Pump control device and pump device

Patent metadata

Field	Value
Publication number	US-9217438-B2
Application number	US-201113246959-A
Country	US
Kind code	B2
Filing date	Sep 28, 2011
Priority date	Oct 20, 2010
Publication date	Dec 22, 2015
Grant date	Dec 22, 2015

Abstract

A pump control device for a pump device having a DC brushless motor as a drive source and a flow rate of the pump device is increased and decreased depending on a corresponding increase and decrease of a rotational speed of the DC brushless motor is structured so that, when the rotational speed of the DC brushless motor is higher than a predetermined speed, the DC brushless motor is controlled in an open loop control and, when the rotational speed of the DC brushless motor is lower than the predetermined speed, the DC brushless motor is controlled in a closed loop control on the basis of a measurement result of an actual rotating speed which is an actual rotational speed of the DC brushless motor.

First claim

What is claimed is:

1. A pump control device for use with a pump device having a DC brushless motor as a drive source wherein a flow rate of the pump device is increased and decreased depending on a corresponding increase and decrease of a rotational speed of the DC brushless motor, the pump control device comprising:
a motor drive section which drives the DC brushless motor;
a comparison section which compares a level of a speed control signal for the DC brushless motor with a predetermined reference value;
a feedback control signal output section into which a detection signal of an actual rotating speed of the DC brushless motor and the speed control signal are inputted and which outputs a feedback control signal for coinciding the actual rotating speed with a target rotational speed of the DC brushless motor that is calculated based on the speed control signal; and
a switching section which outputs one of the speed control signal and the feedback control signal to the motor drive section on a basis of a comparison result in the comparison section;
wherein in a case that the rotational speed of the DC brushless motor is higher than a predetermined speed, the level of the speed control signal for the DC brushless motor is inputted as a higher value than the predetermined reference value,
wherein when the level of the speed control signal is higher than the predetermined reference value, the DC brushless motor is controlled in an open loop control, and when the level of the speed control signal is lower than the predetermined reference value, the DC brushless motor is controlled in a closed loop control on a basis of a measurement result of the actual rotating speed.

2. The pump control device according to claim 1 , wherein the speed control signal is an analog signal corresponding to a speed control voltage for the DC brushless motor.

3. The pump control device according to claim 1 , wherein
in a case that the rotational speed of the DC brushless motor is higher than the predetermined speed, a frequency of the speed control signal for the DC brushless motor is inputted as a higher value than a predetermined frequency reference value,
when the frequency of the speed control signal is higher than the predetermined frequency reference value, the DC brushless motor is controlled in the open loop control and, when the frequency of the speed control signal is lower than the predetermined frequency reference value, the DC brushless motor is controlled in the closed loop control.

4. The pump control device according to claim 1 , wherein the predetermined reference value is determined on a basis of a target flow rate of the pump device to reduce a variation rate of an actual flow rate to the target flow rate at a low flow rate.

5. A pump control device for a pump device having a DC brushless motor as a drive source and a flow rate of the pump device is increased and decreased depending on increase and decrease of a rotational speed of the DC brushless motor, the pump control device comprising:
a motor drive section which drives the DC brushless motor;
a comparison section which compares a level of a speed control signal for the DC brushless motor with a predetermined reference value;
a feedback control signal output section into which a detection signal of the actual rotating speed and the speed control signal are inputted and which outputs a feedback control signal for coinciding an actual rotating speed of the DC brushless motor with a target rotational speed of the DC brushless motor that is calculated based on the speed control signal; and
a switching section which outputs one of the speed control signal and the feedback control signal to the motor drive section on a basis of a comparison result in the comparison section;
wherein when the target rotational speed of the DC brushless motor is higher than a predetermined speed determined by the predetermined reference value, the DC brushless motor is controlled in an open loop control and, when the target rotational speed of the DC brushless motor is lower than the predetermined speed, the DC brushless motor is controlled in a closed loop control on a basis of a measurement result of the actual rotating speed.

6. The pump control device according to claim 5 , wherein
when the comparison result of the comparison section indicates that the target rotational speed of the DC brushless motor is higher than the predetermined speed, the switching section outputs the speed control signal to the motor drive section, and
when the comparison result of the comparison section indicates that the target rotational speed of the DC brushless motor is lower than the predetermined speed, the switching section outputs the feedback control signal to the motor drive section.

7. The pump control device according to claim 5 , wherein the predetermined reference value is determined on a basis of a target flow rate of the pump device to reduce a variation rate of an actual flow rate to the target flow rate at a low flow rate.

8. A pump device comprising: an impeller; a DC brushless motor for rotating the impeller; and a pump control device for controlling the DC brushless motor so as to control a flow rate of the pump device; wherein the pump control device comprises: a motor drive section which drives the DC brushless motor; a comparison section which compares a level of a speed control signal for the DC brushless motor with a predetermined reference value; a feedback control signal output section into which a detection signal of an actual rotating speed of the DC brushless motor and the speed control signal are inputted and which outputs a feedback control signal for coinciding an actual rotating speed with a target rotational speed of the DC brushless motor that is calculated based on the speed control signal; and a switching section which outputs one of the speed control signal and the feedback control signal to the motor drive section on a basis of a comparison result in the comparison section; and wherein when the target rotational speed of the DC brushless motor is higher than a predetermined speed determined by the predetermined reference value, the DC brushless motor is controlled in an open loop control and, when the target rotational speed of the DC brushless motor is lower than the predetermined speed, the DC brushless motor is controlled in a closed loop control on a basis of a measurement result of the actual rotating speed which is the actual rotational speed of the DC brushless motor.

9. The pump device according to claim 8 , wherein
when the comparison result of the comparison section indicates that the target rotational speed of the DC brushless motor is higher than the predetermined speed, the switching section outputs the speed control signal to the motor drive section, and
when the comparison result of the comparison section indicates that the target rotational speed of the DC brushless motor is lower than the predetermined speed, the switching section outputs the feedback control signal to the motor drive section.

10. The pump control device according to claim 9 , wherein the speed control signal is an analog signal corresponding to a speed control voltage for the DC brushless motor.

11. The pump device according to claim 8 , wherein
in a case that the rotational speed of the DC brushless motor is higher than the predetermined speed, a frequency of the speed control signal for the DC brushless motor is inputted as a higher value than a predetermined frequency reference value,
when the frequency of the speed control signal is higher than the predetermined frequency reference value, the DC brushless motor is controlled in the open loop control and, whe

Assignees

• Fujishima Makoto
• Nidec Sankyo Corp

Inventors

• Fujishima Makoto

Classifications

• F04D15/0066 Primary

  by changing the speed, e.g. of the driving engine · CPC title

• H02P1/04

  Means for controlling progress of starting sequence in dependence upon time or upon current, speed, or other motor parameter · CPC title