Engineering topics

Zhang, Yijian

Publications and source records attributed to Zhang, Yijian.

5 records

DOE OSTI2018

Dynamic ADMM for Real-Time Optimal Power Flow

This paper considers distribution networks featuring distributed energy resources (DERs), and develops a dynamic optimization method to maximize given operational objectives in real time while adhering to relevant network constraints. The design of the dynamic algorithm is based on suitable linearization of the AC power flow equations, and it leverages the so-called alternating direction method of multipliers (ADMM). The steps of the ADMM, however, are suitably modified to accommodate appropriate measurements from the distribution network and the DERs. With the aid of these measurements, the resultant algorithm can enforce given operational constraints in spite of inaccuracies in the representation of the AC power flows, and it avoids ubiquitous metering to gather the state of noncontrollable resources. Optimality and convergence of the proposed algorithm are established in terms of tracking of the solution of a convex surrogate of the AC optimal power flow problem.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2018

Dynamic ADMM for Real-Time Optimal Power Flow: Preprint

This paper considers distribution networks featuring distributed energy resources (DERs), and develops a dynamic optimization method to maximize given operational objectives in real time while adhering to relevant network constraints. The design of the dynamic algorithm is based on suitable linearizations of the AC power flow equations, and it leverages the so-called alternating direction method of multipliers (ADMM). The steps of the ADMM, however, are suitably modified to accommodate appropriate measurements from the distribution network and the DERs. With the aid of these measurements, the resultant algorithm can enforce given operational constraints in spite of inaccuracies in the representation of the AC power flows, and it avoids ubiquitous metering to gather the state of non-controllable resources. Optimality and convergence of the propose algorithm are established in terms of tracking of the solution of a convex surrogate of the AC optimal power flow problem.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2017

Upregulation of PAG1/Cbp contributes to adipose-derived mesenchymal stem cells promoted tumor progression and chemoresistance in breast cancer

C-terminal Src kinase (Csk)-binding protein (Cbp) is a ubiquitously expressed transmembrane adaptor protein which regulating Src family kinase (SFK) activities. Although SFKs are well known for their involvement in breast cancer, the function of Cbp in breast carcinogenesis upon the adipose-tumor microenvironment has not been investigated. Here, we reported that adipose-derived mesenchymal stem cells (ASCs) induced increased expression of Cbp accompanied by enhanced cell proliferation and chemotherapy resistance in breast cancer cell MCF-7/ADR. Depletion of Cbp in breast cancer cell by RNA interference led to remarkable inhibition of cell proliferation, invasion as well as synergy with adriamycin hydrochloride to suppress the tumor growth. Furthermore, silencing of Cbp concomitantly inhibited the expression of phosphoryl of Src, AKT and mTOR signals. Our study highlights the underlying mechanism of cross interaction between ASCs and breast cancer cells, and indicates that PAG1/Cbp in breast cancer cell may modulate tumor progression and acquired chemoresistance in the ASCs-associated breast cancer microenvironment through Src and AKT/mTOR pathways.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2017

Regulation of Renewable Energy Sources to Optimal Power Flow Solutions Using ADMM

This paper considers power distribution systems featuring renewable energy sources (RESs), and develops a distributed optimization method to steer the RES output powers to solutions of AC optimal power flow (OPF) problems. The design of the proposed method leverages suitable linear approximations of the AC-power flow equations, and is based on the Alternating Direction Method of Multipliers (ADMM). Convergence of the RES-inverter output powers to solutions of the OPF problem is established under suitable conditions on the stepsize as well as mismatches between the commanded setpoints and actual RES output powers. In a broad sense, the methods and results proposed here are also applicable to other distributed optimization problem setups with ADMM and inexact dual updates.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2017

Distributed Controllers Seeking AC Optimal Power Flow Solutions Using ADMM

This paper focuses on power distribution systems with inverter-interfaced renewable energy sources (RESs), and develops a distributed control framework to steer the RES output powers to solutions of ac optimal power flow (OPF) problems. The design of the distributed control algorithm is based on suitable linear approximation of the ac power-flow equations, and leverages the so-called alternating direction method of multipliers (ADMM). Convergence of the RES-inverter output powers to solutions of the approximate ac OPF problem is established under suitable conditions on the mismatches between the commanded setpoints and actual RES output powers. Overall, since the proposed scheme can be cast as an ADMM with inexact primal and dual updates, the convergence results can be applied to more general distributed optimization settings.

24 POWER TRANSMISSION AND DISTRIBUTION↗