Читать книгу Power Electronics-Enabled Autonomous Power Systems - Qing-Chang Zhong - Страница 20

The large‐scale utilization of DERs, including renewables, EVs and energy storage systems, brings unprecedented challenges to grid stability, reliability, security, and resiliency (Zhong and Hornik 2013). The conventional centralized control paradigm is no longer feasible for power systems with millions of relatively small and distributed generators.

Adding an ICT system into power systems, hence the birth of smart grids, has emerged as a potential solution to make power systems friendlier to the environment as well as more efficient (Amin 2008; Amin and Wollenberg 2005). The main characteristics of smart grids in comparison to today's grids are shown in the second and the third columns of Table 1.1, with a prominent intention to address all problems via adding an ICT system. More details about smart grids can be found from the literature, e.g. (Amin and Wollenberg 2005; DOE 2009; Ekanayake et al. 2012; Fang et al. 2012; Farhangi 2010; Momoh 2012).

Table 1.1 Comparison of today's grids, smart grids, and next‐generation smart grids.

Characteristic	Today's grid	Smart grid	Next‐generation smart grid
Role of ICT	Constantly growing	Tendency to introduce bidirectional ICT into every part and corner of power systems	Unidirectional ICT for monitoring and management but not for control to prevent cyber‐attacks and single point of failures
Load participation in system regulation	Limited, non‐participative (passive)	Binary (ON/OFF) demand responses enabled by ICT	Autonomous, continuous demand responses for fully active regulation of frequency and voltage, without the need of ICT
Generation mix and DER integration	Dominated by central generation with limited but growing current‐controlled DER units	Diversifying, with mostly current‐controlled DERs, strong tendency of relying on ICT	DER dominated or even 100% renewable with grid‐friendly, compatible DERs, autonomous system regulation without the need of ICT
Cascading failures and blackouts	Inherent, systemic flaw	Significantly reduced number of incidents enabled by ICT but catastrophic when it happens	Built‐in capability of preventing local faults from cascading into wide‐area blackouts
Resiliency against faults and natural disaster	Vulnerable to faults, natural disasters, and the resulting cascading failures	Significant improvement enabled by ICT	Fully autonomous, mutually supported, fast recovery, reduced burden on utilities, without the need of ICT
Cyber‐security	Vulnerable to malicious cyber‐attacks	Significantly improved but still a systemic flaw	No access to the system through ICT; no more cyber‐attacks to power systems
Power quality	Focus on outages, sometimes low power quality	A priority with a variety of quality/price options	Built‐in control flexibility and functions to fundamentally reduce faults and outages and improve voltage quality
System‐wide efficiency	Limited means for improvement	Significant improvement enabled by ICT but causing data explosion and ever‐increasing complexity	Organic and harmonious operation underpinned by optimally designed components and system architecture