Harsha Nagarajan

Learning to Accelerate the Global Optimization of Quadratically-Constrained Quadratic Programs

  • Rohit Kannan
  • Harsha Nagarajan
  • Deepjyoti Deka
    • Categories Global Optimization Tags , , , , , ,

    We learn optimal instance-specific heuristics for the global minimization of nonconvex quadratically-constrained quadratic programs (QCQPs). Specifically, we consider partitioning-based mixed-integer programming relaxations for nonconvex QCQPs and propose the novel problem of strong partitioning to optimally partition variable domains without sacrificing global optimality. We design a local optimization method for solving this challenging max-min strong partitioning … Read more

    Tightening Quadratic Convex Relaxations for the AC Optimal Transmission Switching Problem

  • Cheng Guo
  • Harsha Nagarajan
  • Merve Bodur
    • Categories (Mixed) Integer Nonlinear Programming Tags , , ,

    The Alternating Current Optimal Transmission Switching (ACOTS) problem incorporates line switching decisions into the fundamental AC optimal power flow (ACOPF) problem. The advantages of the ACOTS problem are well-known in terms of reducing the operational cost and improving system reliability. ACOTS optimization models contain discrete variables and nonlinear, non-convex constraints, which make it difficult to … Read more

    Optimal Power Flow in Distribution Networks under N-1 Disruptions: A Multi-stage Stochastic Programming Approach

  • Harsha Nagarajan
  • Haoxiang Yang
    • Categories Stochastic Programming Tags , , , ,

    Contingency research to find optimal operations and post-contingency recovery plans in distribution networks has gained a major attention in recent years. To this end, we consider a multi-period optimal power flow (OPF) problem in distribution networks, subject to the N-1 contingency where a line or distributed energy resource fails. The contingency can be modeled as … Read more