  With the increased adoption of distributed energy resources (DERs) in
distribution networks, their coordinated control with a DER management system
(DERMS) that provides grid services (e.g., voltage regulation, virtual power
plant) is becoming more necessary. One particular type of DERMS using
primal-dual control has recently been found to be very effective at providing
multiple grid services among an aggregation of DERs; however, the main
parameter, the primal-dual step size, must be manually tuned for the DERMS to
be effective, which can take a considerable amount of engineering time and
labor. To this end, we design a simple method that self-tunes the step size(s)
and adapts it to changing system conditions. Additionally, it gives the DER
management operator the ability to prioritize among possibly competing grid
services. We evaluate the automatic tuning method on a simulation model of a
real-world feeder in Colorado with data obtained from an electric utility.
Through a variety of scenarios, we demonstrate that the DERMS with
automatically and adaptively tuned step sizes provides higher-quality grid
services than a DERMS with a manually tuned step size.
