A Survey on Hybrid SCADA/WAMS State Estimation Methodologies in Electric Power Transmission Systems

State estimation (SE) is an essential tool of energy management systems (EMS), providing power system operators with overall grasp the actual operating conditions and aiding them in sustaining reliable secure operation grid. In modern transmission sectors, two main measurement are deployed, namely supervisory control data acquisition (SCADA) wide area monitoring (WAMS). The multiple advantages augmenting conventional SCADA-based SE algorithms synchrophasor measurements from WAMS already well-established; thus, abundance different methodologies has been reported field hybrid (HSE). Under this premise, paper provides a thorough literature review novel HSE methods proposes classification based on scope mathematical modeling each method. Following brief introduction to concept SCADA measurements, insight into challenges emerging implementations provided. Various which overcome these reviewed, for both static dynamic implementations. conclusion, research trends summarized, findings discussed.