In the previous article, I described some of the factors that are most challenging to obtain at the moment. RELIABILITY is a highly connected topic with safety. SAFETY FIRST, all over the world the most important sentence in shipping. Safety of Power Distribution is the basis of reliability. For the safety of work with 6,6kV look here!
Today, I will try to explain a little bit about safety onboard. But not about the safety of humans, which is important of course. But we will focus on the safety of networks. Post about safety will be combined from 2. First Important part: POWER NETWORK & Distribution. In 2nd part will be described Cybersecurity.
To be accurate, tho sail the vessel we don’t need electricity. Sails are enough. But with the engine, it is much easier. To run the engine we also don’t need electricity. But if we like to have an autonomous vessel, there is no other option. We need to have a high-reliability power distribution system. Let’s see how it looks over the history and which solutions are now. We will design a step by step Power distribution network from the simplest one to a completely modern one.
Power generation systems onboard the vessels are not much different then this which we can found in power generation plants. The idea is exactly the same. Over the years the most common type of generators that are in use at the vessel is diesel generators. There are also some vessels with nuclear power plants, but let’s focus on the most common solution. Simple and efficient, good old diesel engine connected to the generator. Need fuel, air, and oil. All necessary items can round around thousands of hours.
So the simplest way is to connect the power distribution board to the generator. To distribution, boards are connected consumers. The general schema looks like this:
To make this system safer, it will be good to have at least 2 generators. In case of failure of one, we can still run our systems. Ok, we improve our system, but we are still not satisfied.
Emergency generator = safety of power distribution!
What happens if we will have some trouble with the power distribution board? Good point. We can do two separate distribution boards, and double source of supply, to our most important equipment. In this solution to every important consumer, we have a separate network from each diesel generator, through each power distribution board. Quite convenient.
What we could add is a bus tie between power distribution boards. Then in normal operation, we don’t need to run 2 generators all the time. Looks good, but will be good to have some emergency option as well. This is also a requirement by all kinds of classification societies like DNV GL, Lloyds, RINA, etc… So to our system, we have to add an Emergency generator. Safety first! So separate generators with separate power distribution for emergency purposes.
This is the most standard solution. But very popular are also solutions with higher voltage generators. Ok first point, separate power generation from power distribution, how and why? So first answer about why… If we will generate power at 6,6kV or 15kV it will be much easier to transfer this energy around the unit. Cables will be smaller, and generators will be more efficient. So our consumers will stay on the same level as before 440V, but our generation increases up to 6.6kV as an example. (Since last years this solution comes more and more often in use).
Transformers for galvanizing separation and safety
So to connect two separate systems we need a transformer which will convert voltage from one level to another. Same as before we will use multiple generators, and we use different power distribution boards. We are at the point which is already quite complicated. But ok, You can always ask a question in a comment! From this place, we will modify our system and add one more transformers, add this add that.
But to make this system even more reliable we need to use more distribution boards and more generators. To leave vessel alone for sailing for 3 weeks, better to be double sure!
Ringnet – The safest power distribution
So in this step, we will create a power distribution in RING NET network, which will be possible to use in multiple ways. In case of any trouble, we can eliminate faulty system from network and continue the normal operation of the system. How to do this? I will suggest such a solution.
In this case, we can remove each power distribution board and generator from the network if needed. In my opinion, this is the most reliable and safe solution for the power supply network at the moment. What do You think about the Safety of Power Distribution?