Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
  • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
  • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
  • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
  • H02M7/4826—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode operating from a resonant DC source, i.e. the DC input voltage varies periodically, e.g. resonant DC-link inverters
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
  • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
  • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
  • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
  • H02M7/483—Converters with outputs that each can have more than two voltages levels
  • H02M7/4835—Converters with outputs that each can have more than two voltages levels comprising two or more cells, each including a switchable capacitor, the capacitors having a nominal charge voltage which corresponds to a given fraction of the input voltage, and the capacitors being selectively connected in series to determine the instantaneous output voltage
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect
  • Y02T10/70—Energy storage systems for electromobility, e.g. batteries

Definitions

• the invention relates to the field of polyphase electrical systems, in particular three-phase, such as motor vehicle or renewable energy generator systems.
• the invention relates more particularly to devices for generating a direct voltage for such electrical systems.
• the classic electrical architectures of electric vehicles integrate a set of electronic power devices making it possible to adapt the current/DC voltage torque delivered by the battery on the one hand to the electrical power components of the vehicle, generally at 450V direct current and three-phase for motorization and connection to the network during charging operations on an alternating network; and on the other hand to an on-board network (usually at 12V).
• the components in particular DC/DC converters, inverters and chargers are also present and cohabit with a thermal traction chain.
• This architecture has a DC/AC converter (comprising an H-bridge) associated with a DC/DC converter opposite each cell or cluster of cells.
• an objective of this invention is to generate a DC voltage by forming a constant or adjustable DC voltage bus in an electric vehicle traction chain generating a three-phase current wave to supply the electric traction machine, so as to supply a on-board direct current network.
• the invention relates to a device forming a DC voltage bus for a polyphase electrical system, comprising several voltage branches each comprising a plurality of battery cell modules, each module comprising a cell or a cluster of battery cells, connected to a DC/AC converter comprising an H-bridge; said battery cell modules being connected together in series through the DC/AC converter; said voltage branches being each connected to a specific phase branch for said polyphase electrical system, at least one phase branch comprising a bypass connected to a rectifier module.
• the device comprises control means capable of controlling the converters so as to generate at the output of each voltage branch a voltage corresponding to the sum of a reference voltage required for the operation of the polyphase electrical system and of a identical common mode voltage for each branch, the temporal superposition of the voltages at the output of each voltage branch forming a voltage plateau extracted by the rectifier module to obtain the DC voltage.
• the set of DC/AC converters (each including the H bridge) in line with each cell makes it possible to generate a three-phase current wave to supply an electric traction machine.
• the device makes it possible to eliminate DC/DC converters internal to the battery by adding identical voltage components to the waveforms generated by the traction inverter so as to create a constant DC bus with adjustable amplitude.
• the device comprises three voltage branches connected to three phase branches each comprising a specific branch connected to said rectifier module;
• - Said rectifier module comprises a bypass diode
• Vmc common mode voltage
• the device forming a direct voltage bus comprises a battery charging connection module on a high voltage direct voltage network associated with the voltage branches.
• the invention further relates to a polyphase electrical system for a motor vehicle, comprising a device forming a direct voltage bus according to the invention, characterized in that the phase branches are connected to the traction motor of the motor vehicle, and the branches are connected to at least one electrical device of the vehicle.
• Another object of the invention relates to a motor vehicle comprising a polyphase electrical system according to the invention.
• the invention further relates to a polyphase electrical system for a renewable energy generator, comprising a device forming a DC voltage bus according to the invention, characterized in that the phase branches are connected to an electrical network, and the branches are connected to a renewable energy generator.
• the invention also relates to a renewable energy generator system comprising a polyphase electrical system according to the invention.
• the invention further relates to a method for generating polyphase electric current comprising steps for
• FIG.1 schematically illustrates a battery cell module of a device according to a preferred variant
• FIG.2 schematically illustrates a device forming a DC voltage bus according to a first preferred embodiment
• FIG.3 schematically illustrates the voltages delivered by the voltage branches constituting the phases of the polyphase system with a device according to the first embodiment
• FIG.4 schematically illustrates a bidirectional rectifier module for a device forming a DC voltage bus according to a second embodiment
• FIG.5 schematically illustrates a device forming a DC voltage bus according to a third embodiment
• - [Fig.6] schematically illustrates a device forming a DC voltage bus according to a fourth embodiment.
• the invention relates to a device forming a direct voltage bus for a polyphase electrical system.
• a polyphase electrical system in particular three-phase, can be an electrical system for a motor vehicle traction machine M; or an electrical system connected to the electricity grid and a PV renewable energy generator.
• the device forming a DC voltage bus comprises voltage branches A1, A2, A3 making it possible to produce a polyphase voltage system, in particular three voltage branches.
• Each voltage branch A1, A2, A3 comprises a plurality of battery cell modules C1, C2, C3.
• Each battery cell module comprises a cell or a cluster of battery cells c1.
• the battery cells are connected to a DC/AC converter.
• the cells c1 are connected to a DC/AC converter which mainly comprises, or preferably consists of, an H-bridge circuit (H).
• the cells c1 are also connected to a means of supervision BMS and/or of control Ct of the H-bridge and/or to a means of cell diagnostics.
• the preferred battery cell module can be illustrated in Figure 1.
• the battery cells c1 are connected to a battery management system BMS of the module, configured to supervise the cell or cells, carry out diagnostics and control the H-bridge. The detail of such an assembly can be the one depicted in Figure 1.
• the battery cell modules are connected together in series via the DC/AC converter, so as to form each of said voltage branches A1, A2, A3.
• Control means are provided to control all of the converters so as to obtain the desired voltage across the terminals of each voltage branch A1, A2, A3.
• the set of voltage branches, A1, A2, A3 forms a multilevel inverter integrated into the battery.
• Each voltage branch A1, k1, A3 is connected to a specific phase branch B1, B2, B3 for said polyphase electrical system. Furthermore, at least one phase branch, preferably the three phase branches B1, B2, B3 comprise a corresponding branch D1, D2, D3 connected to a rectifier module R1.
• the DC/AC converter more particularly the H bridge in line with each cell c1 makes it possible, by placing it in series with the other DC/AC converters of the same voltage branch, to generate a three-phase current wave to supply a electric traction machine M.
• the device makes it possible to eliminate DC/DC converters internal to the battery by adding to the reference polyphase voltages to be applied to the windings of the machine M, a set of identical voltages calculated to make it possible to form a constant DC voltage bus and amplitude adjustable.
• the invention makes it possible to use a polyphase alternating current, in particular to supply the motor M with high voltage, and at the same time to use the particular voltage waveforms generated and applied to the terminals of the rectifier R1 to form a bus adjustable direct voltage, in particular at high or low voltage, or even at very low voltage.
• the invention allows the creation of a DC voltage bus for the on-board network of a vehicle from the supply voltages of the traction machine M; to generate a constant or adjustable DC bus from variable amplitude and frequency voltages generated by the vehicle's traction inverter; and (in another embodiment) to generate an adjustable DC bus from alternating voltages imposed by the electrical network connected to PV photovoltaic panels for example.
• the device forming a bus comprises three derivations D1, D2, D3, originating from said three specific phase branches B1, B2, B3.
• the three derivations D1, D2, D3, start from their respective phase branch B1, B2, B3 from a tapping P1, P2, P3 on their respective phase branch B1, B2, B3.
• Said branches D1, D2, D3 are connected together at the output, Sr, of said rectifier module R1.
• said rectifier module R1 comprises a diode d1, d2, d3 per branch D1, D2, D3. This embodiment can be illustrated in Figure 2.
• this embodiment involves a simplified rectifier module R1 having usual components, easy to obtain and to mount.
• diodes are pondered to be particularly reliable and robust components.
• the DC/DC converter of the devices of the prior art disappears and its functionality is replaced by a set of three diodes connected separately to each of the phases of the electric machine M.
• the association of a specific control law in the generation of the voltage waveforms applied to the electric machine M makes it possible to produce a direct voltage of controlled and adjustable amplitude.
• the first embodiment is suitable for use in an electric vehicle in traction or vehicle charging mode, that is to say with discharge or charging of the battery and recovery of energy during braking.
• VMC common mode voltage
• the tensions are here to be understood as instantaneous tensions, evolving according to time.
• VMC common mode voltage
• the control means are therefore provided to control the converters so as to generate at the output of each voltage branch A1, A2, A3 the voltage Vondl, Vond2, Vond3 corresponding to the sum of the reference voltage Vrefl, Vref2, Vref3 required for the operation of the polyphase electrical system, in this example the electrical machine, and of the common mode voltage, Vmc, identical for each voltage branch A1, A2, A3, and this so that the temporal superposition of these Vondl voltages, Vond2, Vond3 form a voltage plateau. It is this voltage plateau which, extracted by the rectifier module, makes it possible to obtain the DC voltage Vdc.
• FIG. 3 illustrates the voltages Vondl, Vond2, Vond3 of the three arms A1, A2, A3 corresponding to the sum of a form of voltage identical to the three arms A1, A2, A3, this form of identical voltage being said to be of common mode Vmc , with respectively the reference voltages Vref1, Vref2, Vref3. The sum of these voltages is the one that we wish to apply to the machine M.
• the three-phase voltages obtained have a characteristic repetitive shape, but not sinusoidal. It is noted in the figure that the temporal superposition of these forms of voltages Vond1, Vond2, Vond3 then causes a plateau p of maximum voltage to appear. This plate p is used to manufacture a DC voltage bus.
• the rectifier module R1 makes it possible to take a DC voltage component which can be used for the on-board network.
• a mode of connection of the windings of the machine M in star or in triangle allows the natural elimination of the form of identical voltage added to each of the references of the voltages of the branches A1, A2, A3 and the voltages at the terminals of the windings of the machine M have the desired perfect sine waveform. The operation of the electric machine M is therefore normal.
• Another advantage of the invention lies in the control mode making it possible to generate the common mode voltage Vmc (that is, the form of identical voltage added to the voltage reference of each phase of the machine) required to obtain the voltage level on the DC network.
• This particular control mode allows the circulation of a high fluctuating power circulating in all the cells of the different arms A1, A2, A3.
• the management of this power in each battery element can be used to manage the balancing of the charge levels of the cells by authorizing in particular transfers of power from one voltage branch A1, k1, A3 to the other via the currents in the traction machine M.
• a second embodiment is based on a rectifier module R2 which is bidirectional.
• the rectifier module is modified by using, in a variant, a switching structure of the PWM type associated with a bridge arm for the management of the potential of the neutral (common mode voltage).
• Figure 4 shows an example of PWM structure compatible with this mode of operation.
• this structure makes it possible on the one hand to ensure the bidirectionality of the DC bus but on the other hand to finely control the drawing of energy in common mode and in differential mode while allowing adjustment of the DC voltage at the desired value. There is then nothing to prevent using the device forming a DC bus to supply another converter and another traction machine to ensure the four-wheel drive operation of a vehicle.
• the device forming a bus comprises a battery charging connection module (socket F) associated with the voltage branches A1, k1, A3.
• ocket F battery charging connection module
• the third embodiment is suitable for use in an electric vehicle (of the rechargeable type) in rapid charging mode (high voltage direct current) of the vehicle battery on the mains.
• Socket F is connected to the electrical network via a charging terminal delivering a direct voltage (for example at 350A - 1000V in maximum values).
• switch(es) are provided to allow the series connection of the voltage branches, the disconnection of the two diodes connected to the voltage branches at the highest potentials and the disconnection of the traction machine M.
• the invention concerns furthermore a polyphase electrical system comprising a device forming a direct voltage bus as described previously.
• the electrical system may be a system for an electric vehicle traction motor, for example of the PHEV, BEV, etc. type; or else an electrical system for a renewable energy generator connected to an electrical network RE via the battery cells c1.
• the first embodiment relates to a polyphase electrical system for a motor vehicle.
• This system comprises the device forming a direct voltage bus as described previously as well as a traction motor M connected to the device forming the bus.
• branches D1, D2, D3 are connected to at least one electrical device of the vehicle, more particularly to the network on board the vehicle. The details of the system have already been described previously. It can be illustrated in figure 2.
• the second embodiment relates to a polyphase electrical system for a motor vehicle, including a bidirectional rectifier module.
• this system comprises the device forming the DC voltage bus as described above, similar to that of the first embodiment with a difference at the level of the rectifier module which can for example be of the PWM type and bidirectional in terms of power transfer. energy (illustrated in Figure 4).
• the third embodiment relates to a polyphase electrical system for a motor vehicle, including a connection module allowing fast charging of the battery on a high voltage DC charging station.
• this system comprises the device forming the DC voltage bus as described previously, similar to that of the first embodiment with a difference at the level of the tap F and the switches s. It can be illustrated in figure 5.
• the invention further relates to a motor vehicle comprising a polyphase electrical system as described previously.
• the fourth embodiment relates to a polyphase electrical system for a renewable energy generator.
• renewable energy generator is meant a device transforming mechanical or solar energy into electrical energy. These include, for example, photovoltaic PV panels, wind turbines, hydroelectric systems or other systems of the dynamo-electric type.
• phase branches B1, B2, B3 are connected to an electrical network, and branches D1, D2, D3 are connected to a PV renewable energy generator. Furthermore, diodes d1, d2, d3 are inverted.
• the MPPT (Maximum Power Point Tracking) control technique is a principle that makes it possible to follow the maximum power point of a nonlinear electrical generator such as the solar panel. The interest is to adjust the output voltage of the solar panels to obtain the maximum power for a given current (which depends on the sunshine).
• the invention makes it possible to connect, via the three diodes d1, d2, d3 (figure 6), the PV solar panels directly to the battery and to eliminate the MPPT regulator, the maximum power search function now being directly managed by the battery .
• the stationary firm application leads to reversing the direction of the diodes d1, d2, d3, the control principle remaining the same.
• the invention makes it possible to connect photovoltaic panels (or other renewable energy generator) directly to the battery, avoiding traditional architecture.
• the elimination of intermediate components brings both a simplification of the system and its assembly, as well as better efficiency.
• a transformer T can be provided between the phase branches B1, B2, B3 and the electrical network RE.
• the invention further relates to a renewable energy generator system comprising a PV renewable energy generator, and a polyphase electrical system as previously described connected to said PV renewable energy generator.
• the possible variants of the invention include all the power electronic structures making it possible to use the common mode voltage generated to create auxiliary voltage sources, such as a module including a power factor corrector (PFC - Power Factor Corrector ) to absorb currents with controllable forms on the different phases of the battery.
• PFC - Power Factor Corrector power factor corrector
• the PFC package would replace diodes with a more complex structure that combines transistors and inductors.
• a rectifier module including a DC-DC converter with or without galvanic isolation.
• a DC-DC converter makes it possible to produce, for example, 12V or 48V.
• the invention also relates to a particular method for generating polyphase electric current.
• the method is preferably based on an architecture as described above.
• the method includes a step for series-connecting battery cell modules C1, C2, C3 via the series connection of H-bridge DC/AC converters (DCAC).
• DCAC H-bridge DC/AC converters
• the method further comprises a step for connecting each of said voltage branches A1, k1, A3 to a specific phase branch B1, B2, B3 for a polyphase electrical system M, RE. This step results in generating a polyphase alternating voltage system, in particular at the terminals of the voltage branches A1, k1, A3.
• the method further comprises a step for connecting at least one branch D1, D2, D3 of at least one phase branch B1, B2, B3 to a rectifier module R1, R2, R3 as the case may be.
• the three branches D1, D2, D3 of the three phase branches B1, B2, B3 are connected to said rectifier module. This step results in forming a DC voltage bus, in particular at the terminals of the rectifier module R1, R2 or R3 as the case may be.
• the basic principle consists in having the conversion structure of the traction chain generate voltages constituted by the superposition of a differential mode seen by the traction machine M and meeting the needs of motorization (traction/braking) of the vehicle ; and an adjustable common mode, naturally eliminated by the machine M (windings of the machine connected in star or delta).
• the voltages of the inverter comprising the common mode and the differential mode are generated between the outputs of the phase branches of the inverter connected in star and the neutral point of this structure.
• This common mode voltage is used to generate a DC on-board network.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Electric Propulsion And Braking For Vehicles (AREA)
• Charge And Discharge Circuits For Batteries Or The Like (AREA)
• Rectifiers (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2021
  • 2021-04-08 FR FR2103578A patent/FR3121797A1/fr active Pending
• 2022
  • 2022-03-16 CN CN202280027104.4A patent/CN117223212A/zh active Pending
  • 2022-03-16 WO PCT/FR2022/050474 patent/WO2022214745A1/fr active Application Filing
  • 2022-03-16 EP EP22713715.5A patent/EP4320720A1/fr active Pending
  • 2022-03-16 US US18/553,807 patent/US20240186914A1/en active Pending

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