Stabilizing a DC electricity network

Patent metadata

Field	Value
Publication number	US-10128652-B2
Application number	US-201214344760-A
Country	US
Kind code	B2
Filing date	Sep 12, 2012
Priority date	Sep 14, 2011
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

A method of stabilizing a DC electricity network, the network including a DC voltage source powering electrical loads that are connected in parallel to terminals of the voltage source and each of which is to receive a current or voltage setpoint. The method stabilizes the network by regulating setpoints applied to the loads by a virtual stabilization impedance generated at terminals of each load, the virtual impedances being dimensioned to stabilize the network in desired operating points and in given configurations of the network including a state in which at least one load is inactive or has failed and a state in which the stabilization of a load is inactive. Each virtual impedance is generated by a non-linear regulation loop acting on the setpoint for the corresponding load.

First claim

The invention claimed is:

1. A method of stabilizing a DC electricity network, the DC electricity network including a DC voltage source powering electrical loads that are connected in parallel to terminals of the DC voltage source, each electrical load to receive a power setpoint, the method comprising:
stabilizing the DC electricity network by regulating the power setpoints applied to the respective electrical loads by virtual stabilization impedances each generated at terminals of each respective electrical load, the virtual stablization impedances being dimensioned to stabilize the DC electricity network in desired operating points and in given configurations of the DC electricity network including a state in which at least one electrical load of the electrical loads is inactive or has failed and a state in which stabilization of an electrical load of the electrical loads is inactive, any one of said virtual stabilization impedances being generated at the terminals of one of said electrical loads by a stabilization block of a non-linear regulation loop that acts on the power setpoint of said one of the electrical loads and that generates a stabilization signal p v (t) for superposing to said power setpoint of said one of the electrical loads, the stabilization signal being so that:
p v ( t )= v s ( t )· C v ·dv s /dt

or
p v ( t )= K·v s 2 −X 3

in which:
v s represents a DC voltage at the terminals of said one of the electrical loads, C v and K are parameters defining the virtual stabilization impedance, and X 3 is an output signal from a filter of cutoff frequency w c that receives the signal K·v s 2 as input.

2. The method according to claim 1 , wherein any one of the non-linear regulation loops acting on the power setpoint of said one of the electrical loads uses a non-linear regulation relationship generating an output signal of type K·f(x), wherein x is a control variable for said one of the electrical loads and K is a correction coefficient specific to said one of the electrical loads, said correction coefficient being determined by performing the steps consisting in:
(a) defining a mathematical model of the DC electricity network, said mathematical model comprising equations including said correction coefficient for ensuring stability of the electrical loads and of the DC electricity network;
(b) defining constraints to be satisfied so that the DC electricity network remains stable, or remains stable in event of the DC electricity network being reconfigured or in event of a failing of at least one electrical load of the electrical loads;
(c) determining an optimum vector (X 0 ) of the correction coefficients by an optimization algorithm for verifying that a given vector satisfies constraints and for calculating a target function for stabilizing the optimum vector; and
(d) repeating operations (a)-(c) until obtaining a vector that satisfies the constraints and that has smallest possible correction coefficients.

3. The method according to claim 2 , wherein the constraints to be satisfied include acceptable ranges of values for the correction coefficients and for maintaining stabilization in event of:
the DC electricity network being reconfigured,
a failure in the stabilization of at least one electrical load of said electrical loads, and
given variations or inaccuracies in parametric values specific to the DC electricity network.

4. The method according to claim 2 , wherein the mathematical model includes equations characterizing the DC electricity network in absence of at least one electrical load of the electrical loads and/or in absence of stabilization for at least one electrical load of the electrical loads.

5. The method according to claim 2 , wherein the optimization algorithm serves to compare a calculation of a target function using a vector with a calculation of a same function using another vector in which the correction coefficients are the smallest possible, and then in repeating operation (a)-(c) until the vector under consideration is identical to the vector having the smallest possible coefficients.

6. A DC electricity network comprising:
a DC voltage source powering electrical loads that are connected in parallel to terminals of the DC voltage source and each of the electrical loads is to receive a power setpoint;
the DC electricity network being stabilized by regulating power setpoints applied to the electrical loads by stabilization blocks installed in non-linear regulation loops, each of the stabilization blocks configured to generate a virtual stabilization impedance for an electrical load of the electrical loads and including an input connected to means for measuring voltage at terminals of the corresponding electrical load and an output connected to a terminal for applying the power setpoint of the electrical load by a summing circuit, wherein
the virtual stabilization impedances are dimensioned to stabilize the DC electricity network in desired operating points and in given configurations of the DC electricity network including a state in which at least one of the electrical load is inactive or has failed and a state in which stabilization of corresponding each of the electrical loads is inactive, any one of said virtual stabilization impedances being generated at the terminals of one of the electrical loads by a stabilization block of a non-linear regulation loop that acts on the power setpoint of the corresponding electrical load and generates a stabilization signal p v (t) for superposing to the power setpoint of said one of the electrical loads, the stabilization signal being so that:
p v ( t )= v s ( t )· C v ·dv s /dt

or
p v ( t )= K·v s 2 −X 3

where:
v s represents a DC voltage at the terminals of said one of the electrical loads, C v and K are parameters defining the virtual stabilization impedance, and X 3 is an output signal from a filter of cutoff frequency w c that receives the signal K·v s 2 as input.

7. The DC electricity network of claim 6 , wherein the stabilization block comprises a lowpass filter and a subtractor, an input of the lowpass filter being connected to the means for measuring and its output being connected to the subtractor for subtracting a filter output signal from a signal coming from the means for measuring.

8. A transport means comprising the DC electricity network according to claim 6 .

9. A method of stabilizing a DC electricity network, the DC electricity network having a DC voltage source powering electrical loads that are connected in parallel to the terminals of the DC voltage source, each electrical load to receive a power setpoint, the method comprising:
stabilizing the DC electricity network by regulating the power setpoints applied to the respective electrical loads by virtual stabilization impedances each generated at the terminals of each respective electrical load, the virtual stabilization impedances being dimensioned to stabilize the DC electricity network in desired operating points and in given configurations of the DC electricity network including a state in which at least one electrical load of the electrical loads is inactive or has failed and a state in which stabilization of an electrical load of the electrical loads is inactive, any one of said virtual stabilization impedances being generated at the terminals of one of said electrical loads by a stabilization block of a non-linear regulation loop that acts on the power setpoint of said one of the electrical loads and that generates a stabilization signal p v (t) for superposing to said power setpoint of said one of the electrical loads, the stabilization signal of at least one of the stabilization b

Assignees

• Vieillard Sebastien
• Magne Pierre
• Meibody Tabar Farid
• Nahid Mobarakeh Babak
• Pierfederici Serge
• Labinal Power Systems
• Univ De Lorraine

Inventors

• Vieillard Sebastien
• Magne Pierre
• Meibody-Tabar Farid
• Nahid-Mobarakeh Babak
• Pierfederici Serge

Classifications

• H03H7/0138

  Electrical filters or coupling circuits · CPC title

• H02J3/24

  Electricity · mapped topic

• Y10T307/43

  Cross-Sectional Technologies · mapped topic

• G06F17/10

  Complex mathematical operations {(function generation by table look-up G06F1/03; evaluation of elementary functions by calculation G06F7/544)} · CPC title

• B60R16/03

  for supply of electrical power to vehicle subsystems {or for (circuit arrangements for charging batteries H02J7/00)} · CPC title