Motor device

Patent metadata

Field	Value
Publication number	US-9797406-B2
Application number	US-201514616960-A
Country	US
Kind code	B2
Filing date	Feb 9, 2015
Priority date	Feb 10, 2014
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A motor device configured to convey a fluid by driving a fan with a motor includes a position/speed acquirer configured to acquire a current rotation angle and a current rotation speed of the motor, a multiplier configured to calculate a flow-rate-constant target driving current by multiplying the rotation speed and a flow rate coefficient, and a current controller configured or programmed to control a motor driving current by setting, as a control target, the flow-rate-constant target driving current and to control a flow rate of the fluid to be maintained at a constant value which depends on the flow rate coefficient.

First claim

What is claimed is:

1. A motor device which conveys a fluid by driving a fan with a motor, the motor device comprising:
a position/speed acquirer configured to acquire a current rotation angle and a current rotation speed of the motor;
a multiplier configured to calculate a flow-rate-constant target driving current by multiplying the rotation speed acquired in the position/speed acquirer and a flow rate coefficient;
and a current controller configured to control a motor driving current by setting, as a control target, the flow-rate-constant target driving current and to control a flow rate of the fluid to be maintained at a constant value which depends on the flow rate coefficient, where in the current controller includes:
a current sensor configured to detect the motor driving current;
a Clarke transformer configured to Clarke-transform the motor driving current and to generate an output;
a Park transformer configured to Park-transform the output of the Clarke transformer and the rotation angle acquired in the position/speed acquirer and to generate an output;
a subtractor configured to calculate a difference value between the flow-rate-constant target driving current and the output of the Park transformer and to generate an output;
a controller configured to generate a control value based on the output of the subtractor;
an inverse Park transformer configured to inversely Park-transform the control based on the rotation angle acquired in the position/speed acquirer and to generate an output;
an inverse Clarke transformer configured to inversely Clarke-transform the output of the inverse Park transformer and to generate an output;
and an inverter configured to drive the motor based on the output of the inverse Clarke transformer,
the device further comprising: a determiner configured to determine the rotation speed of the motor based on an upper limit determination reference value and a lower limit determination reference value;
wherein when the determination result of the determiner reveals that the rotation speed of the motor is higher than the upper limit determination reference value, instead of the flow-rate-constant target driving current, a speed-constant target driving current calculated by a difference value between an upper limit rotation speed and the rotation speed acquired in the position/speed acquirer is set as the control target to thus drive the motor at the upper limit rotation speed;
and when the determination result of the determiner reveals that the rotation speed of the motor is lower than the lower limit determination reference value, instead of the flow-rate-constant target driving current, a speed-constant target driving current calculated by difference value between a lower limit rotation speed and the rotation speed acquired in the position/speed acquirer is set as the control target to thus drive the motor at the lower limit rotation speed.

2. The device of claim 1 , wherein the position/speed acquirer includes a position sensor configured to acquire the rotation angle and the rotation speed.

3. The device of claim 1 , wherein the flow rate of the fluid is changed by receiving the setting of the flow rate coefficient.

4. The device of claim 2 , wherein the flow rate of the fluid is changed by receiving the setting of the flow rate coefficient.

Assignees

• Nidec Servo Corp

Inventors

• Ishikawa Masatomo

Classifications

• H02P21/26

  Rotor flux based control · CPC title

• H02P21/18

  Estimation of position or speed · CPC title

• F04D27/004 Primary

  by varying driving speed · CPC title

• Y02B30/70

  Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating · CPC title