Single-controllable low voltage microgrid, control process and use

Patent metadata

Field	Value
Publication number	US-12322972-B2
Application number	US-202318543496-A
Country	US
Kind code	B2
Filing date	Dec 18, 2023
Priority date	Dec 19, 2022
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

This technology refers to a control process for single-controllable low-voltage microgrids (Mgs) (SCM) having centralized communication. The process is based on the “Power-Based Control” (PBC) technique by adapting it to the context of SCMs through a modified PBC process (MPBC). The technology includes a process that provides the following technical effects: (1) sharing of active power and reactive power proportionately to the capacity of distributed energy resources (DERs or DGs) in the MG, for example, rendering the use of batteries based on different technologies (lead-acid, ion-lithium, etc.) compatible; (2) compensation for the current unbalance at the point of common coupling (PAC); (3) allows exploration of battery banks by balancing the charging status of storage elements; (4) allows implementation of the control process without knowing the electrical grid's parameters and topology; (5) is able to deal with the arbitrary connection of inverters into the MG, in addition to other advantages. The technology is applied in the technical field of equipment and infrastructure for the development of MGs.

First claim

The invention claimed is:

1. A control process for a single-controllable low voltage microgrid, the control process comprising:
a) temporally delimiting a control cycle k;
b) measuring for control cycle k found in step “a” the status of each DER mn , where index mn represents the connections between phases in the three-phase system a, b and c (mn=ab,bc,ca) and j is a numeric identifier for each DER in the microgrid, wherein such status is represented by:
(i) P DERj mn (k), Q DERj mn (k), output active and reactive power, respectively;
(ii) actual maximum capacity to provide active power P DERj mn max (k), actual maximum capacity to absorb active power p DERj mn min (k), expressed as a negative value;
(iii) maximum capacity of processing reactive power Q DERj mn max as calculated by expression (1), where A DERj mn (k) is the DER apparent power:

Q

DERj
mn

max

(
k
)

=

A

DERj
mn

(
k
)

2

-

P

DERj
mn

(
k
)

2

;

(
1
)

c) once a central controller located at a secondary level has gathered all the required data packets from each DER in the microgrid, calculating the status of the microgrid in terms of power quantities, with the first step calculating the total power and energy E DERj mn (k) quantities stored in DER battery banks connected between the mn phases using expression (2):

[

P

DERt
mn

,

Q

DERt
mn

,

P

DERt
mn

max

,

Q

DERt
mn

max

,

E

DERt
mn

]

=

∑

j
=
1

J

[

P

DERj
mn

,

Q

DERj
mn

,

P

DERj
mn

max

,

Q

DERj
mn

max

,

E

DERj
mn

]

;

(
2
)

d) converting the power computed per phase in the PCC (P PCC a , P PCC b and P PCC c ) by the central controller due to power star measurement between phases (P PCC ab , P PCC bc and P PCC ca ) using conversion matrix (A) using expression (3) and analogously converting the reactive powers using expression (4), where P PCCm and Q PCCm are the active and reactive powers, respectively, as measured in m phase on the grid side at the PCC:

[

P

PCC
ab

Assignees

• Petroleo Brasileiro S A —Petrobras
• Univ Minas Gerais

Inventors

• Brandão Danilo Iglesias
• Dos Reis Geovane Luciano

Classifications

• H02J2103/35

  Grid-level management of power transmission or distribution systems, e.g. load flow analysis or active network management · CPC title

• H02J2101/24

  Photovoltaics · CPC title

• H02J2105/10

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

• H02J3/32 Primary

  using batteries or super capacitors with converting means · CPC title

• H02J3/388

  Arrangements for the handling of islanding, e.g. for disconnection or for avoiding the disconnection of power · CPC title