Long Cruising Trial of AUV “URASHIMA”

Author(s):  
Hidehiko Nakajo ◽  
Taro Aoki ◽  
Takashi Murashima ◽  
Satoshi Tsukioka ◽  
Tadahiro Hyakudome ◽  
...  

A Deep Sea Cruising AUV “URASHIMA” has been developed by JAMSTEC since 1998. The dimensions and weight are 10m (L), 1.3m (W), 1.5m (H), and about 7.5 tons in air. A main power source device system of AUV “URASHIMA” is a large capacity of lithium-ion (Li-ion) rechargeable battery system or Solid Polymer Electrolyte Fuel Cell (PEFC) system. AUV “URASHIMA” will be able to cruise for about 100km with Li-ion battery system and it will cruise for about 300km with fuel cell system. The cruising trial used by the fuel cell system will start at the end of 2002. The instruments for science researches are an automatic multi-water-sampling system, a CTDO, a side-scan sonar, a digital still camera with a thermoelectrically cooled CCD image sensor, a TV camera, and so on. Three operation modes, which are UROV mode, acoustic remote control mode and autonomous mode, are available. Those three kinds of modes are used acceding to each development stage and ocean researches. UROV mode is to monitor the state of the vehicle with fiber optics. At the first development stage of AUV “URASHIMA”, we carried out long cruising trial for about 100km and maximum operational depth trial at 3,500m used by Li-ion rechargeable battery system. URASHIMA was succeeded to reach at 3,518m depth of the seafloor at the sea trial of August 2001. We also carried out long cruising trial that was controlled by autonomous mode. Then, URASHIMA was cruised 70km distance at the sea trial of December 2001. We will have a next sea trail on May 2002 for 100km long cruising test. At the next development stage, we will carried out long cruising trial for 300km used by the fuel cell system.

Electronics ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 331 ◽  
Author(s):  
Tae-Ho Eom ◽  
Jin-Wook Kang ◽  
Jintae Kim ◽  
Min-Ho Shin ◽  
Jung-Hyo Lee ◽  
...  

In this paper, a voltage drop compensation method for hybrid hydrogen fuel cell battery system, with a hydrogen recirculation powering a forklift, is studied. During recirculating hydrogen fuel to recycle hydrogen that has not reacted enough at the system, impurities can be mixed with the hydrogen fuel. This leads to low hydrogen concentration and a drop in the output voltage of the fuel cell system. In excessive voltage drop, the fuel cell system can be shutdown. This paper proposes a voltage drop compensation method using an electrical control algorithm to prevent system shutdown by reducing voltage drop. Technically, voltage drop is typically caused by three kinds of factors: (1) The amount of pure hydrogen supply; (2) the temperature of fuel cell stacks; and (3) the current density to catalysts of the fuel cell. The proposed compensation method detects voltage drop caused by those factors, and generates compensation signals for a controller of a DC–DC converter connecting to the output of the fuel cell stack; thus, the voltage drop is reduced by decreasing output current. At the time, insufficient output current to a load is supplied from the batteries. In this paper, voltage drop caused by the abovementioned three factors is analyzed, and the operating principle of the proposed compensation method is specified. To verify this operation and the feasibility of the proposed method, experiments are conducted by applying it to a 10 kW hybrid fuel cell battery system for a forklift.


Author(s):  
T. Murashima ◽  
T. Aoki ◽  
S. Tsukioka ◽  
T. Hyakudome ◽  
H. Yoshida ◽  
...  

2012 ◽  
Vol 132 (10) ◽  
pp. 997-1002 ◽  
Author(s):  
Koji Maekawa ◽  
Kenji Takahara ◽  
Toshinori Kajiwara

2011 ◽  
Vol 131 (12) ◽  
pp. 927-935
Author(s):  
Yusuke Doi ◽  
Deaheum Park ◽  
Masayoshi Ishida ◽  
Akitoshi Fujisawa ◽  
Shinichi Miura

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