Abstract: A new power supply technique, in which electricity is generated from seawater pressure at deep sea bottom directly, is put forward. Switchmode hydraulic power supply theory is applied in the driving and control of its seawater hydraulic motor so that its flow rate could be duplicated used and its output torque could adapt the load automatically. Energy converting efficiency is increased considerably. Based on these, correspondent output voltage control method is put forward. Theoretical analyses and simulations show that its anti-disturbance ability is good, but its response is relatively slow.

Key words: Deep-sea, Power supply, Seawater pressure, Switchmode hydraulic power supply