Recently, China Shipbuilding Heavy Industry Co., Ltd. successfully completed the short-circuit and protection test of the ship’s medium-voltage DC integrated electric propulsion system, which marked the successful completion of China’s domestic ship integrated power system. Its installation on the ship is just around the corner.
The Integrated Power System (IPS) is the development direction of the ship propulsion system in the new century. It combines the two systems of ship power and energy into one, which not only improves the propulsion efficiency, reduces noise and fuel consumption, but also increases the system power density, laying a solid foundation for high-energy weapons and high-power electronic equipment. Both domestic and foreign shipbuilding industry believe that water surface ships should adopt electric propulsion technology in whole or in part after 2020 to enhance their combat capability.
According to relevant reports, China’s domestic integrated power system adopts medium voltage DC system. In contrast, western countries such as the United States and the United Kingdom currently adopt a medium-voltage exchange system. The latter’s advantage is that the technology is mature and less difficult, but the disadvantage is that the system power is small, the generator is difficult to connect in parallel, the system voltage drop is large, and so on.
Judging from the actual use situation in the United States and the United Kingdom, the performance of the medium-voltage AC integrated power system was not satisfactory, and Type 45 destroyer once had all the embarrassing situation of failures. The advantage of the medium voltage DC system used in the domestic integrated power system is that the system is small in size and light in weight, the cost is low, and the parallel connection of the generator is relatively easy. It is regarded as the development direction of the ship’s integrated power system. According to overseas data, the United States also decided to adopt a medium voltage DC system for the next generation integrated power system.
However, one difficulty of the medium voltage DC integrated power system is the system short circuit and protection problem. At present, there is a big difference between the protection based on alternating current and direct current.
For example, the alternating current can be grounded, while the direct current cannot be grounded, otherwise the DC waveform will be destroyed, resulting in unstable operation of the equipment and even burning of the equipment. For an integrated power system, its power line is short and the wiring network is complicated. If the fault cannot be isolated in time, the entire system will be de-energized, and the ship will lose its energy supply and lose its operational capability. From this perspective, the short circuit and protection of the medium voltage DC integrated power system is a key part of the system. According to relevant news, China’s domestic medium voltage DC integrated power system developed by 704 institution successfully breaks the faulty branch fuses in the case of simulated faults, isolates faults, and operates normally in non-faulty areas, fully implementing selective protection. It marks that China’s homemade medium voltage DC integrated power system has broken through a key technical problem and laid a solid foundation for comprehensive usage.
According to relevant information, China’s Naval Engineering University, 704 and 712 institutions have all developed domestically produced integrated power systems, and have made great progress. The medium-voltage direct integrated power system has been developed, and the medium-voltage AC integrated power system has been localized. These systems have been used in domestic military auxiliary vessels, marine police vessels, semi-submersible vessels, etc., and can also be used in its homemade export-oriented frigates as an option. However, considering factors such as schedule and cost, the first batch of domestically produced water surface ships, such as Type 052C/052D and 055 destroyers, did not choose China’s homemade integrated power system.
However, along with the development and installation of new weapons and systems such as China’s homemade electromagnetic guns, laser cannons, and integrated radio frequency systems, it will be a general trend for domestically produced new water surface ships to adopt integrated power systems.
Therefore, it is generally speculated that China’s Navy will choose domestic integrated power system systems for the second batch of Type 055 destroyers, the new generation of general-purpose destroyers and the new generation of frigates, and even future domestic aircraft carriers may adopt integrated power systems to improve combat capability.