Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
  • H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
  • H02P27/047—V/F converter, wherein the voltage is controlled proportionally with the frequency
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
  • H02P21/34—Arrangements for starting
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
  • H02P6/20—Arrangements for starting

Definitions

• the present invention relates to the supply of electric motors.
• a particularly interesting application of the invention lies in the field of supply of electric motors used in motor vehicles.
• a power supply system of an electric motor used in a motor vehicle comprises a power circuit for transmitting the voltage of the vehicle battery to an electronic card managing the power supply of said motor.
• An example of such a power supply system is shown diagrammatically in FIG. 1 for the supply of a three-phase electronically commutated motor 1 capable of driving a fan 2 of a heating, ventilation and air-conditioning system of a motor vehicle.
• Such a motor also known under the name of "brushless" motor (English terminology meaning "brushless"), or synchronous motor self-controlled magnets, comprises three stator windings, represented here in a triangle assembly, of which the voltages U, V and W are delivered by the power system.
• This power system includes:
• a power circuit 3 whose input terminals are connected to a voltage source (not shown) formed by the vehicle battery, and an electronic control circuit 4 for powering the motor
• the power system further comprises a safety switch 5 for selectively connecting the battery to the power circuit 3 and the circuit 4.
• this safety switch 5 is placed in series on the -BATT connection terminal, but could equivalently be connected in series to the + BATT terminal.
• the safety switch 5 is traditionally an enhancement type MOSFET transistor, for example N type, whose drain and source are connected in series on the -BATT connection terminal, and whose gate receives a control signal SW_CMD allowing to switch the transistor between a blocked state (open switch), or a saturated operating state (closed switch) in which the transistor behaves between its drain and its source as a very low value resistor.
• the fact of reducing the supply voltage during very precise operating phases of the engine for which the set speed is low makes it possible to significantly reduce the noise emissions due to the stator windings.
• the system according to the invention may also have one or more of the following characteristics, considered individually or in any technically possible combination:
• the power system further comprises a MOSFET transistor forming a safety switch, which, in the closed position, allows the connection of the power circuit to said DC voltage source, and a gate control means of the MOSFET transistor suitable for placing said transistor in the closed position in a saturated operating mode for a set speed higher than said threshold speed, or in a closed position in a linear operating mode for a set speed lower than said threshold speed.
• the MOSFET transistor is controlled to produce between the drain and the source a voltage increasing linearly as a function of the set speed.
• the threshold speed is between 10% and 30% of the maximum speed possible for the electric motor.
• the threshold speed is preferably equal to 20% of the maximum speed possible for the electric motor.
• the electric motor is brushless or with brushes.
• the electric motor is preferably without brushes.
• FIG. 1 is a simplified schematic representation of a power system of an electric motor according to the prior art
• Figure 1 has been described above with reference to the prior art.
• Figure 2 is a simplified schematic representation of a power system of an electric motor 1 according to the invention.
• a power circuit 3 whose input terminals are connected to a voltage source (not shown) formed by the vehicle battery, and
• a safety switch 5 for selectively connecting the battery to the power circuit 3 and the electronic control circuit 4.
• the power circuit 3 and consequently the electronic control circuit 4 are powered by the value of the voltage as delivered by the vehicle battery typically of the order of 13 volts.
• control module 6 making the system capable of reducing the value of DC voltage received by the power circuit during the operating phases of the engine for which the emissions sound are the most troublesome, typically when starting the electric motor and / or during operating phases for which the target speed of the electric motor is below a threshold speed.
• control module 6 represented here schematically in the form of an electronic circuit interposed between the safety switch 5 and the input of the power circuit 3 is therefore:
• the power circuit 3 be powered by the DC voltage from the battery when the target speed for the motor is greater than the threshold speed and
• FIG. 3 illustrates a particularly clever implementation in that it makes best use of the components already available in the system, in particular the MOSFET transistor 5 used as a safety switch to interrupt the power supply in the event of overheating, or to put on standby the system.
• the way the gate of the transistor is controlled so that it is not used as a simple switch More specifically, the transistor that was until now only used in saturated mode, regardless of the setpoint speed, will now be driven according to the target speed so as to:
• the control signal SW_CMD is generated by the module 6 as a function of the set speed SCONS -
• the control module 6 can be entirely software, managed for example by a microcontroller capable of generating, for linear operation, a Pulse Width Modulation (PWM) signal proportional to the reference speed.
• PWM Pulse Width Modulation

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Control Of Motors That Do Not Use Commutators (AREA)
• Control Of Ac Motors In General (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2013
  • 2013-11-20 FR FR1361377A patent/FR3013534B1/fr active Active
• 2014
  • 2014-11-18 WO PCT/EP2014/074946 patent/WO2015075039A2/fr active Application Filing
  • 2014-11-18 JP JP2016532606A patent/JP6445556B2/ja active Active
  • 2014-11-18 EP EP14799483.4A patent/EP3072232A2/de not_active Withdrawn
  • 2014-11-18 CN CN201480071059.8A patent/CN105850028B/zh active Active
  • 2014-11-18 US US15/038,210 patent/US9722527B2/en active Active

Non-Patent Citations (2)

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