US 6,864,649 B2 · Method and apparatus for supplying current to an electronically commutatable electric motor

Abstract

A method and an apparatus for current supply of an electronically commutated electric motor by a semiconductor power end stage are described, which has an arrangement for ascertaining the current received by the motor and an electronic controller for controlling the branch currents of the motor. For this purpose the electronic controller receives an input signal from a single current sensor (24) in a common conductor (26) of the semiconductor switches of the end stage, the terminal voltages (U1, U2, U3) of the individual branch windings (16, 18, 20) as well as the total voltage (U) applied to the end stage. From these input voltages and the input signal the electronic controller determines respective voltage drops at the individual semiconductor switches under logical incorporation of control signals (G1-G6) produced by the electronic controller. For the voltage drop at a particular semiconductor switch its respective conducting state D.C. resistance can be ascertained, so that additional current sensors in the individual branches for controlling the branch currents (I1, I2, I3) are not necessary.

Claims10

Dependent claims

A method for supplying current to an electronically commutated electric motor, especially a three-phase direct current motor, by a semiconductor power end stage, with means for measuring the current delivered to said motor and with an electronic controller for controlling branch currents of said motor, said method comprising the steps of:

a) supplying to said electronic controller a signal from a current sensor (24) in a common conductor (26) of semiconductor switches of said semiconductor power end stage, winding terminal voltages (U1,U2, U3) of respective branch windings (16, 18, 20) of said motor and a total supply voltage (U) applied to said semiconductor power end stage;
and
b) determining respective conducting state D.C. resistances of the semiconductor switches and said branch currents (I1, I2, I3) with said electronic controller from said signals and voltages supplied to said electronic controller with logical incorporation of control signals (G1-G6) produced by said electronic controller.

An apparatus for supplying current to an electronically commutated electric motor, especially a three-phase direct current motor, with means for determining said current supplied to said motor;

said apparatus comprising
a semiconductor power end stage comprising semiconductor switches, said semiconductor switches comprising means for controlling branch currents in branch windings of said motor;
an electronic controller for controlling said branch currents;
said electronic controller comprising a microcomputer (22);
a current sensor (24) arranged in a common conductor (26) of the semiconductor switches to supply a signal depending on a current in said common conductor to said electronic controller;
means for supplying terminal voltages (U1, U2, U3) of said branch windings (16, 18, 20) to said electronic controller;
a rotor position transmitter (28) for supplying a signal characteristic of a rotary position of a rotor of said motor to said electronic controller as an input signal;
and
means for supplying a total voltage (U) applied to the semiconductor end stage or respective individual voltages (UDS1-UDS6) at corresponding ones of said semiconductor switches to said electronic controller;
wherein said electronic controller comprising means for generating control signals (G1-G6) for said semiconductor switches in order to control said branch currents from said signal characteristic of said rotary position of said rotor, said signal from said current sensor (24), and from said respective individual voltages (UDS1-UDS6) at said semiconductor switches or said total voltage applied to the semiconductor end stage and said terminal voltages (U1, U2, U3) of said branch windings (16, 18, 20).

7 more elements

Dependencies are inferred from the claim text.

Method and apparatus for supplying current to an electronically commutatable electric motor

Life of this patent

Method and apparatus for supplying current to an electronically commutatable electric motor

Life of this patent

Abstract

Claims10