Frequency-conversion soft starter

Abstract

The invention discloses a frequency-conversion soft starter. The on-off sequence of breakers is controlled by a controller so that a frequency converter can start two motors at different time, and after one motor is started, the corresponding frequency converter bypass can be switched on. Thus, the frequency-conversion soft starter can be stably switched to a power-frequency power source without current impact after starting is finished, the starting current can be effectively reduced, ships cannot be impacted, and the frequency-conversion soft starter has obvious advantages in the aspects of structures and control. In addition, it is not needed to equip frequency converters for all the motors, and therefore the manufacturing cost of the ships is saved.

Description

technical field [0001] The application relates to the technical field of shipbuilding, in particular to a variable frequency soft starter. Background technique [0002] Ships are usually equipped with multiple AC high-power propulsion motors at the same time, which are used to provide lateral propulsion power and propulsion power for electric propulsion ships. However, the ship power station is limited, and the starting current is too large, which will cause impact or even collapse of the ship power station. [0003] At present, the starting of marine motors mainly adopts three methods: autotransformer, soft starting and variable frequency starting. For the starting of high-power propulsion motors, if the first two methods are used, it will often cause large fluctuations in the voltage of the grid, and even cause the grid to collapse; However, in the way of starting with a frequency converter, each motor must be equipped with a frequency converter, and the cost is too high ...

AI Technical Summary

Problems solved by technology

However, the ship's power station is limited, and the starting current is too large, which will cause impact or even collapse of the ship's power station

[0003] At present, the starting of marine motors mainly adopts three methods: autotransformer, soft starting and variable frequency starting, but for the starting of high-power propulsion motors, if the first two methods are used, it will often lead to large fluctuations in the voltage of the grid, and even cause the grid to collapse; However, if the inverter is used to start, each motor must be equipped with an inverter, which is too expensive and cannot be widely used.

[0004] Therefore, the current way of starting the ship's motor cannot avoid the impact on the ship's power station

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