Power supply system suitable for electric propulsion cruise ship

Abstract

The utility model provides a power supply system suitable for an electric propulsion cruise ship, which comprises generator sets, a primary alternating current distribution board, a daily load distribution module, a feed branch and a propulsion motor, the plurality of generator sets are connected with the input end of the primary alternating current distribution board, the daily load distribution module is connected with the output end of the primary alternating current distribution board, and the feed branch is connected with the propulsion motor. One end of the feed branch is connected with the output end of the primary alternating current distribution board, and the other end of the feed branch is connected with the propulsion motor; wherein the feed branch comprises an AC voltage acquisition module and a frequency conversion module, the output end of the primary AC distribution board, the frequency conversion module and the propulsion motor are connected in sequence, and the AC voltage acquisition module is arranged between the output end of the primary AC distribution board and the frequency conversion module; the AC voltage acquisition module acquires voltage data to adjust the output of the frequency conversion module.

Description

Technical Field

[0001] This utility model relates to the field of electric ship power supply technology, and in particular to a power supply system suitable for electric propulsion cruise ships. Background Technology

[0002] Currently, most inland river cruise ships use electric propulsion systems as their main propulsion system. Inland waterways are complex, and navigation conditions are varied. Electric propulsion systems can meet the power demands of different operating conditions while maintaining the on-grid generator sets at their optimal load rate, effectively reducing fuel consumption. AC electric propulsion systems are mainly powered by generator sets, with power distributed and managed through AC switchboards. All propulsion motor loads and general daily loads are fed by the AC switchboards. Some daily loads have voltage differences from the main AC switchboard voltage, requiring transformer transformation before power supply. The propulsion load accounts for over 60% of the total power station capacity.

[0003] For electric propulsion ships, the continuity of power supply to the ship's power station is particularly important. Once the power station loses power, not only will the daily loads be unable to be powered, but the entire ship's propulsion system will also lose power, which will affect the safety of the entire ship. Therefore, it is necessary to monitor the load of electric propulsion ships.

[0004] The load on electrically propelled ships changes dynamically in real time, including propulsion load and daily operating load. Load fluctuations cause fluctuations in the power station load rate. Generally, a power management system is configured on the AC switchboard to monitor the power station load rate in real time. When the power station load rate exceeds a set threshold, the power management system communicates this status to the propulsion control system, which then limits the increase in propulsion power to prevent power station overload. This method of limiting propulsion power has certain drawbacks. This power limiting method is suitable for overloads caused by small-range load fluctuations. Because the power management system detects that the power station load rate exceeds the threshold and communicates the detection result to the propulsion control system, which then takes power limiting action, the whole process takes tens to hundreds of milliseconds. Since the power station has a certain overload capacity, it can withstand the entire time during which the detection is made and the action is taken.

[0005] However, when a power station experiences a sudden surge in power load, the aforementioned power limiting methods have excessively long response times and cannot meet practical needs. For example, during navigation, if one or more of the power station's grid-connected generators suddenly stop operating, the propulsion load will remain at the power level before the generator failure, causing a severe instantaneous overload of the entire power station. Obviously, the backup generators cannot restore power in such a short time. If the grid load cannot be limited in time, the entire power station will lose power. As mentioned earlier, the propulsion load of electric propulsion vessels accounts for more than 60% of the total power station load rate. Therefore, only by limiting the propulsion load can the load rate be effectively reduced, and the response time needs to be in the millisecond range.

[0006] While some electric propulsion ships have previously adopted a method of quickly limiting propulsion power through frequency converters to maintain the continuity of power supply from the power station, the specific approach involves connecting the digital signal of each generator set failure to each propulsion frequency converter, forming a matrix wiring method. This scheme limits propulsion power in a "tiered" manner, meaning that when one on-grid generator set fails to shut down, it triggers the first-level power limit of the propulsion frequency converter; when two on-grid generator sets fail to shut down, it triggers the second-level power limit of the propulsion frequency converter, and so on, with higher levels of power limit being more severe. The existing matrix wiring method requires a number of cables equal to the number of generators multiplied by the number of propulsion frequency converters, consuming a lot of cables and making the wiring complex. Utility Model Content

[0007] This invention provides a power supply system suitable for electric propulsion cruise ships, which solves the problem that the existing technology requires a large number of cables, which is equal to the number of generators multiplied by the number of propulsion frequency converters, resulting in a lot of cables and complicated wiring.

[0008] According to an embodiment of the present invention, a power supply system suitable for electric propulsion cruise ships includes:

[0009] The system includes generator sets, a primary AC distribution board, a daily load distribution module, a feeder branch, and a propulsion motor. Several generator sets are connected to the input terminal of the primary AC distribution board, the daily load distribution module is connected to the output terminal of the primary AC distribution board, one end of the feeder branch is connected to the output terminal of the primary AC distribution board, and the other end of the feeder branch is connected to the propulsion motor.

[0010] The power supply branch includes an AC voltage acquisition module and a frequency converter module. The output terminal of the primary AC distribution board, the frequency converter module, and the propulsion motor are connected in sequence. The AC voltage acquisition module is located between the output terminal of the primary AC distribution board and the frequency converter module, and is used to collect voltage data through the AC voltage acquisition module to adjust the output of the frequency converter module.

[0011] Preferably, the daily load power distribution module includes: a transformer and an AC power distribution board for headphones, one end of the transformer is connected to the output end of the primary AC power distribution board, and the other end of the transformer is connected to the input end of the secondary AC power distribution board.

[0012] Preferably, the daily load power distribution module also includes:

[0013] The direct power supply line connects one end to the primary AC distribution board and the other end to the required load.

[0014] Preferably, the frequency converter module includes: a frequency converter body and a controller, the output terminal of the primary AC distribution board is connected to the input terminal of the frequency converter body, the output terminal of the frequency converter body is connected to the input terminal of the propulsion motor, and both the frequency converter body and the AC voltage acquisition module are electrically connected to the controller.

[0015] Preferably, several generator sets are connected in parallel, and several power supply branches are connected in parallel.

[0016] Compared with existing technologies, this utility model has the following advantages: by adjusting the propulsion power of the propulsion motor through an AC voltage acquisition module and a frequency conversion module, so many control cables are not required; at the same time, compared with existing adjustment methods, this technical solution has "stepless" limitation on propulsion power. At the same time, different numbers of grid-connected generators fail to operate and the grid load rate is different, resulting in different voltage drops in the grid voltage (voltage in the direction of the primary AC distribution board), thus resulting in different propulsion power limitation ranges. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the power supply system according to an embodiment of the present utility model;

[0018] Figure 2 This is a schematic diagram of the power supply branch according to another embodiment of the present invention.

[0019] In the above attached diagram: 1. Generator set; 2. Primary AC distribution board; 3. Feeder branch; 4. Propulsion motor; 5. Transformer; 6. Secondary AC distribution board; 7. AC voltage acquisition module; 8. Inverter body; 9. Controller. Detailed Implementation

[0020] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0021] like Figures 1 to 2 As shown in the figure, this utility model embodiment proposes a power supply system suitable for electric propulsion cruise ships, including:

[0022] Generator set 1, primary AC distribution board 2, daily load power distribution module, feeder branch 3 and propulsion motor 4. Several generator sets 1 are connected to the input terminal of primary AC distribution board 2, daily load power distribution module is connected to the output terminal of primary AC distribution board 2, one end of feeder branch 3 is connected to the output terminal of primary AC distribution board 2, and the other end of feeder branch 3 is connected to propulsion motor 4.

[0023] Among them, the power supply branch 3 includes: AC voltage acquisition module 7 and frequency conversion module. The output end of the first-stage AC distribution board 2, the frequency conversion module and the propulsion motor are connected in sequence. The AC voltage acquisition module 7 is located between the output end of the first-stage AC distribution board 2 and the frequency conversion module, and is used to collect voltage data through the AC voltage acquisition module 7 to adjust the output of the frequency conversion module.

[0024] Several generator sets are connected in parallel (1), and several power feeder branches are connected in parallel (3).

[0025] The working principle of the above technical solution is as follows: During the ship's navigation, several generator sets 1 generate electricity as the ship's energy source. This electricity is then connected to multiple input terminals of the primary AC distribution board 2, allowing the primary AC distribution board 2 to distribute the generated electrical energy. On one hand, the electricity drives the propulsion motor 4 load through the feeder branch 3, and on the other hand, it supplies power to the daily load through the daily load distribution module. When the generator set 1 stops due to a fault, the AC voltage acquisition module 7 collects voltage data in the direction of the primary AC distribution board 2. When the voltage data drops, the frequency converter module will reduce its output, thereby adjusting the propulsion power of the propulsion motor 4.

[0026] The beneficial effects of the above technical solution are as follows: By using the above technical solution, the propulsion power of the propulsion motor can be adjusted by setting up an AC voltage acquisition module 7 and a frequency conversion module, eliminating the need for so many control cable connections; at the same time, compared with the existing adjustment methods, this technical solution has a "stepless" limitation on propulsion power. At the same time, different numbers of grid-connected generators fail to shut down and the grid load rate is different, resulting in different voltage drops in the grid voltage (voltage in the direction of the primary AC distribution board 2), thus causing different propulsion power limitation ranges.

[0027] In one embodiment, the daily load power distribution module includes: a transformer 5 and an earphone AC power distribution board 6, one end of the transformer 5 is connected to the output end of the primary AC power distribution board 2, and the other end of the transformer 5 is connected to the input end of the secondary AC power distribution board 6.

[0028] The daily load power distribution module also includes:

[0029] Direct power supply line 10, one end of which is connected to the primary AC distribution board 2, and the other end of which is connected to the required load;

[0030] The working principle and beneficial effects of the above technical solution are as follows: In actual use, the power supply line 10 supplies power to daily loads of the same voltage level. Furthermore, the power is fed to the secondary AC distribution board 6 through the transformer 5 to supply power to daily loads of other voltage levels.

[0031] In one embodiment, the frequency converter module includes: a frequency converter body 8 and a controller 9. The output terminal of the primary AC power distribution board 2 is connected to the input terminal of the frequency converter body 8, the output terminal of the frequency converter body 8 is connected to the input terminal of the propulsion motor 4, and both the frequency converter body 8 and the AC voltage acquisition module 7 are electrically connected to the controller.

[0032] The working principle and beneficial effects of the above technical solution are as follows: In actual use, the AC voltage acquisition module 7 collects the voltage data of the primary AC distribution board 2 in real time, and then transmits it to the controller 9 in real time. The controller 9 receives the voltage data from the AC voltage acquisition module 7 in real time, makes a power limitation judgment based on the voltage data, and then transmits it to the inverter body 8, thereby limiting the output current of the inverter unit of the inverter body 8, achieving the purpose of limiting the propulsion power of the propulsion motor 4, thereby quickly reducing the shaft power of the propulsion motor 4, restoring the grid load rate to normal, and increasing the grid voltage.

[0033] Meanwhile, the upper and lower limits of the trigger voltage for the power limit of the feeder branch can be set according to the voltage regulation characteristics of generator set 1; the power limit amplitude between the upper and lower voltage thresholds adopts a linear relationship.

[0034] This solution directly detects the AC voltage at the power input terminal and limits the propulsion power based on the voltage drop. The voltage data is transmitted to the controller 9 via fiber optic communication. The communication time is short, and the controller makes a judgment after receiving the voltage data. The response speed is very fast, and it can respond in the millisecond level.

[0035] After the inverter body 8 performs a power limiting action, the grid voltage will gradually recover. During the grid voltage recovery process, the feeder branch will gradually release the inverter's output current limit value according to the current voltage value until the voltage recovers to the upper limit threshold of the power limiting trigger voltage, and then the power limit will be completely released to prevent oscillations during the recovery process.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A power supply system suitable for an electrically propelled cruise ship, characterized in that, It comprises: A generator set (1), a primary AC distribution panel (2), a daily load distribution module, a feeder branch (3) and a propulsion motor (4), the generator set (1) is connected with the input end of the primary AC distribution panel (2), the daily load distribution module is connected with the output end of the primary AC distribution panel (2), one end of the feeder branch (3) is connected with the output end of the primary AC distribution panel (2), and the other end of the feeder branch (3) is connected with the propulsion motor (4); Wherein, the feeder branch (3) comprises: an AC voltage acquisition module (7) and a frequency conversion module, the output end of the primary AC distribution panel (2), the frequency conversion module and the propulsion motor are sequentially connected, the AC voltage acquisition module (7) is arranged between the output end of the primary AC distribution panel (2) and the frequency conversion module, and the output of the frequency conversion module is adjusted by collecting voltage data through the AC voltage acquisition module (7).

2. The power supply system suitable for the electric propulsion cruise ship according to claim 1, wherein, The daily load distribution module comprises: a transformer (5) and a secondary AC distribution panel (6), one end of the transformer (5) is connected with the output end of the primary AC distribution panel (2), and the other end of the transformer (5) is connected with the input end of the secondary AC distribution panel (6).

3. The power supply system suitable for the electric propulsion cruise ship according to claim 1, wherein, The daily load distribution module further comprises: A direct power supply line (10), one end of the direct power supply line (10) is connected with the primary AC distribution panel (2), and the other end of the direct power supply line (10) is connected with the required load.

4. The power supply system suitable for the electric propulsion cruise ship according to claim 1, wherein, The frequency conversion module comprises: a frequency converter body (8) and a controller (9), the output end of the primary AC distribution panel (2) is connected with the input end of the frequency converter body (8), the output end of the frequency converter body (8) is connected with the input end of the propulsion motor (4), and the frequency converter body (8) and the AC voltage acquisition module (7) are electrically connected with the controller.

5. The power supply system suitable for the electric propulsion cruise ship according to claim 1, wherein, The plurality of generator sets (1) are connected in parallel, and the plurality of feeder branches (3) are connected in parallel.

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