CN111585270B - Marine direct current grid-connected system and simulation method for short-circuit protection of marine direct current grid-connected system - Google Patents
Marine direct current grid-connected system and simulation method for short-circuit protection of marine direct current grid-connected system Download PDFInfo
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- CN111585270B CN111585270B CN202010474235.XA CN202010474235A CN111585270B CN 111585270 B CN111585270 B CN 111585270B CN 202010474235 A CN202010474235 A CN 202010474235A CN 111585270 B CN111585270 B CN 111585270B
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- 230000000087 stabilizing effect Effects 0.000 claims description 15
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 12
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/10—Parallel operation of dc sources
- H02J1/12—Parallel operation of dc generators with converters, e.g. with mercury-arc rectifier
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/30—Circuit design
- G06F30/36—Circuit design at the analogue level
- G06F30/367—Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
- H02H3/087—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current for dc applications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/268—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for dc systems
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2113/00—Details relating to the application field
- G06F2113/04—Power grid distribution networks
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Abstract
The invention belongs to the technical field of protection circuits, and relates to a ship direct current grid-connected system and a short circuit protection simulation method thereof, wherein the method comprises the following steps: analyzing a main circuit of the system at the moment of short-circuit fault and building an equivalent circuit model of the main circuit; building an internal model of each functional module in the equivalent circuit model; establishing an overall simulation model of the system and setting simulation environment parameters; and simulating each short-circuit fault point of the system in sequence, analyzing the fusing time sequence of each fuse, and adjusting the parameters of the fuses to meet the design requirements of short-circuit protection of the system. Based on the simulation method, when each branch fault is accurately and intuitively reflected, transient state change and fusing time sequence of the system are checked and corrected, the design scheme of short-circuit protection and coordination protection of the system is checked and corrected, theoretical basis and support are provided for a short-circuit test of a real object, and accuracy of a simulation result is ensured.
Description
Technical Field
The invention belongs to the technical field of protection circuits, relates to a marine direct current grid-connected system, and in particular relates to a marine direct current grid-connected system and a short-circuit protection simulation method thereof.
Background
In recent years, pure electric ships are popularized in ship type test points such as public service ships and sightseeing ships in two rivers and internal lakes by virtue of the advantages of zero pollution, zero emission, low noise, low vibration and the like. The direct current grid-connected technology is a core technology of the pure battery ship. For a power distribution system of ship direct current grid connection, china Class Society (CCS) has stricter requirements on short circuit current calculation, coordination protection analysis and the like, namely when a short circuit fault occurs in one branch in the system, the short circuit branch is required to be cut off and isolated, and other systems are reserved and work normally. Then, when designing the short-circuit protection of the system, checking and verifying the short-circuit protection scheme and the type selection of the protection device by a simulation method is needed.
At present, a ship power system mostly adopts two modes of traditional diesel engine driving and alternating current grid-connected power pushing. The method for calculating the short-circuit current of the alternating-current system is carried out according to the standard GB/T15544.1-2013 part 1 of current calculation for calculating the short-circuit current of the three-phase alternating-current system, and meanwhile, according to the requirement of China Class Society (CCS) for coordination protection, mature software is used for designing a short-circuit protection scheme and selecting fuse parameters, so that a fixed accounting method is formed.
However, the standards and methods of ac systems are not applicable for dc systems. The number of electric pushing modes of direct current grid connection of the pure electric ship is small, and the method is not authenticated by China Class Service (CCS), so that an inherent direct current grid connection short circuit current calculation method and a verification method of a coordination protection scheme are not formed at present.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, and provides a marine direct current grid-connected system and a simulation method of short-circuit protection thereof, which ensure the correctness of the design of the short-circuit protection and the harmony protection of a direct current power grid; meets the requirement of continuous power supply for the whole ship.
In order to achieve the above purpose, the present invention provides the following technical solutions:
in one aspect, the invention provides a marine DC grid-connected system, comprising at least two groups of main circuit topologies with the same structure, wherein the main circuit topologies comprise,
the power battery pack is powered to the direct current busbar through the bidirectional DC-DC voltage stabilizing module and the fuse;
the direct current busbar is used for accessing and distributing the whole ship electric energy, and is provided with at least one fuse; the direct current of the power battery pack is accessed through a bidirectional DC-DC voltage stabilizing module and a fuse, and is inverted into alternating current through the fuse and a DC-AC inversion module to be used for supplying power to an electric propulsion system and auxiliary loads of a whole ship; the direct current busbar is also connected with an AC-DC rectifying module and is used for being matched with a bidirectional DC-DC voltage stabilizing module to finish charging when the busbar is parked;
the AC-DC rectifying module is connected with the ship shore power distribution box under the control of the AC contactor, and the ship shore power distribution box is used for connecting AC380V commercial power to the DC bus through the AC contactor, the AC-DC rectifying module and the fuse and distributing electric energy.
Further, the direct current busbar is powered by two paths, the first path of direct current flows through the fuse and the DC-AC auxiliary inverter to be inverted into alternating current, and then the alternating current flows through the filter unit, the transformer and the AC contactor to be connected at the position of the alternating current busbar to supply alternating current required by auxiliary loads and daily loads for the whole ship; the second direct current power supplies power to the propulsion motor through the fuse and the DC-AC propulsion inverter.
Further, the power battery pack adopts two independent lithium battery packs.
Further, the direct current busbar is further provided with a capacitor for providing short-circuit current to accelerate the fusing of the busbar fuses, and the capacitor is located between the two fuses of the direct current busbar.
On the other hand, the invention provides a simulation method for short-circuit protection of a marine direct current grid-connected system, which specifically comprises the following steps:
1) Analyzing a main circuit of the system at the moment of short-circuit fault and building an equivalent circuit model of the main circuit;
2) Building an internal model of each functional module in the equivalent circuit model;
3) Establishing an overall simulation model of the system and setting simulation environment parameters;
4) And simulating each short-circuit fault point of the system in sequence, analyzing the fusing time sequence of each fuse, and adjusting the parameters of the fuses to meet the design requirements of short-circuit protection of the system.
Further, in the equivalent circuit model of the step 1),
the power battery pack at the moment of short circuit fault is equivalent to a constant voltage source with internal resistance;
modeling the inversion module at the moment of short circuit fault into a discharge capacitor and internal impedance;
the wires and copper bars at the moment of the short circuit fault are modeled as a resistor and a direct current inductance.
Further, the step 3) specifically includes:
establishing a system integral simulation model according to a single line diagram of the system;
increase the current, voltage and I of each branch 2 A T data display model is added with a short circuit fault point model, and simulation environment parameters are set;
setting short-circuit fault point resistance, fault point starting time and fault point ending time, adding simulation environment parameters of the system into a simulation model, and debugging to work normally.
Further, the step 4) specifically includes:
selecting a plurality of short circuit fault points to perform simulation analysis respectively;
observing short-circuit currents of different short-circuit fault points, comparison of fusing capacity and heating value of each fuse, fusing tense and time sequence of each fuse, variation trend of bus voltage and stability of a system;
through adjusting the fuse parameters, the design requirement of the system short-circuit protection is met.
Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects: the simulation method for the short-circuit protection of the marine direct-current grid-connected system can accurately and intuitively reflect faults of all branches, transient state change and fusing time sequence of the system, check and correct design schemes of the short-circuit protection and coordination protection of the system, provide theoretical basis and support for short-circuit tests of objects, and ensure accuracy of simulation results.
Drawings
FIG. 1 is a single line diagram of a marine DC grid-connected system provided by the invention;
FIG. 2 is a flow chart of a simulation method for short-circuit protection of the marine DC grid-connected system;
FIG. 3 is an equivalent circuit model diagram of the marine DC grid-connected system provided by the invention;
fig. 4 is a discharge current diagram of the marine dc grid-connected system according to the present invention when the lithium battery pack is operating normally;
FIG. 5 is an internal model diagram of a bidirectional DC-DC voltage stabilizing module in the marine DC grid-connected system provided by the invention;
FIG. 6 is an internal model diagram of a DC-AC propulsion inverter in a marine DC grid-connected system provided by the invention;
fig. 7 is a schematic diagram of a DC-AC auxiliary inverter and a load circuit thereof in the marine DC grid-connected system according to the present invention;
FIG. 8 is a model diagram of a fuse in the marine DC grid-connected system provided by the invention;
FIG. 9 is a schematic diagram of a short circuit fault in the marine DC grid-connected system provided by the invention;
FIG. 10 is a schematic diagram of a short-circuit protection simulation overall model of the marine DC grid-connected system provided by the invention;
fig. 11 is a schematic diagram of a short-circuit fault point of the marine direct current grid-connected system provided by the invention.
Detailed Description
The invention is described in further detail below with reference to the attached drawings and examples:
example 1
Referring to fig. 1, the invention provides a single line diagram of a marine direct current grid-connected system, which comprises at least two groups of main circuit topologies with the same structure, wherein the main circuit topologies comprise,
the power battery pack is powered to the direct current busbar through the bidirectional DC-DC voltage stabilizing module and the fuse;
the direct current busbar is used for accessing and distributing the whole ship electric energy, and is provided with at least one fuse; the direct current of the power battery pack is accessed through a bidirectional DC-DC voltage stabilizing module and a fuse, and is inverted into alternating current through the fuse and a DC-AC inversion module to be used for supplying power to an electric propulsion system and auxiliary loads of a whole ship; the direct current busbar is also connected with an AC-DC rectifying module and is used for being matched with a bidirectional DC-DC voltage stabilizing module to finish charging when the busbar is parked;
the AC-DC rectifying module is connected with the ship shore power distribution box under the control of the AC contactor, and the ship shore power distribution box is used for connecting AC380V commercial power to the DC bus through the AC contactor, the AC-DC rectifying module and the fuse and distributing electric energy.
Further, the direct current busbar is powered by two paths, the first path of direct current flows through the fuse and the DC-AC auxiliary inverter to be inverted into alternating current, and then the alternating current flows through the filter unit, the transformer and the alternating current contactor to be connected at the alternating current busbar to supply alternating current required by auxiliary loads and daily loads for the whole ship; the second direct current power supplies power to the propulsion motor through the fuse and the DC-AC propulsion inverter.
Further, the power battery pack adopts two independent lithium battery packs.
Further, the direct current busbar is further provided with a capacitor for providing short-circuit current to accelerate the fusing of the busbar fuses, and the capacitor is located between the two fuses of the direct current busbar so as to improve the safety of the whole system when short-circuit faults occur.
Specifically, in the marine direct current grid-connected system shown in fig. 1, two groups of power lithium battery packs are stabilized by a bidirectional DC-DC voltage stabilizer (U1/1 and U1/2) and then are connected with each other, a direct current bus provides a whole ship DC750V direct current power supply, an AC380V shore power provided by a ship shore power distribution box charges the two groups of batteries by a shipborne AC-DC rectification module (U2/1 and U2/2), and a whole ship load consists of two sets of DC-AC propulsion inverters (U4/1 and U4/2) and two sets of DC-AC auxiliary inverters (U3/1 and U3/2). In the whole main circuit of the power distribution system, fuses (FU 1-FU 6) are designed between each branch and each busbar at the joint of each branch and each busbar, so that when a short circuit fault occurs in one branch in the system, the short circuit branch is cut off and isolated, and the other systems are reserved and work normally.
In addition, the invention also provides a simulation method for short-circuit protection based on the marine direct current grid-connected system, which is shown in combination with fig. 2, and specifically comprises the following steps:
s1: analyzing a main circuit of the system at the moment of short-circuit fault and building an equivalent circuit model of the main circuit;
s2: building an internal model of each functional module in the equivalent circuit model;
s3: establishing an overall simulation model of the system and setting simulation environment parameters;
s4: and simulating each short-circuit fault point of the system in sequence, analyzing the fusing time sequence of each fuse, and adjusting the parameters of the fuses to meet the design requirements of short-circuit protection of the system.
Further, in the equivalent circuit model of the above step S1, as shown in fig. 3,
the power battery pack at the moment of short circuit fault is equivalent to a constant voltage source with internal resistance;
modeling the inversion module at the moment of short circuit fault into a discharge capacitor and internal impedance;
the wires and copper bars at the moment of the short circuit fault are modeled as a resistor and a direct current inductance.
Further, in the step S2, an internal model of each element in the equivalent circuit model is built, which specifically includes:
and analyzing the short circuit fault moment, setting up an internal model of the system according to the electrical parameters and the transient changes of key equipment and elements in the system, and defining a short circuit fault model. Specifically, building an internal model of each key device and element, specifically including:
1) Lithium battery model
And calculating data such as internal resistance of a battery core, internal resistance of a connection power cable, internal resistance of a control box, cable inductance and the like in the lithium battery pack, wherein a standard battery model is adopted as a lithium battery model, and a discharge current simulation diagram of the lithium battery pack in normal operation is shown in fig. 4.
2) Model of bidirectional DC-DC voltage stabilizing module
The control model of the bidirectional DC-DC voltage stabilizing module is shown in fig. 5, a standard PI controller is adopted, and the control mode is constant voltage control. When the output current of the bidirectional DC-DC voltage stabilizing module is larger than 4 times of rated current according to actual equipment, the pulse is immediately blocked, when a short circuit occurs outside at the moment of 1s, the short circuit current rapidly reaches more than 4 times of rated current, the IGBT gate electrode drives the pulse to be immediately blocked under the action of the controller, and the output logic value is 0. When the lithium battery side voltage is detected to be higher than the direct current bus side voltage, the flywheel Diode is conducted, and the lithium battery supplies short-circuit current to the direct current bus.
3) Model of DC-AC propulsion inverter
Rpm1 is an equivalent load for converting the propulsion load to a direct current side, L2 is an internal equivalent capacitor, an internal model of the DC-AC propulsion inverter is shown in FIG. 6, input and output ends of the DC-AC propulsion inverter are connected with the anode and the cathode of a direct current bus through a fuse FU4, an output end model adopts a standard PI controller, and a control mode is voltage control.
4) DC-AC auxiliary inverter model
The DC-AC auxiliary inverter needs to be able to feed current both inside and outside when the bus or other branch is short circuited; the internal equivalent capacitance is L8, the output reactor RCL, the DC-AC auxiliary inverter and the control model of the AC load are shown in figure 7, the input end of the DC-AC auxiliary inverter is connected with a DC bus through a fuse FU3, the output end of the DC-AC auxiliary inverter is connected with the AC auxiliary load of the whole ship through an air circuit breaker, the inverter adopts a standard PI controller, and the control mode is constant voltage control.
5) Model of fuse
The fuse adopts a custom model, and specific modeling is shown in fig. 8, wherein the front section of the fuse model is an anti-interference section, and the disturbance of the simulation model just started to the I of the fuse model is avoided 2 t is calculated to cause interference; the middle section is a judging starting section, and is used for starting the integrating module at the rear section when the Relay module detects that the current value is larger than the starting value 2 t, otherwise, outputting 0; the rear section also comprises I 2 t comparison module, when I 2 When the integral value of t is larger than the pre-arc capacity, the output value of the fuse model is 1, and when I 2 When the integral value of t is greater than the full capacity, the output value of the fuse model is 2, and the output value of the fuse is normally 0.
6) Short circuit fault model
The short circuit fault model adopts a custom model, and the specific modeling is shown in fig. 9. The model consists of a waveform generator (Wave form Generator) and an Ideal Switch (Ideal Switch). The ideal switch has its front end (1 in fig. 9) connected to the preset short-circuit fault point, its back end (2 in fig. 9) grounded, and its control signal end (9 in fig. 9) connected to the output of the waveform generator. When the control signal is 0, the switch is opened; when the control signal is 1, the switch is closed. The waveform generator is arranged to output a square wave signal with pulse height of 1 and pulse width of 0.2 at the moment of 1S, and the ideal switch is controlled to be closed at the moment of 1S so as to simulate short circuit fault.
Further, in the step S3, an overall simulation model of the system is built, and simulation environment parameters are set, which specifically includes:
the system overall simulation model is built according to a single line diagram of the system, as shown in FIG. 10, the system mainly comprises a line model, a fuse model (FU), a bidirectional DC-DC voltage stabilizing device model (U1/1, U2/1), a DC-AC auxiliary inverter circuit model (U3/1+LCL+T1, U3/2+LCL+T2) and a DC-AC boosting inverter circuit model (U4/1+M1, U4/2+M2); the circuit model defines the inductance and the impedance of the circuit between the models, the function of the fuse model is referred to in the 5 th step of the S2), the function of the bidirectional DC-DC voltage stabilizing device model is referred to in the 2 nd step of the S2), the function of the DC-AC auxiliary inverter circuit model is referred to in the 4 th step of the S2), and the function of the DC-AC boosting inverter circuit model is referred to in the 3 rd step of the S2); the working principle and the logical relation of the whole system can be seen from the working principle of fig. 1. The system overall simulation model increases the current, voltage and I of each branch 2 A T data display model is added with a short circuit fault point model, and simulation environment parameters are set; setting short-circuit fault point resistance, fault point starting time and fault point ending time, adding simulation environment parameters of the system into a simulation model, and debugging until normal operation is achieved.
In the step S3, after setting the simulation environment parameters, the influence of scaling of the distribution parameters on the simulation result needs to be analyzed, which specifically includes:
calculating distribution parameters of each line according to the cable parameter conversion and finite element analysis method;
selecting line standard distribution parameters as references, and respectively simulating different percentage parameters;
selecting a designated short-circuit fault point, displaying short-circuit currents of different reference groups in the same simulation diagram, and observing the amplitude values and the change conditions of different curves.
Specifically, a large number of distributed inductances, resistances and capacitances exist on the ship direct current grid-connected power distribution system; including cables, bus bars, lithium battery interiors, etc., and distributed throughout the dc system. In order to simplify the simulation, the cables of each branch are equivalent, and the parameters of each equivalent part are obtained according to the cable parameter conversion and finite element analysis method.
When line parameters select line standard distribution parameters (100% numerical value) as a benchmark, simulation is respectively carried out aiming at different percentage parameters, in order to examine the influence of the line distribution parameters on direct current busbar short-circuit current, a certain short-circuit point is selected, the short-circuit currents of different reference groups are presented in a simulation diagram, the amplitude values and the change conditions of different curves are observed, and according to simulation results, when the line parameters fluctuate within +/-40% of the reference values, the influence of the different line parameters on response time is 2.5x10 -5 s is within s. It can thus be inferred that the line parameter pair I 2 t is much less than the system demand error.
Further, the step S4 specifically includes:
selecting a plurality of short circuit fault points to perform simulation analysis respectively;
observing short-circuit currents of different short-circuit fault points, comparison of fusing capacity and heating value of each fuse, fusing tense and time sequence of each fuse, variation trend of bus voltage and stability of a system;
through adjusting the fuse parameters, the design requirement of the system short-circuit protection is met.
Specifically, as shown in fig. 11, 10 short-circuit points were simulated and analyzed, and when different short-circuit points were observed, the short-circuit current at the short-circuit point, the fusing capacity and the heat generation amount (I 2 t), the fusing state and time sequence of each fuse, the variation trend of bus voltage and the stability of the system, and the coordination of the system is ensured by adjusting the parameters of the fusesAnd (5) realizing protection.
In summary, the simulation method for the short-circuit protection of the marine direct-current grid-connected system provided by the invention can accurately and intuitively reflect faults of each branch, transient state change and fusing time sequence of the system, check and correct design schemes of the short-circuit protection and coordination protection of the system, provide theoretical basis and support for a short-circuit test of a real object, and ensure accuracy of simulation results.
The foregoing is only a specific embodiment of the invention to enable those skilled in the art to understand or practice the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention.
It will be understood that the invention is not limited to what has been described above and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.
Claims (4)
1. A simulation method for short-circuit protection of a marine direct current grid-connected system is characterized by comprising the marine direct current grid-connected system using the simulation method for short-circuit protection, wherein the marine direct current grid-connected system comprises at least two groups of main circuit topologies with the same structure, the main circuit topologies comprise,
the power battery pack is powered to the direct current busbar through the bidirectional DC-DC voltage stabilizing module and the fuse;
the direct current busbar is used for accessing and distributing the whole ship electric energy, and is provided with at least one fuse; the direct current of the power battery pack is accessed through a bidirectional DC-DC voltage stabilizing module and a fuse, and is inverted into alternating current through the fuse and a DC-AC inversion module to be used for supplying power to an electric propulsion system and auxiliary loads of a whole ship; the direct current busbar is also connected with an AC-DC rectifying module and is used for being matched with a bidirectional DC-DC voltage stabilizing module to finish charging when the busbar is parked; the direct current busbar is also provided with a capacitor for providing short-circuit current to accelerate the fusing of the busbar fuses, and the capacitor is positioned between the two fuses of the direct current busbar;
the AC-DC rectifying module is connected with a ship shore power distribution box under the control of an AC contactor, and the ship shore power distribution box is used for connecting AC380V commercial power to a DC bus through the AC contactor, the AC-DC rectifying module and a fuse to distribute electric energy;
the direct current busbar is powered by two paths, the first path of direct current flows through the fuse and the DC-AC auxiliary inverter to be inverted into alternating current, and then the alternating current flows through the filtering unit, the transformer and the AC contactor to be connected at the position of the alternating current busbar to supply alternating current required by auxiliary loads and daily loads for the whole ship; the second path of direct current power is supplied to the propulsion motor through the fuse and the DC-AC propulsion inverter;
the power battery pack adopts two groups of mutually independent lithium battery packs;
the simulation method for short-circuit protection specifically comprises the following steps:
1) Analyzing a main circuit of the system at the moment of short-circuit fault and building an equivalent circuit model of the main circuit;
2) Building an internal model of each functional module in the equivalent circuit model;
3) Establishing an overall simulation model of the system and setting simulation environment parameters; after setting the simulation parameters, the influence of scaling of the distribution parameters on the simulation result needs to be analyzed, and the method specifically comprises the following steps:
calculating distribution parameters of each line according to the cable parameter conversion and finite element analysis method; selecting line standard distribution parameters as references, and respectively simulating different percentage parameters;
4) And simulating each short-circuit fault point of the system in sequence, analyzing the fusing time sequence of each fuse, and adjusting the parameters of the fuses to meet the design requirements of short-circuit protection of the system.
2. The method for simulating short-circuit protection according to claim 1, wherein in the equivalent circuit model of step 1),
the power battery pack at the moment of short circuit fault is equivalent to a constant voltage source with internal resistance;
modeling the inversion module at the moment of short circuit fault into a discharge capacitor and internal impedance;
the wires and copper bars at the moment of the short circuit fault are modeled as a resistor and a direct current inductance.
3. The method for simulating short-circuit protection according to claim 1, wherein the step 3) specifically comprises:
establishing a system integral simulation model according to a single line diagram of the system;
increase the current, voltage and I of each branch 2 A T data display model is added with a short circuit fault point model, and simulation environment parameters are set;
setting short-circuit fault point resistance, fault point starting time and fault point ending time, adding simulation environment parameters of the system into a simulation model, and debugging to work normally.
4. The method for simulating short-circuit protection according to claim 1, wherein the step 4) specifically comprises:
selecting a plurality of short circuit fault points to perform simulation analysis respectively;
observing short-circuit currents of different short-circuit fault points, comparison of fusing capacity and heating value of each fuse, fusing tense and time sequence of each fuse, variation trend of bus voltage and stability of a system;
through adjusting the fuse parameters, the design requirement of the system short-circuit protection is met.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010474235.XA CN111585270B (en) | 2020-05-29 | 2020-05-29 | Marine direct current grid-connected system and simulation method for short-circuit protection of marine direct current grid-connected system |
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| CN202010474235.XA CN111585270B (en) | 2020-05-29 | 2020-05-29 | Marine direct current grid-connected system and simulation method for short-circuit protection of marine direct current grid-connected system |
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| Publication Number | Publication Date |
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| CN111585270A CN111585270A (en) | 2020-08-25 |
| CN111585270B true CN111585270B (en) | 2024-03-26 |
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| CN112949062B (en) * | 2021-03-02 | 2022-12-06 | 中车青岛四方车辆研究所有限公司 | Short-circuit protection analysis method and short-circuit test method for urban rail transit traction system |
| CN114336548B (en) * | 2021-12-31 | 2024-05-24 | 苏州汇川控制技术有限公司 | Short-circuit parameter determining method, short-circuit parameter determining device, storage medium and short-circuit protection method |
| CN114336539B (en) * | 2021-12-31 | 2024-02-23 | 苏州汇川控制技术有限公司 | Short-circuit protection device determining method, short-circuit protection circuit, equipment and storage medium |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN209225376U (en) * | 2018-11-01 | 2019-08-09 | 上海中车汉格船舶与海洋工程有限公司 | A kind of pure electric propulsion system of ferryboat |
| CN110932252A (en) * | 2019-11-18 | 2020-03-27 | 西安中车永电电气有限公司 | Electrical system of direct-current distribution board of pure electric ship and control method |
| CN210416940U (en) * | 2019-07-16 | 2020-04-28 | 上海航盛船舶设计有限公司 | Marine power system for water quality monitoring |
-
2020
- 2020-05-29 CN CN202010474235.XA patent/CN111585270B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN209225376U (en) * | 2018-11-01 | 2019-08-09 | 上海中车汉格船舶与海洋工程有限公司 | A kind of pure electric propulsion system of ferryboat |
| CN210416940U (en) * | 2019-07-16 | 2020-04-28 | 上海航盛船舶设计有限公司 | Marine power system for water quality monitoring |
| CN110932252A (en) * | 2019-11-18 | 2020-03-27 | 西安中车永电电气有限公司 | Electrical system of direct-current distribution board of pure electric ship and control method |
Non-Patent Citations (1)
| Title |
|---|
| 兰喆 等.基于MAYR电弧模型的船舶直流配电系统熔断器仿真研究.《通信电源技术》.第37卷(第1期),第18-20+23页. * |
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