The State Estimator function in a control center today is a suite of three programs solved sequentially: topology processing, state estimation, and bad data detection-identification. The state estimation equations are nonlinear because the inputs are mostly real and reactive power measurements. A linear state estimator is possible if the inputs are only complex currents and voltages and if there are enough such measurements to meet observability and redundancy requirements. The main contribution in this paper is the suggestion that the topology processing function and the bad data detection-identification be done at each substation rather than at the control center. It is shown how this two-level processing is faster and more accurate leaving the control center level state estimator solution free of the bad data errors that are major problems today.

%B 2009 IEEE/PES Power Systems Conference and Exposition (PSCE) %I IEEE %C Seattle, WA, USA %P 1 - 6 %8 03/2009 %@ 978-1-4244-3810-5 %R 10.1109/PSCE.2009.4840218 %0 Journal Article %J IEEE Transactions on Power Systems %D 2008 %T Design of Wide-Area Damping Controllers for Interarea Oscillations %A Zhang, Yang %A Anjan Bose %K AA05-002 %K AARD %K Automatic Switchable Network (ASN) %K oscillations %K Power system stability %X This paper develops a systematic procedure of designing a centralized damping control system for power grid interarea oscillations putting emphasis on the signal selection and control system structure assignment. Geometric measures of controllability/observability are used to select the most effective stabilizing signals and control locations. Line power flows and currents are found to be the most effective input signals. The synthesis of the controller is defined as a problem of mixed H 2/H infin output-feedback control with regional pole placement and is resolved by the linear matrix inequality (LMI) approach. A tuning process and nonlinear simulations are then used to modify the controller parameters to ensure the performance and robustness of the controller designed with linear techniques. The design process is tested on the New England 39-bus ten-machine system. %B IEEE Transactions on Power Systems %V 23 %P 1136 - 1143 %8 08/2008 %N 3 %! IEEE Trans. Power Syst. %R 10.1109/TPWRS.2008.926718 %0 Journal Article %J IEEE Transactions on Power Systems %D 2004 %T Communication Models for Third Party Load Frequency Control %A Sudipto Bhowmik %A Kevin Tomsovic %A Anjan Bose %K AA05-002 %K AARD %K advanced measurements and control %XWith deregulation of the power generation sector, the necessity for an enhanced and open communication infrastructure to support an increasing variety of ancillary services is apparent. A duplex and distributed communication system seems to be the most suitable solution to meet and ensure good quality of these services. Parameters needed and additional limits introduced by this new communication topology must be investigated and defined. This paper focuses on the communication network requirements for a third party load frequency control service. Data communication models are proposed based on queuing theory. Simulation is performed to model the effects of certain types of signal delays on this ancillary service.

%B IEEE Transactions on Power Systems %V 19 %P 543-548 %8 02/2004 %N 1 %R 10.1109/TPWRS.2003.818700