Solar circulation pump and method for controlling a solar circulation pump, for controlling the starting of and for setting the performance of a solar circulation pump

• US 20070285039A1
• Filed: 03/22/2007
• Published: 12/13/2007
• Est. Priority Date: 03/29/2006
• Status: Active Grant

• Current Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Original Assignee: Birger Laing, Karsten Laing, Oliver Laing
• Inventors: Laing, Oliver
• Granted Patent: US 7,619,382 B2
• Time in Patent Office: Days
• US Class Current: 318/254.100
• CPC Class Codes: F04D 15/0245 responsive to a condition of the pump
• CPC Class Codes: F24D 2200/14 Solar energy
• CPC Class Codes: H02P 29/026 the fault being a power fluctuation
• CPC Class Codes: H02P 6/22 in a selected direction of rotation
• CPC Class Codes: Y02B 10/20 Solar thermal
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

To provide a solar circulation pump for connection to a photovoltaic panel device, comprising an electric motor which is electronically commutated and has a control device for supplying a periodic commutation signal, it is proposed that the control device be so configured that the commutation signal is varied with respect to the ratio of switch-on time to switch-off time.

Claims

1. Solar circulation pump for connection to a photovoltaic panel device, comprising:

an electric motor which is electronically commutated and has a control device for supplying a periodic commutation signal;

wherein the control device is so configured that the commutation signal is varied with respect to the ratio of switch-on time to switch-off time.

2. Solar circulation pump in accordance with claim 1, wherein the commutation signal is continuously variable.

3. Solar circulation pump in accordance with claim 1, wherein a variation of the commutation signal in at least one of its shape and its amplitude is provided.

4. Solar circulation pump in accordance with claim 1, wherein the variation of the commutation signal with respect to switch-on time and switch-off time takes place on a time scale which is very much larger than a period of the commutation signal.

5. Solar circulation pump in accordance with claim 4, wherein the variation of the commutation signal with respect to switch-on time and switch-off time takes place on a time scale lying in the order of magnitude of greater than one tenth of a second.

6. Solar circulation pump in accordance with claim 1, wherein the variation of the ratio of switch-on time and switch-off time takes place in the commutation signal by steps of increasing or decreasing the ratio.

7. Solar circulation pump in accordance with claim 1, wherein the control device comprises a control circuit in which the rotational speed of a rotor of the electric motor is the controlled magnitude, and the ratio of switch-on time and switch-off time in the commutation signal is the control quantity.

8. Solar circulation pump in accordance with claim 7, wherein the control aim for the controlled magnitude is maximization of the rotational speed.

9. Solar circulation pump in accordance with claim 7, wherein a measuring device is provided for the rotational speed or for a magnitude that characterizes the rotational speed.

10. Solar circulation pump in accordance with claim 9, wherein the measuring device is formed by an integrated position transducer of the electric motor.

11. Solar circulation pump in accordance with claim 9, wherein a power measuring device is provided for the electric motor.

12. Solar circulation pump in accordance with claim 7, wherein the control circuit is integrated into the electric motor.

13. Solar circulation pump in accordance with the claim 1, wherein it is possible to check with the control device whether sufficient electrical energy is available for at least one of aligning and subsequently starting a rotor of the electric motor.

14. Solar circulation pump in accordance with claim 13, wherein a buffer store for electrical energy is associated with the electric motor.

15. Solar circulation pump in accordance with claim 14, wherein the buffer store is integrated into the solar circulation pump.

16. Solar circulation pump in accordance with claim 14, wherein the buffer store is integrated into the electric motor.

17. Solar circulation pump in accordance with claim 14, wherein the buffer store is arranged between a motor electronics assembly of the electric motor and the photovoltaic panel device.

18. Solar circulation pump in accordance with claim 17, wherein the buffer store is arranged between the motor electronics assembly and an electric connection for the photovoltaic panel device.

19. Solar circulation pump in accordance with claim 1, wherein a time slot between aligning the rotor and starting the electric motor is prescribable by the control device.

20. Solar circulation pump in accordance with claim 13, wherein the electric motor comprises a plurality of coils, and the control device is configured to apply a load to a coil in order to check whether sufficient electrical energy is available for at least one of aligning the rotor and starting the electric motor.

21. Solar circulation pump in accordance with claim 20, wherein the load is applied in such a way that no movement of the rotor of the electric motor takes place.

22. Solar circulation pump in accordance with claim 20, wherein the load is applied to the coil by the control device after an initialization procedure before aligning the rotor of the electric motor.

23. Solar circulation pump in accordance with claim 1, wherein the control device comprises a setting device by means of which a bottom limit for applying voltage to the electric motor is settable in a fixed manner.

24. Solar circulation pump in accordance with claim 23, wherein a throttling of the performance of the solar circulation pump is settable by the setting device.

25. Solar circulation pump in accordance with claim 23, wherein the bottom limit for applying voltage is settable in a fractional range of the maximum no-load voltage of the photovoltaic panel device by the setting device.

26. Solar circulation pump in accordance with claim 25, wherein the fractional range lies between at least 50% and at the most 95% of the maximum no-load voltage.

27. Solar circulation pump in accordance with claim 1, wherein the electric motor is a brushless DC motor.

28. Solar circulation pump in accordance with claim 1, wherein the electric motor comprises a permanent-magnetic rotor or a permanent-magnetic stator.

29. Method for controlling a solar circulation pump which is supplied with electrical energy by a photovoltaic panel device and which comprises an electronically commutated electric motor, comprising:

varying a commutation signal continuously with respect to the ratio of switch-on time and switch-off time.

30. Method in accordance with claim 29, wherein the variation is carried out in steps.

31. Method in accordance with claim 29, wherein the variation is carried out with the aim of maximizing the rotational speed of a rotor of the electric motor.

32. Method in accordance with claim 29, wherein the commutation signal is varied in at least one of its shape and its amplitude.

33. Method in accordance with claim 29, wherein the variation is carried out on a very much slower time scale than the time scale of the commutation of the electric motor.

34. Method for controlling the starting of a solar circulation pump which is supplied with electrical energy by a photovoltaic panel device and which comprises an electronically commutated electric motor with a rotor, comprising:

prior to suitable initiation of rotation of the rotor, carrying out a check as to whether sufficient electrical energy is available for at least one of aligning the rotor and starting the electric motor.

35. Method in accordance with claim 34, wherein the electrical energy for at least one of aligning the rotor of the electric motor and starting the electric motor is withdrawn from a buffer store.

36. Method in accordance with claim 35, wherein starting of the electric motor is not initiated whenever insufficient electrical energy is detected.

37. Method in accordance with claim 34, wherein a time slot is placed between alignment of the rotor and starting of the electric motor.

38. Method in accordance with claim 34, wherein a load is applied to a coil of the electric motor to check whether sufficient electrical energy is available.

39. Method in accordance with claim 38, wherein the load is applied prior to a possible procedure for aligning the rotor of the electric motor.

40. Method for setting the performance of a solar circulation pump which is supplied with electrical energy by a photovoltaic panel device and which comprises an electronically commutated electric motor, comprising:

setting a bottom limit for applying voltage to the electric motor.

41. Method in accordance with claim 40, wherein the bottom limit is set in dependence upon the number of solar collectors to which the solar circulation pump is connected.

42. Method in accordance with claim 40, wherein a throttling of the performance of the solar circulation pump is set in a fixed manner.

43. Method in accordance with claim 40, wherein the bottom limit is set in such a way that the conveying capacity of the solar circulation pump is at least approximately proportionally reduced whenever there is a reduction in the insolation.

44. Solar circulation pump for connection to a photovoltaic panel device, comprising:

an electric motor which is electronically commutated and has a control device for supplying a periodic commutation signal;

wherein it is possible to check with the control device whether sufficient electrical energy is available for at least one of aligning and subsequently starting a rotor of the electric motor.

45. Solar circulation pump for connection to a photovoltaic panel device, comprising:

an electric motor which is electronically commutated and has a control device for supplying a periodic commutation signal;

wherein the control device comprises a setting device by means of which a bottom limit for applying voltage to the electric motor is settable in a fixed manner.