Inverter for driving an electric motor comprising an integrated regulator
First Claim
1. An inverter for driving an AC electric motor that includes a stator having at least two phases and a rotor, the inverter comprising:
- a plurality of connection terminals configured to connect to a DC bus associated with a DC electrical energy source and a DC electric voltage;
an AC generator configured to deliver a current to a terminal block that is to be connected to phases of the AC electric motor;
a power supply line positioned between the connection terminals and the AC generator;
a power supply current measurement line on which circulates a measurement of current on the power supply line;
a plurality of motor current measurement lines on which circulate measurements of alternating current on a plurality of the phases of the AC electric motor, to enable alternating current circulating in each of the plurality of the phases to be known;
a first input configured to receive information that includes at least one source limit current value, which corresponds to the current on the power supply line, and a driving torque setpoint (Ccons) obtained from a torque demand setpoint (C CAN); and
a controller configured to receive the measurement of current on the power supply line, the alternating current circulating in each of the plurality of the phases of the AC electric motor, maximum and minimum limit currents of the DC electrical energy source, the torque demand setpoint (C CAN), and the driving torque setpoint (Ccons),wherein the controller drives phase currents of the AC electric motor according to the torque demand setpoint (C CAN) by keeping a current flowing in the power supply line at a value compatible with the limit currents of the DC electrical energy source,wherein, in order to drive the phase currents of the AC electric motor, the controller is configured to;
receive the measurement of the voltage on the power supply line and the signal from the resolver,determine a driving torque (Cpil) for the AC electric motor to drive the phase currents of the AC electric motor, so that the driving torque (Cpil) is identical to the driving torque setpoint (Ccons) when the current on the power supply line is different from the limit currents of the DC electrical energy source, and, if the current on the power supply line reaches any of the limit currents of the DC electrical energy source, the driving torque (Cpil) is reduced relative to the driving torque setpoint (Ccons) so as not to exceed any of the limit currents of the DC electrical energy source on the power supply line, andwherein, when the current on the power supply line reaches a limit current of the DC electrical energy source, the driving torque (Cpil) is reduced relative to the driving torque setpoint (Ccons) by a difference torque (Ct) with a value proportional to an overshoot of the limit current of the DC electrical energy source.
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Accused Products
Abstract
A driving inverter for a multi-phase electric motor includes an alternating current (AC) generator, at least one AC sensor, a power supply line, a current sensor, an input, and a controller. The AC delivers current to a terminal block that is connectable to the phases of the electric motor. The at least one AC sensor is arranged on a certain phase or certain phases powering the electric motor. The current sensor is arranged on the power supply line and senses a current thereon. The input receives information that includes a torque demand setpoint and at least one limit current value of a power source. The controller drives phase currents of the electric motor according to the torque demand setpoint and by keeping the current of the power supply line at an acceptable value according to the at least one limit current value of the power source. With the arrangement of the driving inverter, a maximum current can always be imposed on the power source with no risk of degrading it.
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Citations
12 Claims
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1. An inverter for driving an AC electric motor that includes a stator having at least two phases and a rotor, the inverter comprising:
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a plurality of connection terminals configured to connect to a DC bus associated with a DC electrical energy source and a DC electric voltage; an AC generator configured to deliver a current to a terminal block that is to be connected to phases of the AC electric motor; a power supply line positioned between the connection terminals and the AC generator; a power supply current measurement line on which circulates a measurement of current on the power supply line; a plurality of motor current measurement lines on which circulate measurements of alternating current on a plurality of the phases of the AC electric motor, to enable alternating current circulating in each of the plurality of the phases to be known; a first input configured to receive information that includes at least one source limit current value, which corresponds to the current on the power supply line, and a driving torque setpoint (Ccons) obtained from a torque demand setpoint (C CAN); and a controller configured to receive the measurement of current on the power supply line, the alternating current circulating in each of the plurality of the phases of the AC electric motor, maximum and minimum limit currents of the DC electrical energy source, the torque demand setpoint (C CAN), and the driving torque setpoint (Ccons), wherein the controller drives phase currents of the AC electric motor according to the torque demand setpoint (C CAN) by keeping a current flowing in the power supply line at a value compatible with the limit currents of the DC electrical energy source, wherein, in order to drive the phase currents of the AC electric motor, the controller is configured to; receive the measurement of the voltage on the power supply line and the signal from the resolver, determine a driving torque (Cpil) for the AC electric motor to drive the phase currents of the AC electric motor, so that the driving torque (Cpil) is identical to the driving torque setpoint (Ccons) when the current on the power supply line is different from the limit currents of the DC electrical energy source, and, if the current on the power supply line reaches any of the limit currents of the DC electrical energy source, the driving torque (Cpil) is reduced relative to the driving torque setpoint (Ccons) so as not to exceed any of the limit currents of the DC electrical energy source on the power supply line, and wherein, when the current on the power supply line reaches a limit current of the DC electrical energy source, the driving torque (Cpil) is reduced relative to the driving torque setpoint (Ccons) by a difference torque (Ct) with a value proportional to an overshoot of the limit current of the DC electrical energy source. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 12)
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11. A process for checking torque consistency in an AC electric motor driven by an inverter that includes:
- a plurality of connection terminals configured to connect to a DC bus associated with a DC electrical energy source and a DC electric voltage;
an AC generator configured to deliver a current to a terminal block that is to be connected to phases of the AC electric motor;
a power supply line positioned between the connection terminals and the AC generator;
a power supply current measurement line on which circulates a measurement of current on the power supply line;
a plurality of motor current measurement lines on which circulate measurements of alternating current on a plurality of the phases of the AC electric motor, to enable alternating current circulating in each of the plurality of the phases to be known;
a first input configured to receive information that includes at least one source limit current value, which corresponds to the current on the power supply line, and a driving torque setpoint (Ccons) obtained from a torque demand setpoint (CCAN); and
a controller configured to receive the measurement of current on the power supply line, the alternating current circulating in each of the plurality of the phases of the AC electric motor, maximum and minimum limit currents of the DC electrical energy source, the torque demand setpoint (C CAN), and the driving torque setpoint (Ccons), wherein the controller drives phase currents of the AC electric motor according to the torque demand setpoint (C CAN) by keeping a current flowing in the power supply line at a value compatible with the limit currents of the DC electrical energy source, the process comprising steps of;measuring a current and a voltage on the power supply line of the inverter; determining, from measurements of the current and the voltage, an electrical power consumed at the input of the inverter; determining, by subtracting a plausible losses value, a mechanical power from the electrical power consumed; determining, from the mechanical power determined and a motor shaft rotation speed, a mechanical torque on an output shaft of the AC electric motor; comparing the mechanical torque to the driving torque setpoint (Ccons) to obtain a difference; activating a warning in a case where the difference exceeds a predetermined threshold; and reducing the mechanical torque relative to the driving torque setpoint (Ccons) by a difference torque (Ct) in a case where the difference exceeds the predetermined threshold, wherein the difference torque (Ct) has a value proportional to an overshoot of a limit current of the DC electrical energy source.
- a plurality of connection terminals configured to connect to a DC bus associated with a DC electrical energy source and a DC electric voltage;
Specification