Design and Analysis of an Equivalent Load Power-Stability Control Circuit for Cabled Underwater Information Networks

Cabled underwater information networks (CUINs) have evolved over the last decade to provide abundant power and broad bandwidth communication to enable marine science. To ensure reliable operation of the CUINs, the stability of the remote power supply system, a key component of underwater power facilities, is essential. To avoid instability and collapse of the power system caused by rapid changes in load, we propose an equivalent load power-stability control circuit suited for an underwater constant current power supply system. This circuit can change its own working state according to the size of the load and play a role in power compensation. In order to prove the feasibility of the converter design, the working state of the circuit under different load values was analyzed and the performance of circuit was verified through simulation and experiments. The results show that when the load resistance changes within a large range (including when the load has an open circuit or short circuit fault), the equivalent load is basically unchanged or changed within a very small range for the constant current source, causing the constant current source to maintain stable output voltage and output power. Thus, the influence of the branch line cable on the trunk line cable is reduced, and the reliability of the underwater constant current power supply system is improved. Furthermore, the equivalent load power-stability control circuit would facilitate live equipment replacement and maintenance for CUINs.