A Local parameter estimator based on robust LAV estimation

Download
2015
Özdemir, Volkan
There are parameter errors in power system models due to the change of weather conditions, such as temperature and humidity changes, miscommunication between the control center and the transducers of circuit breakers and tap changers, etc. Because of the incorrect parameters, the state estimator may provide biased state estimates which may lead to many serious economic and operational results. In order to prevent that, one must identify and correct those parameter errors. This work proposes a local parameter estimator based on the robust Least Absolute Value (LAV) estimator. Considering the increasing number of Phasor Measurement Units (PMUs), their fast refreshing rate and high accuracy, the proposed method will employ PMU measurements in local parameter estimation which will provide a more reliable system model. In general, a PMU measures the current phasor owing through a branch, and the voltage phasor of the sending bus of the considered branch. However, it is known that those two measurements are not enough to estimate the parameters of that branch. Therefore, multiple measurements taken in di erent time instants will be used in the parameter estimation process for measurement redundancy, assuming that the state estimates are also available. It is known that the LAV estimator is a computationally expensive despite being robust in the presence of enough measurement redundancy. Note that, the parameter estimation problem is a non-linear problem, which increases the computational burden; since the vector to be estimated consists of not only the parameters of the considered branch, but also the bus voltages of the sending and the receiving ends of the considered branch. This de ciency will be eliminated by performing local parameter estimation, which is a very small sized problem compared to the state estimation problem's size.

Suggestions

A Robust Parameter Estimation Method Based on LAV Estimator
Özdemir, Volkan; Göl, Murat (2015-07-09)
In a power system, it is known that parameters may carry small errors due to the weather conditions, such as temperature and humidity changes, as well as gross errors due to the miscommunication between the control center and circuit breakers and tap changers. Those incorrect parameters may cause biased state estimates, which may have serious results. Therefore, those parameter errors should be identified and corrected. Considering the increasing number of Phasor Measurement Units (PMUs), in this paper it i...
Robust local parameter estimator based on least absolute value estimator
ÖZDEMİR, VOLKAN; Göl, Murat (2017-01-01)
Changes in weather conditions such as temperature and humidity, miscommunication between the control center and circuit breaker transducers and tap changers, and inaccurate manufacturing data may cause parameter errors. Because of incorrect parameters, the state estimator may provide biased state estimates, which may lead to many serious economic and operational results. In order to prevent that, one must identify and correct those parameter errors. This work proposes a local parameter estimator based on th...
A thermal conductivity based humidity sensor in a standard CMOS process
Okean, B; Akın, Tayfun (2004-01-29)
This paper presents a low-cost, thermal conductivity based humidity sensor implemented using a 0.6 mum CMOS process where suspended p-n junction diodes are used as the humidity sensitive elements. In this method, the difference between the thermal conductivities of air and water vapor at high temperatures is used. Humidity sensing idea is to compare the output voltages of two heated and thermally isolated diodes one of which is exposed to the environment and has a humidity dependent thermal conductance whil...
A low-power robust humidity sensor in a standard CMOS process
Okcan, Burak; Akın, Tayfun (2007-11-01)
This paper presents a low-cost thermal-conductivity-based humidity sensor implemented using a 0.6-mu m CMOS process, where suspended p-n junction diodes are used as the humidity-sensitive elements. The measurement method uses the difference between the thermal conductivities of air and water vapor at high temperatures by comparing the output voltages of two hea ted and thermally isolated diodes; one of which is exposed to the environment and has a humidity-dependent thermal conductance, while the other is s...
A Generalized Scalar PWM Approach With Easy Implementation Features for Three-Phase, Three-Wire Voltage-Source Inverters
Hava, Ahmet Masum (Institute of Electrical and Electronics Engineers (IEEE), 2011-05-01)
The generalized scalar pulse width modulation (PWM) approach, which unites the conventional PWM methods and most recently developed reduced common mode voltage PWM methods under one umbrella, is established. Through a detailed example, the procedure to generate the pulse patterns of these PWM methods via the generalized scalar PWM approach is illustrated. With this approach, it becomes an easy task to program the pulse patterns of various high performance PWM methods and benefit from their performance in mo...
Citation Formats
V. Özdemir, “A Local parameter estimator based on robust LAV estimation,” M.S. - Master of Science, Middle East Technical University, 2015.