Finite time power control for smart-grid distributed system

Patent metadata

Field	Value
Publication number	US-9419437-B2
Application number	US-201314134075-A
Country	US
Kind code	B2
Filing date	Dec 19, 2013
Priority date	Dec 19, 2013
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A distributed energy resource (DER) exchanges with each neighboring DER portions of the total demand for power accumulated by the DER and each neighboring DER and portions of a total capability of the network to generate the total power accumulated by the DER and each neighboring DER before each communication step. The DER updates the portion of the total demand for power and total capability accumulated by the DER using the portions of the total demand and the portions of the total capability received from the neighboring DERs. After the fixed number of communication steps, the DER accumulates the total demand for power and the total capability of the network and generates an amount of the power as a product of the total demand for the power and a ratio of a maximum capability of the DER to generate the power and the total capability of the network.

First claim

The invention claimed is:

1. A method for generating power by a distributed energy resource (DER) for a power grid including a network of DERs, such that a total demand for the power in the power grid is jointly satisfied by the network of DERs, comprising:
exchanging, between the DER and each neighboring DER at each communication step of a fixed number of communication steps, portions of the total demand for power accumulated by the DER and each neighboring DER before the communication step, and portions of a total capability of the network to generate the total power accumulated by the DER and each neighboring DER before the communication step;
updating, after each communication step, the portion of the total demand for power accumulated by the DER before the communication step using the portions of the total demand for power received from the neighboring DERs;
updating, after each communication step, the portion of the total capability of the network accumulated by the DER before the communication step using the portions of the total capability of the network received from the neighboring DERs;
accumulating, after the fixed number of communication steps, the total demand for power and the total capability of the network; and
generating an amount of the power as a product of the total demand for the power and a ratio of a maximum capability of the DER to generate the power and the total capability of the network.

2. The method of claim 1 , further comprising
encoding the portion of the total demand for power and the portion of the total capability of the network accumulated by the DER with a weight factor randomly selected from a continuous distribution for a current communication step;
decoding the portion of the total demand for power and the portion of the total capability of the network received from each neighboring DERs with a contribution coefficient predetermined for the current communication step to produce an update of the total demand and an update of the total capability corresponding to the current communication step;
summing the updates of the total demand determined for a finite number of communication steps to produce the total demand of the reactive power in the network; and
summing the updates of the total capability determined for the finite number of communication steps to produce the total capability of the network.

3. The method of claim 2 , wherein the contribution coefficients are determined based on a topology and a size of the network of DERs.

4. The method of claim 1 , wherein the total demand for power is a demand for reactive power, and the total capability of the network is a capability of the network to generate the reactive power.

5. The method of claim 4 , wherein the DER generates the reactive power Q i * determined according to

Q
i
*

Q
TOTAL

=

Q
i
MAX

∑
i

⁢

Q
i
MAX

,

wherein i is an index of the DER in the network, Q i MAX is a maximum reactive power capability of the DER, and Σ i Q i MAX is the total capability of the network to generate the reactive power.

6. The method of claim 1 , wherein the finite number of communication steps is N−2, and wherein N is a size of the network.

7. A method for generating a reactive power by a distributed energy resource (DER) into a power grid including a network of DERs, comprising:
a receiving, from neighboring DERs at each communication step, at least a portion of a total demand of reactive power in the network and at least a portion of a total capability of the network to generate the reactive power, wherein, at each communication step, each neighboring DER recursively updates the portion of the total demand and the portion of the total capability based on information propagated within the network at each communication step;
determining, at each current communication step, an update of the total demand and an update of the total capability corresponding to the current communication step using a contribution coefficient predetermined for the current communication step;
summing the updates of the total demand determined for a finite number of communication step to produce the total demand of the reactive power in the network;
summing the updates of the total capability determined for the finite number of communication step to produce the total capability of the network; and
generating an amount of the reactive power proportional to the total demand and a ratio of a maximum capability of the DER to generate the reactive power and the total capability of the network.

8. A distributed energy resource (DER), comprising:
a memory storing a finite number of contribution coefficients, each contribution coefficient corresponds to a communication step from the finite number of communication steps and indicates an update of a total demand for power at the corresponding communication step;
a receiver for receiving, at each communication step, a portion of the total demand for power accumulated by each of neighboring DERs;
a transmitter for transmitting, to each of the neighboring DERs at each communication step, a portion of the total demand for power accumulated by the DER; and
a processor for decoding from the received portion of the total demand for power the update of the total demand for power using a contribution coefficient corresponding to a current communication step and for accumulating the updates of the total demand for power determined for the finite number of communication steps to produce the total demand for power in the network.

Assignees

• Mitsubishi Electric Res Laboratories Inc

Inventors

• Benosman Mouhacine
• Polymeneas Evangelos

Classifications

• H02J3/003

  Load forecast, e.g. methods or systems for forecasting future load demand · CPC title

• G06Q50/06

  Energy or water supply · CPC title

• H02J3/48

  Controlling the sharing of active power · CPC title

• H02J3/381 Primary

  Dispersed generators · CPC title

• Y04S10/12

  Monitoring or controlling equipment for energy generation units, e.g. distributed energy generation [DER] or load-side generation · CPC title