Struggling with Power-Solver

klinki · November 29, 2023, 6:49am

Hi Forum,

I have a problem with the power-solver. It tells the ESS how to charge or discharge. However, there are sporadic values that don’t match the others. For example, 30 times -100W and then twice 300W, then again -100W. I suspect a problem with reading the data from the inverter - but I can’t figure it out.

Since the seemingly incorrect values only occur sporadically, debugging is difficult. At which point should I expand the DebugLog to output the input values for the Solver class?

Regards,
klinki

tsicking · November 30, 2023, 8:09am

Hi klinki,

You may have already done this, but you can enable the debug mode in the Ess.Power-component. You will get all active EQUALS-constraints as log output together with the component it comes from.
If you want to see even more, you can remove the if-clause in line 145 here:

github.com

OpenEMS/openems/blob/edfe1f0ac47a70f25c7c6456289d58344b6c3ab7/io.openems.edge.ess.core/src/io/openems/edge/ess/core/power/Solver.java#L145


      
          			allConstraints = this.data.getConstraintsForAllInverters();
          
          			// Add Strict constraints if required
          			AddConstraintsForNotStrictlyDefinedCoefficients.apply(allInverters, this.data.getCoefficients(),
          					allConstraints);
          
          			// Print log with currently active EQUALS != 0 Constraints
          			if (this.debugMode) {
          				this.log.info("Currently active EQUALS constraints");
          				for (Constraint c : allConstraints) {
          					if (c.getRelationship() == Relationship.EQUALS && c.getValue().orElse(0d) != 0d) {
          						this.log.info("- " + c.toString());
          					}
          				}
          			}
          
          			// Evaluates whether it is a CHARGE or DISCHARGE problem.
          			targetDirection = TargetDirection.from(//
          					this.data.getInverters(), //
          					this.data.getCoefficients(), //
          					this.data.getConstraintsForAllInverters() //

Then you even see all constraints, could be quite many though.
I hope that helps a bit.

Best regards,
Thomas

klinki · December 1, 2023, 1:16pm

Hi Thomas,

Thanks for the advice - but it’s not quite what I am looking for. The immediate issue is the problems that occur with my PV inverter/ESS. The solver works properly in simulation. However, there appears to be a problem in the actual implementation, described here. I’ve implemented a workaround with a moving average, which works well, but nobody’s happy using workarounds…

I want to find out what the solver takes as input, e.g., Grid-Power. The strategy is “moving towards target”.

But it´s in fact interesting seeing all the constraints

Regards, Thomas (klinki)

EDIT: I think I have to look further into the component which controls the ESS
EDIT: I´ve implemented a DebugLog in the BalancingController. So I can have a real-time look on what´s being passed to the Solver class