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NREL / OCHRE

A Python-based building energy modeling (BEM) tool designed to model flexible loads in residential buildings
https://www.nrel.gov/grid/ochre.html
BSD 3-Clause "New" or "Revised" License
40 stars 4 forks source link

Temperatures exceeding thermostat deadbands #95

Open mnblonsky opened 9 months ago

mnblonsky commented 9 months ago

When running at 1 minute timesteps, the thermostat control with deadband can exceed the deadband limits. It's mainly an issue for the water heater, which can increase in temperature pretty quickly. It's an issue for HVAC too, but not as significant.

It'd be nice to add a feature to reduce the power of the equipment when it hits the top/bottom of the deadband. This would be similar to the ideal capacity algorithm, but not exactly the same. Maybe an algorithm like this:

Might need to think a little harder about this for HPWH and ASHP. But I think something should be able to work. It might even simplify the methods we have for ideal capacity now (at least for HPWH).

mnblonsky commented 1 month ago

@jmaguire1 I think this covers the discussion around overshoot, right?

I think the process above works well, but we should also limit the max capacity further if the equipment starts as off. For example, if time_res is 1 minute and we hit the deadband limit at 30 seconds, then the max duty cycle should be 50%.

jmaguire1 commented 1 month ago

Yeah, I forgot we had this issue, but it definitely covers it.

I'll definitely have to test this with a HPWH when we do have an idea for a fix in place, I don't think it gets that much more complicated but maybe there's a point where there should be a HP>element switch that causes some issues?