Green Ship
Ship High Voltage DC Micro-grid Control technology
In recent years, the International Environmental Conventions has put great effort into green ship technology development. Following this trend, on Asia’s First Hybrid Ferry “Happiness”, SOIC established a ship-class hybrid power system . On board, the main circuit is designed with a fixed 750 voltage regulated DC bus, stand-alone rated power of 250kW supply, and total system processing power of around 1MW. It integrates digital communication between the propulsion motor, lithium battery pack, and generator set according to the SAE-J1939 standard, and calculates the load of the generator sets, power quality control, and fault current protection using real time numerical analysis. The ships installed with PMS developed by SOIC can save at least 30% fuel consumption (the operating mode will provide different fuel consumption performance).
The power drive technology uses several power electronic components which combine for a total power greater than 1 MW. The key to the ship’s micro-grid: an IGBT integrated module hardware open platform. This platform uses the ship’s SAE J-1939 communication protocol and digital signal processor (DSP) to perform electrical testing of the system components, including the ship’s DC micro-grid feeder voltage variation rate ＜ (±5%), current peak variation rate < (±10%), and total harmonic distortion THD ＜5%.
Technical Achievement
- Power quality control technical specifications (in compliance with MIL-STD-1399 and other standards)
- PMS system total processing power > 1MW
- Power conversion efficiency > 95%
- Shared DC bus bar voltage = 750VDC (controllable)
- Equipped with bi-directional power flow control (AFE/Micro-grid function) with switching time < 500msec
- Feeder voltage variation rate <5%
- Feeder current peak variation rate <10%
- Total harmonic distortion THD <5%
- The modified ferry has achieved good results (saving fuel consumption >30%, vibration noise is reduced significantly, odor-free), assisting with low carbon emission reduction in the Port of Kaohsiung and facilitating the ferry replacement plan of Kaohsiung City Shipping Company.
