Yuan Class AIP & Kilo Submarine Thread

[tphuang]

I don't quite understand your contact's point on diesel submarines and DC power. Almost all modern generators are alternators, fitted with AC-DC converters if needed. In particular all PLAN vessals use high-speed alternators.

Please, Log in or Register to view URLs content!

The article is about Xiao Fei and his work. Xiao Fei worked on high speed induction generators for PLAN in the early 2010s and worked as part of Ma Weiming's team on subsequent new generator designs which are installed on all PLAN vessels in active service or under development. Xiao Fei is an expert on power conversion and has been in charge of converter design for those generators.

In around 2008, at the suggestion of Ma Weiming, Xiao Fei had applied his work on high speed marine generators to solve Chinese wind turbine industry's struggle with converters, and successfully designed a converter for a 2MW direct drive wind turbine PMSG.

Anyway it's clear from the article that all PLAN vessals use high speed alternators and then convert AC to DC if needed. This is not surprising at all since almost nobody uses DC generators nowadays.

Also it's interesting that the article claims Ma Weiming's high speed generators are now standard on all PLAN vessels in active service. PLAN must have done a lot of retrofitting.

hmm, I don't see anything in that article that would say diesel submarines are using AC generators or anything here would disprove the idea that diesel submarines largely use DC electrical power, but I'm sure you know best. I will just leave it as that.

 

[OppositeDay]

hmm, I don't see anything in that article that would say diesel submarines are using AC generators or anything here would disprove the idea that diesel submarines largely use DC electrical power, but I'm sure you know best. I will just leave it as that.

According to the article
”高速感应发电机系统是战舰的核心系统。”

”High-speed induction generators system is a core system of warships."

Induction generators are AC generators. Diesel submarines using DC power grid is fully compatible with them using AC generators. One of Ma Weiming's major achievement is his medium voltage DC IEPS system. According to the article Xiao Fei is a core member of the team in charge of 电力电子电能变换 (electronic electric power conversion). So his expertise is power conversion using power semiconductors.

 

[gelgoog]

You can easily convert AC power into DC power with a rectifier.
Modern systems typically use thyristors.

 

[OppositeDay]

You can easily convert AC power into DC power with a rectifier.
Modern systems typically use thyristors.

CRRC is major manufacturer of IGCT.

Please, Log in or Register to view URLs content!

Germany and Switzerland might still lead the world in electrical engineering but China is catching up fast. In particular, power generation and distribution is one of PLAN's comparative advantages.

Quote from the article
"牢牢确立了我国在舰船发供电领域的国际领先地位，大幅提升了舰船性能和战略威慑力。"

[Xiao Fei's works] solidified Chinese leadership in marine power generation and distribution, significantly improved naval vessels' performance and strategic deterrence values.

 

[by78]

Some images to mark the Mid-Autumn Festival.

 

[PaTu]

712th Institute's work was on the enclosure. The battery packs are enclosed in an oxygen-free environment to prevent combustion and there is a heat control system to prevent one overheated unit from in turn overheating its neighbors.

I don't think PMSGs are particularly sensitive. They're located in the engine room with plenty of dampening applied. Just use a different engine room quieting design on domestic subs and they can't identify the signature. I don't think German subs' sonar signatures are compromised by MTU selling diesel engines to China.

If CHD620 is noisier than MTU396 then that's a reason for China to offer quieter alternators to offset noisier prime movers. Even if CHD620 is as quiet as MTU396, it's better both economically and geopolitically to get Thailand to alter the contract than letting Thailand cancel the order and demand compensation. Throwing in some alternator upgrades for free is probably cheaper than paying compensation for failing to fulfill the contract. Also China gets more money from selling CHD620s to Thailand than being a middleman for German made MTUs.

Not sure if this has already been mention in this thread or not but in my opinion, the reason for Thailand to prefer the MTU396 over CHD620 because MTU396 has already been used on existing submarine both PLA Navy's and even German boats (e.g. Type212A), whereas CHD620 is not yet submarine proven. If CHD620's manufacturer could provide prove of usage in a submarine (e.g. produce one of the Yuan class boat with CHD620 and put it into PLA Navy service) or certified document that the performance of CHD620 is better or equivalent to MTU396, if so the Royal Thai Navy would probably reconsider ongoing with the S26T contract.

 

[PaTu]

Photos of Type039G1 (Song) class submarine with scope of unknown type.

https://twitter.com/i/web/status/1579480198478958593

Could this be an optronics mast/non-penatrating perisscope?

 

[by78]

A new retractable surface search/navigation radar for the Yuan class.

 

[badoc]

You can easily convert AC power into DC power with a rectifier.
Modern systems typically use thyristors.

Should be the other way round.
I remember 40 years ago, we were doing induction hardening using thyristors.
It was very expensive semiconductor.

Later machines used IGBT.
.

 

[Strangelove]

Please, Log in or Register to view URLs content!

China’s submarine fleet may soon be powered by lithium batteries​

• Technical solutions have been found through extensive development and testing in booming electric car market, according to navy study
• Researchers say that replacing problematic lead-acid batteries with lithium could significantly boost subs’ survival and combat abilities

Please, Log in or Register to view URLs content!

in Beijing

Published: 12:00pm, 29 Oct, 2022 Updated: 12:00pm, 29 Oct, 2022

Please, Log in or Register to view URLs content!

China’s military has been planning to replace lead-acid batteries with lithium in its conventional submarines for more than a decade. Photo: Twitter

China’s large fleet of conventional submarines could soon be powered by lithium-ion batteries as a result of advances in the country’s world-leading

Please, Log in or Register to view URLs content!

, according to a Chinese navy study.

A lithium power source – instead of lead-acid batteries – could more than double the time a submarine can spend under water, give it Tesla-style acceleration and create more room for weapons, said researchers with the Naval Submarine Academy in Qingdao, Shandong province.

The changes could significantly boost a submarine’s survival and combat abilities, they said in a paper published in peer-reviewed Chinese journal Marine Electric and Electronic Engineering on October 15.