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Happy new year Eurocircuits community! We are Solar Boat Twente, a new partner of Eurocircuits.
We have noticed that the maritime industry is not as sustainable as other sectors, which is what we are trying to change. We build a solar powered motorboat with which we will compete in multiple Dutch competitions, and the yearly world championship in Monaco, the Monaco Solar & Energy Boat Challenge. The end goal is to be challenged by these competitions to innovate and design new technologies, and to show the world what is possible!
Every year, our team of ambitious and passionate students work hard to improve the performance, efficiency and reliability of the boat. As you can imagine, with a limited supply of energy (because of the maximum allowed solar panel area), efficiency is a key factor to achieve optimal performance. Additionally, monitoring and read-out of the boat’s state are vital too, such that during the series of events, the optimal strategy can be chosen.
This is where the aid of Eurocircuits comes in. Firstly, we are integrating power sensors in the MPPTs (Maximum Power Point Trackers) this year. MPPTs are the devices that change the internal load in order to extract the maximum power of the solar panels. This is necessary, since this maximum power point changes with among other things, temperature and light radiation.
In order to know the actual output power of each solar panel, we will add these power sensors to the MPPTs that will measure the voltage of the panel and the current that is leaving it. Since our 384 cells are divided over 8 panels, we have 8 MPPTs installed, and consequently need 8 of these sensors.
Because our boat is all about efficiency, it has hydrofoils below the water surface so that the hull is lifted out of the water above a certain speed, making for significantly less drag and thereby increasing the achievable speed and distance. For this, the boat needs to be as light as possible. Therefore, these sensors should be very light, and impede the incoming power as little as possible. As such, small, accurate, low-impedance current sense amplifiers will be used together with a microcontroller that will read out all the voltages and calculate the power consequently.
Another project for this year is the improvement of the battery cell’s SoC estimation, but this involves mainly an update in software. In line with it is the production of a smaller battery management system (BMS). We are using a BMS that consists of 2 boards, one main board that does the regulation and computing, and a board that takes care of the cell balancing. Our partner has released a newer and smaller version of the balance board, which we aim to have produced at Eurocircuits this year.
The third project where we expect to need the help of Eurocircuits is for the height detection system. In order for the boat to fly above the water in a stable manner, a sophisticated control circuit is required. For this to work, the boat’s orientation must be sensed accurately, for which, among other things, a robust height sensor is necessary. Up till now, this has been done using so-called floats (see image below), where the angle of the stick hanging below the boat is measured. This system adds weight and resistance. We are starting to develop sensors that use mmWave radar, and for this to work we will need advanced and accurate PCBs, which we will also to do together with Eurocircuits.
Figure 1: At the front of the boat, the floats can be seen, hanging down to the water at an angle.