  We explore methods to use thermostatically controlled loads (TCLs), such as
water heaters and air conditioners, to provide ancillary services by assisting
in balancing generation and load. We show that by adding simple imbedded
instructions and a small amount of memory to temperature controllers of TCLs,
it is possible to design open-loop control algorithms capable of creating
short-term pulses of demand response without unwanted power oscillations
associated with temporary synchronization of the TCL dynamics. By moving a
small amount of intelligence to each of the end point TCL devices, we are able
to leverage our knowledge of the time dynamics of TCLs to shape the demand
response pulses for different power system applications. A significant benefit
of our open-loop method is the reduction from two-way to one-way broadcast
communication which also eliminates many basic consumer privacy issues. In this
work, we focus on developing the algorithms to generate a set of fundamental
pulse shapes that can subsequently be used to create demand response with
arbitrary profiles. Demand response control methods, such as the one developed
here, open the door to fast, nonperturbative control of large aggregations of
TCLs.
