Selective fluid pumping system

1. A control system comprising circuitry configured to:

calculate amplitude index values of electrically powered pumping devices based on driving currents provided to the pumping devices, the amplitude index values indicating amplitudes of oscillations of driving forces for driving the pumping devices;

estimate deterioration levels of the pumping devices based on the calculated amplitude index values;

select a pumping device from the pumping devices based on a comparison of the estimated deterioration levels; and

control the selected pumping device to pump fluid.

2. The control system according to claim 1 , wherein the pumping devices include a first pumping device and a second pumping device, and

wherein the circuitry is further configured to select the first pumping device in response to determining that a deterioration level of the first pumping device is lower than a deterioration level of the second pumping device.

3. The control system according to claim 1 , wherein the circuitry is configured to select the pumping device from the pumping devices based on the comparison of the estimated deterioration levels by using a first selection criterion, and based on a comparison of cumulative operation periods of the pumping devices by using a second selection criterion.

4. The control system according to claim 3 , wherein the pumping devices include a first pumping device and a second pumping device,

wherein the first selection criterion is predetermined so that the first pumping device is selected if a deterioration level of the first pumping device is lower than a deterioration level of the second pumping device, and

wherein the second selection criterion is predetermined so that the first pumping device is selected if a cumulative operation period of the first pumping device is shorter than a cumulative operation period of the second pumping device.

5. The control system according to claim 1 , wherein each of the pumping devices is configured to pump fluid from a primary line to a secondary line, and

wherein the circuitry is further configured to select the pumping device from the pumping devices in response to determining that a pressure in the secondary line is lower than a lower limit value.

6. The control system according to claim 5 , wherein the circuitry is further configured to deselect the selected pumping device in response to determining that the pressure in the secondary line is higher than an upper limit value.

7. The control system according to claim 5 , wherein the circuitry is further configured to:

select an additional pumping device from the pumping devices in response to determining that the pressure in the secondary line is lower than a target value that is equal to or higher than the lower limit value while the selected pumping device is controlled to pump fluid from the primary line to the secondary line; and

control both the selected pumping device and the additional pumping device to concurrently pump fluid from the primary line to the secondary line.

8. The control system according to claim 7 , wherein the additional pumping device has a higher deterioration level compared to the selected pumping device.

9. The control system according to claim 1 , wherein the circuitry is further configured to notify a user that at least one of the deterioration levels exceeds a notification threshold value.

10. The control system according to claim 9 , wherein the circuitry is further configured to notify which of the pumping devices has a deterioration level exceeding the notification threshold value.

11. The control system according to claim 1 , further comprising power conversion circuitry configured to output a driving current to each of the pumping devices.

12. A fluid pumping system comprising:

the control system according to claim 1 ; and

the pumping devices configured to be controlled by the control system.

13. A fluid pumping method, comprising:

calculating amplitude index values of electrically powered pumping devices based on driving currents provided to the pumping devices, the amplitude index values indicating amplitudes of oscillations of driving forces for driving the pumping devices;

estimating deterioration levels of the pumping devices based on the calculated amplitude index values;

selecting a pumping device from the pumping devices based on a comparison of the estimated deterioration levels; and

controlling the selected pumping device to pump fluid.

14. A non-transitory memory device having instructions stored thereon that, in response to execution by a processing device, cause the processing device to perform operations comprising:

calculating amplitude index values of electrically powered pumping devices based on driving currents provided to the pumping devices, the amplitude index values indicating amplitudes of oscillations of driving forces for driving the pumping devices;

estimating deterioration levels of the electrically powered pumping devices based on the calculated amplitude index values;

selecting a pumping device from the pumping devices based on a comparison of the estimated deterioration levels; and

controlling the selected pumping device to pump fluid.

15. The fluid pumping method according to claim 13 , wherein each of the pumping devices is configured to pump fluid from a primary line to a secondary line, and

wherein the method further comprises deselecting the selected pumping device in response to determining that a pressure in the secondary line is higher than an upper limit value.