US 11,699,969 B2Granted

Compressor and method for controlling the compressor

AssigneeDanfoss (Tianjin) Ltd.

InventorsShizhong Ji, Li Yao, Wanzhen Liu

Life of this patent

Estimating the term…

Loading patent…

Abstract

A compressor and a control method thereof are provided. The compressor includes a motor with a rotor of a permanent magnet. According to embodiments, the method of controlling the compressor includes: applying a detection current to the motor in response to a command of starting the compressor; detecting whether there is demagnetization of the permanent magnet of the rotor according to a response of the motor to the applied detection current; resetting an operating parameter of the compressor if there is the demagnetization; and starting the compressor according to the reset operating parameters. According to embodiments of the present disclosure, when the compressor is to be started, demagnetization is detected first, and the operating parameter are set accordingly, so as to suppress or avoid performance degeneration due to the demagnetization.

Claims18

Dependent claims

A method of controlling a variable-speed compressor comprising a motor with a rotor of a permanent magnet, the method comprising:

applying a detection current to the motor in response to a command of starting the compressor;
detecting, according to a response of the motor to the detection current, whether there is demagnetization of the permanent magnet of the rotor;
resetting an operating parameter of the compressor if there is the demagnetization;
and
starting the compressor according to the reset operating parameter;
wherein the detection current has a q-axis component, with a d-axis component of zero, and the detection current is a predetermined percentage of a rated operating current of the compressor;
wherein detecting whether there is demagnetization of the permanent magnet of the rotor comprises:
determining a level of demagnetization;
and
wherein resetting an operating parameter of the compressor comprises:
setting the operating parameter according to the level of demagnetization.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/942,122Filed 29 Jul 2020
Priority: CN 201910705228.330 Jul 2019
Published: US 2021/0058019 A125 Feb 2021
Granted: 11 Jul 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H02P 21/34
Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation: arrangements for starting
F25B 31/026
Of motor-compressor units: with compressor of rotary type
H02P 21/09
Indirect field-oriented control; Rotor flux feed-forward control: field phase angle calculation based on rotor voltage equation by adding slip…
H02P 21/14
Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation: estimation or adaptation of…