# US 2014/0197795 A1 · System for Balancing, by Magnetic Coupling, an Association in Series of Elements for Generating or Storing Electrical Energy > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197795 A1 - Document ID: US20140197795A1 - Status: Published application - Kind: A1 - Application number: 13/579,786 - Filed: 2011-02-14 - Published: 2014-07-17 - Earliest claimed: 2010-02-17 - Assignees: Institut Polytechnique De Grenoble; Centre National De La Recherche Scientifique - Inventors: Jean-Christophe Crebier; Alexandre Chureau - Web page: https://patentgrep.com/patent/US20140197795A1 ## CPC - H02J 7/56: Active balancing, e.g. using capacitor-based, inductor-based or DC-DC converters - H02J 7/35: with light sensitive cells - H02J 7/52: for charge balancing, e.g. equalisation of charge between batteries - Y02E 10/56: Power conversion systems, e.g. maximum power point trackers - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract The invention relates to a system for balancing an association in series of elements for generating and/or storing electrical energy, characterised in that it comprises: a plurality of full bridge inverters (OPC1, OPC2, OPCN), each consisting of two inverter arms connected in parallel between two end ports of the inverter, each inverter arm, in turn, consisting of two switches (Th1, Tb1; Th2, Tb2) connected in series by a so-called median point (P11, P12) of the arm; a plurality of connectors for connecting the two end ports of each full bridge inverter to a respective element (CA1, CA2, CAN, PV1, PV2, PVN) of said association in series; and a magnetic coupler (NM) formed by a magnetic core on which a plurality of windings (ŴW2, WN) is formed, each winding being connected to the median points of the arms of one of said inverters. The invention also relates to an association in series of elements (CA1, CA2, CAN) for the electrochemical storage of electrical energy, provided with such a balancing system. The invention further relates to an association in series of photovoltaic cells (PV1, PV2, PVN) provided with such a balancing system. ## Claims ### Claim 1 A system for balancing a series association of elements for generating and/or storing electrical energy, the system being characterized in that it comprises: a plurality of full-bridge inverters (OPC1, OPC2, OPCN) each of which is constituted by two inverter arms connected in parallel between two end ports of the inverter, each inverter arm being constituted in turn by two switches (Th1, Tb1; Th2, Tb2) connected in series via a midpoint (P11, P12) of the arm; a plurality of connectors for connecting the two end ports of each full-bridge inverter to a respective element (CA1, CA2, CAN, PV1, PV2, PVN) of said series association; and a magnetic coupler (NM) formed by a magnetic core having a plurality of windings (W1, W2, WN) wound thereon, each of said windings being connected to the midpoints of the arms of a respective one of said inverters. ### Claim 2 (depends on 1) A balancing system according to claim 1, wherein a protection switch (Tpi) is connected in series with an end port of each inverter. ### Claim 3 (depends on 1) A balancing system according to claim 1, wherein each of said elements of said series association is constituted by a parallel association of sub-elements, and wherein each protection switch (Tpi1, Tpi2, Tpi3) is connected in series between each of said sub-elements and an end port of the corresponding inverter. ### Claim 4 (depends on 1) A balancing system according to claim 1, wherein a respective filter capacitor (C1, C2, CN) is connected in parallel with each element of said series association, between the two end ports of the corresponding inverter. ### Claim 5 (depends on 1) A balancing system according to claim 1, also including control means (MP) for generating control signals for controlling said inverters so as to balance said elements. ### Claim 6 (depends on 5) A balancing system according to claim 5, also including measurement means (CC) for measuring the voltage across the terminals of each element of said series association, said control means being adapted to operate said inverters when the maximum voltage difference between two elements exceeds a first threshold, and until said difference drops below a second threshold. ### Claim 7 (depends on 6) A balancing system according to claim 6, wherein said measurement means comprise a current sensor (CC) connected in parallel with a switch of an inverter, the control means being adapted to control each inverter in individual manner in order to store energy in magnetic form in the core of the magnetic coupler, and then to control the inverter fitted with said current sensor so as to discharge said energy in the form of an electric current directed through said sensor. ### Claim 8 (depends on 5) A balancing system according to claim 5, wherein said control means are adapted to control a plurality of said inverters in synchronous manner, with a common duty ratio substantially equal to 0.5. ### Claim 9 (depends on 8) A balancing system according to claim 8, wherein: said control means are arranged to control a single one of said inverters, to form a master inverter; and the switches of the other inverters of the system, form slave inverters which are controlled by the voltages that appear at the terminals of the respective windings as a result of the operation of said master inverter. ### Claim 10 (depends on 8) A balancing system according to claim 8, wherein said control means are adapted to control said inverters in synchronous manner with an adjustable phase shift between the signals controlling the various inverters. ### Claim 11 (depends on 5) A balancing system according to claim 5, wherein said control means are adapted: to act over one half-cycle to control one or more inverters connected to one or more elements of said series association presenting a voltage greater than a reference value in such a manner as to store energy in magnetic form in the core of the magnetic coupler; and then over a half-cycle, to control the inverter(s) connected to one or more elements of said series association presenting a lower voltage in such a manner as to discharge said magnetic energy; and to repeat the above operations cyclically. ### Claim 12 (depends on 1) A balancing system according to claim 1, wherein each inverter is monolithically integrated on a respective chip. ### Claim 13 (depends on 12) A balancing system according to claim 12, wherein each of said chips also integrates close control means (CR1, CR2, CTP) for said switches, which are implemented in the form of power transistors. ### Claim 14 (depends on 12) A balancing system according to claim 12, wherein said chips are made using CMOS technology. ### Claim 15 (depends on 1) A series association of elements (CA1, CA2, CAN) for electrochemically storing electrical energy and including a voltage balancing system according to claim 1. ### Claim 16 (depends on 1) A series association of photovoltaic cells (PV1, PV2, PVN) including a balancing system according to claims 1.