Ankush Sharma

A Multi-Agent-Based Power System Hybrid Dynamic State Estimator

This article proposes a multi-agent-based power system hybrid dynamic state estimator (PSHDSE) that uses field measurements from remote terminal units (RTUs) as well as phasor measurement units (PMUs). The standard cubature Kalman filter (CKF) process is modified to make it suitable for PSHDSE execution, and software agents are utilized to receive data and run PSHDSE for the RTU and PMU measurements separately. PSHDSE is solved by utilizing the CKF, the extended Kalman filter (EKF), and the unscented Kalman filter (UKF). The relative performances of the EKF, UKF, and CKF in executing PSHDSE are established through simulations on the IEEE 30 bus and practical 246-bus Indian test systems.

Testing and Validation of Power System Dynamic State Estimators Using Real Time Digital Simulator (RTDS)

This paper presents an approach to test and validate a number of power system dynamic state estimation (PSDSE) algorithms, utilizing Real Time Digital Simulator (RTDS), a real-time simulation tool. WSCC 9-bus and IEEE 30-bus systems have been utilized to demonstrate the proposed approach. The test systems are developed on the RSCAD software of the RTDS. The conventional remote terminal unit (RTU) measurements and the phasor measurement unit (PMU) measurements are sent from the RTDS runtime environment to the MATLAB based PSDSE application at regular intervals for the estimation of the states, using software-in-the-loop (SIL) configuration. The PSDSE is solved by utilizing the extended Kalman filter (EKF), the unscented Kalman filter (UKF), and the cubature Kalman filter (CKF) approaches, and their relative performances are studied with the help of the simulation results on the two test systems.

Multi Area State Estimation using area slack bus angle adjustment with minimal data exchange

This paper proposes a new Multi Area State Estimation (MASE) approach, which is suitable for the power system networks that can be divided into several sub-areas. In this approach, the Central Coordinator (CC) utilizes results of one extended sub-area state estimator to estimate the bus angles of the other sub-areas. It has been demonstrated that, with this approach, there is no requirement to share the topology information among the sub-areas and from sub-areas to the central coordinator. Also, with the lesser data exchange, communication bandwidth requirement will reduce. The effectiveness of the proposed method has been demonstrated on IEEE30 bus system and 246-Bus reduced Northern Regional Power Grid (NRPG) Indian system.

An Iterative Multiarea State Estimation Approach Using Area Slack Bus Adjustment

This paper proposes a new multiarea state estimation (MASE) approach, which estimates the overall system states by utilizing the state estimation (SE) results of the subareas iteratively. In this approach, all the subareas run their SE sequentially in each iteration. The SE results of the boundary buses in a subarea are used as pseudomeasurements for running the SEs of the nearby subareas. An area slack bus angle adjustment approach has been utilized for estimating the bus angles of the overall system with reference to the global slack bus. It has been demonstrated that the use of the subarea SE results, as pseudomeasurements, provides better state estimates for the complete system. The effectiveness of the proposed method has been demonstrated on an IEEE 30-bus system and a 246-bus reduced Northern Regional Power Grid Indian system.

A Cubature Kalman Filter Based Power System Dynamic State Estimator

This paper proposes an application of the cubature Kalman filter (CKF) to the power system dynamic state estimation (PSDSE) utilizing the measurements from the remote terminal units as well as the phasor measurement units. The CKF process utilizes the spherical cubature and Gaussian quadrature rules to estimate the probability density functions of the state space and the measurement space. This helps in linearization of the nonlinear measurement function without loss of accuracy. The CKF does not require formation of the Jacobian and Hessian matrices to execute the PSDSE, which saves the execution time. A state forecasting technique is utilized to forecast the states during the interval between two time instants of receiving the measurement sets from the field. This helps in estimating the states of the power system during the period when the field measurements are not available. The effectiveness of the application of the CKF to the PSDSE has been demonstrated on IEEE 30 bus system and 246 bus Northern Regional Power Grid Indian system.

An Extension of Common Information Model for Power System Multiarea State Estimation

This paper proposes an extension of International Electrotechnical Commission (IEC) Common Information Model (CIM) to accomplish the interoperability requirements for the power system state estimation (SE). The proposed method utilizes a multiarea SE (MASE) approach, suitable for the power system networks, which can be divided into several independently controlled subareas. The standard IEC CIM model is extended for exchanging the SE results of the MASE from subareas to a central coordinator (CC) in the standard format, which might individually use diverse proprietary software applications and databases. The suggested schema defines the data exchange format among the subareas and the CC without modifying proprietary databases and software applications. The new MASE approach, used to demonstrate the proposed CIM extension process, requires lesser data exchange as there is no topology information exchange among the subareas and the CC, thus resulting in reduced communication bandwidth requirement. The effectiveness of the proposed approach has been demonstrated on IEEE 30 bus system and 246-bus reduced Northern Regional Power Grid Indian system.

Progressive damage modeling and interface delamination of cross-ply laminates subjected to low-velocity impact

In this study, Hashin failure criteria were enhanced with Puck’s action plane concept to develop a user material model that can accurately predict the damage development inside the composite laminate when it is subjected to low-velocity impact. A simple cross-ply laminate [0/90]s was chosen to demonstrate the applicability of the material model. Experiments were also performed to observe the real behavior of the laminate. A good correlation between the experiment and simulation results was obtained in terms of peak force and displacement. However, the model under-predicted the absorbed energy, but the discrepancy decreased with the increase in impact energy. Moreover, the interface delamination study was performed by comparing the signatures in post-impact samples of the experiment and numerical simulation. It was observed that the experimentally detected delamination area was closely predicted by the simulation. It was further noticed that the top interface delamination increases faster than bottom interface delamination. Furthermore, the total energy absorbed by the laminates in intralaminar and interlaminar damage modes and friction effects were found to be closely matching with the final absorbed energy of the laminate. Hence, it was seen that the developed finite element model was able to closely capture the behavior occurring in experiments.

High Strain Rate Tensile Behavior of Fiber Metal Laminates

Fiber metal laminates (FMLs) consist of thin metallic layers alternately bonded together with layers of fiber reinforced composite. FMLs are reported to possess excellent impact properties, improved damage tolerance and outstanding in-plane fatigue and fracture properties. In the present study, FML based on 2024-T3 aluminum (Al) alloy sheet and composite layer consisting of uni-directional glass fiber reinforced epoxy is prepared using hand layup process. High strain rate response of the FML in tension is measured using split Hopkinson pressure bar. High-speed imaging is used to record real time deformation and failure of the FML during high strain rate experiment. Digital Image Correlation is employed to measure the sample strain directly in quasi-static and high strain rate test. Dynamic and quasi-static stress-strain responses of the FML are compared.