US 12,119,769 B2Granted

Method for controlling a rotary electric machine and a system thereof

AssigneeSedemac Mechatronics Pvt Ltd

InventorsAnaykumar Joshi, Amit Dixit

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Abstract

The present invention relates to a method (200) and system (100) for controlling a rotary electric machine wherein a state of the rotary electric machine is determined between a low speed state and a high speed state. In the low speed state, a first rotor position (P1) and a first rotor speed (S1) are estimated based on intra-PWM current ripple (ΔX), a mean current vector (Y) and an inductance vector. A second rotor position (P2) and second rotor speed (S2) is estimated based on average current flowing through stator phase windings. State of rotary electric machine is selected based on estimated first rotor speed (S1) and/or estimated second rotor speed (S2). At low speed state, PWM signals are updated based on estimated first rotor position (P1), and at high speed state, PWM signals are updated based on estimated second rotor position (P2).

Claims19

Dependent claims

A method (200) for controlling a rotary electric machine, comprising the steps of:

determining a state of the rotary electric machine based on speed of a rotor of the rotary electric machine, the state comprising a high-speed state when the rotor speed is more than a predetermined threshold speed and a low-speed state when speed of the rotor is less than the predetermined threshold speed;
if the rotary electric machine is in the low-speed state:
calculating an intra-PWM current ripple (ΔX) and a mean current vector (Y) by measuring current in stator phase windings of the rotary electric machine within a Pulse Width Modulation Cycle;
computing an inductance vector based on the intra-PWM current ripple (ΔX);
estimating a first rotor position (P1) and a first rotor speed (S1) based on the inductance vector and the mean current vector (Y);
if the rotary electric machine is in the high speed state:
measuring current in stator phase windings of the rotary electric machine within a Pulse Width Modulation Cycle;
determining average current for each stator phase winding of the rotary electric machine within the Pulse Width Modulation cycle;
estimating a second rotor position (P2) and second rotor speed (S2) based on the average currents in stator phase windings within the Pulse Width Modulation cycle;
selecting the state of the rotary electric machine between the high-speed state and the low-speed state based on the estimated first rotor speed (S1) and/or the estimated second rotor speed (S2);
if the low-speed state is selected, updating Pulse Width Modulation signals based on the estimated first rotor position (P1);
and
if the high-speed state is selected, updating Pulse Width Modulation signals based on the estimated second rotor position (P2).

10 more elements

A system (100) for controlling a rotary electric machine, comprising:

a pulse width modulator (120) for applying Pulse Width Modulation signals to stator phase windings of the rotary electric machine;
a plurality of semi-conductor power switches (130) for receiving Pulse Width Modulation signals and converting the signals into AC voltage for stator phase windings of the rotary electric machine;
a plurality of current sensing devices (140) for sensing the current in the stator phase windings corresponding to phases of the rotary electric machine;
and
a control unit (150) configured for determining a state of the rotary electric machine based on speed of a rotor of the rotary electric machine between a high-speed state when the rotor speed is more than a predetermined threshold speed and a low-speed state when speed of the rotor is less than the predetermined threshold speed, if the rotary electric machine is in the low-speed state:
calculating an intra-PWM current ripple (ΔX) and a mean current vector (Y) by measuring current in stator phase windings of the rotary electric machine within a Pulse Width Modulation Cycle, computing an inductance vector based on the intra-PWM current ripple (ΔX), estimating a first rotor position (P1) and a first rotor speed (S1) based on the inductance vector and the mean current vector (Y), if the rotary electric machine is in the high speed state:
measuring current in stator phase windings of the rotary electric machine within a Pulse Width Modulation Cycle, determining average current for each stator phase winding of the rotary electric machine within the Pulse Width Modulation cycle, estimating a second rotor position (P2) and second rotor speed (S2) based on average current in stator phase windings within the Pulse Width Modulation cycle, selecting the state of the rotary electric machine between the high-speed state and the low-speed state based on the estimated first rotor speed (S1) and/or the estimated second rotor speed (S2), if the low-speed state is selected:
updating Pulse Width Modulation signals based on the estimated first rotor position (P1), and if the high-speed state is selected:
updating Pulse Width Modulation signals based on the estimated second rotor position (P2).

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/014,539Filed 21 May 2021
Priority: IN 20202102144221 May 2020
Published: US 2023/0268864 A124 Aug 2023
Granted: 15 Oct 2024
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

H02P 6/16
Electronic commutators: circuit arrangements for detecting position
H02P 27/085
With pulse width modulation: wherein the PWM mode is adapted on the running conditions of the motor, e.g. the switching frequency
H02P 6/007
Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position;…:…
H02P
Control or regulation of electric motors, electric generators or dynamo-electric converters