US 9,654,048 B2Granted

Variable frequency drive self-check

AssigneeTrane International Inc.

InventorsNathan Thomas West, Benjamin James Sykora, Korwin Jay Anderson, Matthew August Shepeck, David Marshall Foye

Life of this patent

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Abstract

Diagnostic and/or control methods, systems and apparatuses for variable frequency drives are disclosed. The variable frequency drive may be controlled by a controller that may conduct one or more tests or evaluations. The tests or evaluations may include determining whether a switching device in the variable frequency drive is open-circuited, short-circuited, or operating normally. The tests may include determining whether current provided at an inverter output of the variable frequency drive is within a predetermined range. An exemplary embodiment evaluates the drive for a short circuit condition, an open circuit condition, and a sensor error or failure condition, controls operation of the drive based upon these one or more evaluations, may abort operation of the drive based upon one or more evaluations, and may set a fault code indicative of the type of error encountered.

Claims29

Dependent claims

A method, comprising:

providing a variable frequency drive including a DC bus configured to provide a positive DC voltage and a negative DC voltage to an inverter, wherein the inverter includes one or more pairs of transistors, wherein an upper transistor of the one or more pairs of transistors is configured to receive the positive DC voltage and a lower transistor of the one or more pairs of transistors is configured to receive the negative DC voltage;
and
before operating the variable frequency drive to drive a motor, operating a controller operatively coupled with the variable frequency drive to complete a set of pre-operation tests, the set of pre-operation tests performed by the controller comprising:
testing for a short circuit condition of one or more of the transistors including switching the transistors off, measuring a voltage at a node in electrical communication with an output of one or more of the transistors, and evaluating the voltage relative to a first expected value,
testing for an open circuit condition of one or more of the transistors including switching the transistors off, switching on one of the transistors, measuring a voltage at a node in electrical communication with an output of the transistor switched on, and evaluating the voltage relative to a second expected value, and
testing for a sensor error condition of one or more current sensors including switching on an upper transistor coupled to a first node and switching on a lower transistor coupled to a second node, measuring a first current at the first node and a second current at the second node, and evaluating the first current and the second current relative to one another.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/791,858Filed 6 Jul 2015 · continuation
Priority: 23 Jan 2013
Published: US 2016/0056750 A125 Feb 2016
Granted: 16 May 2017
Term ends: Not estimatedThe source records don’t support an estimate.

Classification14 codes

G01R 31/42
Testing power supplies: aC power supplies
H02M 1/32
Details of apparatus for conversion: means for protecting converters other than automatic disconnection
H02M 1/36
Details of apparatus for conversion: means for starting or stopping converters
H02M 7/53871
In a bridge configuration: with automatic control of output voltage or current

Family

Application61/755,713Us provisional application · filed 23 Jan 2013
PCT/US2014/012627Parent of this continuation · filed 23 Jan 2014
US 2016/0056750 A1Pre-grant publication · published 25 Feb 2016
US 2016/0329854 A9Pre-grant publication · published 10 Nov 2016
US 9,654,048 B2This patent

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