US 2019/0158008 A1Published application

Variable speed drive with active converter

AssigneeJohnson Controls Technology Company

InventorsKonstantin A. Borisov, Ivan Jadric

Life of this patent

Estimating the term…

Loading patent…

Abstract

A system or method for a VSD with an active converter including a controller, an inductor, an active converter, a DC link, and an inverter. The active converter is controlled to receive an input AC voltage and output a boosted DC voltage to a DC link, up to 850 VDC, the active converter using only low voltage semiconductor switches to provide the 850 VDC DC link voltage. The controller is configured to operate with a reactive input current magnitude equal to zero at a predetermined system load, and at system loads less than the predetermined system load, to introduce a reactive input current that results in a converter voltage having a magnitude less than the input voltage, wherein the vector sum of the input voltage and an inductor voltage is equal to the converter voltage.

Claims20

Dependent claims

A variable speed drive, comprising:

an active converter configured to convert input alternating current electrical power received from an alternating current power source into first direct current electrical power that comprises a direct current voltage;
a direct current (DC) link electrically coupled to the active converter, wherein the DC link is configured to:
store electrical energy based at least in part on the first direct current electrical power received from the active converter;
and
output second direct current electrical power by filtering the direct current voltage using the electrical energy stored by the DC link;
an inverter electrically coupled to the DC link, wherein the inverter is configured to convert the second direct current electrical power received from the DC link into output alternating current electrical power to be supplied to an electrical load;
and
a control system communicatively coupled to the active converter, wherein the control system is configured to:
determine a DC link voltage present on the DC link;
and
output control signals that control operation of the variable speed drive to:
maintain the DC link voltage below a DC link voltage threshold;
and
introduce a non-zero reactive current when magnitude of a ripple on the DC link voltage exceeds a ripple threshold.

11 more elements

A tangible, non-transitory, computer-readable medium storing instructions executable by one or more processors of a control system, wherein the instructions comprise instructions to:

determine, using the one or more processors, voltage present on a direct current (DC) link electrically coupled between a converter and an inverter of a motor drive based at least in part on sensor data received from a sensor;
and
control, using the one or more processors, operation of the motor drive based at least in part on the voltage of the direct current (DC) link at least in part by outputting control signals to each of a plurality of semiconductor switches implemented in the motor drive to:
introduce a first non-zero reactive current when magnitude of a ripple on the voltage of the DC link exceeds a first ripple threshold;
and
introduce a second non-zero reactive current when the magnitude of the ripple on the voltage of the DC link exceeds a second ripple threshold, wherein magnitude of the second non-zero reactive current is greater than magnitude of the first non-zero reactive current when the second ripple threshold is greater than the first ripple threshold.

3 more elements

A control system configured to control operation of a motor drive, comprising:

a sensor configured to measure voltage present on a direct current (DC) link electrically coupled between a converter and an inverter of the motor drive;
and
one or more processors communicatively coupled to the sensor and a plurality of semiconductor switches in the motor drive, wherein the one or more processors are configured to:
determine the voltage present on the DC link of the motor drive based at least in part on one or more sensor readings received from the sensor;
and
control operation of the motor drive at least in part by outputting gate signals to the plurality of semiconductor switches to:
introduce non-zero reactive current in the motor drive when magnitude of a voltage ripple on the DC link of the variable speed drive exceeds a ripple threshold;
and
produce a unity power factor when the magnitude of the voltage ripple of the DC link does not exceed the ripple threshold.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/253,054Filed 21 Jan 2019
Priority: 8 May 2015
Published: 23 May 2019
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

H02M 1/32
Details of apparatus for conversion: means for protecting converters other than automatic disconnection
H02M 1/4216
Arrangements for improving power factor of AC input: operating from a three-phase input voltage
H02M 1/4233
Arrangements for improving power factor of AC input: using a bridge converter comprising active switches
H02M 5/4585
Using semiconductor devices only: having a rectifier with controlled elements

Family

Application62/158,749Us provisional application · filed 8 May 2015
Application15/148,451Continuation · filed 6 May 2016
Application16/253,054Continuation
US 10,187,000 B2Related patent
US 10,693,406 B2Related patent
US 2016/0329851 A1Published application
US 2019/0158008 A1This patent

From the US filing history. Foreign family members aren’t listed.