US 7,923,944 B2 · Single processor dual motor control

Abstract

A motor control processor is provided for motor phase current sampling of multiple variable frequency controlled electric motors, and includes an analog-to-digital (A/D) converter and a controller. The A/D converter has multiple analog inputs and generates a digital output signal in response to the multiple analog inputs. The controller is coupled to the A/D converter and determines a maximum desired switching frequency for a first one of the multiple variable frequency controlled electric motors. The controller further selects a base period in response to the maximum desired switching frequency and defines a phase shift time delay as a fraction of the base period so the controller may control the multiple analog inputs of the A/D converter to sample motor phase currents of each of the multiple variable frequency controlled electric motors at sample times determined by the controller in response to the base period and the phase shift time delay.

Claims20

Dependent claims

A method for motor phase current sampling of multiple variable frequency controlled electric motors comprising the steps of:

determining a maximum desired switching frequency for a first one of the multiple variable frequency controlled electric motors;
selecting a base period in response to the maximum desired switching frequency;
defining a phase shift time delay as a fraction of the base period;
and
sampling motor phase currents of each of the multiple variable frequency controlled electric motors at sample times determined in response to the base period and the phase shift time delay.

2 more elements

A motor control processor for motor phase current sampling of multiple variable frequency controlled electric motors comprising:

an analog-to-digital (A/D) converter having multiple analog inputs and generating a digital output signal in response thereto;
and
a controller coupled to the A/D converter and determining a maximum desired switching frequency for a first one of the multiple variable frequency controlled electric motors, the controller further selecting a base period in response to the maximum desired switching frequency and defining a phase shift time delay as a fraction of the base period, wherein the controller controls the multiple analog inputs of the A/D converter for sampling motor phase currents of each of the multiple variable frequency controlled electric motors at sample times determined by the controller in response to the base period and the phase shift time delay.

A multiple electric motor system comprising:

a first variable frequency controlled electric motor having a maximum desired switching frequency associated therewith;
a second variable frequency controlled electric motor;
a clock generating a timing signal;
and
an analog-to-digital (A/D) converter having multiple analog inputs coupled to the first and second variable frequency controlled electric motors and generating a digital output signal in response to the multiple analog inputs, wherein the A/D converter samples motor phase currents of the first variable frequency controlled electric motor at first sample times determined in response to the timing signal and a base period and samples motor phase currents of the second variable frequency controlled electric motor at second sample times determined in response to the timing signal, the base period and a phase shift time delay, wherein the base period is selected in response to the maximum desired switching frequency of the first variable frequency controlled electric motor and the phase shift time delay is defined as a fraction of the base period.

2 more elements

Dependencies are inferred from the claim text.

Single processor dual motor control

Life of this patent

Single processor dual motor control

Life of this patent

Abstract

Claims20