discrete series and calculate the S matrix as follows Among them, S T S must be reversible. If it is not reversible, increase n appropriately until S T S is reversible; Calculation of SFOC (0) (k) discrete sequence and SFOC (1) (k) cumulative discrete series Right now The estimated value of the SFOC uncertainty parameter is calculated as in, The SFOC gray model is Wherein, the subscript S represents SFOC.

8. The hybrid ship energy efficiency control method according to claim 7, characterized in that: EEOI grey prediction optimizes the energy efficiency of the ship as a whole, and controls the ship speed by adjusting the propeller speed, thereby controlling the time required to reach the voyage D. The EEOI grey prediction results are used for route planning and voyage design, which requires comprehensive optimization and analysis of the voyage D and the time required from the departure point to the destination. D 、Fuel consumption M FO and the capacity of the energy storage unit, determine the reasonable ship speed to minimize the EEOI; the EEOI grey prediction control algorithm is: SFOC grey prediction takes diesel engine energy efficiency as optimization target and realizes minimum fuel consumption SFOC control by adjusting diesel engine fuel injection amount. The SFOC grey prediction control algorithm is:

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