Linear motor control apparatus and compressor equipped with the same

Patent metadata

Field	Value
Publication number	US-2020195119-A1
Application number	US-201716341177-A
Country	US
Kind code	A1
Filing date	Oct 5, 2017
Priority date	Oct 13, 2016
Publication date	Jun 18, 2020
Grant date	—

Abstract

Provided is a linear motor control apparatus capable of improving estimation accuracy of a resonance frequency immediately after start, and a compressor equipped with the linear motor control apparatus. A linear motor control apparatus includes a winding to which an AC voltage is applied and a mover which is connected to an elastic body, in which the linear motor control apparatus includes an operation mode (1) which monotonously increases amplitude of the AC voltage while keeping a frequency of the AC voltage substantially constant, and an operation mode (2) which changes the frequency of the AC voltage while keeping the amplitude of the AC voltage substantially constant, and executes the operation mode (1) and the operation mode (2) in this order.

First claim

1 . A linear motor control apparatus including a winding to which an AC voltage is applied and a mover which is connected to an elastic body, the linear motor control apparatus, comprising:
an operation mode (1) which monotonously increases amplitude of the AC voltage while keeping a frequency of the AC voltage substantially constant, and an operation mode (2) which changes the frequency of the AC voltage while keeping the amplitude of the AC voltage substantially constant, wherein the linear motor control apparatus executes the operation mode (1) and the operation mode (2) in this order.

2 . The linear motor control apparatus according to claim 1 , wherein the operation mode (1) is executed immediately after start of the linear motor, and
a position of the mover and/or a resonance frequency of the mover is estimated after amplitude of the mover is increased to a predetermined value or more in the operation mode (1).

3 . The linear motor control apparatus according to claim 2 , wherein control is performed to change a frequency while keeping amplitude of the AC voltage substantially constant and then control is performed to increase amplitude of the AC voltage in the operation mode (2).

4 . The linear motor control apparatus according to claim 1 , further comprising:
a load which is connected to the mover, wherein a fluctuation of the load is estimated from a difference between a frequency of the AC voltage and a resonance frequency of the mover detected or estimated, and one, two, or three time differential values of the amplitude of the AC voltage, the frequency of the AC voltage, and the amplitude of the mover are larger when the load is a heavy load than when the load is a light load.

5 . The linear motor control apparatus according to claim 2 , further comprising:
a load which is connected to the mover, wherein a fluctuation of the load is estimated from a difference between a frequency of the AC voltage and the resonance frequency of the mover detected or estimated, and one, two, or three time differential values of the amplitude of the AC voltage, the frequency of the AC voltage, and the amplitude of the mover are larger when the load is a heavy load than when the load is a light load.

6 . The linear motor control apparatus according to claim 3 , further comprising:
a load which is connected to the mover, wherein a fluctuation of the load is estimated from a difference between a frequency of the AC voltage and the resonance frequency of the mover detected or estimated, and one, two, or three time differential values of the amplitude of the AC voltage, the frequency of the AC voltage, and the amplitude of the mover are larger when the load is a heavy load than when the load is a light load.

7 . The linear motor control apparatus according to claim 1 , further comprising:
a load which is connected to the mover, wherein a fluctuation of the load is estimated from a difference between a frequency of the AC voltage and a resonance frequency of the mover detected or estimated, and a control gain or a control time constant for a stroke of the mover, a current flowing in the winding, or a speed of the mover is changed according to the load.

8 . The linear motor control apparatus according to claim 2 , further comprising:
a load which is connected to the mover, wherein a fluctuation of the load is estimated from a difference between a frequency of the AC voltage and the resonance frequency of the mover detected or estimated, and a control gain or a control time constant for a stroke of the mover, a current flowing in the winding, or a speed of the mover is changed according to the load.

9 . The linear motor control apparatus according to claim 3 , further comprising:
a load which is connected to the mover, wherein a fluctuation of the load is estimated from a difference between a frequency of the AC voltage and the resonance frequency of the mover detected or estimated, and a control gain or a control time constant for a stroke of the mover, a current flowing in the winding, or a speed of the mover is changed according to the load.

10 . A compressor, comprising:
the linear motor control apparatus according to claim 1 , wherein a position of the mover is estimated using voltage and current values of the winding.

11 . A compressor, comprising:
the linear motor control apparatus according to claim 2 , wherein a position of the mover is estimated using voltage and current values of the winding.

12 . A compressor, comprising:
the linear motor control apparatus according to claim 3 , wherein a position of the mover is estimated using voltage and current values of the winding.

13 . A compressor, comprising:
the linear motor control apparatus according to claim 4 , wherein a position of the mover is estimated using voltage and current values of the winding.

14 . A compressor, comprising:
the linear motor control apparatus according to claim 5 , wherein a position of the mover is estimated using voltage and current values of the winding.

15 . A compressor, comprising:
the linear motor control apparatus according to claim 6 , wherein a position of the mover is estimated using voltage and current values of the winding.

16 . A compressor, comprising:
the linear motor control apparatus according to claim 7 , wherein a position of the mover is estimated using voltage and current values of the winding.

17 . A compressor, comprising:
the linear motor control apparatus according to claim 8 , wherein a position of the mover is estimated using voltage and current values of the winding.

18 . A compressor, comprising:
the linear motor control apparatus according to claim 9 , wherein a position of the mover is estimated using voltage and current values of the winding.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Suzuki Takahiro
• Nagata Shuhei
• Hatsuse Wataru
• Koyama Masaki

Classifications

• H02K41/033 Primary

  with armature and magnets on one member, the other member being a flux distributor · CPC title

• H02P6/20 Primary

  Arrangements for starting (H02P6/08 takes precedence) · CPC title

• H02P25/066

  of the stepping type · CPC title

• F04B2203/0401

  Current · CPC title

• F04B2203/0404

  Frequency of the electric current · CPC title