Secure distributed state estimation for networked microgrids

Patent metadata

Field	Value
Publication number	US-12483063-B2
Application number	US-201816142103-A
Country	US
Kind code	B2
Filing date	Sep 26, 2018
Priority date	Sep 26, 2018
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

Systems, methods, techniques and apparatuses of networked microgrids are disclosed. One exemplary embodiment is a method for removing false data from a networked microgrid system including: calculating a first local state estimation with the microgrid control system; calculating a plurality of global state estimations with the microgrid control system and the plurality of microgrids; determining the plurality of global state estimations did not converge; detecting false data in a first global state estimation of the plurality of global state estimations calculated with the microgrid control system using the microgrid control system and the plurality of microgrids; and removing the first global state estimation from the plurality of global state estimations; and iteratively updating the remaining global state estimations of the plurality of global state estimations with the microgrid control system and the plurality of microgrids until the remaining global state estimations of the plurality of global state estimations converge.

First claim

What is claimed is:

1 . A method of operating a first microgrid of a networked microgrid system that includes the first microgrid and a plurality of other microgrids, the method comprising:
measuring a first plurality of local measurements using a plurality of field devices of the first microgrid; calculating a first local state estimation with a microgrid control system of the first microgrid, the calculating using the first plurality of local measurements; receiving, by the microgrid control system, a plurality of local state estimations from the plurality of other microgrids, the local state estimations being received by way of a microgrid communication network; calculating, by the microgrid control system, a plurality of global state estimations with the microgrid control system and the plurality of other microgrids using the first local state estimation and the plurality of local state estimations; determining that the plurality of global state estimations did not converge; based on the determination that the plurality of global state estimations did not converge, detecting false data in a first global state estimation of the plurality of global state estimations calculated with the microgrid control system using the microgrid control system and the plurality of other microgrids; removing the first global state estimation from the plurality of global state estimations; iteratively updating the remaining global state estimations of the plurality of global state estimations with the microgrid control system and the plurality of other microgrids; determining that the global state estimations are not converging; using a modified global state estimation equation to detect a compromised microgrid control system; cutting links with the compromised microgrid control system; again iteratively updating the remaining global state estimations without global state estimations of the compromised microgrid control system until the remaining global state estimations of the plurality of global state estimations converge thereby obtaining converged global state estimations; monitoring the first microgrid using the converged global state estimations; and operating controllable devices of the first microgrid and protecting devices coupled to the first microgrid from faults and other conditions by using the converged global state estimations for stability analysis and demand response.

2 . The method of claim 1 , further comprising determining a topology of the microgrid communication network by receiving, with the microgrid control system, information from a first portion of the plurality of other microgrids in direct communication related to the first portion, and subsequently receiving, from the first portion, information related to a second portion of the plurality of other microgrids in indirect communication with the microgrid control system.

3 . The method of claim 1 , wherein the plurality of global state estimations converge when each global state estimation has a standard deviation less than a threshold value.

4 . The method of claim 1 , wherein calculating the plurality of global state estimations occurs using a plurality of iterations and determining that the plurality of global state estimations did not converge occurs after the plurality of iterations.

5 . The method of claim 1 , wherein detecting false data in the first global state estimation includes updating a dynamic trust matrix including a plurality of trust factors including a first trust factor corresponding to a weight applied to the global state estimation received by the microgrid control system from one microgrid of the plurality of other microgrids and a second trust factor corresponding to a weight applied to the global state estimation calculated by the microgrid control system.

6 . The method of claim 1 , wherein detecting false data in the first global state estimation includes updating the plurality of global state estimations using the following equation set:
[ x _MGglobal]_( k,i )=ω_( k,i− 1)−μ_ k ∇_ω J _1(ω_( k,i− 1)) γ_ kl{circumflex over ( )} 2( i )=(1− v _ k )γ_ kl{circumflex over ( )} 2+ v _ k |ω_( k,i− 1)−[ x _MGglobal]_( k,i )|_2{circumflex over ( )}2 a _ kl ( i )=(γ_ kl {circumflex over ( )}(−2)( i ))/(Σ_( n∈N _ k )|[γ_ kn {circumflex over ( )}(−2)( i )]) ω_( k,i )=Σ_( l∈N _ i )| a _ kl[x _MGglobal]_( k,i )

where k is an agent microgrid control system, l is a neighbor microgrid control system, [x_MGglobal]_(k,i)∈R denotes the global state estimation of the agent microgrid control system k at iteration i, ω_(k,i) is an intermediate variable for agent microgrid control system k at iteration i, μ_k is a nonnegative updating parameter of agent microgrid control system k, ∇_ω J_1 (ω_(k,i−1)) is a stochastic gradient for agent microgrid control system k of an intermediate state ω at iteration i−1, v_k is a forgetting factor, and γ_kl{circumflex over ( )}2 is an instantaneous error metric.

7 . The method of claim 1 , wherein each global state estimation of the plurality of global state estimations corresponds to a voltage magnitude of a bus of the first microgrid.

8 . A non-transitory computer readable medium storing a set of instructions for performing certain steps of the method of claim 1 when executed by a processing device of the microgrid control system, the certain steps including calculating the first local state estimation, calculating the plurality of global state estimations, determining that the plurality of global state estimations did not converge, detecting the false data, removing the first global state estimation from the plurality of global state estimations, and iteratively updating the remaining global state estimations.

9 . A method operating a microgrid system that includes a first microgrid, a second microgrid and a third microgrid that communicate via a microgrid communication network that includes communication channels coupling the first, second and third microgrids with each other, the method comprising:
operating a first microgrid control system of a first microgrid, a second microgrid control system of a second microgrid, and a third microgrid control system of a third microgrid; obtaining a first plurality of measurements using a first plurality of field devices of the first microgrid, obtaining a second plurality of measurements using a second plurality of field devices of the second microgrid, and obtaining a third plurality of measurements using a third plurality of field devices of the third microgrid; calculating a first local state estimation with the first microgrid control system using the first plurality of measurements, a second local state estimation with the second microgrid control system using the second plurality of measurements, and a third local state estimation with the third microgrid control system using the third plurality of measurements; communicating between the first microgrid, the second microgrid and the third microgrid via the microgrid communication network to receive the first local state estimation by the second and third microgrid control systems, the second local state estimation by the first and third microgrid control systems, and the third local state estimation by the first and second microgrid control systems; using the first, second, and third local state estimations to calculate a first global state estimation of an electrical characteristic of the first microgrid with the first microgrid control system, a second global state estimation of the electrical characteristic with the second microgrid control system, and a third global state estimation of the electrical characteristic with the third microgrid control system; determining, with the first microgrid contro

Assignees

• Abb Schweiz Ag
• Hitachi Energy Ltd

Inventors

• Cintuglu Mehmet H
• Ishchenko Dmitry

Classifications

• H02J13/10 Primary

  characterised by displaying of information or by user interaction, e.g. supervisory control and data acquisition [SCADA] systems · CPC title

• H02J2105/10

  Local stationary networks having a local or delimited stationary reach · CPC title

• G06F17/16

  Matrix or vector computation {, e.g. matrix-matrix or matrix-vector multiplication, matrix factorization (matrix transposition G06F7/78)} · CPC title

• G01R21/133

  by using digital technique · CPC title

• G06Q10/06

  Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling · CPC title