OpenEMS with OCPP Server and smart charging

Vincent · June 8, 2023, 12:52pm

Hi everyone!

I’ve recently learned about OpenEMS and I’m trying to discover whether OpenEMS is the right solution for our desired solution.

I’d like to run OpenEMS edge as the manager for a location where there are multiple charging stations, a solar installation and possibly even a battery. As far as I understand it, OpenEMS is perfectly capable of load-balancing the stations based on data acquired by modbus and other inputs. However, I’d also like to dynamically prioritize certain charging stations based on a 3rd party system. How would I be able to achieve this?

I have been testing running everything in docker (should someone also want to easily run this locally):

I enabled the OCPP Server (on port 8887) and used simple OCPP charging point simulators to connect. However, although I get a ‘connected’ state back. I can’t find any dashboarding and/or logging that tells me the OCPP server is running and charging stations are connected. Do I need any other plugins?

Would I be correct in assuming that in order my to prioritize my charging stations based on an external system, I’d need to implement my own controller to achieve this?

Any remarks and insights regarding OpenEMS and OCPP are welcome!

Kind regards,
Vincent

p.wimmer · June 8, 2023, 1:10pm

you also need to aktivate an ocpp-wallbox in openems, so that you will see something in the ui. (i guess). Never tried it in detail.

we, consolinno, went a second way, because ocpp is often blocked or used for billing. so we integrated an modul, what is connected to “BILL” (our billing solution) and the Billing-Solution handles the requests.
right now we mainly use “ABL”-Wallboxes.

OCPP is no real standard, so many wallboxes make there own stuff. so there is ABL which is not “normal” on regulating the power over ocpp. Keywatt i did not look in detail, but perhaps it is fitting to another wallbox

best regards

paul

Vincent · June 8, 2023, 1:15pm

Thanks for the swift answer. I will look into enabling a wallbox. The brand we use is not listed (ecotap) but it should be compatible with OCPP1.6J. Which wallbox implementation would match that the closest?

p.wimmer · June 10, 2023, 8:50am

I guess none of them are fitting. You have to read the manual. Like i said “ocpp” is not standardised. its getting better with smartcharging (a ocpp2.0 feature what also got downgraded to ocpp 1.6). But nobody has implemented this feature yet in openems.
there are only two ways right now.

ABL setting a datarequest with logicalid and value (guess no other wallbox is doing it this way)

github.com

OpenEMS/openems/blob/0d6e3f28a9949585d26a4753c2b34d241d5e4519/io.openems.edge.evcs.ocpp.abl/src/io/openems/edge/evcs/ocpp/abl/EvcsOcppAblImpl.java#L146


      
          
          
			@Override
          			public Request setChargePowerLimit(int chargePower) {
          				var request = new DataTransferRequest("ABL");
          				var phases = evcs.getPhasesAsInt();
          				var target = Math.round(chargePower / phases / 230.0);
          				var maxCurrent = evcs.getMaximumHardwarePower().orElse(DEFAULT_HARDWARE_LIMIT) / phases / 230;
          
          
				target = target > maxCurrent ? maxCurrent : target;
          				request.setMessageId("SetLimit");
          				request.setData(
          						"logicalid=" + EvcsOcppAblImpl.this.config.limitId() + ";value=" + String.valueOf(target));
          				return request;
          			}
          
          
			@Override
          			public Request setDisplayText(String text) {
          				// Feature not supported
          				return null;
          			}
          		};

keywatt is changing the configurationParameter “Powerlimit”

github.com

OpenEMS/openems/blob/0d6e3f28a9949585d26a4753c2b34d241d5e4519/io.openems.edge.evcs.ocpp.ies.keywatt.singleccs/src/io/openems/edge/evcs/ocpp/ies/keywatt/singleccs/EvcsOcppIesKeywattSingleImpl.java#L138


      
          	@Override
          	public void handleEvent(Event event) {
          		super.handleEvent(event);
          	}
          
          
	@Override
          	public OcppStandardRequests getStandardRequests() {
          		return new OcppStandardRequests() {
          
          
			@Override
          			public Request setChargePowerLimit(int chargePower) {
          				// There is no best practice for DC Chargers for now. Currently, the user has to
          				// set the AC-Target and not the DC
          
          
				return new ChangeConfigurationRequest("PowerLimit", String.valueOf(chargePower));
          			}
          
          
			@Override
          			public Request setDisplayText(String text) {
          				return null;
          			}

If Ecotap is use one or the other it would work, but i dont think so. or you need to make your own module.

best regards

pauli

Vincent · June 12, 2023, 11:10am

Thanks, I guess implementing an ecotap specific charging station in openems would be best.

In regards with my other question; what approach would be best to prioritize certain vehicles at certain times when they hook up to a charging station?

p.wimmer · June 19, 2023, 1:26pm

hi,
if you want something “special” you need to write your own controller. there you can handle priorized, like you want, depending of the charged energy or on the time the session startet (not sure, if you see out of the box the startsession time, but you can implement that in the ecotap).

best regards