A Stability Analysis of Thermostatically Controlled Loads for Power System Frequency Control

Table 1

Comparison of centralised and decentralised TCL control strategies. Informed by, for example, [19, 38].

	Centralised control	Decentralised control
Key features	(i) TCLs instructed by a central controller	(i) Autonomous local control
	(ii) 2-way communication in all TCLs	(ii) Control scheme established once, may be updated periodically
Advantages	(i) Highly controllable	(i) No communications infrastructure required
	(ii) Reasonably predictable	(ii) No security risks
		(iii) Very fast response possible
Disadvantages	(i) Establishing and maintaining a secure communications network are very expensive; (ii) Response time limited by communication speed; (iii) Vast amounts of data to manage; (iv) Data and appliance control security risks; (v) Negative public perceptions of external control of home appliances	(i) Response is less predictable than with centralised control; (ii) Synchronisation and instability effects possible and not yet fully understood; (iii) Errors and noise in local frequency measurements more likely