Marine medium-voltage grid structure base on multi-terminal DC-DC converter and energy control method thereof

Abstract

The invention discloses a marine medium-voltage grid structure base on a multi-terminal DC-DC converter, comprising a power generator, a propulsion motor and a low-voltage direct-current grid. CascadeH-bridge three-phase converter I is connected with the power generator; cascade H-bridge three-phase converter II is connected with the propulsion motor; the low-voltage direct-current grid is connected with low-voltage equipment. The power generator, the propulsion motor and the low-voltage direct-current grid are connected through a triple-terminal DC-DC converter; three terminals of the triple-terminal DC-DC converter have identical structure, all the three terminals are of half-bridge structure and are connected to a high-frequency transformer via a connection inductor. The marine medium-voltage grid structure base on the multi-terminal DC-DC converter provided herein allows energy to be transmitted from a high-capacitance high-voltage module to a low-voltage module, so that three-phase capacitance and voltage balance is achieved.

Description

technical field [0001] The invention relates to a structural design of a medium-voltage ship power grid, belonging to the technical field of ship power grids. Background technique [0002] Compared with the traditional DC power grid, the new power grid uses more power electronic converters, which can drive AC propulsion motors, and has attracted the attention of marine engineering and researchers in recent years. With a DC grid, the generator and propulsion motor are isolated via the DC grid, so the generator can operate at any frequency optimized to improve fuel efficiency. In addition, the DC power grid does not have various power quality problems caused by the synchronization of equipment in the AC power grid, such as grid-connected impact, multiple harmonics, reactive power, etc. These power quality problems will cause the instability of the AC power grid. [0003] Considering the various advantages of DC power grids in ships, IEEE proposed the standards for the constru...

AI Technical Summary

Problems solved by technology

This kind of DC power grid has a clear structure and strong compatibility, but it requires a large number of converters, and more importantly, the structure requires the use of large-capacity DC circuit breakers, which makes the system complex and expensive

At the same time, the lack of uniform standards for related DC / AC converter equipment has resulted in the fact that the current new-type ship DC power grid is rarely used in practice. Only ABB has built a DC power grid on a small number of ships, and the DC voltage is only 1kV

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