Diesel-electric hybrid propulsion system for ships with AC / DC networking

Abstract

The invention discloses a diesel-electric hybrid electric propulsion system for ship AC-DC networking, comprising: a diesel generator set, a battery set, a supercapacitor set, an active rectifier, a variable / fixed frequency inverter, a bidirectional DC-DC unit, an AC bus, a DC bus, a daily power transformer, and a shore power interface; the diesel generator set is connected to the AC bus by a switch controlled by a parallel vehicle controller, each section of the AC bus is connected by a switch bus, the AC bus is connected to the DC bus through an active rectifier, each section of the DC bus is connected by a switch bus, the DC bus is connected to the battery set through a bidirectional DC-DC unit, the supercapacitor set is connected to the DC bus through the bidirectional DC-DC unit, the DC bus is connected to a propulsion motor through a variable frequency inverter, the upper end of the daily power transformer is switched by two switches to connect the AC bus or the fixed frequency inverter, and the lower end of the daily power transformer is connected to the ship's daily load. The invention has both the mature reliability of AC networking and the energy-saving economy of DC networking.

Description

Technical Field

[0001] The present invention relates to a power propulsion system for ships, and in particular to a hybrid power propulsion system of a diesel generator set and a power storage battery for ship AC / DC networking. Background Art

[0002] In ship engineering, traditional propulsion systems generally use diesel engines as prime movers. The propulsion system consists of a diesel engine, a reduction gearbox, a shaft system and a propeller. The shaft of the diesel engine is connected to the propeller shaft through a reduction gearbox. The entire shaft system occupies most of the space in the cabin, and has strong vibration and noise. When the ship load changes greatly, the diesel engine cannot follow the changes quickly, causing the diesel engine's operating conditions to deteriorate and fuel consumption to increase.

[0003] With the development of technology, the ship AC network electric propulsion system has emerged to save the layout space of the ship shaft system and improve the response speed and operability of the ship electrical drive. The ship AC network electric propulsion system is driven by each diesel engine to drive the synchronous generator to generate electricity, generate constant frequency and constant voltage AC power for synchronous parallel or split, and the AC distribution panel is used to establish the ship AC power grid for AC networking. The ship AC power grid distributes power to the AC-DC-AC inverter, and the AC-DC-AC inverter drives the ship propulsion motor, and the propulsion motor drives the ship propeller to drive the ship. When the ship load changes, the load power change is adapted by synchronous parallel or split of the diesel generator set, which is a nonlinear switching method. The ship AC networking method can make the diesel engine run at the optimal power efficiency point during economic cruising propulsion, and will cause the diesel engine to fail to run at the optimal power efficiency point during low load and low speed propulsion. Its characteristics are mature, reliable and tough.

[0004] In recent years, a DC network electric propulsion system has emerged. Each generator set on the ship is connected to a rectifier, and the rectified DC power is connected to a public DC bus. Multiple inverters are connected in parallel on the public DC bus. Each inverter is connected to its own propulsion motor, and each propulsion motor is connected to its own ship propeller. When the ship load changes, the speed of each diesel engine can be continuously and dynamically adjusted to make the diesel engine run at the optimal fuel consumption point, realizing variable speed operation of the diesel engine and reducing diesel engine fuel consumption. Summary of the invention

[0005] In view of the above technical problems, the present invention proposes a diesel-electric hybrid electric propulsion system for ship AC / DC networking, which is a highly redundant technical problem that pursues the safety and reliability of ship operation and the energy-saving economy of ship operation.

[0006] To achieve the above objectives, the following technical solutions are used.

[0007] A diesel-electric hybrid electric propulsion system for a ship AC / DC network includes: a diesel generator set, b diesel generator set, c diesel generator set, and d diesel generator set, an AC bus, a active rectifier, b active rectifier, c active rectifier, d active rectifier, e active rectifier, and f active rectifier, a bidirectional DC-DC unit, b bidirectional DC-DC unit, c bidirectional DC-DC unit, d bidirectional DC-DC unit, e bidirectional DC-DC unit, and f bidirectional DC-DC unit, a battery pack and b battery pack, a daily power transformer and b daily power transformer, a daily load and b daily load, a fixed frequency inverter and b fixed frequency inverter, a DC bus, a variable frequency inverter and b variable frequency inverter, c variable frequency inverter and d variable frequency inverter, a main propulsion motor and b side propulsion motor and c side propulsion motor and d main propulsion motor, a supercapacitor group and b supercapacitor group and c supercapacitor group and d supercapacitor group, a shore power interface and b shore power interface.

[0008] A diesel generator set, b diesel generator set, c diesel generator set and d diesel generator set, each of which consists of a synchronous generator set and a switch controlled by a parallel controller. Each is equipped with a parallel controller and connected to the AC bus through a switch controlled by the parallel controller. Among them: a main diesel generator set is connected to a bus, b diesel generator set is connected to b bus, c diesel generator set is connected to c bus, and d main diesel generator set is connected to d bus. In AC mode, each generator set is synchronously connected to the AC bus or disconnected from the AC bus through a switch controlled by the parallel controller. In DC mode, each generator set operates independently with speed regulation.

[0009] The AC bus includes: bus a, bus b, bus c, bus d, switch a, switch b, and switch c.

[0010] Active rectifier a, active rectifier b, active rectifier c, active rectifier d, active rectifier e and active rectifier f are all composed of LC filters and AC-DC converters, with input ends connected to the AC bus and output ends connected to the DC bus through fast fuses. In DC mode, active rectifier a, active rectifier b, active rectifier c and active rectifier d are powered by diesel generator set a, diesel generator set b, diesel generator set c and diesel generator set d, respectively, and each generator set operates with independent speed regulation. The input voltage and frequency of each active rectifier change with the speed regulation, and the output end of each active rectifier is connected to the DC bus through a fast fuse, and the DC voltage at the output end is constant. The output ends of active rectifier e and active rectifier f are connected to the DC bus through fast fuses, and their input ends are connected to shore power interface a and shore power interface b, respectively. When the ship docks, the shore power is rectified into direct current and transmitted to the DC bus, and then charged to battery group a and battery group b respectively through bidirectional DC-DC unit a and bidirectional DC-DC unit b.

[0011] The bidirectional DC-DC unit a, the bidirectional DC-DC unit b, the bidirectional DC-DC unit c, the bidirectional DC-DC unit d, the bidirectional DC-DC unit e and the bidirectional DC-DC unit f are all composed of a DC reactor and a DC-DC converter. Electric energy can flow in both directions. The DC-DC converter ends of all bidirectional DC-DC units are connected to the DC bus through fast fuses. Among them: the DC reactor ends of the bidirectional DC-DC unit a and the bidirectional DC-DC unit b are connected to the battery group a and the battery group b respectively. The DC reactor ends of the bidirectional DC-DC unit c and the bidirectional DC-DC unit d and the bidirectional DC-DC unit e and the bidirectional DC-DC unit f are connected to the supercapacitor group a and the supercapacitor group b and the supercapacitor group c and the supercapacitor group d respectively.

[0012] The a battery group and the b battery group are composed of high energy density units. The a battery group and the b battery group are connected to the DC bus through the a bidirectional DC-DC unit and the b bidirectional DC-DC unit respectively. The a battery group and the b battery group are discharged to the DC bus through the a bidirectional DC-DC unit and the b bidirectional DC-DC unit respectively, and can also be charged from the DC bus.

[0013] A daily power transformer and b daily power transformer are composed of an isolation transformer and two sets of switches at the input end of the isolation transformer. One set of switches is connected to the AC bus, the other set of switches is connected to the LC filter end of the fixed frequency inverter, and the output end of the isolation transformer is connected to the daily load. Among them: a set of switches at the input end of the daily power transformer a and the daily power transformer b are respectively connected to the LC filter end of the fixed frequency inverter a and the fixed frequency inverter b, and their output ends are respectively connected to the daily load a and the daily load b. In the AC mode, the switch connected to the AC bus is closed, and the switch connected to the LC filter end is opened. In the DC mode, the switch connected to the LC filter end is closed, and the switch connected to the AC bus is opened.

[0014] A fixed frequency inverter and b fixed frequency inverter are composed of LC filter and DC-AC converter. Their input end is connected to the DC bus through a fast fuse, and their output end is connected to the input end switch of a daily power transformer and b daily power transformer respectively. In DC mode, the DC power on the DC bus is inverted into high-quality fixed frequency AC power, which is supplied to daily loads through the daily power transformer.

[0015] The DC bus includes: bus A, bus B, bus C, and bus D, fast fuse a, fast fuse b, and fast fuse c, switch A, switch B, and switch C. In AC mode, switch A, switch B, and switch C are open, and in DC mode, switch A, switch B, and switch C are closed.

[0016] The input ends of the variable frequency inverter a, variable frequency inverter b, variable frequency inverter c, and variable frequency inverter d are connected to the DC bus through a fast fuse, and the output ends are connected to the main propulsion motor a, the side propulsion motor b, the side propulsion motor c, and the main propulsion motor d, respectively, so as to control the torque, power, and speed of the propulsion system. When the propulsion system performs reverse work, the electric energy can be fed to the DC bus. Among them: the reverse work performed by the main propulsion motor a, the side propulsion motor b, the side propulsion motor c, and the main propulsion motor d is fed to the DC bus through the variable frequency inverter a, variable frequency inverter b, variable frequency inverter c, and variable frequency inverter d, respectively. The electric energy is charged and consumed to the super capacitor group a, the super capacitor group b, the super capacitor group c, and the super capacitor group d through the bidirectional DC-DC unit c, the bidirectional DC-DC unit d, the bidirectional DC-DC unit e, and the bidirectional DC-DC unit f, respectively.

[0017] Supercapacitor group a and supercapacitor group b, supercapacitor group c and supercapacitor group d are connected to the DC bus through: c bidirectional DC-DC unit and d bidirectional DC-DC unit and e bidirectional DC-DC unit and f bidirectional DC-DC unit. When the DC bus is underpowered, supercapacitor group a and supercapacitor group b and supercapacitor group c and supercapacitor group d are instantaneously discharged through: c bidirectional DC-DC unit and d bidirectional DC-DC unit and e bidirectional DC-DC unit and f bidirectional DC-DC unit, respectively, and inject DC bus power. When the DC bus is full of power, the power on the DC bus is instantaneously charged through: c bidirectional DC-DC unit and d bidirectional DC-DC unit and e bidirectional DC-DC unit and f bidirectional DC-DC unit to: supercapacitor group a and supercapacitor group b and supercapacitor group c and supercapacitor group d, and absorb the power of the DC bus. Power balance and fault ride-through are achieved.

[0018] The AC networking mode can be entered by closing the switches a, b and c on the AC bus, opening the switches A, B and C on the DC bus, closing the switches connecting the daily power transformer a and b to the AC bus, and opening the switches connected to the LC filter ends of the fixed frequency inverter a and b to the AC bus. Each diesel generator set is synchronously connected to the AC bus or disconnected from the AC bus through the switch controlled by the paralleling controller. The active rectifier a and the active rectifier b and the active rectifier c and the active rectifier d are respectively combined with the variable frequency inverter a and b and the variable frequency inverter c and d to form a complete AC-DC-AC inverter, which respectively control and drive the main propulsion motor a and the side propulsion motor b and the side propulsion motor c and the main propulsion motor d. Due to the effect of the LC filters configured in the active rectifiers a and b and the active rectifiers c and d, the harmonic distortion rate on the AC bus is less than 5%. The load fluctuations of the main propulsion motor a and the side propulsion motor b and the side propulsion motor c and the main propulsion motor d are balanced by: the super capacitor group a connected to the bidirectional DC-DC unit c, the super capacitor group b connected to the bidirectional DC-DC unit d, the super capacitor group c connected to the bidirectional DC-DC unit e, and the super capacitor group d connected to the bidirectional DC-DC unit f. By closing the switch connecting the daily power transformer a and the daily power transformer b to the AC bus, the daily power transformer a and the daily power transformer b are powered by the AC bus, providing power to the daily load a and the daily load b respectively.

[0019] The DC networking mode can be entered by opening the switches a, b and c on the AC bus, closing the switches A, B and C on the DC bus, opening the switches connecting the daily power transformer a and b to the AC bus, and closing the switches connected to the LC filter ends of the fixed frequency inverter a and b. The a diesel generator set b and the c diesel generator set d diesel generator set operate independently, and provide power to the DC bus through the active rectifier a and b active rectifiers and the active rectifier c and d active rectifiers respectively. The a battery set and the b battery set provide power to the DC bus through the a bidirectional DC-DC unit and the b bidirectional DC-DC unit respectively for independent propulsion, or can be jointly propelled with the diesel generator set, or can be powered from the DC bus through the a bidirectional DC-DC unit and the b bidirectional DC-DC unit respectively, and charge the a battery set and the b battery set respectively. The switch connected to the LC filter end of fixed-frequency inverter a and fixed-frequency inverter b is closed, so that daily power transformer a and daily power transformer b are powered by the DC bus through fixed-frequency inverter a and fixed-frequency inverter b respectively, providing low-harmonic high-quality electricity to daily load a and daily load b respectively.

[0020] The system is equipped with AC bus and DC bus. In the first case where active rectifier a and frequency converter d fail to work with main diesel generator set d, and in the second case where active rectifier d and frequency converter a fail to work with main diesel generator set a, both AC networking mode and DC networking mode may cause the ship's main propulsion system to lose power. In the first extreme case, the problem can be solved by: the power flows from diesel generator set a → bus a → switch a → bus b → switch b → bus c → switch c → bus d → active rectifier d → bus D → switch c → fast fuse c → bus C → switch b → fast fuse b → bus B → switch a → fast fuse a → bus a → frequency converter a → main propulsion motor a, so that the port side thruster of the ship can get power. The second extreme case can be solved by: the electric energy flows from d diesel generator set → d bus → c switch → c bus → b switch → b bus → a switch → a bus → a active rectifier → A bus → a fast fuse → A switch → B bus → b fast fuse → B switch → C bus → c fast fuse → C switch → D bus → d variable frequency inverter → arrive at d main propulsion motor, so that the ship's starboard thruster can get power. This makes the entire electric propulsion system more redundant and safe, using AC mode at constant speed to make the system reliable and tough, and using DC mode at low speed or port to make the system energy-saving, low-emission, quiet and economical.

[0021] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention has 5 drawings in total, among which.

[0023] Figure 1 Port and starboard standard.

[0024] Figure 2 AC networking mode.

[0025] Figure 3 DC networking mode.

[0026] Figure 4 Shore charging mode.

[0027] Figure 5 Troubleshooting in extreme situations.

[0028] In the figure: 1a, a main diesel generator set, 1b, b diesel generator set, 1c, c diesel generator set, 1d, d diesel generator set, 1.1, synchronous diesel generator set, 1.2, switch controlled by parallel controller, 2, AC bus, 2.1a, a bus, 2.1b, b bus, 2.1c, c bus, 2.1d, d bus, 2.2a, a switch, 2.2b, b switch, 2.2c, c switch, 3a, a active rectifier, 3b, b active rectifier, 3c, c active rectifier, 3d, d active rectifier, 3e, e active rectifier, 3f, f Source rectifier, 3.1, LC filter, 3.2, AC-DC converter, 4a, a bidirectional DC-DC unit, 4b, b bidirectional DC-DC unit, 4c, c bidirectional DC-DC unit, 4d, d bidirectional DC-DC unit, 4e, e bidirectional DC-DC unit, 4f, f bidirectional DC-DC unit, 4.1, DC reactor, 4.2, DC-DC converter, 5a, a battery pack, 5b, b battery pack, 6a, a daily power transformer, 6b, b daily power transformer , 6.1, input switch 1, 6.2, input switch 2, 6.3, isolation transformer, 7a, a daily load, 7b, b daily load, 8a, a fixed frequency inverter, 8b, b fixed frequency inverter, 8.1, LC filter, 8.2, DC-AC converter, 9, DC bus, 9.1a, A bus, 9.1b, B bus, 9.1c, C bus, 9.1d, D bus, 9.2a, a fast fuse, 9.2b, b fast fuse, 9.2c, c fast fuse, 9.3 a, A switch, 9.3b, B switch, 9.3c, C switch, 10a, a frequency conversion inverter, 10b, b frequency conversion inverter, 10c, c frequency conversion inverter, 10d, d frequency conversion inverter, 11a, a main propulsion motor, 11b, b side propulsion motor, 11c, c side propulsion motor, 11d, d main propulsion motor, 12a, a supercapacitor group, 12b, b supercapacitor group, 12c, c supercapacitor group, 12d, d supercapacitor group, 13a, a shore power interface, 13b, b shore power interface. DETAILED DESCRIPTION

[0029] like Figures 1 to 5 A diesel-electric hybrid electric propulsion system for a ship with AC / DC networking is shown, comprising:

[0030] a diesel generator set 1a and b diesel generator set 1b and c diesel generator set 1c and d diesel generator set 1d, AC bus 2, a bus 2.1a, b bus 2.1b, c bus 2.1c and d bus 2.1d, a switch 2.2a and b switch 2.2b and c switch 2.2c, a active rectifier 3a, b active rectifier 3b, c active rectifier 3c, d active rectifier 3d, e active rectifier 3e and f active rectifier 3f, a bidirectional DC-DC unit 4a, b bidirectional DC-DC unit 4b, c bidirectional DC-DC unit 4c, d bidirectional DC-DC unit 4d, e bidirectional DC-DC unit 4e and f bidirectional DC-DC unit 4f, a battery set 5a and b battery set 5b, a daily power transformer 6a and b daily power transformer 6b, a daily load 7a and b daily load 7b, a fixed frequency inverter 8a and b fixed frequency inverter 8b, DC bus 9, A bus 9.1a and B bus 9.1b and C bus 9.1c and D bus 9.1d, a fast fuse 9.2a and b fast fuse 9.2b and c fast fuse 9.2c, A switch 9.3a and B switch 9.3b and C switch 9.3c, a variable frequency inverter 10a and b variable frequency inverter 10b and c variable frequency inverter 10c and d variable frequency inverter 10d, a main propulsion motor 11a and b side propulsion motor 11b and c side propulsion motor 11c and d main propulsion motor 11d, a super capacitor group 12a and b super capacitor group 12b and c super capacitor group 12c and d super capacitor group 12d, a shore power interface 13a and a shore power interface 13c.

[0031] Diesel generator set a 1a and diesel generator set b 1b and diesel generator set c 1c and diesel generator set d 1d are all composed of synchronous generator set 1.1 and switch 1.2, and are all equipped with parallel controllers. They are connected to AC bus 2 through switch 1.2 controlled by the parallel controller. Among them: diesel generator set a 1a is connected to bus a 2.1a, diesel generator set b 1b is connected to bus b 2.1b, diesel generator set c 1c is connected to bus c 2.1c, and diesel generator set d 1d is connected to bus d 2.1d. In AC mode, each generator set is synchronously connected to AC bus 2 or disconnected from AC bus 2 through parallel controller and switch 1.2. In DC mode, each generator set operates with independent speed regulation.

[0032] The AC bus 2 is composed of bus a 2.1a, bus b 2.1b, bus c 2.1c, bus d 2.1d, switch a 2.2a, switch b 2.2b, and switch c 2.2c. In the AC mode, switch a 2.2a, switch b 2.2b, and switch c 2.2c are closed, and in the DC mode, switch a 2.2a, switch b 2.2b, and switch c 2.2c are opened.

[0033] Active rectifier a 3a, active rectifier b 3b, active rectifier c 3c, active rectifier d 3d, active rectifier e 3e and active rectifier f 3f are composed of LC filter 3.1 and AC-DC converter 3.2, with input end connected to AC bus 2 and output end connected to DC bus 9 through fast fuse. In DC mode, diesel generator set a 1a operates independently with speed regulation, the input voltage and frequency of active rectifier a 3a change with speed regulation, while the output end of active rectifier a 3a is connected to A bus 9.1a through fast fuse and the DC voltage is constant. Diesel generator set b 1b operates independently with speed regulation, the input voltage and frequency of active rectifier b 3b change with speed regulation, while the output end of active rectifier b 3b is connected to B bus 9.1b through fast fuse and the DC voltage is constant. c Diesel generator set 1c operates with independent speed regulation, the voltage and frequency at the input end of c active rectifier 3c change with the speed regulation, while the DC voltage at the output end of c active rectifier 3c connected to C bus 9.1c through a fast fuse is constant. d Diesel generator set 1d operates with independent speed regulation, the voltage and frequency at the input end of d active rectifier 3d change with the speed regulation, while the DC voltage at the output end of d active rectifier 3d connected to D bus 9.1d through a fast fuse is constant. The output end of e active rectifier 3e is connected to A bus 9.1a through a fast fuse, and its input end is connected to a shore power interface 13a. When the ship docks, the shore power is rectified and the electric energy is transmitted to A bus 9.1a, and the a storage battery group 5a is charged through a bidirectional DC-DC unit 4a. The output end of the f active rectifier 3f is connected to the D bus 9.1d through a fast fuse, and its input end is connected to the b shore power interface 13b. When the ship docks, the shore power is rectified and the electric energy is transmitted to the D bus 9.1d, and the b battery group 5b is charged through the b bidirectional DC-DC unit 4b.

[0034] The bidirectional DC-DC unit a 4a, the bidirectional DC-DC unit b 4b, the bidirectional DC-DC unit c 4c, the bidirectional DC-DC unit d 4d, the bidirectional DC-DC unit e 4e and the bidirectional DC-DC unit f 4f are composed of a DC reactor 4.1 and a DC-DC converter 4.2, and electric energy can flow in both directions. Among them, the DC-DC converter 4.2 end of the bidirectional DC-DC unit a 4a is connected to the A bus 9.1a through a fast fuse, and its DC reactor 4.1 end is connected to the a battery group 5a. The DC-DC converter 4.2 end of the b bidirectional DC-DC unit 4b is connected to the D bus 9.1d through a fast fuse, and its DC reactor 4.1 end is connected to the b battery group 5b. The DC-DC converter 4.2 end of the c bidirectional DC-DC unit 4c is connected to the A bus 9.1a through a fast fuse, and its DC reactor 4.1 end is connected to the a super capacitor group 12a. The DC-DC converter 4.2 end of the d bidirectional DC-DC unit 4d is connected to the B bus 9.1b through a fast fuse, and its DC reactor 4.1 end is connected to the b supercapacitor group 12b. The DC-DC converter 4.2 end of the e bidirectional DC-DC unit 4e is connected to the C bus 9.1c through a fast fuse, and its DC reactor 4.1 end is connected to the c supercapacitor group 12c. The DC-DC converter 4.2 end of the f bidirectional DC-DC unit 4f is connected to the D bus 9.1d through a fast fuse, and its DC reactor 4.1 end is connected to the d supercapacitor group 12d.

[0035] The a battery group 5a and the b battery group 5b are composed of high energy density units. The a battery group 5a is connected to the A bus 9.1a through the a bidirectional DC-DC unit 4a. The a battery group 5a can discharge to the A bus 9.1a through the a bidirectional DC-DC unit 4a, and can also be charged from the A bus 9.1a through the a bidirectional DC-DC unit 4a. The b battery group 5b is connected to the D bus 9.1d through the b bidirectional DC-DC unit 4b. The b battery group 5b can discharge to the D bus (9.1d) through the b bidirectional DC-DC unit 4b, and can also be charged from the D bus 9.1d through the b bidirectional DC-DC unit 4b.

[0036] The daily power transformer a 6a and the daily power transformer b 6b are composed of an isolation transformer 6.3 and a switch 6.1 and a switch 6.2 at the input end of the isolation transformer 6.3. The switch 6.2 of the daily power transformer a 6a is connected to the b bus 2.1b, the switch 6.1 is connected to the LC filter 8.1 end of the a fixed frequency inverter 8a, and the output end of the isolation transformer 6.3 is connected to the a daily load 7a. The switch 6.2 of the daily power transformer b 6b is connected to the c bus 2.1c, the switch 6.1 is connected to the LC filter 8.1 end of the b fixed frequency inverter 8b, and the output end of the isolation transformer 6.3 is connected to the b daily load 7b. In the AC mode, the switch connected to the AC bus 2 is closed, and the switch connected to the LC filter 8.1 end is opened. In the DC mode, the switch connected to the LC filter 8.1 end is closed, and the switch connected to the AC bus 2 is opened.

[0037] The fixed frequency inverter a 8a and the fixed frequency inverter b 8b are composed of an LC filter 8.1 and a DC-AC converter 8.2. The input end of the fixed frequency inverter a 8a is connected to the B bus 9.1b through a fast fuse, and the output end is connected to the switch 6.1 of the daily power transformer a 6a. In the DC mode, the DC power on the B bus 9.1b is inverted into high-quality fixed-frequency AC power, which is supplied to the daily load a 7a. The input end of the fixed frequency inverter b 8b is connected to the C bus 9.1c through a fast fuse, and the output end is connected to the switch 6.1 of the daily power transformer b 6b. In the DC mode, the DC power on the C bus 9.1c is inverted into high-quality fixed-frequency AC power, which is supplied to the daily load b 7b.

[0038] The DC bus 9 is composed of the A bus 9.1a, the B bus 9.1b, the C bus 9.1c, and the D bus 9.1d, the a fast fuse 9.2a, the b fast fuse 9.2b, and the c fast fuse 9.2c, the A switch 9.3a, the B switch 9.3b, and the C switch 9.3c. In the AC mode, the A switch 9.3a, the B switch 9.3b, and the C switch 9.3c are open. In the DC mode, the A switch 9.3a, the B switch 9.3b, and the C switch (9.3c) are closed.

[0039] The a variable frequency inverter 10a, the b variable frequency inverter 10b, the c variable frequency inverter 10c and the d variable frequency inverter 10d have input ends connected to the DC bus 9 through fast fuses and output ends connected to the propulsion motor, which can control the torque, power and speed of the propulsion system. When the propulsion system performs reverse work, the electric energy can be fed to the DC bus 9. Among them: the a variable frequency inverter 10a controls the a main propulsion motor 11a. When the a main propulsion motor 11a performs reverse work, the a variable frequency inverter 10a feeds the electric energy to the A bus 9.1a, and the c bidirectional DC-DC unit 4c charges and absorbs the a super capacitor group 12a. The b variable frequency inverter 10b controls the b side propulsion motor 11b. When the b side propulsion motor 11b performs reverse work, the b variable frequency inverter 10b feeds the electric energy to the B bus 9.1b, and the d bidirectional DC-DC unit 4d charges and absorbs the b super capacitor group 12b. The c variable frequency inverter 10c controls the c side propulsion motor 11c. When the c side propulsion motor 11c performs reverse work, the c variable frequency inverter 10c feeds electric energy to the C bus 9.1c, and the e bidirectional DC-DC unit 4e charges and dissipates the c super capacitor group 12c. The d variable frequency inverter 10d controls the d main propulsion motor 11d. When the d main propulsion motor 11d performs reverse work, the d variable frequency inverter 10d feeds electric energy to the D bus 9.1d, and the f bidirectional DC-DC unit 4f charges and dissipates the d super capacitor group 12d.

[0040] The super capacitor group a 12a and the super capacitor group b 12b and the super capacitor group c 12c and the super capacitor group d 12d are connected to the DC bus 9 through the bidirectional DC-DC unit c 4c and the bidirectional DC-DC unit d 4d and the bidirectional DC-DC unit e 4e and the bidirectional DC-DC unit f 4f. When the A bus 9.1a is depleted, the super capacitor group a 12a is discharged instantaneously through the bidirectional DC-DC unit c 4c to inject the electric energy of the A bus 9.1a. When the A bus 9.1a is full of power, the super capacitor group a 12a is charged by absorbing the electric energy of the A bus 9.1a instantaneously through the bidirectional DC-DC unit c 4c. When the B bus 9.1b is underpowered, the b supercapacitor group 12b discharges instantaneously into the B bus 9.1b through the d bidirectional DC-DC unit 4d, and when the B bus 9.1b is overpowered, the b supercapacitor group 12b absorbs the B bus 9.1b's power instantaneously through the d bidirectional DC-DC unit 4d for charging. When the C bus 9.1c is underpowered, the c supercapacitor group 12c discharges instantaneously into the C bus 9.1c through the e bidirectional DC-DC unit 4e, and when the C bus 9.1c is overpowered, the c supercapacitor group 12c absorbs the C bus 9.1c's power instantaneously through the e bidirectional DC-DC unit 4e for charging. When the D bus 9.1d is underpowered, the d supercapacitor group 12d injects the electric energy of the D bus 9.1d through the f bidirectional DC-DC unit 4f for instantaneous discharge. When the D bus 9.1d is overpowered, the d supercapacitor group 12d absorbs the electric energy of the D bus 9.1d for instantaneous charging through the f bidirectional DC-DC unit 4f. The a supercapacitor group 12a and the b supercapacitor group 12b, the c supercapacitor group 12c and the d supercapacitor group 12d realize power balance and fault ride-through.

[0041] The AC networking mode can be entered by closing the switch a 2.2a and switch b 2.2b and switch c 2.2c on the AC bus 2, and opening the switch A 9.3a and switch B 9.3b and switch C 9.3c on the DC bus 9, closing the switch connecting the daily power transformer a 6a and daily power transformer b 6b to the AC bus 2, and opening the switch connected to the LC filter 8.1. Each diesel generator set is synchronously connected to the AC bus 2 or disconnected from the AC bus 2 through the parallel controller and switch 1.2. The active rectifier a 3a and the variable frequency inverter a 10a are combined into a complete AC-DC-AC inverter to control and drive the main propulsion motor a 11a. Due to the effect of the active rectifier a 3a and the active rectifier b 3b and the LC filter 3.1 in the active rectifier c 3c and the active rectifier d 3d, the harmonic distortion rate on the AC bus 2 is less than 5%. The load fluctuation of the a main propulsion motor 11a is balanced by the a supercapacitor group 12a connected to the c bidirectional DC-DC unit 4c. The b active rectifier 3b and the b frequency conversion inverter 10b are combined into a complete AC-DC-AC inverter to control and drive the b side propulsion motor 11b. The load fluctuation of the b side propulsion motor 11b is balanced by the b supercapacitor group 12b connected to the d bidirectional DC-DC unit 4d. The c active rectifier 3c and the c frequency conversion inverter 10c are combined into a complete AC-DC-AC inverter to control and drive the c side propulsion motor 11c. The load fluctuation of the c side propulsion motor 11c is balanced by the c supercapacitor group 12c connected to the e bidirectional DC-DC unit 4e. The d active rectifier 3d and the d variable frequency inverter 10d are combined into a complete AC-DC-AC inverter to control and drive the d main propulsion motor 11d. The load fluctuation of the d main propulsion motor 11d is balanced by the d super capacitor group (12d) connected to the f bidirectional DC-DC unit (4f). By closing the switch 6.2 of the a daily power transformer 6a, the a daily power transformer 6a is powered by the AC bus 2 to provide power to the a daily load 7a. By closing the switch 6.2 of the b daily power transformer 6b, the b daily power transformer 6b is powered by the AC bus 2 to provide power to the b daily load 7b.

[0042] Open the switch a 2.2a and switch b 2.2b on the AC bus 2 and switch c 2.2c, and close the switch A 9.3a and switch B 9.3b and switch C 9.3c on the DC bus 9, open the switch 6.2 on the daily power transformer a 6a, and close the switch 6.1, open the switch 6.2 on the daily power transformer b 6b, and close the switch 6.1, and then enter the DC networking mode. The a diesel generator set 1a and the b diesel generator set 1b and the c diesel generator set 1c and the d diesel generator set 1d are independently regulated. The a diesel generator set 1a provides power to the DC bus 9 through the a active rectifier 3a, the b diesel generator set 1b provides power to the DC bus 9 through the b active rectifier 3b, the c diesel generator set 1c provides power to the DC bus 9 through the c active rectifier 3c, and the d diesel generator set 1d provides power to the DC bus 9 through the d active rectifier 3d. The a battery group 5a provides power to the DC bus 9 through the a bidirectional DC-DC unit 4a for independent propulsion, or can be jointly propelled with the diesel generator set, or can receive power from the DC bus 9 through the a bidirectional DC-DC unit 4a to charge the a battery group 5a. The b battery group 5b provides power to the DC bus 9 through the b bidirectional DC-DC unit 4b for independent propulsion, or can be jointly propelled with the diesel generator set, or can receive power from the DC bus 9 through the b bidirectional DC-DC unit 4b to charge the b battery group 5b. The switch 6.1 of the a daily power transformer 6a is closed and connected to the a fixed frequency inverter 8a, so that the a daily power transformer 6a receives power from the DC bus 9 through the a fixed frequency inverter 8a, providing low harmonic high-quality power for the a daily load 7a. The switch 6.1 of the daily power transformer 6b is closed and connected to the fixed-frequency inverter 8b, so that the daily power transformer 6b receives power from the DC bus 9 through the fixed-frequency inverter 8b, and provides low-harmonic high-quality power for the daily load 7b.

[0043] The system is configured with an AC bus 2 and a DC bus 9. In the first case where a active rectifier 3a, d variable frequency inverter 10d and d diesel generator set 1d fail, and in the second case where d active rectifier 3d, a variable frequency inverter 10a and a diesel generator set 1a fail, in these two extreme cases, both the AC networking mode and the DC networking mode may cause the ship's main propulsion system to lose power. In the first extreme case, the problem can be solved by: the electric energy flows from a diesel generator set 1a→a bus 2.1a→a switch 2.2a→b bus 2.1b→b switch 2.2b→c bus 2.1c→c switch 2.2c→d bus 2.1d→d active rectifier 3d→D bus 9.1d→C switch 9.3c→c fast fuse 9.2c→C bus 9.1c→B switch 9.3b→b fast fuse 9.2b→B bus 9.3b→A switch 9.3a→a fast fuse 9.2a→A bus 9.1a→a variable frequency inverter 10a→to a main propulsion motor 11a, so that the port side thruster of the ship can get power. The second extreme case can be solved by: the electric energy flows from d diesel generator set 1d→d bus 2.1d→c switch 2.2c→c bus 2.1c→b switch 2.2b→b bus 2.1b→a switch 2.2a→a bus 2.1a→a active rectifier 3a→A bus 9.1a→a fast fuse 9.2a→A switch 9.3a→B bus 9.1b→b fast fuse 9.2b→B switch 9.3b→C bus 9.1c→c fast fuse 9.2c→C switch 9.3c→D bus 9.1d→d variable frequency inverter 10d→reaching d main propulsion motor 11d, so that the starboard thruster of the ship can get power. This makes the entire electric propulsion system more redundant and safer. Using AC mode during cruise control makes the system reliable and robust, and using DC mode at low speed or when approaching a port makes the system energy-saving, low-emission, quiet and economical.

[0044] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A diesel-electric hybrid electric propulsion system for ship AC / DC networking, characterized in that: include, a diesel generator set (1a) and b diesel generator set (1b) and c diesel generator set (1c) and d diesel generator set (1d), AC bus (2), a active rectifier (3a), b active rectifier (3b), c active rectifier (3c), d active rectifier (3d), e active rectifier (3e) and f active rectifier (3f), a bidirectional DC-DC unit (4a), b bidirectional DC-DC unit (4b), c bidirectional DC-DC unit (4c), d bidirectional DC-DC unit (4d), e bidirectional DC-DC unit (4e) and f bidirectional DC-DC unit (4f), a battery pack (5a) and b battery pack (5b), a daily power supply Transformer (6a) and daily power transformer (6b), daily load (7a) and daily load (7b), fixed frequency inverter (8a) and fixed frequency inverter (8b), DC bus (9), variable frequency inverter (10a) and variable frequency inverter (10b) and variable frequency inverter (10c) and variable frequency inverter (10d), main propulsion motor (11a) and side propulsion motor (11b) and side propulsion motor (11c) and main propulsion motor (11d), super capacitor group (12a) and super capacitor group (12b) and super capacitor group (12c) and super capacitor group (12d), shore power interface (13a) and shore power interface (13b); The diesel generator set a (1a), diesel generator set b (1b), diesel generator set c (1c), and diesel generator set d (1d) comprise: a synchronous generator set (1.1) and a switch (1.2), all of which are equipped with a paralleling controller and are connected to an AC bus (2) via the switch (1.2) controlled by the paralleling controller; wherein: the diesel generator set a (1a) is connected to the bus a (2.1a), the diesel generator set b (1b) is connected to the bus b (2.1b), the diesel generator set c (1c) is connected to the bus c (2.1c), and the diesel generator set d (1d) is connected to the bus d (2.1d); The AC busbar (2) comprises: busbar a (2.1a), busbar b (2.1b), busbar c (2.1c), busbar d (2.1d), switch a (2.2a), switch b (2.2b), and switch c (2.2c); The active rectifier a (3a), the active rectifier b (3b), the active rectifier c (3c), the active rectifier d (3d), the active rectifier e (3e) and the active rectifier f (3f) are composed of an LC filter (3.1) and an AC-DC converter (3.2), the input end of which is connected to the AC bus (2), and the output end of which is connected to the DC bus (9) via a fast fuse; Wherein: the input end of the a active rectifier (3a) is connected to the a bus (2.1a), and the output end is connected to the A bus (9.1a) through a fast fuse; The input end of the b active rectifier (3b) is connected to the b bus (2.1b), and the output end is connected to the B bus (9.1a) through a fast fuse; The input end of the c active rectifier (3a) is connected to the c bus (2.1b), and the output end is connected to the C bus (9.1c) through a fast fuse; The input end of the d active rectifier (3d) is connected to the d busbar (2.1d), and the output end is connected to the D busbar (9.1d) through a fast fuse; The output end of the e active rectifier (3e) is connected to the A busbar (9.1a) through a fast fuse, and its input end is connected to the a shore power interface (13a); The output end of the f active rectifier (3f) is connected to the D busbar (9.1d) through a fast fuse, and its input end is connected to the b shore power interface (13b); The a bidirectional DC-DC unit (4a), b bidirectional DC-DC unit (4b), c bidirectional DC-DC unit (4c), d bidirectional DC-DC unit (4d), e bidirectional DC-DC unit (4e) and f bidirectional DC-DC unit (4f) are composed of a DC reactor (4.1) and a DC-DC converter (4.2), and electric energy can flow in both directions; Wherein: the DC-DC converter (4.2) end of the bidirectional DC-DC unit (4a) is connected to the A busbar (9.1a) through a fast fuse, and the DC reactor (4.1) end thereof is connected to the a storage battery group (5a); The DC-DC converter (4.2) end of the b bidirectional DC-DC unit (4b) is connected to the D bus (9.1d) through a fast fuse, and the DC reactor (4.1) end thereof is connected to the b storage battery group (5b); The DC-DC converter (4.2) end of the c bidirectional DC-DC unit (4c) is connected to the A bus (9.1a) through a fast fuse, and the DC reactor (4.1) end thereof is connected to the a supercapacitor group (12a); The DC-DC converter (4.2) end of the d bidirectional DC-DC unit (4d) is connected to the B bus (9.1b) through a fast fuse, and its DC reactor (4.1) end is connected to the b supercapacitor group (12b); The DC-DC converter (4.2) end of the e bidirectional DC-DC unit (4e) is connected to the C busbar (9.1c) through a fast fuse, and the DC reactor (4.1) end thereof is connected to the c supercapacitor group (12c); The DC-DC converter (4.2) end of the f bidirectional DC-DC unit (4f) is connected to the D busbar (9.1d) through a fast fuse, and the DC reactor (4.1) end thereof is connected to the d supercapacitor group (12d); The a storage battery group (5a) and the b storage battery group (5b) are composed of high energy density units, and can discharge to the DC bus (9) through the bidirectional DC-DC unit, and can also receive power from the DC bus (9) for charging through the bidirectional DC-DC unit; Wherein: the a storage battery group (5a) is connected to the DC reactor (4.1) end of the a bidirectional DC-DC unit (4a), and the b storage battery group (5b) is connected to the DC reactor (4.1) end of the b bidirectional DC-DC unit (4b); The daily power transformer a (6a) and the daily power transformer b (6b) are composed of an isolation transformer (6.3) and a switch (6.1) and a switch (6.2) at the input end of the isolation transformer (6.3); Wherein: the switch (6.2) of the daily power transformer (6a) is connected to the busbar (2.1b), the switch (6.1) is connected to the LC filter (8.1) end of the fixed frequency inverter (8a), and the output end of the isolation transformer (6.3) is connected to the daily load (7a); The switch (6.2) of the b daily power transformer (6b) is connected to the c busbar (2.1c), the switch (6.1) is connected to the LC filter (8.1) end of the b fixed frequency inverter (8b), and the output end of the isolation transformer (6.3) is connected to the b daily load (7b); The a fixed-frequency inverter (8a) and the b fixed-frequency inverter (8b) are composed of an LC filter (8.1) and a DC-AC converter (8.2); Wherein: the input end of a fixed frequency inverter (8a) is connected to the B bus (9.1b) through a fast fuse, and the output end is connected to the switch (6.1) of a daily power transformer (6a); The input end of the b fixed frequency inverter (8b) is connected to the C bus (9.1c) through a fast fuse, and the output end is connected to the switch (6.1) of the b daily power transformer (6b); The DC bus (9) comprises: bus A (9.1a), bus B (9.1b), bus C (9.1c), bus D (9.1d), a fast fuse (9.2a), fast fuse (9.2b), fast fuse (9.2c), switch A (9.3a), switch B (9.3b), and switch C (9.3c); The a variable frequency inverter (10a), b variable frequency inverter (10b), c variable frequency inverter (10c), and d variable frequency inverter (10d) have input ends connected to a DC bus (9) via a fast fuse, and output ends connected to a propulsion motor, and can control the torque, power, and speed of the propulsion system. When the propulsion system performs reverse work, electric energy can be fed to the DC bus (9); Wherein: a variable frequency inverter (10a) controls a main propulsion motor (11a), b variable frequency inverter (10b) controls b side propulsion motor (11b), c variable frequency inverter (10c) controls c side propulsion motor (11c), and d variable frequency inverter (10d) controls d main propulsion motor (11d); The a supercapacitor group (12a), the b supercapacitor group (12b), the c supercapacitor group (12c), and the d supercapacitor group (12d) are connected to the DC reactor (4.1) end of the bidirectional DC-DC unit; When the DC bus (9) loses power, electric energy is injected into the DC bus (9) through instantaneous discharge of the bidirectional DC-DC unit; When the DC bus (9) is full of power, the electric energy of the DC bus (9) is instantaneously absorbed by the bidirectional DC-DC unit for charging; Wherein: the super capacitor group a (12a) is connected to the DC reactor (4.1) end of the bidirectional DC-DC unit c (4c), the super capacitor group b (12b) is connected to the DC reactor (4.1) end of the bidirectional DC-DC unit d (4d), the super capacitor group c (12c) is connected to the DC reactor (4.1) end of the bidirectional DC-DC unit e (4e), and the super capacitor group d (12d) is connected to the DC reactor (4.1) end of the bidirectional DC-DC unit f (4f), so as to achieve power balance and fault ride-through.

2. A diesel-electric hybrid electric propulsion system for ship AC / DC networking according to claim 1, characterized in that: The a switch (2.2a), the b switch (2.2b) and the c switch (2.2c) on the AC bus (2) are closed, and the A switch (9.3a), the B switch (9.3b) and the C switch (9.3c) on the DC bus (9) are opened, and the switch (6.2) connecting the a daily power transformer (6a) and the b daily power transformer (6b) to the AC bus (2) is closed, and the switch (6.1) connected to the LC filter (8.1) end is opened, and the AC networking mode can be entered.

3. A diesel-electric hybrid electric propulsion system for ship AC / DC networking according to claim 1, characterized in that , disconnect the switch a (2.2a) and switch b (2.2b) and switch c (2.2c) on the AC bus (2), and simultaneously close the switch A (9.3a) and switch B (9.3b) and switch C (9.3c) on the DC bus (9), disconnect the switch (6.2) connecting the daily power transformer a (6a) and the daily power transformer b (6b) to the AC bus (2), and simultaneously close the switch (6.1) connected to the LC filter (8.1) end, and then enter the DC networking mode.

4. According to claim 1, a diesel-electric hybrid electric propulsion system for ship AC / DC networking is configured with an AC bus (2) and a DC bus (9), so that the entire electric propulsion system is more redundant and safer, and the AC networking mode and the DC networking mode can be switched between each other. The AC networking mode system is reliable and rugged, and the DC networking mode system is energy-saving, low-emission, quiet and economical.

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