Patent ID: 12224582

DETAILED DESCRIPTION

FIG.1shows a top view of an aircraft2in the form of a vertical take-off and landing (VTOL) aircraft. The aircraft2includes a fuselage20, wings21, and a plurality of electric machines23.

The electric machines are mounted on the wings21. Each of the electric machines23drives a rotor unit22. Each rotor unit22includes rotor blades220. In the present example, each rotor unit22is designed as a propeller.

The aircraft2has a plurality of (e.g., four) front electric machines23and rotor units22. Therein, each of the front rotor units22(or one or more of these and/or other rotor units22) are pivoted so as to selectively provide thrust in a (at least predominantly) vertical direction, or in a (at least predominantly) horizontal direction. Further, the aircraft2includes a plurality of (e.g., four) rear electrical machines23and rotor units22, wherein each of the (rear) rotor unis22has a propeller rotational axis with a fixed orientation of with respect to the fuselage20. These (rear) rotor units22are oriented so as to provide thrust in a (at least predominantly) vertical direction.

FIG.2shows an aircraft2′ in the form of an airplane having a fuselage20, wings21, and one front rotor unit22.

The aircraft2′ includes an electric machine and/or an engine combusting fuel for driving the rotor unit22. The rotor unit22includes a plurality of rotor blades220, in this example, two rotor blades220. In the example shown, the rotor blades220are mounted on a hub to form a propeller. In alternative embodiments, the aircraft2′ (or the aircraft2ofFIG.1) includes, for example, a fan instead of a propeller and/or a plurality of propellers, fans or the like.

The aircraft2′ further includes one or more energy sources24,24′. In the present example, the aircraft2′ includes an electric battery as an energy source24and an electric generator as another energy source24′. The electric generator energy source24′ is driven by a turbine or other engine, e.g., in the form of an auxiliary power unit (APU). Alternatively, or in addition, the electric generator energy source24′ may be driven by an engine driving the rotor unit22.

It may be provided that electric energy supplied by the electric generator energy source24′ can be stored in the electric battery energy source24.

FIG.3shows a system3of the aircraft2ofFIG.1and, similarly, of the aircraft2′ ofFIG.2. The system3includes at least one energy source. In this example, the electric battery is an energy source24. Alternatively, or in addition, the system may include the electric generator as energy source24′ or another type of energy source such as a fuel cell. The energy source24of the system3is electrically connected to a power supply1of the system3. The power supply3receives electrical power from the energy source24and provides electrical power for use by one or more power consumers26. As an example, one of the one or more power consumers26may be a flight control system configured to control maneuvers of the respective aircraft2;2′. Another example of a power consumer is an air conditioning system. The power supply1includes a cooling system18to dissipate heat produced by the power supply1.

In the present example, the power supply1receives high voltage (HV) direct current (DC) and provides low voltage (LV) DC, but other configurations are also conceivable. For example, the power supply1can be configured to receive DC and supply DC, to receive DC and supply AC, to receive AC and supply DC, or to receive AC and supply AC. Further, the power supply1can be configured to receive HV and supply LV (or MV), to receive HV and supply HV, to receive LV (or MV) and supply HV, or to receive LV (or MV) and supply LV (or vice versa).

As disclosed herein, high voltage is higher than medium voltage and low voltage, and medium voltage is higher than low voltage. In certain examples, high voltage may refer to any voltage above that which may cause partial or disruptive discharges in air, e.g., 300 V peak. High voltage may exceed 3 kV. Medium voltage may be in a range of 28 V to 3 kV (e.g., 270 V), and low voltage on aircraft may be 28 V or lower.

In the present example, the energy source24is a HV battery, which supplies HV current to drive one or more electric machines23, which drives one or more rotor units22. The HV is too high for the power consumers26, so the power supply1converts the HV to LV.

FIG.4shows a schematic block diagram of the power supply1package. As shown, the power supply1includes an input10, wherein the input10is configured to receive electrical power from the energy source24. In use, the input10is electrically connected to the energy source24. The power supply1further includes an output11for supplying electrical power for the one or more power consumers26. The power supply1further includes a plurality of converters12, in this example exactly three converters12. Each converter of the plurality of converters12is electrically connected to the input10to receive electrical power from the input10and is configured to convert the electrical power from the input10and to provide the converted electrical power to the output11. The power supply1also includes a control unit14being configured to individually control each of the plurality of converters12.

The converters12are DC-DC converters each. The converters12are electrically connected in parallel to one another. For this, each of the converters12has an input120electrically connected to the power supply1input10. Further, each of the converters12has an output121electrically connected to the power supply1output11. The connections to the input10and the connections to the output11include parallel power paths13.

While the converters could be designed differently, in the present example, the converters12are all designed the same.

The converters12are arranged within a housing19, in this example. Here, the input10and output11are provided on walls of the housing19, but other arrangements are also possible. In the present example, the control unit14is arranged in the housing, too.

Each converter of the plurality of converters12further includes a communication interface122. The control unit14includes a communication interface140. The communication interface140of the control unit14is communicatively connected with each of the communication interfaces122of the converters12via a communication link17. The control unit14controls the converters12by communication via the communication interfaces140,122and the communication link17there between.

The control unit14further includes a sensor input141. The sensor input141is coupled to a current sensor15(or other type of sensor). The current sensor15senses the current provided at the power supply1output11. The current sensor15senses the sum of the currents provided by the converters12.

Furthermore, the control unit14includes a communication interface142for communication with an external device, (e.g., a flight control, an engine, an electric machine control, or the like).

The control unit14includes a processor143and memory144readable by the processor143. The memory144stores a program executable by the processor143for controlling the converters12.

The control unit14controls the converters12in accordance with a current demand that may be received via its communication interface142. Specifically, the control unit14is configured to receive an indication for a current demand (e.g., via the communication interface142) and to individually control each of the plurality of converters12based on the indication for the current demand. As an example, each of the converters12is configured to provide 10 KW (maximum). Thus, when 20 kW are needed, the control unit14activates two of the converters12and deactivates the remaining converter12. Therefore, the control unit14is configured to selectively activate or deactivate each converter of the plurality of converters12individually. However, if the current demand is only 10 KW or less, the control unit14activates only one converter12. For example, 10 KW may be required in a nominal, long-term operation (e.g., cruising flight), while 20 kW may be required only in short-term operations, such as transient flight situations, e.g., take-off, landing other specific maneuvering situations, or in exceptional cases in which other devices, (e.g., another power supply), of the aircraft2,2′ fail. As an example, the indication for the current demand may indicate a first value for the nominal long-term operation and a second value for the short-term operation, wherein the second value is lower than the first value. Since the higher current demand is only active for a comparably short time period, the cooling system18may be designed comparably small and lightweight.

The control unit14is configured to activate a first predefined number (e.g., one) of the converters12when the indication for the current demand indicates the first value and to activate a second predefined number (e.g., 2 or 3) of the converters12when the indication for the current demand indicates the second value. The second predefined number of the converters12may be larger than the first predefined number of the converters12.

In operation, the converters12are configured to convert a first voltage (e.g., a HV DC) to a second voltage (e.g., a LV DC), lower than the first voltage.

Using the current sensor15, the control unit14is further configured to monitor whether the provided current at the output11corresponds to the setting of the converters12made by the control unit14in response to the received current demand. In case of a mismatch, the control unit14may detect an internal fault, e.g., a defective converter12. In such a case, the control unit14changes the selection of the activated and deactivated converters12.

In addition to such a redundancy, the control unit14of the present example is configured to activate at least one first converter12of the converters12and deactivate at least one second converter12of the converters12at a first point in time and to deactivate the at least one first converter12and activate the at least one second converter12at a second point in time. A period between the first point in time and the second point in time may be preconfigured, e.g., stored in the memory144. By changing the activated one of the converters12, the lifetime of all of the converters12can be increased. As a specific example, the control unit14may be configured to activate and deactivate the converters12at regular time intervals.

FIG.5shows a system3′ of the aircraft2ofFIG.1and, similarly, of the aircraft2′ ofFIG.2. The system3′ includes at least one power bus31,32,33, in this example, a plurality of power buses31,32,33, (e.g., three power buses), to supply electrical power to one or more power consumers, at least one power supply1, in particular, a plurality of power supplies1, in this example three. Each of the power supplies1includes: an input10configured to receive electrical power from an energy source24,24′; an output11for supplying electrical power; a plurality of converters12, each converter being electrically connected to the input10to receive electrical power from the input10and being configured to convert the electrical power and to provide the converted electrical power at the output11; and a control unit14configured to control each of the plurality of converters12. Each of the power supplies1may be designed as the power supply1ofFIG.4. The system3′ further includes a power distribution unit30configured to electrically connect the at least one power supply1(the power supplies1) to the at least one power bus31,32,33(the power buses31,32,33). This allows additional redundancy, provides sufficient power even if one control unit14fails, or the like.

FIG.6shows a method of controlling a power supply1(e.g., the power supply1ofFIG.4), wherein the power supply includes: an input10configured to receive electrical power; an output11for supplying electrical power; a plurality of converters12, each converter being electrically connected to the input10to receive electrical power from the input10and being configured to convert the electrical power and to provide the converted electrical power to the output11; and a control unit14. The method includes, in Step S1, receiving, at the input10, electrical power from an energy source24;24′. In Step S2, the method includes receiving, by the control unit14, an indication for a current demand. In Step S3, the method includes individually controlling, by the control unit14, each converter of the plurality of converters12based on the indication for the current demand.

The described design of the power supply1as a package with a set of multiple power electronics paths allows to optimize each converter12individually for the nominal condition and can be switched in parallel to handle higher transient conditions.

Although the disclosure has been described and illustrated more specifically in detail by the exemplary embodiments, the disclosure is not restricted by the disclosed examples and other variations may be derived therefrom by a person skilled in the art without departing from the scope of protection of the disclosure. It is therefore intended that the foregoing description be regarded as illustrative rather than limiting, and that it be understood that all equivalents and/or combinations of embodiments are intended to be included in this description.

It is to be understood that the elements and features recited in the appended claims may be combined in different ways to produce new claims that likewise fall within the scope of the present disclosure. Thus, whereas the dependent claims appended below depend on only a single independent or dependent claim, it is to be understood that these dependent claims may, alternatively, be made to depend in the alternative from any preceding or following claim, whether independent or dependent, and that such new combinations are to be understood as forming a part of the present specification.

LIST OF REFERENCE SIGNS

1power supply10input11output12converter120input121output122communication interface13power path14control unit140communication interface141sensor input142communication interface143processor144memory15current sensor16communication link17communication link18cooling system19housing2;2′ aircraft20fuselage21wings22rotor unit220rotor blade23electric machine24;24′ energy source25turbine26power consumersystem3;3′30power distribution unit31,32,33power bus