After working on smart charging solutions for the past 15 years, I thought I had seen it all. Well, I was wrong. Over the past few weeks, I have had the pleasure of helping AMPECO with a challenge I had never even thought of: smart charging in so-called IT grids (grids without a connection to ground). Fortunately, there are charging stations that can cope with the lack of a PE, but they have to be connected between two phases instead of phase and neutral. As a result, your chargers are suddenly connected in a delta configuration instead of the usual star configuration (see picture). This presents an interesting challenge: if you want to determine the current through the circuit breaker, you can no longer simply add up the current of the individual chargers. Instead, you need to use the formulas in the second picture. Unless, of course, the power electronics in the EV's on-board converters cause a phase shift, then these equations become a little more complex. The biggest challenge, however, is to determine which charger should be allocated what power under all circumstances. It took some blood, sweat and tears, but we figured it out😊. It was great to meet the Ampeco team in Sofia last Tuesday to discuss all this. Thank you Natalia Aleksandrova and ⚡ Orlin RadEV ⚡ for asking Krachtwerk to support this very interesting challenge!
Lennart Verheijen it is fun working together on such projects
Paul Mignot
6d
Lennart Verheijen thanks for sharing! Cool challenge. That's exactly the nitty gritty needed to make a solution scalable. Filip Forro If you want to see how we handle star and delta configurations in the Teleport: https://teleport.withthegrid.com/data-forwarding/destinations/https/#ev-power ""currentType": "ac-3-phase-wye", // can be "ac-3-phase-wye", "ac-3-phase-delta", "ac-1-phase" and "dc"
IT Process Manager @ NIBC Bank
6dAs always, very interesting explanation, Lennart! The calculations are accurate and valid, as they are based on the power calculation per phase. In this approach, the total power is determined by multiplying the factors: 3 multiplied by (phase voltage, phase current, and the cosine of the phase angle (the angle between the phase voltage and phase current, rather than between line voltage and line current)) This method ensures that the line currents are equal across all lines, with each line current being equal to the square root of three times the phase current.