AC power distribution system and AC power distribution method

Abstract

The present disclosure relates to an AC power distribution system and an AC power distribution method. Specifically, an AC power distribution system may include an independent speed variable frequency ISVF generator, which is configured to generate an AC power signal, and the frequency of the AC power signal is independent of the frequency of the prime mover. The system may also include at least one AC load, which is configured to receive the AC power signal without performing full distribution rated power power conversion. In another embodiment, an AC power distribution system includes: a generator, which is configured to generate an AC power signal; and an AC motor, which is configured to receive the AC power signal without performing full distribution rated power power conversion, wherein the AC motor is configured to rotate at a rotation frequency independent of the frequency of the AC power signal.

Description

Technical Field

[0001] The present disclosure relates generally to the field of alternating current (AC) power distribution, and more particularly to an independent speed variable frequency (ISVF) based electrified propulsion system. Background Art

[0002] Commercial vehicles, particularly aircraft, typically include complex propulsion systems that generate sufficient thrust for operation. In a typical aircraft, an AC generator may be coupled to the engine to generate an AC power signal on an AC bus. However, the AC power signal typically does not meet the frequency requirements of an AC motor configured to drive a propulsion system (e.g., a propeller, etc.). In order to generate a direct current (DC) power signal on the DC bus, the AC power signal may be rectified. An independent motor controller may then convert the DC power signal into an AC power signal that meets the frequency requirements of the AC motor.

[0003] The apparatus for rectifying the AC power signal created by the generator may include an automatic transfer rectifier unit or another rectifier. This apparatus may add significant weight to the aircraft. Further, the rectification of the AC power signal inherently results in some power losses. Likewise, the motor controllers used to control the AC motors may add weight and result in significant power losses as they typically convert the DC power signal into an AC power signal for driving the AC motor using an inverter. Other disadvantages may exist. Summary of the invention

[0004] Systems and methods are disclosed that can overcome at least one of the above identified disadvantages. For example, an AC power distribution system can avoid full-distribution-power-rated power conversion when operating an AC motor propulsion system as defined herein. In some embodiments, the system can include an ISVF generator as described herein that enables the frequency of the AC power signal on the AC bus to be within the frequency requirements of the AC motor propulsion system. In some embodiments, the system can include a variable speed independent frequency (VSIF) motor as described herein that enables the AC motor to operate at a rotational frequency independent of the AC power signal on the AC bus.

[0005] In an embodiment, an AC power distribution system includes an ISVF generator configured to generate an AC power signal having a frequency independent of a frequency of a prime mover. The system also includes an AC bus configured to receive the AC power signal from the ISVF generator. The system also includes at least one AC load configured to receive the AC power signal from the AC bus without performing full distributed rated power power conversion, wherein the frequency of the AC power signal generated by the ISVF generator meets the frequency requirements of the AC load.

[0006] In some embodiments, the AC load is an AC motor, and the frequency requirement of the AC load corresponds to the rotational frequency requirement of the AC motor. In some embodiments, the motor is included in an aircraft propulsion system. In some embodiments, the system includes a generator control unit configured to control the frequency of the AC power signal generated by the ISVF generator to meet the frequency requirement of the AC load. In some embodiments, the system includes at least one additional AC load, the at least one additional AC load being configured to receive the AC power signal from the AC bus. In some embodiments, the at least one additional AC load has the same frequency requirement as the AC load. In some embodiments, the system includes: a second ISVF generator configured to generate a second AC power signal, the frequency of the second AC power signal being independent of the frequency of the prime mover; a second AC bus configured to receive the AC power signal from the second ISVF generator; and a second AC load configured to receive the second AC power signal from the second AC bus without performing full distribution rated power power conversion, wherein the frequency of the second AC power signal generated by the second ISVF generator meets the frequency requirement of the second AC load. In some embodiments, the prime mover is a vehicle engine.

[0007] In an embodiment, an alternating current (AC) power distribution system includes a generator configured to generate an AC power signal. The system also includes an AC bus configured to receive the AC power signal from the generator. The system also includes an AC motor configured to receive the AC power signal from the AC bus without performing full distributed rated power power conversion, wherein the AC motor is configured to rotate at a rotational frequency independent of the frequency of the AC power signal. The system also includes a motor control unit configured to receive the AC power signal from the AC bus, perform partial power conversion of the AC power signal to generate a converted power signal, and provide the converted power signal to the AC motor to control the rotational frequency of the AC motor.

[0008] In some embodiments, the AC motor is included in an aircraft propulsion system. In some embodiments, the generator is an ISVF generator, a variable speed variable frequency (VSVF) generator, or a constant speed constant frequency (CSCF) generator. In some embodiments, the system includes at least one additional AC motor configured to receive an AC power signal from an AC bus. In some embodiments, the frequency requirement of the AC motor is different from the frequency requirement of the additional AC motor. In some embodiments, the at least one additional AC motor is a non-propulsion motor load. In some embodiments, the system includes at least one utility load configured to receive an AC power signal from an AC bus. In some embodiments, the system includes: a second generator configured to generate a second AC power signal; a second AC bus, in which the second AC bus is configured to receive a second AC power signal from the second generator; and a second AC motor, which is configured to receive a second AC power signal from the second AC bus without performing full distribution rated power power conversion. In some embodiments, the second AC motor is configured to rotate at a rotational frequency independent of the frequency of the second AC power signal. In some embodiments, the system includes a second motor control unit configured to receive a second AC power signal from a second AC bus, perform partial power conversion of the second AC power signal to generate a second converted power signal and provide the second converted power signal to the second AC motor, thereby controlling the rotation frequency of the second AC motor.

[0009] In an embodiment, an AC power distribution method includes the steps of generating an AC power signal at an ISVF generator, the frequency of the AC power signal being independent of the frequency of a prime mover. The method further includes the steps of receiving the AC power signal from the ISVF generator at an AC bus. The method further includes the steps of receiving the AC power signal from the AC bus at an AC load without performing full distribution rated power power conversion, wherein the frequency of the AC power signal generated by the ISVF generator meets the frequency requirement of the AC load.

[0010] In some embodiments, the method includes the steps of: receiving an AC power signal from an AC bus at an additional AC load, wherein the additional AC load has the same frequency requirement as the AC load. In some embodiments, the method includes the steps of: controlling, at a generator control unit, the frequency of the AC power signal generated by the ISVF generator. In some embodiments, the method includes the steps of: generating, at a second ISVF generator, a second AC power signal, the frequency of the second AC power signal being independent of the frequency of the prime mover; receiving, at a second AC bus, a second AC power signal from the ISVF generator; and receiving, at a second AC load, a second AC power signal from the second AC bus without performing full distributed rated power power conversion, wherein the frequency of the second AC power signal generated by the second ISVF generator meets the frequency requirement of the second AC load.

[0011] In an embodiment, the AC power distribution method includes the steps of generating an AC power signal at a generator. The method also includes the steps of receiving the AC power signal from the generator at an AC bus. The method also includes the steps of receiving the AC power signal from the AC bus at an AC motor without performing full distributed rated power power conversion. The method includes the steps of rotating the AC motor using the AC power signal at a rotational frequency that is independent of the frequency of the AC power signal.

[0012] In some embodiments, the method includes the steps of: receiving an AC power signal at a motor control unit; performing partial power conversion of the AC power signal to generate a converted power signal; and providing the converted power signal to the AC motor, thereby controlling the rotational frequency of the AC motor. In some embodiments, the method includes the steps of: receiving an AC power signal from an AC bus at another AC motor connected to the AC bus; and rotating the other AC motor using the AC power signal at a rotational frequency different from the rotational frequency of the AC motor, wherein the frequency requirement of the AC motor is different from the frequency requirement of the other AC motor. In some embodiments, the method includes the steps of: generating a second AC power signal at a second generator; receiving the second AC power signal from the generator at a second AC bus; receiving the second AC power signal from the second AC bus at a second AC motor without performing full distributed rated power power conversion; and rotating the second AC motor using the second AC power signal at a rotational frequency independent of the frequency of the second AC power signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram depicting an embodiment of an AC power distribution system.

[0014] Figure 2is a schematic diagram depicting an embodiment of an AC power distribution system.

[0015] Figure 3 is a flow chart depicting an embodiment of an AC power distribution method.

[0016] Figure 4 is a flow chart depicting an embodiment of an AC power distribution method.

[0017] Figure 5 is a block diagram depicting an embodiment of an aircraft including an AC power distribution system.

[0018] Although the present disclosure is susceptible to various modifications and alternative forms, it has been shown in the drawings by way of example and will be described in detail herein. However, it should be understood that the present disclosure is not intended to be limited to the particular form disclosed. On the contrary, it is intended to cover all modifications, equivalents, and alternatives that fall within the scope of the present disclosure. DETAILED DESCRIPTION

[0019] Reference Figure 1 , depicts an embodiment of an AC power distribution system 100. System 100 may include an engine 102. Engine 102 may be an engine of a vehicle such as an aircraft, and may provide a primary power source for the vehicle. For example, engine 102 may be a jet engine, a turboprop engine, a turbine engine, an internal combustion engine, another mechanical engine, or a combination thereof.

[0020] The system 100 may also include a first ISVF generator 104 and a second ISVF generator 154. The first ISVF generator 104 and the second ISVF generator 154 may be coupled to the engine 102 such that the engine 102 operates as a prime mover for generating an electrical power signal. For example, the first ISVF generator 104 may receive mechanical power from the engine 102 and convert the mechanical power into a first AC electrical power signal. Similarly, the second ISVF generator 154 may receive mechanical power from the engine 102 and convert the mechanical power into a second AC electrical power signal. Although the system 100 is depicted as including two ISVF generators, in reality, the system 100 may include more or less than two ISVF generators.

[0021] As used herein, an ISVF generator is an AC generator that converts mechanical rotation from a prime mover into an AC power signal whose frequency is independent of the rotational frequency of the prime mover. The ISVF generator may not rely on a gearbox or additional AC / DC power conversion, which may be applied to the AC power signal after it leaves the generator to achieve an independent frequency. Background examples of ISVF generators can be found in U.S. Patent Application No. 15 / 819919, filed on November 21, 2017 and entitled "Independent Speed ​​Variable Frequency Alternating Current Generator." Other types of ISVF generators may also be used. Because the respective frequencies of the first AC power signal generated by the first ISVF generator 104 and the second AC power signal generated by the second ISVF generator 154 are independent of the rotational frequency of the engine 102, they do not need to be equal to each other. Instead, in some cases, each ISVF generator 104, 154 may be operated to generate an AC power signal having an independent and different frequency.

[0022] In order to control the frequency of the AC power signal, the system 100 may include: a first generator control unit 106, which is configured to control the frequency of the AC power signal generated by the first ISVF generator 104; and a second generator control unit 156, which is configured to control the frequency of the AC power signal generated by the second ISVF generator 154.

[0023] The system 100 may also include a first AC bus 108 and a second AC bus 158. The first AC bus 108 may be configured to receive an AC power signal generated by the first ISVF generator 104. Likewise, the second AC bus 158 may be configured to receive an AC power signal generated by the second ISVF generator 154.

[0024] In some embodiments, the first AC bus 108 can be coupled to the output of the first ISVF generator 104 via a first circuit breaker 110. Likewise, the second AC bus 158 can be coupled to the output of the second ISVF generator 154 via a second circuit breaker 160. A third circuit breaker 111 can couple the first AC bus 108 to the second AC bus 158. The circuit breakers 110, 111, 160 enable the system 100 to be configured in multiple states. In the first state, the circuit breakers 110, 160 are closed (enabling the AC power signals generated by the first ISVF generators 104, 154 to pass to their respective AC buses 108, 158). The third circuit breaker 111 is open (separating the AC buses 108, 158). In this configuration, each of the AC buses 108, 158 can receive different AC power signals having different frequencies. In the second state, the circuit breakers 110, 111 can be closed while the second circuit breaker 160 is open. In this configuration, the first ISVF generator 104 can drive both the first AC bus 108 and the second AC bus 158. It can be seen that each of the AC buses 108, 158 can carry the same AC power signal with the same frequency. In the third state, the circuit breakers 111, 160 can be closed while the first circuit breaker 110 is open. In this configuration, the second ISVF generator 154 can drive both the first AC bus 108 and the second AC bus 158. In the fourth state, each of the circuit breakers 110, 111, 160 can be closed. In this configuration, the ISVF generators 104, 154 can be coordinated to drive both AC buses 108, 158 at the same frequency. This state can be used to enable one of the ISVF generators 104, 154 to supplement the AC power signal from the other.

[0025] The system 100 may include at least one first distribution line 112 that provides power from the first AC bus 108 to a first AC motor 114 via a fourth circuit breaker 116. The first AC motor 114 may provide mechanical power to a first propulsion system 118, such as a thruster or other thrust generating device. The system 100 may also include at least one second distribution line 162 that provides power from the second AC bus 158 to a second AC motor 164 via a fifth circuit breaker 166. The second AC motor 164 may provide power to a second propulsion system 168. Additional distribution lines 120, 170 may provide AC power from the AC bus 108, 158 to other AC loads, such as additional AC motors or utility loads. Any additional AC motors coupled to the additional distribution lines 120, 170 may have the same frequency requirements as the AC motors 114, 164.

[0026] Significantly, the system 100 is able to function without performing full distributed rated power conversion after the AC power signal is generated by the ISVF generators 104, 154. Specifically, the AC motors 114, 164 can receive AC power signals directly from their respective buses 108, 158 without such full distributed rated power conversion.

[0027] As used herein, full distributed rated power power conversion is the conversion of an AC power signal to a DC power signal, or the conversion of a DC power signal to an AC power signal, wherein substantially all of the electrical energy distributed within the power signal (e.g., all of the electrical energy generated by a generator or all of the electrical energy required by a particular load) is converted. For example, full distributed rated power power conversion typically relies on an intervening rectifier, inverter, motor controller, or other type of power converter placed between the distribution bus and the load. In contrast, Figure 1 As depicted, the first AC motor 114 may be coupled directly to the first AC bus 108 without an intervening rectifier, inverter, motor controller, or other type of power converter placed therebetween.

[0028] In order to meet the frequency requirements of the AC motors 114, 164, the generator control unit 106, 156 may adjust the frequency of the AC power signal generated by the ISVF generator 104, 154. It can be seen that the frequency of the AC power signal present on the AC bus 108, 158 may be used to directly drive the AC motors 114, 164. This may eliminate any need for additional conversion of the AC power signal on the AC bus 108, 158.

[0029] During operation, the ISVF generators 104, 154 may generate AC power signals having frequencies that are independent of the frequency of the engine 102 and that meet the frequency requirements of the AC motors 114, 164. The AC power signals may be received at their respective AC buses 108, 158. From the AC buses 108, 158, power signals may be received at the AC motors 114, 164 without performing full distributed rated power power conversion.

[0030] A benefit of the system 100 is that by using an ISVF generator to match the frequency of the AC power signal on the AC bus 108, 158 to the frequency requirements of the AC motors 114, 164, additional conversion elements such as full distribution rated power rectifiers and inverters can be omitted from the power distribution architecture. This can result in more efficient power distribution and lighter weight. When included in an aircraft vehicle, the system 100 can reduce costs associated with the production, maintenance, and operation of the aircraft. Further, the system 100 is simplified as compared to a typical aircraft vehicle power distribution system, so the system can result in an increased life. There can be other advantages.

[0031] Reference Figure 2 , depicting an embodiment of an AC power distribution system 200. System 200 may include engine 102, circuit breakers 110, 111, 116, 160, 166, first AC bus 108, second AC bus 158, distribution lines 112, 120, 162, 170, and propulsion systems 118, 168, similar to system 100.

[0032] The system 200 may also include a first generator 204 and a second generator 254. The generators 204, 254 may include Figure 1 The described ISVF generator or other types of generators, such as a variable speed variable frequency (VSVF) generator, a constant speed constant frequency (CSCF) generator, etc. The first generator 204 and the second generator 254 can be coupled to the engine 102 so that the engine 102 operates as a prime mover for generating an electrical power signal. For example, the first generator 204 can receive mechanical power from the engine 102 and convert the mechanical power into a first AC power signal. Similarly, the second generator 254 can receive mechanical power from the engine 102 and convert the mechanical power into a second AC power signal. Although the system 200 is depicted as including two generators, in reality, the system 200 can include more or less than two generators.

[0033] The system 200 may include a first generator control unit 206 and a second generator control unit 256. In embodiments where the generators 204, 254 include ISVF generators, the generator control units 206, 256 may control the frequency of the AC power signal generated by the generators 204, 254. In other embodiments, the frequency of the AC power signal may depend on the rotational frequency of the engine 102 or other factors, and the generator control units 206, 256 may control other aspects of power generation at the generators 204, 254. In some embodiments, the generator control units 206, 256 may be omitted.

[0034] The AC power signals generated by the first generator 204 and the second generator 254 can be transmitted to the first AC bus 108 and the second AC bus 158, respectively. The circuit breakers 110, 111, 160 can enable the system 200 to operate in different states, which provides a reference to Figure 1 The same configuration of power distribution on the AC buses 108 , 158 as described for the system 100 .

[0035] System 200 may include a first variable speed independent frequency (VSIF) motor 214 and a second VSIF motor 264. First VSIF motor 214 may receive a first AC power signal from first AC bus 108 and second VSIF motor 264 may receive a second AC power signal from second AC bus 158.

[0036] As used herein, a VSIF motor is an AC motor that converts an AC power signal into a mechanical rotation having a rotational frequency that is independent of the frequency of the AC power signal. The VSIF motor does not rely on a gearbox or additional AC / DC power conversion, which can be applied to the AC power signal before the AC power signal powers the motor to achieve an independent rotational frequency. In contrast, a VSIF motor can use multiple phases of windings on the stator and rotor. At least one phase on the stator can generate a rotating magnetic field configured to rotate the rotor, while at least another phase on the rotor generates a second rotating magnetic field that increases or decreases the rotational frequency of the rotor relative to the rotational frequency of the rotating magnetic field generated by the first phase. In a typical VSIF motor, three or more windings can be used to separate the rotational frequency of the rotor from the frequency of the AC signal that drives the motor.

[0037] In order to control the rotation frequency of the VSIF motors 214 and 264, the system 200 may include: a first motor control unit 222, which is configured to control the rotation frequency of the first VSIF motor 214; and a second motor control unit 272, which is configured to control the rotation frequency of the second VSIF motor 264.

[0038] As used herein, a motor control unit is different from a motor controller used in a typical vehicle electrical system. Specifically, motor controllers used in typical vehicle electrical systems rely on full allocated rated power power conversion in order to drive their respective motors. In contrast, a motor control unit as used herein may only perform a partial power conversion sufficient to generate a rotating magnetic field at a set of windings attached to the rotor of the VSIF motor, while most of the power within the AC power signal is passed directly to the VSIF motor without any conversion. The VSIF motors 214, 263 can be used to drive the propulsion systems 118, 168.

[0039] The system 200 may also include non-propulsion AC motor loads. For example, the system 200 may include a third distribution line 224 that provides a first AC power signal from the first AC bus 108 to a third VSIF motor 228 via a sixth circuit breaker 226. The third VSIF motor 228 may be controlled by a third motor control unit 230. The system 200 may also include a fourth distribution line 274 that provides a second AC power signal from the second AC bus 158 to a fourth VSIF motor 278 via a seventh circuit breaker 276. The fourth VSIF motor 278 may be controlled by a fourth motor control unit 280. The third VSIF motor 228 and the fourth VSIF motor 278 may be used as part of a non-propulsion system such as a ventilation system, an electric actuation system, other motorization systems, or a combination thereof.

[0040] During operation, the generators 204, 254 can generate AC power signals and transmit the AC power signals to their respective AC buses 108, 158. The frequency of the AC power signal can fall outside the rotational frequency requirements of the propulsion system 118, 168 or the requirements of other motorized systems powered by the system 200. From the AC bus 108, 158, the power signal can be received at the VSIF motor 214, 264 without performing full allocated rated power power conversion. The motor control unit 222, 272 can control the VSIF motor 214, 264 to operate independently of the frequency of their respective AC power signals. In this way, the rotational frequency of the VSIF motor 214, 264 can be independent of the frequency of the AC power signal and fall within the requirements of the propulsion system 118, 168. Similarly, the VSIF motors 228, 278 associated with non-propulsion related loads can be operated at a rotational frequency independent of the frequency of the AC power signal.

[0041] The benefit of system 200 is that by using VSIF motors to drive propulsion systems 118, 168, propulsion systems 118, 168 can operate within their respective frequency requirements. Further, as with system 100, additional conversion elements such as full distribution rated power rectifiers and inverters can be omitted from the power distribution architecture. This can result in more efficient power distribution and lighter weight. When included in an aircraft vehicle, system 200 can reduce the costs associated with the production, maintenance, and operation of the aircraft. Further, as compared to a typical aircraft vehicle power distribution system, system 200 is simplified, so the system has an increased lifespan. Other advantages may exist.

[0042] Reference Figure 3, depicting an embodiment of an AC power distribution method 300. The method 300 may include the following steps: At 302, an AC power signal is generated at an ISVF generator, the frequency of the AC power signal being independent of the frequency of the prime mover. For example, the first ISVF generator 104 may generate an AC power signal that is independent of the rotational frequency of the engine 102.

[0043] The method 300 may also include the step of receiving an AC power signal from the ISVF generator at an AC bus at 304. For example, the AC power signal may be received at the first AC bus 108.

[0044] The method 300 may also include the following step: At 306, at the AC load, an AC power signal is received from the AC bus without performing full distributed rated power power conversion, wherein the frequency of the AC power signal generated by the ISVF generator meets the frequency requirement of the AC load. For example, the AC power signal may be received at the first AC motor 114. Figure 1 As depicted, the AC power signal may be transmitted directly to the first AC motor 114 without passing through any conversion circuitry.

[0045] A benefit of the method 300 is that by using an ISVF generator to match the frequency of the AC power signal on the AC bus to the frequency requirements of the AC load, additional conversion elements such as full distribution rated power rectifiers and inverters can be omitted from the power distribution architecture. When included in an aircraft vehicle, the method 300 can reduce costs associated with the production, maintenance, and operation of the aircraft. Further, the method 300 is simplified as compared to typical aircraft vehicle power distribution methods, and therefore, the method enables the life of the aircraft vehicle to be increased. Other advantages may exist.

[0046] Reference Figure 4 , depicting an embodiment of an AC power distribution method 400. The method 400 may include the following steps: At 402, an AC power signal is generated at a generator. For example, the generator 204 may generate the AC power signal.

[0047] The method 400 may also include the step of receiving an AC power signal at an AC bus from a generator, at 404. For example, the AC power signal may be received at the AC bus 108.

[0048] The method 400 may also include the step of receiving an AC power signal from the AC bus without performing full-distribution rated power power conversion at the AC motor at 406. For example, the AC power signal may be received directly at the AC motor 214 without any intervening rectifier, inverter, motor controller, or other type of power converter that performs full-distribution rated power power conversion.

[0049] Method 400 includes the step of rotating the AC motor using the AC power signal at a rotation frequency independent of the frequency of the AC power signal at 408. For example, AC motor 214 may be controlled by motor control unit 222 to operate at a frequency independent of the frequency of the AC power signal.

[0050] Reference Figure 5 , depicting an embodiment of an aircraft 500. Aircraft 500 may include fuselage 502, interior 504, and multiple systems 510. Examples of high-level systems 510 include one or more of propulsion system 512, electrical system 514, hydraulic system 520, environmental system 518, navigation system 520, and control system 522. Any number of other systems may be included. Although an aerospace example is shown, the principles of the present disclosure may be applied to other industries, such as the automotive industry.

[0051] As described herein, systems 100, 200 may be included in aircraft 500. For example, electrical system 514 may include Figure 1 The ISVF generator 104, 154, the generator control unit 106, 156, the AC bus 108, 158 and / or the AC motor 114, 164. The electrical system 514 may alternatively or additionally include Figure 2 The generator 204, 254, the generator control unit 206, 256, the VSIF motor 214, 228, 264, 278, and / or the motor control unit 222, 230, 272, 280.

[0052] Further, the present disclosure includes implementations according to the following clauses:

[0053] Item 1: An alternating current (AC) power distribution system comprising: an independent speed variable frequency (ISVF) generator, the ISVF generator being configured to generate an AC power signal having a frequency that is independent of a frequency of a prime mover; an AC bus, the AC bus being configured to receive the AC power signal from the ISVF generator; and at least one AC load, the at least one AC load being configured to receive the AC power signal from the AC bus without performing full distributed rated power power conversion, wherein the frequency of the AC power signal generated by the ISVF generator meets the frequency requirement of the AC load.

[0054] Clause 2: The system of claim 1, wherein the AC load is an AC motor, and wherein the frequency requirement of the AC load corresponds to the rotational frequency requirement of the AC motor.

[0055] Clause 3: The system of claim 2, wherein the AC motor is included in an aircraft propulsion system.

[0056] Clause 4: The system of claim 1, further comprising: a generator control unit configured to control a frequency of the AC power signal generated by the ISVF generator to meet a frequency requirement of the AC load.

[0057] Clause 5: The system of claim 1, further comprising: at least one additional AC load configured to receive an AC power signal from the AC bus.

[0058] Clause 6: The system of claim 5, wherein the at least one additional AC load has the same frequency requirement as the AC load.

[0059] Clause 7: The system of claim 1, further comprising: a second ISVF generator configured to generate a second AC power signal having a frequency independent of a frequency of the prime mover; a second AC bus configured to receive the second AC power signal from the second ISVF generator; and a second AC load configured to receive the second AC power signal from the second AC bus without performing full distributed rated power power conversion, wherein the frequency of the second AC power signal generated by the second ISVF generator meets a frequency requirement of the second AC load.

[0060] Clause 8: The system of claim 1, wherein the prime mover is a vehicle engine.

[0061] Item 9: An alternating current (AC) power distribution system, the AC power distribution system comprising: a generator configured to generate an AC power signal; an AC bus configured to receive the AC power signal from the generator; an AC motor configured to receive the AC power signal from the AC bus without performing full distributed rated power power conversion, wherein the AC motor is configured to rotate at a rotational frequency independent of the frequency of the AC power signal; and a motor control unit configured to receive the AC power signal from the AC bus, perform partial power conversion of the AC power signal to generate a converted power signal, and provide the converted power signal to the AC motor to control the rotational frequency of the AC motor.

[0062] Clause 10: The system of claim 9, wherein the AC motor is included in an aircraft propulsion system.

[0063] Clause 11: The system of claim 9, wherein the generator is an independent speed variable frequency (ISVF) generator, a variable speed variable frequency (VSVF) generator, or a constant speed constant frequency (CSCF) generator.

[0064] Clause 12: The system of claim 9, further comprising: at least one additional AC motor configured to receive an AC power signal from an AC bus.

[0065] Clause 13: The system of claim 12, wherein the frequency requirement of the AC motor is different than the frequency requirement of the other AC motor.

[0066] Clause 14: The system of claim 12, wherein the at least one additional AC motor is a non-propulsion motor load.

[0067] Clause 15: The system of claim 9, further comprising: at least one utility load configured to receive an AC power signal from the AC bus.

[0068] Clause 16: The system of claim 9, further comprising: a second generator configured to generate a second AC power signal; a second AC bus configured to receive the second AC power signal from the second generator; a second AC motor configured to receive the second AC power signal from the second AC bus without performing full allocated rated power power conversion, wherein the second AC motor is configured to rotate at a rotational frequency independent of the frequency of the second AC power signal; and a second motor control unit configured to receive the second AC power signal from the second AC bus, perform partial power conversion of the second AC power signal to generate a second converted power signal, and provide the second converted power signal to the second AC motor to control the rotational frequency of the second AC motor.

[0069] Item 17: An alternating current (AC) power distribution method, the AC power distribution method comprising the steps of: generating an AC power signal at an independent speed variable frequency (ISVF) generator, the frequency of the AC power signal being independent of the frequency of a prime mover; receiving the AC power signal from the ISVF generator at an AC bus; and receiving the AC power signal from the AC bus at an AC load without performing full distributed rated power power conversion, wherein the frequency of the AC power signal generated by the ISVF generator meets the frequency requirement of the AC load.

[0070] Clause 18: The method of claim 17, further comprising the step of receiving an AC power signal from the AC bus at an additional AC load, wherein the additional AC load has a same frequency requirement as the AC load.

[0071] Clause 19: The method of claim 17, further comprising the step of controlling, at a generator control unit, a frequency of the AC power signal generated by the ISVF generator.

[0072] Clause 20: The method of claim 17, further comprising the steps of: generating a second AC power signal at a second ISVF generator, the frequency of the second AC power signal being independent of the frequency of the prime mover; receiving the second AC power signal from the second ISVF generator at a second AC bus; and receiving the second AC power signal from the second AC bus at a second AC load without performing full distributed rated power power conversion, wherein the frequency of the second AC power signal generated by the second ISVF generator meets the frequency requirement of the second AC load.

[0073] Item 21: An alternating current (AC) power distribution method, the AC power distribution method comprising the steps of: generating an AC power signal at a generator; receiving the AC power signal from the generator at an AC bus; receiving the AC power signal from the AC bus at an AC motor without performing full distributed rated power power conversion; and using the AC power signal to rotate the AC motor at a rotational frequency that is independent of the frequency of the AC power signal.

[0074] Clause 22: The method of claim 21, further comprising the steps of: receiving an AC power signal at a motor control unit; performing partial power conversion of the AC power signal to generate a converted power signal; and providing the converted power signal to the AC motor to control the rotation frequency of the AC motor.

[0075] Clause 23: The method of claim 21, further comprising the steps of: receiving an AC power signal from an AC bus at another AC motor connected to the AC bus; and using the AC power signal to rotate the other AC motor at a rotational frequency different from the rotational frequency of the AC motor, wherein the frequency requirement of the AC motor is different from the frequency requirement of the other AC motor.

[0076] Clause 24: The method of claim 21, further comprising the steps of: generating a second AC power signal at a second generator; receiving the second AC power signal from the generator at a second AC bus; receiving the second AC power signal from the second AC bus at a second AC motor without performing full allocated rated power power conversion; and using the second AC power signal to rotate the second AC motor at a rotational frequency that is independent of the frequency of the second AC power signal.

[0077] While various embodiments have been shown and described, the disclosure is not so limited, and is to be construed to include all such modifications and alterations as would be apparent to those skilled in the art.

Claims

1. An AC power distribution system, comprising: a first independent speed variable frequency generator configured to generate a first AC power signal having a frequency independent of a frequency of the prime mover; a second independent speed variable frequency generator configured to generate a second AC power signal having a frequency independent of the frequency of the prime mover; a first AC bus coupled to an output of the first independent speed variable frequency generator via a first circuit breaker; a second AC bus coupled to an output of the second independent speed variable frequency generator via a second circuit breaker, wherein a third circuit breaker couples the first AC bus to the second AC bus; at least one AC load, the at least one AC load being directly coupled to the first AC bus, wherein a frequency of a first AC power signal generated by the first independent speed variable frequency generator meets a frequency requirement of the at least one AC load; and A second AC load is directly coupled to the second AC bus, wherein a frequency of a second AC power signal generated by the second independent speed variable frequency generator meets a frequency requirement of the second AC load.

2. The AC power distribution system according to claim 1, wherein: The at least one AC load is a first AC motor, and wherein a frequency requirement of the at least one AC load corresponds to a rotation frequency requirement of the first AC motor.

3. The AC power distribution system according to claim 2, wherein: The first AC motor is included in an aircraft propulsion system.

4. The AC power distribution system according to claim 1, further comprising: A generator control unit is configured to control the frequency of the first AC power signal generated by the first independent speed variable frequency generator to meet the frequency requirement of the at least one AC load.

5. The AC power distribution system according to claim 1, further comprising: At least one additional AC load is configured to receive the first AC power signal from the first AC bus.

6. The AC power distribution system according to claim 5, wherein: The at least one additional AC load has the same frequency requirement as the at least one AC load.

7. The AC power distribution system according to claim 1, wherein: The prime mover is a vehicle engine.

8. An AC power distribution method, the AC power distribution method comprising the following steps: generating a first AC power signal at a first independent speed variable frequency generator, the first AC power signal having a frequency independent of a frequency of the prime mover; and generating a second AC power signal at a second independent speed variable frequency generator, the second AC power signal having a frequency independent of the frequency of the prime mover; wherein a first AC bus is coupled to an output of the first independent speed variable frequency generator via a first circuit breaker; wherein a second AC bus is coupled to an output of the second independent speed variable frequency generator via a second circuit breaker, wherein a third circuit breaker couples the first AC bus to the second AC bus; wherein at least one AC load is directly coupled to the first AC bus, wherein a frequency of the first AC power signal generated by the first independent speed variable frequency generator meets a frequency requirement of the at least one AC load; and wherein a second AC load is directly coupled to the second AC bus, wherein a frequency of the second AC power signal generated by the second independent speed variable frequency generator meets a frequency requirement of the second AC load.

9. The AC power distribution method according to claim 8, further comprising the following steps: The first AC power signal is received from the first AC bus at an additional AC load, wherein the additional AC load has the same frequency requirement as the at least one AC load.

10. The AC power distribution method according to claim 8, further comprising the following steps: At a generator control unit, a frequency of the first AC power signal generated by the first independent speed variable frequency generator is controlled.

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