On phasor measurement unit placement against state and topology attacks

Cyber attacks on the SCADA system can mislead the control center to produce incorrect state and topology estimate. If undetected, state and topology attacks can have detrimental impacts on the real-time operation of a power system. The problem of placing secure phasor measurement units (PMUs) to detect such attacks is considered. It is shown that any state or topology attack is detectable if and only if buses with secure PMUs form a vertex cover of the system topology. This condition leads to the countermeasures constructed by available graph algorithms. The examples with IEEE 14-bus, 118-bus, and 300-bus systems demonstrate applications of the countermeasures.