Annular direct-current busbar power system used in ship dynamic positioning mode and control method of annular direct-current busbar power system

Abstract

The invention discloses an annular direct-current busbar power system used in a ship dynamic positioning mode and a control method of the annular direct-current busbar power system. According to the annular direct-current busbar power system, due to the annular direct-current busbar networking mode, more flexible and rapid protection performance is achieved, that is, before a ship power grid is affected by faults, the frequency converter can rapidly detect abnormal conditions and actively complete isolation of fault points, so that the whole power grid and normal branches are not affected, and after the faults are eliminated, the frequency converter can rapidly detect the abnormal conditions and actively complete isolation of the fault points. And normal connection is quickly recovered. The variable-speed generator set is adopted in the system, the speed regulation range of the variable-speed generator set is expanded, the variable-speed generator set can automatically regulate the running speed according to loads, and load oil consumption can be always kept within an economic range, so that oil is saved, emission is reduced, the energy efficiency utilization rate of the generator set is remarkably improved, and the flexibility of the system is improved. The method is more suitable for ships with ship dynamic positioning working condition requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of ship propulsion power systems, and in particular to a ring-shaped DC busbar power system used in a ship dynamic positioning mode and a control method thereof. Background Art

[0002] For large offshore platforms and offshore maintenance vessels, automatic dynamic positioning capabilities are required to ensure stable posture and safe operation during offshore operations. At present, the technology of ship dynamic positioning system (DP) is relatively mature, and a variety of power system configuration schemes have been derived according to the requirements of different ship dynamic positioning levels. Among them, the closed-loop operation of the power grid has better energy saving and emission reduction, lower operating costs, and increased safety and reliability. It has become the industry's first choice, but the safety and reliability of the power grid under DP conditions are also subject to severe challenges. Each classification society has higher and higher requirements for the protection system of closed busbar operation. For example, for DP2 ships, ABS classification society requires simulated short-circuit tests to verify the fault-crossing capability of the power system.

[0003] Patent application CN117613832A discloses a ship DC ring network system and a bus tie switch selective short-circuit protection method thereof, including a DC main distribution board, a test distribution board, a plurality of bus tie switches connected by cables to form a ring network, and a bus tie switch selective short-circuit protection method. The invention uses a current high-speed sampling unit in a bus tie switch controller to collect the instantaneous current value and current direction output by the solid-state switch in the bus tie switch cabinet in real time, judge the occurrence of a short circuit, and can quickly respond to perform selective protection; Patent CN209150720U discloses "a DC ring network electric propulsion system" including a plurality of annular DC busbar modules, a plurality of bus tie breakers, a plurality of power supply branches, and a plurality of power consumption branches; the power supply branches correspond to the annular DC busbar modules one by one; the annular DC busbar modules are connected end to end in sequence to form a ring network; the annular DC busbar module includes annular DC busbars and bus tie breakers connected in series, and the bus tie breakers are connected in series between every two adjacent annular DC busbars. The invention adopts three annular DC busbars connected in a ring shape. When any one of the annular DC busbars fails and is isolated from the other two annular DC busbars, the other two annular DC busbars are still connected to each other, thereby improving the reliability of the system.

[0004] However, once a short circuit occurs in the ship's annular DC busbar power system, the DC busbar voltage drops rapidly and a fault protection occurs, making the equipment in the system unable to work. On the other hand, the short circuit fault of the annular busbar is prone to fault extension, causing the entire power grid to lose power. In response to the above problems, the present invention provides an annular DC busbar power system and control method in a ship's dynamic positioning mode, which has higher integrity and fault tolerance than traditional segmented busbar operation, and effectively ensures the safety and reliability of the entire ship's operation. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a ring-shaped DC busbar power system for a ship dynamic positioning mode.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a ring-shaped DC busbar power system for ship dynamic positioning mode, comprising n groups of variable speed generator sets, a lithium battery group, a ring-shaped DC busbar, at least two load units and a monitoring center;

[0007] The annular DC busbar includes n+1 busbar main lines and n-1 busbar branch lines, wherein the n busbar branch lines are sequentially connected to n groups of variable speed generator sets and lithium battery packs, the n+1 busbar main line connects the ends of the first busbar main line and the nth busbar main line, and the annular DC busbar main line is provided with a circuit breaker and a monitoring component;

[0008] One end of the n-1 busbar branches is connected in sequence to the node between the circuit breaker and the monitoring component on the first n-1 busbar main lines, and the other end is connected to the n+1 section busbar main line; the n+1 section busbar main line is also provided with circuit breakers and monitoring components in sequence; each busbar branch line is provided with a circuit breaker; under the working condition of the dynamic positioning mode, the circuit breakers of all busbar branches are disconnected, and all circuit breakers on the busbar main line remain closed; the monitoring component includes a current sensor 1, an IGBT solid-state switch, a current sensor 2, and a mechanical switch connected in sequence;

[0009] The variable speed generator set includes a variable speed generator, a circuit breaker, an AC / DC module, and a current sensor connected to a ring-shaped DC busbar in sequence; the lithium battery pack is provided with a plurality of lithium battery clusters, a circuit breaker, a rectifier inverter module AC / DC module, and a current sensor;

[0010] The load unit is connected to the busbar main line; the load unit includes a current sensor, an inverter module, a circuit breaker and a propulsion device; the inverter module includes a DC / AC module and a circuit breaker; the propulsion device includes a propulsion motor and a propeller, and the load unit also includes a daily load;

[0011] The variable speed generator set and lithium battery pack provide power to the load unit through the ring DC busbar, and the monitoring center is used for system operation process monitoring and fault handling.

[0012] As a preferred solution, the monitoring center includes a monitoring platform and a monitoring subsystem S-Link, which are used to perform operation control, process monitoring and fault handling on the ring DC bus power system; the monitoring platform includes a control device, communication equipment, monitoring equipment, a cloud server, and a remote client.

[0013] As a preferred solution, the control device includes a power distribution system PMS, several propulsion central control modules, and an integrated power distribution module; the integrated power distribution module is equipped with an energy management subsystem EMS, and adopts a distributed layout structure according to the main control and sub-control hierarchical control mode according to the needs of different monitoring domains to meet the requirements of the dynamic positioning mode.

[0014] As a preferred solution, the power distribution system PMS monitors and controls the operating status of the power system in real time, including various parameters of the power system, to reduce the system downtime caused by equipment failure or parameter abnormality. It has fault alarm and prompt functions, and promptly alarms when a fault occurs, and records fault information for the monitoring subsystem S-Link to analyze and process it, and promptly discover and handle potential faults and abnormal conditions; the monitoring subsystem S-Link is mainly composed of data acquisition, data flow display, and data expansion modeling. The ship-side monitoring station S-Link host performs data acquisition, data integration and data flow, and the data sources include variable speed generator sets, lithium battery packs, monitoring alarm systems, and communication and navigation equipment;

[0015] The integrated power distribution module is equipped with a main controller PLC, a switch and a sub-controller for each load unit; when an overcurrent occurs between current sensor 1 and current sensor 2 at a certain position, it indicates a short circuit fault, and the corresponding monitoring component transmits information to the main controller PLC of the integrated power distribution module, and the main controller PLC shuts down the relevant components on the ring DC busbar.

[0016] As a preferred solution, the communication and navigation equipment is used to obtain ship navigation information, and the monitoring equipment is used to monitor the operating status of the power system; the energy management subsystem EMS of the integrated power distribution module performs energy management according to the load conditions, automatically adjusts the speed of each variable-speed generator and the number of variable-speed generator units on the grid, so that the output power of the variable-speed generator set matches the load power, so as to optimize the fuel consumption of the variable-speed generator set.

[0017] Another technical problem to be solved by the present invention is to provide a control method for the above-mentioned annular DC busbar power system used in the ship dynamic positioning mode.

[0018] In order to solve the above technical problems, the technical solution adopted by the present invention is: a control method of a ring-shaped DC busbar power system in a ship dynamic positioning mode, comprising the following steps:

[0019] Step 1: Starting the diesel generator set

[0020] The variable speed generator starts running, and the system self-checks. If the system reports an error and sends the error information to the monitoring terminal, the maintenance personnel will control all variable speed generators to stop through the remote control system and repair the variable speed generators; otherwise, it will enter normal operation;

[0021] Step 2: Pre-charging of the ring DC busbar

[0022] After the variable speed generator operates normally, the ring DC busbar is charged through the AC / DC module, the monitoring component works, and the corresponding monitoring tasks are performed; if a fault occurs, step three is performed, otherwise, step four is performed;

[0023] Step 3: Ring DC busbar fault handling

[0024] When a short circuit fault occurs in the system, the fault isolation method includes the following steps:

[0025] S31: Overcurrent monitoring

[0026] The n+1-segment busbar main line of the annular DC busbar monitors the overcurrent of the current segment busbar main line of the annular DC busbar through the monitoring components thereon in turn through the current sensor 1 and the current sensor 2; until it is detected that the current exceeds the set value;

[0027] S32: Overcurrent protection

[0028] When overcurrent occurs, the IGBT module on the main line section of the busbar automatically shuts down for overcurrent protection and opens the mechanical switch. At the same time, the main controller PLC of the integrated power distribution module sends overcurrent information;

[0029] S33: Fault information processing: the main controller PLC of the integrated power distribution module receives the fault information and notifies the remaining IGBT modules on the ring DC bus to shut down and the corresponding mechanical switches to open;

[0030] S34: After the fault is resolved, execute step 2;

[0031] Step 4: Start the load operation

[0032] After the pre-charging of the annular DC busbar is completed, it starts to supply power to the load unit; the DC power is converted into the AC power required by the propulsion motor and the daily load through the DC / AC module; at the same time, the system self-checks and meets the power supply requirements, supplies power to the daily load and the propulsion motor respectively, and executes step five; otherwise, executes step six;

[0033] Step 5: System operation status monitoring and adjustment

[0034] The power distribution system PMS distributes power to each variable speed generator in the variable speed generator set and performs fault diagnosis and repair on the DC system; when a short circuit fault signal of the DC system is received, step three is executed; when a power-off instruction is received, step six is ​​executed; otherwise, step five is repeated;

[0035] Step 6: End of judgment

[0036] Power off and end system operation.

[0037] The beneficial effects of the present invention are:

[0038] 1. The annular DC busbar power system for ship dynamic positioning provided by the present invention has a more flexible and rapid protection performance due to its annular DC busbar networking form, that is, before the ship power grid is affected by the fault, the frequency converter can quickly detect the abnormal situation and actively complete the isolation of the fault point, so that the entire power grid and normal branches are not affected, and then quickly restore normal connection after the fault is eliminated.

[0039] 2. The variable speed generator set has a wider speed regulation range. The variable speed generator set can adjust the operating speed according to the load, and will always keep the load fuel consumption in the economic range, thereby saving fuel and reducing emissions, significantly improving the energy efficiency of the generator set, and increasing the flexibility of the system, making it more suitable for ships with dynamic positioning requirements.

[0040] 3. The system provided by the present invention can also be connected to various energy storage devices such as lithium batteries and capacitors to expand the capacity of the power station, add more load regulation points, and at the same time increase the power upper limit of the generator set, with higher single-point safety. At the same time, the battery pack can have the function of peak shaving and valley filling. When the generator power is redundant, the lithium battery is charged to recover energy; when the generator set is underloaded, the lithium battery is discharged to supplement, which can effectively improve the energy utilization rate, smooth the load curve, increase the unit load rate, reduce the loss of frequent start and stop of the generator set, and stabilize the operation of the power grid.

[0041] 4. Develop a selective short-circuit protection device and method for the ship's DC ring network busbar switch. Compared with mechanical circuit breaker protection, the misjudgment rate of non-fault points in the DC ring network busbar is reduced, and it has higher integrity and fault tolerance than traditional segmented busbar operation, which plays a vital role in the safety and reliability of the entire ship's operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the system composition of the present invention;

[0043] Figure 2 An exemplary single-line diagram of the system of the present invention is shown;

[0044] Figure 3 It is a diagram of the monitoring component structure of the present invention;

[0045] Figure 4 It is a composition diagram of the control system of the present invention;

[0046] Figure 5 A connection diagram of the control device of the present invention;

[0047] Figure 6 is a system control flow chart of the present invention;

[0048] In the figure:

[0049] Variable speed generator set, 2-lithium battery pack, 3-ring DC busbar, 4-load unit, 5-monitoring center; 110-variable speed generator, 120-AC / DC module, 121-circuit breaker, 122-current sensor;

[0050] 210-lithium battery cluster, 221-circuit breaker, 222-current sensor;

[0051] 310-busbar main line, 320-busbar branch line, 330-circuit breaker, 311-circuit breaker, 312-monitoring component, 312a-current sensor 1, 312b-solid-state switch, 312c-current sensor 2, 312d-mechanical switch;

[0052] 410 - DC / AC module, 420 - propulsion device, 411 - current sensor, 415 - circuit breaker, 421 - propulsion motor, 425 - thruster;

[0053] 50-monitoring platform, 50a-monitoring subsystem S-Link, 510-control device, 520-communication equipment, 530-monitoring equipment, 540-cloud server, 550-remote client,

[0054] 511-power distribution system PMS, 512-control module, 513-integrated power distribution module. DETAILED DESCRIPTION

[0055] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0056] like Figure 1-6 As shown, a ring-shaped DC busbar power system for ship dynamic positioning mode includes n groups of variable speed generator sets 1, a lithium battery group 2, a ring-shaped DC busbar 3, at least two load units 4 and a monitoring center 5;

[0057] The annular DC busbar 3 includes a busbar main line 310 and a plurality of busbar branches 320. The busbar main line 310 is connected to n groups of variable speed generator sets 1 and lithium battery sets 2. The variable speed generator sets 1 and lithium battery sets 2 provide power to the load unit 4 through the annular DC busbar 3. The monitoring center 5 is used for system operation process monitoring and fault handling to ensure safe and stable system operation.

[0058] The annular DC busbar 3 includes n+1 busbar main lines 310 and n-1 busbar branch lines 320, wherein the n busbar branch lines are sequentially connected to n groups of variable speed generator sets 1 and lithium battery sets 2, the n+1 busbar main line is connected to the ends of the first busbar main line and the nth busbar main line, and the annular DC busbar main line is provided with a circuit breaker 311 and a monitoring component 312;

[0059] One end of the n-1 busbar branches 320 is sequentially connected to the node between the circuit breaker 311 and the monitoring component 312 on the first n-1 busbar main line, and the other end is connected to the n+1 section busbar main line; the n+1 section busbar main line is also sequentially provided with a circuit breaker and a monitoring component; each busbar branch 320 is provided with a circuit breaker 330; under the working condition of the dynamic positioning mode, the circuit breakers of all busbar branches are disconnected, and all circuit breakers on the busbar main line remain closed; the monitoring component 312 includes a current sensor 1 312a, an IGBT solid-state switch 312b, a current sensor 2 312c, and a mechanical switch 312d connected in sequence;

[0060] The solid-state switch 312b used in the monitoring component 312 is turned on and off mainly by turning on and off the upper tube of the IGBT half-bridge, and the lower tube is in the off state for a long time; the current at both ends of the solid-state switch is detected by the current sensor 1 312a and the current sensor 2 312c. When overcurrent occurs, it indicates that a short circuit fault occurs. The system automatically turns off all IGBTs inside the module, and reports the fault information of the integrated power distribution module main controller PLC at the same time, turns off the opposite module of the same solid-state switch, and turns off the mechanical switch 312d after a short delay, so that the entire system can autonomously perform instant fault isolation. The specific process is: overcurrent disconnection, IGBT overcurrent protection, current module IGBT shutdown, PLC receives a fault, and notifies the remaining modules on the ring DC bus 3 to shut down the IGBT and its mechanical switch to open; the whole process has a fast response time, the main line voltage of the ring DC bus will not drop significantly, and the current will last for a sufficient time to ensure that the circuit breaker or fuse in the load circuit can be selectively triggered;

[0061] The use of the busbar main line 310 and the busbar branch line 320 to form a ring DC busbar 3 is conducive to isolating the fault point and avoiding a single fault point from affecting the entire power grid; in the dynamic positioning mode (DP2 or DP3), all busbar branch lines 320 are disconnected and the busbar main line 210 remains closed;

[0062] The variable speed generator set 1 includes a variable speed generator 110, a circuit breaker 111, an AC / DC module 120, and a current sensor 122 which are sequentially connected to a ring-shaped DC busbar 3; the lithium battery pack 2 is provided with a plurality of lithium battery clusters 210, a circuit breaker 221, a rectifier inverter module (AC / DC module) 220, and a current sensor 222; once an abnormality is detected, the AC / DC module 120 completes power control of the variable speed generator 110 through the inverter power electronic device, and simultaneously starts the standby machine or connects to the lithium battery pack 2 to quickly compensate for power grid fluctuations;

[0063] The load unit 4 is connected to the busbar main line 310; the load unit 4 includes a current sensor 411, an inverter module 410, a circuit breaker 415 and a propulsion device 420; the inverter module 410 includes a DC / AC module 410 and a circuit breaker 412; the propulsion device 420 includes a propulsion motor 421 and a propeller 425, and the load unit 4 also includes a daily load.

[0064] The power system adopts a DC networking form, and separates the variable speed generator 110, the propulsion device 420 and the annular DC busbar 3 through the AC / DC module 120 and the DC / AC module 410. The monitoring center 5 adjusts the start and stop of the variable speed generator 110 and the propulsion device 420 in the form of automatic control, which fully ensures that when a short circuit fault occurs in the dynamic positioning (DP2 or DP3) mode of the ship, rapid detection and rapid disconnection can be achieved.

[0065] like Figure 4 and Figure 5 As shown, the monitoring center 5 includes a monitoring platform 50 and a monitoring subsystem S-Link50a, which are used to perform operation control, process monitoring and fault handling on the ring DC busbar power system; the monitoring platform 50 includes a control device 510, a communication and navigation device 520, a monitoring device 530, a cloud server 540, and a remote client 550;

[0066] The control device 510 includes a power distribution system PMS511, a propulsion central control module 512, and an integrated power distribution module 513; the integrated power distribution module 513 is provided with an energy management subsystem EMS, and according to the needs of different monitoring domains, such as the port or starboard engine room, generator set, battery pack, annular DC busbar, etc., according to the master control and sub-control hierarchical control mode, a distributed layout structure is adopted to meet the requirements of the dynamic positioning mode;

[0067] The power distribution system PMS511 monitors and controls the operating status of the power system in real time, including various parameters of the power system, to reduce system downtime caused by equipment failure or parameter abnormalities. It has fault alarm and prompt functions, and promptly alarms when a fault occurs, and records fault information for the monitoring subsystem (S-Link) 50a to analyze and process it, so as to promptly discover and handle potential faults and abnormal conditions;

[0068] The integrated power distribution module 513 is respectively configured with a main controller PLC, a switch and a sub-controller for each load unit 4;

[0069] When one of the current sensor 1 312a and the current sensor 2 312c at a certain position generates an overcurrent, it indicates that a short circuit fault occurs, and the corresponding monitoring component 312 transmits information to the main controller PLC of the integrated power distribution module 513, and the main controller PLC shuts down the relevant components on the ring DC bus 3;

[0070] The communication and navigation equipment 520 is used to obtain the navigation information of the ship, and the monitoring equipment 530 is used to monitor the operation status of the system; the energy management subsystem EMS performs energy management according to the load conditions, automatically adjusts the speed of each variable speed generator 110 and the number of variable speed generators 110 on the grid, so that the output power of the variable speed generator set 1 matches the load power, so as to optimize the fuel consumption of the variable speed generator set 1 and save the ship operation cost;

[0071] The monitoring subsystem S-Link50a is mainly composed of data collection, data flow display, and data expansion modeling. The ship-side monitoring station S-Link host performs data collection, data integration, and data flow. The data sources include the ship's power system, monitoring and alarm system, and communication and navigation equipment.

[0072] For example, S-Link can obtain the ship's operating status data from the propulsion device 420, control device 510, communication and navigation equipment 520, monitoring equipment 530, etc. of the load unit 4 through communication equipment, and store and upload it to the cloud server 540; the S-Link subsystem 50a can realize cross-regional and cross-platform display of collected data, remote data backtracking, data modeling and remote fault analysis. Users can use the remote client 550 to log in with an account on the WEB browser and view the latest status of the ship and operating data in real time.

[0073] The annular DC busbar power system adopts a variable speed generator 110, which can adjust or increase multiple generator speed points according to actual tests, expand the adjustment capacity of the power station capacity, and make the variable speed generator set 1 operate under more economical fuel consumption, which is more advantageous than the traditional generator set. If there are n variable speed generators 110, each with m output power levels, the adjustment capacity of the power station capacity will be increased to (n*m) levels;

[0074] For ships with DP working conditions, on the basis of using DC network variable speed unit technology, various energy storage devices such as lithium battery packs and capacitors can also be connected, which not only increases the capacity range of the power station (increases the power upper limit of the variable speed generator set), but also can broaden the capacity adjustment points of the power station, that is, increase more load adjustment points (number of gears):

[0075] Assume that the capacity of each variable speed generator set is Qi, and the capacity of the lithium battery set is Qj. For a power station with n variable speed generators, each with m output power levels, and connected to k lithium battery sets, the total capacity is:

[0076]

[0077] The adjustment range of power station capacity QF is:

[0078] When Qjmin<Qimin, Qjmin≤QF≤QZ;

[0079] When Qjmin>Qimin, Qimin≤QF≤QZ;

[0080] When using pure battery packs for power supply, the total number of power station capacity adjustment points is [(n*m)+1];

[0081] The access of lithium battery pack not only provides single-point security for the system, but also has the function of peak shaving and valley filling. When the generator power is redundant, the lithium battery is charged to recover energy and absorb power to fill the valley. When the generator set is underloaded, the lithium battery is discharged to supplement (peak shaving), which can effectively improve energy utilization, smooth the load curve, increase the load rate of the generator set, reduce the loss caused by frequent start and stop of the generator set, and stabilize the operation of the power grid.

[0082] The monitoring center 5 of the annular DC busbar power system can monitor and process three types of system faults, including equipment overheating or overspeeding, current overload and bus short circuit; for relatively controllable fault conditions such as equipment overheating and overspeeding, the device triggers the power module overcurrent warning current, and the system maintains the working state to alarm, or stops the system after emergency speed reduction to complete the protection action; for equipment problems with more serious current overload, the device triggers a long-delay protection current, and the protection response speed is 10s (can be set, the frequency conversion module cuts off the current); for equipment problems with extremely serious bus short circuits, the device triggers a short-delay protection current, which requires rapid protection, and the protection response speed is 10μs (frequency conversion module switching circuit).

[0083] Before the ship's power grid is affected by the fault, the system can quickly detect the abnormal situation and actively complete the isolation of the fault point, so that the entire power grid and normal branches are not affected. After the fault is eliminated, the normal connection is quickly restored. The DC ring network form makes the system more flexible and further improves the safety and reliability of the power grid under DP conditions.

[0084] like Figure 6 As shown, the control method of the annular DC busbar power system in the ship dynamic positioning mode comprises the following steps:

[0085] Step 1: Starting the diesel generator set

[0086] The variable speed generator 110 starts to run, and the system self-checks. If the system reports an error and sends the error information to the monitoring terminal, the maintenance personnel control all variable speed generators 110 to stop through the remote control system and repair the variable speed generators 110; otherwise, it enters normal operation;

[0087] Step 2: Pre-charging of the ring DC busbar

[0088] After the variable speed generator 110 operates normally, the annular DC busbar 3 is charged through the AC / DC module 120, and the monitoring component 312 works to perform corresponding monitoring tasks; if a fault occurs, step three is executed, otherwise, step four is executed;

[0089] Step 3: Ring DC busbar fault handling

[0090] When a short circuit fault occurs in the system, the fault isolation method includes the following steps:

[0091] S31: Overcurrent monitoring

[0092] The n+1-segment busbar main line 310 of the annular DC busbar 3 monitors the overcurrent of the current segment busbar main line of the annular DC busbar 3 through the monitoring component 312 thereon in turn through the current sensor 1 312a and the current sensor 2 312c; until it is detected that the overcurrent exceeds the set value;

[0093] S32: Overcurrent protection

[0094] When an overcurrent occurs, the IGBT module on the busbar main line 310 section automatically shuts down for overcurrent protection and opens the mechanical switch 312d. At the same time, the main controller PLC of the integrated power distribution module 513 sends overcurrent information;

[0095] S33: Fault information processing: the main controller PLC of the integrated power distribution module 513 receives the fault information and notifies the remaining IGBT modules on the ring DC bus 3 to shut down and the corresponding mechanical switches to open;

[0096] S34: After the fault is resolved, execute step 2;

[0097] Step 4: Start the load operation

[0098] After the pre-charging of the annular DC busbar 3 is completed, it starts to supply power to the load unit 4; the DC power is converted into the AC power required by the propulsion motor 421 and the daily load through the DC / AC module 410; at the same time, the power system self-checks, and if it meets the power supply requirements, it supplies power to the daily load and the propulsion motor respectively, and executes step five; otherwise, executes step six;

[0099] Step 5: System operation status monitoring and adjustment

[0100] The power distribution system PMS511 distributes power to each variable speed generator 110 in the variable speed generator set 1, and performs fault diagnosis and repair on the DC system; when a short circuit fault signal of the DC system is received, step three is executed; when a power-off instruction is received, step six is ​​executed; otherwise, step five is repeated;

[0101] Step 6: End of judgment

[0102] Power off and end system operation.

[0103] The above-mentioned embodiments are only illustrative of the principles and effects of the invention, as well as some embodiments of its application, and are not intended to limit the invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the invention, and all of these belong to the protection scope of the invention.

Claims

1. A ring-shaped DC busbar power system for use in a ship dynamic positioning mode, comprising n groups of variable speed generator sets (1), a lithium battery group (2), a ring-shaped DC busbar (3), at least two load units (4) and a monitoring center (5); Features: The annular DC busbar (3) comprises n+1 busbar main lines (310) and n-1 busbar branch lines (320), wherein the n busbar branch lines are sequentially connected to n groups of variable speed generator sets (1) and lithium battery sets (2), the n+1 busbar main line is connected to the ends of the first busbar main line and the nth busbar main line, and a circuit breaker (311) and a monitoring component (312) are provided on the annular DC busbar main line; One end of the n-1 busbar branches (320) is sequentially connected to the node between the circuit breaker (311) and the monitoring component (312) in the first n-1 busbar main lines, and the other end is connected to the n+1 section busbar main line; the n+1 section busbar main line is also sequentially provided with a circuit breaker and a monitoring component; each busbar branch (320) is provided with a circuit breaker (330); under the working condition of the dynamic positioning mode, the circuit breakers of all busbar branches are disconnected, and all circuit breakers on the busbar main lines remain closed for operation; the monitoring component (312) includes a current sensor 1 (312a), an IGBT solid-state switch (312b), a current sensor 2 (312c), and a mechanical switch (312d) which are sequentially connected; The variable speed generator set (1) comprises a variable speed generator (110), a circuit breaker (111), an AC / DC module (120), and a current sensor (122) which are sequentially connected to a ring-shaped DC busbar (3); the lithium battery pack (2) is provided with a plurality of lithium battery clusters (210), a circuit breaker (221), a rectifier inverter module AC / DC module (220), and a current sensor (222); The load unit (4) is connected to the busbar main line (310); the load unit (4) includes a current sensor (411), an inverter module (410), a circuit breaker (415) and a propulsion device (420); the inverter module (410) includes a DC / AC module (410) and a circuit breaker (412); the propulsion device (420) includes a propulsion motor (421) and a propeller (425); and the load unit (4) also includes a daily load; N groups of variable speed generator sets (1) and lithium battery groups (2) provide power to a load unit (4) via a ring-shaped DC busbar (3), and a monitoring center (5) is used for system operation process monitoring and fault handling.

2. A ring-shaped DC busbar power system for ship dynamic positioning mode according to claim 1, characterized in that: The monitoring center (5) comprises a monitoring platform (50) and a monitoring subsystem S-Link (50a), which are used to perform operation control, process monitoring and fault handling on a ring-shaped DC busbar power system; the monitoring platform (50) comprises a control device (510), a communication and navigation device (520), a monitoring device (530), a cloud server (540), and a remote client (550).

3. A ring-shaped DC busbar power system for ship dynamic positioning mode according to claim 2, characterized in that: The control device (510) includes a power distribution system PMS (511), a plurality of propulsion central control modules (512), and an integrated power distribution module (513); the integrated power distribution module (513) is provided with an energy management subsystem EMS, and adopts a distributed layout structure according to the main control and sub-control hierarchical control mode according to the needs of different monitoring domains to meet the requirements of the dynamic positioning mode.

4. A ring-shaped DC busbar power system for ship dynamic positioning mode according to claim 3, characterized in that: The power distribution system PMS (511) monitors and controls the operating status of the power system in real time, including various parameters of the power system, so as to reduce the system downtime caused by equipment failure or parameter abnormality. It has fault alarm and prompt functions, and promptly alarms when a fault occurs, and records fault information for the monitoring subsystem S-Link (50a) to analyze and process it, so as to promptly discover and process potential faults and abnormal conditions. The monitoring subsystem S-Link (50a) mainly consists of data collection, data flow display, and data expansion modeling. The ship-side monitoring station S-Link host performs data collection, data integration and data flow. The data sources include the variable speed generator set (1), the lithium battery pack (2), the monitoring alarm system (530), and the communication and navigation equipment (520). The integrated power distribution module (513) is respectively configured with a main controller PLC, a switch and a sub-controller for each load unit (4); when one of the current sensor 1 (312a) and the current sensor 2 (312c) at a certain position generates an overcurrent, it indicates that a short circuit fault has occurred, and the corresponding monitoring component (312) transmits information to the main controller PLC of the integrated power distribution module (513), and the main controller PLC controls the shutdown of relevant components on the ring DC busbar (3).

5. A ring-shaped DC busbar power system for ship dynamic positioning mode according to claim 4, characterized in that: The communication and navigation equipment (520) is used to obtain ship navigation information, and the monitoring equipment (530) is used to monitor the operating status of the power system; the energy management subsystem EMS of the integrated power distribution module (513) performs energy management according to the load conditions, automatically adjusts the rotation speed of each variable speed generator (110) and the number of variable speed generators (110) on the grid, so that the output power of the variable speed generator set (110) matches the load power, thereby optimizing the fuel consumption of the variable speed generator set (110).

6. The control method of the annular DC busbar power system in the ship dynamic positioning mode according to any one of claims 3 to 5, comprising the following steps: Step 1: Starting the diesel generator set The variable speed generator (110) starts to operate, and the system self-checks. If the system reports an error and sends the error information to the monitoring terminal, the maintenance personnel control all variable speed generators to stop through the remote control system and repair the variable speed generators; otherwise, it enters normal operation; Step 2: Pre-charging of the ring DC busbar After the variable speed generator (110) operates normally, the annular DC busbar (3) is charged through the AC / DC module (120), and the monitoring component (312) works to perform corresponding monitoring tasks; if a fault occurs, step three is executed, otherwise, step four is executed; Step 3: Ring DC busbar fault handling When a short circuit fault occurs in the system, the fault isolation method includes the following steps: S31: Overcurrent monitoring The n+1-segment busbar main line of the annular DC busbar monitors the overcurrent condition of the current segment busbar main line of the annular DC busbar (3) through the monitoring component (312) thereon in turn through the current sensor 1 (312a) and the current sensor 2 (312c); until it is detected that the overcurrent exceeds the set value; S32: Overcurrent protection The IGBT module on the main line section of the busbar where overcurrent occurs is automatically shut down for overcurrent protection and the mechanical switch (312d) is opened, and at the same time the main controller PLC of the integrated power distribution module (513) sends overcurrent information; S33: Fault information processing, the main controller PLC of the integrated power distribution module (513) receives the fault information and notifies the remaining IGBT modules on the ring DC busbar (3) to shut down and the corresponding mechanical switches to open; S34: After the fault is resolved, execute step 2; Step 4: Start the load operation After the annular DC busbar (3) is pre-charged, it starts to supply power to the load unit (4); the DC power is converted into the AC power required by the propulsion motor (421) and the daily load through the DC / AC module (410); at the same time, the system self-checks and if it meets the power supply requirements, it supplies power to the daily load and the propulsion motor respectively, and executes step five; otherwise, executes step six; Step 5: System operation status monitoring and adjustment The power distribution system PMS (511) distributes power to each variable speed generator (110) in the variable speed generator set (1), and performs fault diagnosis and repair on the DC system; when a short circuit fault signal of the DC system is received, step three is executed; when a power-off instruction is received, step six is ​​executed; otherwise, step five is repeated; Step 6: End of judgment Power off and end system operation.

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