157 citations · 266 across the 22 of their papers we have counts for
24 papers
Criteria-Aware EMT-Based Short-Term Voltage Performance Index for Dynamic Assessment of Inverter-Dominated Power Systems
Mohammad Almomani, Venkataramana Ajjarapu
The increasing penetration of inverter-based resources (IBRs) into bulk power systems has fundamentally altered short-term voltage dynamics following disturbances. Conventional sho…
Online Long-Term Voltage Stability Margin Estimation for IBR/DER Dominated Power System with Integrated VSM-Aware TSO-DSO Framework
Ahmed Alkhonain, Kiran Kumar Challa, Amarsagar Reddy Ramapuram Matavalam +2
The rapid growth of inverter-based resources (IBRs) and distributed energy resources (DERs) has fundamentally altered the long-term voltage stability characteristics of modern powe…
Consensus Clustering for the Identification of Coherent Regions with Varied Generation Mix
Kiran Kumar Challa, Alok Kumar Bharati, Venkataramana Ajjarapu
With a steady increase in the inverter technology integration to the grid, frequency response of the large inter-connection system becomes more unpredictable. This leads to a signi…
TSO-DSO Coordinated Reactive Power Dispatch for Smart Inverters with Multiple Control Modes Real-Time Implementation
Mohammad Almomani, Ahmed Alkhonain, Venkataramana Ajjarapu
This paper presents TSO-DSO coordinated reactive power dispatch, with a focus on real-time implementation. A sensitivity-aware, mixed-integer linear programming (MILP) formulation…
Trajectory-Based Nonlinear Indices for Real-Time Monitoring and Quantification of Short-Term Voltage Stability
Mohammad Almomani, Muhammad Sarwar, Venkataramana Ajjarapu
Existing short term voltage stability (STVS) methods typically address either voltage oscillations or delayed voltage recovery; however, the coexistence of both phenomena has not b…
Enhanced Entropy-Based Metric for Characterization of Delayed Voltage Recovery
Mohammad Almomani, Muhammad Sarwar, Venkataramana Ajjarapu
Ensuring accurate violation detection in power systems is paramount for operational reliability. This paper introduces an enhanced voltage recovery violation index (EVRVI), a compr…
Novel Data-Driven Indices for Early Detection and Quantification of Short-Term Voltage Instability from Voltage Trajectories
Mohammad Almomani, Muhammad Sarwar, Venkataramana Ajjarapu
This paper presents a novel Short-Term Voltage Stability Index (STVSI), which leverages Lyapunov Exponent-based detection to assess and quantify short-term stability triggered by O…
Extended Sensitivity-Aware Reactive Power Dispatch Algorithm for Smart Inverters with Multiple Control Modes
Mohammad Almomani, Ahmed Alkhonain, Venkataramana Ajjarapu
The increasing integration of Distributed Energy Resources (DERs) in distribution networks presents new challenges for voltage regulation and reactive power support. This paper ext…
Robust VAR Capability Curve of DER with Uncertain Renewable Generation
Aditya Shankar Kar, Kiran Kumar Challa, Alok Kumar Bharati +2
Active distribution system with high penetration of inverter based distributed energy resources (DER) can be utilized for VAR-related ancillary services. To utilize the DER flexibi…
Curriculum Based Reinforcement Learning of Grid Topology Controllers to Prevent Thermal Cascading
Amarsagar Reddy Ramapuram Matavalam, Kishan Prudhvi Guddanti, Yang Weng +1
This paper describes how domain knowledge of power system operators can be integrated into reinforcement learning (RL) frameworks to effectively learn agents that control the grid'…
Data-Driven Approach for Uncertainty Propagation and Reachability Analysis in Dynamical Systems
Amarsagar Reddy Ramapuram Matavalam, Umesh Vaidya, Venkataramana Ajjarapu
In this paper, we propose a data-driven approach for uncertainty propagation and reachability analysis in a dynamical system. The proposed approach relies on the linear lifting of…
Information Based Data-Driven Characterization of Stability and Influence in Power Systems
Subhrajit Sinha, Pranav Sharma, Venkataramana Ajjarapu +1
Stability analysis of a power network and its characterization (voltage or angle) is an important problem in the power system community. However, these problems are mostly studied…
Investigation of Relevant Distribution System Representation with DG for Voltage Stability Margin Assessment
Alok Kumar Bharati, Venkataramana Ajjarapu
This paper emphasizes the importance of including the unbalance in the distribution networks for stability studies in power systems. The paper aims to: discuss the various simulati…
Counterintuitive VSM Behavior under CVR Incorporating Distribution System
Alok Kumar Bharati, Venkataramana Ajjarapu, Zhaoyu Wang
This paper analyses the impact of conservation by voltage reduction (CVR) on voltage stability margin (VSM) considering transmission and distribution (T&D) systems. VSM is determin…
Deriving DERs VAR-Capability Curve at TSO-DSO Interface to Provide Grid Services
Ankit Singhal, Venkataramana Ajjarapu
The multitudes of inverter-based distributed energy resources (DERs) can be envisioned as distributed reactive power (var) devices (\textit{mini-SVCs}) that can offer var flexibili…
Monitoring Long Term Voltage Instability due to Distribution & Transmission Interaction using Unbalanced μPMU & PMU Measurements
Amarsagar Reddy Ramapuram Matavalam, Ankit Singhal, Venkataramana Ajjarapu
This paper extends the idea of the Thevenin equivalent into unbalanced 3ϕ circuits and proposes a 3ϕ long-term voltage stability indicator (VSI), that can identify critical loads i…
Monitoring & Mitigation of Delayed Voltage Recovery using μPMU Measurements with Reduced Distribution System Model
Amarsagar Reddy Ramapuram Matavalam, Ramakrishna Venkatraman, Venkataramana Ajjarapu
This paper proposes a new method to monitor and mitigate fault induced delayed voltage recovery (FIDVR) phenomenon in distribution systems using μPMU measurements in conjunction wi…
Identifying Long Term Voltage Stability Caused by Distribution Systems vs Transmission Systems
Amarsagar Reddy Ramapuram Matavalam, Ankit Singhal, Venkataramana Ajjarapu
Monitoring the long term voltage stability of the power grid is necessary to ensure its secure operation. This paper presents a new phasor based methodology that distinguishes betw…
On Information Transfer Based Characterization of Power System Stability
Subhrajit Sinha, Pranav Sharma, Umesh Vaidya +1
In this paper, we present a novel approach to identify the generators and states responsible for the small-signal stability of power networks. To this end, the newly developed noti…
PMU based Monitoring and Mitigation of Delayed Voltage Recovery using Admittances
Amarsagar Reddy Ramapuram Matavalam, Venkataramana Ajjarapu
This paper analyzes the delayed voltage recovery phenomenon by simplifying the Western Electricity Coordinating Council (WECC) composite load model using the load admittance and th…
Dynamic Co-Simulation Methods for Combined Transmission-Distribution System and Integration Time Step Impact on Convergence
Ramakrishnan Venkatraman, Siddhartha Kumar Khaitan, Venkataramana Ajjarapu
Combined Transmission and Distribution Systems (CoTDS) simulation for power systems requires development of algorithms and software that are numerically stable and at the same time…
A Framework to Utilize DERs' VAR Resources to Support the Grid in an Integrated T-D System
Ankit Singhal, Venkataramana Ajjarapu
Increasing penetration of inverter-based distributed energy resources (DERs) opens up interesting opportunities for the transmission systems. We present a hypothesis that the numer…
Long-Term Voltage Stability Assessment of an Integrated Transmission Distribution System
Ankit Singhal, Venkataramana Ajjarapu
Long-term voltage stability assessment (VSA) of independent transmission (T-VSA) and distribution (D-VSA)systems have been studied since long to estimate load margins. However, the…
Real-Time Local Volt/VAR Control Under External Disturbances with High PV Penetration
Ankit Singhal, Venkataramana Ajjarapu, Jason. C. Fuller +1
Volt/var control (VVC) of smart PV inverter is becoming one of the most popular solutions to address the voltage challenges associated with high PV penetration. This work focuses o…