Method For Operating The Fluid Delivery System

Abstract

A method for operating a fluid delivery system, with a fluid delivery pump, voltage manipulator and an electric motor integrated into an electrical grid. The electric motor is controlled by a voltage applied to the electric motor and the voltage manipulator is upstream from the electric motor. The following steps include determining the desired fluid output, determining the required rotational speed of the pump to convey the desired fluid output, determining the required voltage to reach the required pump rotational speed, and activating the voltage manipulator to achieve the required voltage.

Claims

1.-12. (canceled)

13. A method for operating a fluid delivery system integrated into an electrical grid, having a fluid delivery pump, a voltage manipulator and an electric motor downstream of the voltage manipulator and controlled by a voltage applied to the electric motor, comprising: determining a desired fluid output; determining a required rotational speed of the fluid delivery pump to convey the desired fluid output; determining a required voltage to reach the required rotational speed of the fluid delivery pump; and activating the voltage manipulator to achieve the required voltage.

14. The method as claimed in claim 13, further comprising: activating the voltage manipulator when required voltage to reach the required rotational speed of the fluid delivery pump is outside a pre-defined voltage range.

15. The method as claimed in claim 14, further comprising: determining the pre-defined voltage range based at least in part on a voltage level of the electrical grid.

16. The method as claimed in claim 13, wherein the electrical grid is operated at a specifiable mains voltage, and wherein the voltage applied to the electric motor can be reduced to a level below the specifiable mains voltage by the voltage manipulator.

17. The method as claimed in claim 13, wherein the electrical grid is operated at a specifiable mains voltage, and wherein the voltage applied to the electric motor can be increased to a level above the specifiable mains voltage by the voltage manipulator.

18. The method as claimed in claim 13, wherein the voltage manipulator is configured to act as a filter between the electric motor and a remaining electrical grid.

19. The method as claimed in claim 18, wherein the fluid delivery system is decoupled from the remaining electrical grid by the voltage manipulator with regard to a switching frequency of at least one control signal, whereby a lower switching frequency is predominant between the voltage manipulator and the electric motor than between the electrical grid and the voltage manipulator.

20. The method as claimed in claim 19, wherein a voltage emitted by the voltage manipulator to the electric motor corresponds to a voltage in the remaining electrical grid, whereby a switching frequency between electric motor and voltage manipulator is different than a switching frequency in the remaining electrical grid.

21. The method as claimed in claim 19, wherein the voltage manipulator is configured as an attenuator between a switching frequency of a control signal of the electric motor and a switching frequency in the remaining electrical grid.

22. The method as claimed in claim 13, wherein the voltage manipulator is composed of a booster, wherein the booster is constructed according to one of a ZETA principle, a SEPIC principle, a BUCK principle, or a BOOST principle.

23. The method as claimed in claim 13, wherein a voltage generated by the voltage manipulator and guided to the electric motor exactly corresponds to a required voltage to achieve one of a certain rotational speed of the fluid delivery pump and to convey a desired fluid output.

24. The method as claimed in claim 13, wherein a power module for block commutation is arranged between the voltage manipulator and the electric motor, and wherein the power module is operated with a duty cycle of 90% to 100% and the rotational speed of the electric motor is controlled by the voltage emitted by the voltage manipulator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In the following, the invention is explained in detail using exemplary embodiments taking the drawings into consideration. The drawings show:

[0040] FIG. 1 is a block diagram to illustrate the procedural steps of the method; and

[0041] FIG. 2 is a block diagram to illustrate the separation of the frequency bands in the rest of the electrical grid and the path between the voltage manipulator and the electric motor through the voltage manipulator.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0042] FIG. 1 shows a block diagram 1, wherein the block diagram shows the individual procedural steps of the method according to the invention.

[0043] The desired fluid output is determined in Block 2. This can happen, for example, via an appropriate sensor or by specification deriving from a control unit. In the case of a fuel delivery system, the fluid output within the motor control unit is precisely known on a regular basis and can be provided by this as a value.

[0044] In Block 3, a rotational speed is determined from the determined fluid output at which the fluid delivery pump must rotate in order to convey the appropriate amount of fluid. For this purpose, further values are additionally included such as, for example, the pressure in the fluid delivery system, the temperature of the fluid to be conveyed or the viscosity of the fluid to be conveyed. The properties of the fluid delivery system, which are determined by the respective constructional embodiment, can also flow into the determination of the rotational speed.

[0045] Block 4 serves to determine the voltage that is required to allow the electric motor powering the fluid delivery pump to rotate at the determined rotational speed. The rotational speed of electric motors can be determined, among other ways, in particular, by the variation of the voltage applied to the electric motors.

[0046] Finally, in Block 5, a voltage manipulator is activated that influences the voltage signal in its amplitude in such a way that an increase or decrease of voltage is achieved. This then results in an increase or decrease of the rotational speed of the electric motor. Being particularly advantageous, the voltage manipulator can also change the voltage to a value above or below the voltage introduced into it. In addition, by activating the voltage manipulator, only a change in the switching frequency of the voltage can be achieved without increasing or decreasing the amplitude in the process.

[0047] FIG. 2 shows a block diagram 6 illustrating a connection of the voltage manipulator 7 to an electric motor 8. On the left of the voltage manipulator 7, the remaining electrical grid is indicated. For example, this may include voltage sources, control units and other consumers.

[0048] On the right of the voltage manipulator 7, an electrical path 9 is shown, via which the voltage manipulator 7 is electrically conductively connected to a power module 10. The power module 10 serves to provide block commutation of the voltage and the voltage signal emitted by the voltage manipulator 7. A brushless direct-current motor can be powered by block commutation for example.

[0049] A filter 11 is arranged between the voltage manipulator 7 and the power module 10, which serves to filter the voltage emitted by the voltage manipulator 7.

[0050] Preferably, the voltage manipulator 7 is a so-called booster that is composed of a circuit consisting of a plurality of electrical and/or electronic elements. The booster can be constructed according to the various principles known from the most recent background art.

[0051] It is particularly advantageous if a frequency decoupling between the remaining electrical grid indicated on the left and the path 9 between the voltage manipulator 7 and the electric motor 8 can also be achieved by the voltage manipulator 7. The path 9 to the electric motor 8 is preferably operated at a switching frequency of approximately 20 kHz while the remaining electrical grid is operated at a considerably higher switching frequency of 500 kHz for example.

[0052] Another filter is shown with the reference number 12 that makes filtering of the voltages and voltage signals coming from the remaining electrical grid possible prior to reaching the voltage manipulator 7.

[0053] In particular, the exemplary embodiments in FIGS. 1 and 2 do not have any limiting character and serve to clarify the concept of the invention. In particular, the voltage manipulator shown by Block 7 can be designed in a very diverse manner. In addition, the connection of the electric motor 8, as shown in FIG. 2, only serves as an example and does not rule out alternative embodiments.

[0054] Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.