Control of internal power flow of an electrical system

Abstract

The present disclosure relates to a method for controlling an internal power flow of an AC electrical system comprising an AC power source, an electrical component, and a power converter having a primary side wherein the primary side of the power converter is electrically coupled to the AC power source via the electrical component wherein the power converter comprises a plurality of cells, the plurality of cells are electrically coupled to each other in series at a primary side of the plurality of cells, where each of the plurality of cells includes an AC-to-DC converter having a first AC portion electrically coupled to the primary side of the plurality of cells or an AC-to-AC converter having a first AC portion electrically coupled to the primary side of the plurality of cells, the method comprises: obtaining at least one electrical parameter of the AC electrical system; generating a control signal for each of the plurality of cells based on the obtained at least one electrical parameter; and controlling an internal power flow of the AC electrical system by adjusting the voltages of the primary sides of the plurality of cells based on the generated control signal such that a voltage difference between the voltage of the AC power source and a sum of the voltages of the primary sides of the plurality of cells causes a controlled current to flow through the electrical component, adjusting the voltage of the primary side of the plurality of cells includes adjusting a magnitude and a phase of the voltage of the primary side of the plurality of cells by controlling a first AC portion of the AC-to-DC converter based on the generated control signal or by controlling the first AC portion of the AC-to-AC converter based on the generated control signal, and wherein, the sum of the amplitudes of the voltages of the primary sides of the plurality of cells is greater than the amplitude of the voltage of the AC power supply.

Description

Technical Field

[0001] This disclosure relates to methods, apparatus, and systems for controlling the internal power flow of an electrical system. Background Technology

[0002] With technological advancements, electric vehicles (EVs) are equipped with increasingly larger battery capacities and faster charging speeds (e.g., DC fast charging power is also required to reach 350 kW to 600 kW). Consequently, the voltage platform for new EVs is shifting from 400 V to 800 V-1 kV. This indicates that in the coming years, different charging infrastructures may require different battery voltage platforms and / or charging power levels. However, due to limited available floor space, such as at highway rest stops, service stations, and gas stations, installing different individual chargers to meet changing demands is impractical.

[0003] Therefore, it is desirable to develop a modular and reconfigurable power converter capable of delivering power to EVs at different voltage and power levels, preferably for different charging ports, but only within a single power conversion. Such a power converter can be referred to as a multiplexed power converter. Furthermore, in the EV charging infrastructure (EVCI), it is further desirable to flexibly connect the vehicle battery, which has bidirectional flow capability, to other loads and power sources.

[0004] This desired modularity and reconfigurability of power converters can be achieved by stacking multiple units within the power converter. However, without proper control, this is insufficient to meet the aforementioned requirements, particularly power control of the active power flow in each of the stacked units, managing voltage balance, flexibly routing the power involved, and rapidly responding to any new reconfiguration requests arising from the presence of EVs. For this purpose, SSTs can be used, thanks to the controllability of solid-state transformers (SSTs), etc. Specifically, modular AC / DC-based (or DC / DC-based with a large-capacity AC / DC) units incorporating SSTs can be used. On the AC side, control of both active and reactive power is typically required, which can be challenging when full flexibility is demanded at the individual unit level.

[0005] Therefore, there is a need to improve the methods, devices, and systems for controlling the internal power flow of electrical systems, particularly to enable flexible adherence to P and Q setpoints in various ways while maintaining voltage balance at the various output ports of the units included in the power converter, and further, to simultaneously reroute power according to the requirements of EV batteries, which can be charged or discharged as needed for possible support. Summary of the Invention

[0006] This disclosure relates to a method for controlling the internal power flow of an electrical system, the electrical system including a power source, electrical components, and a power converter having a primary side, wherein the primary side of the power converter is electrically coupled to the power source via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units, the method comprising: obtaining at least one electrical parameter of the electrical system; generating a control signal for each of the plurality of units based on the obtained at least one electrical parameter; and controlling the internal power flow of the electrical system by adjusting the voltage of the primary side of the plurality of units based on the generated control signal, such that a voltage difference between the voltage of the power source and the sum of the voltages of the primary side of the plurality of units causes a controlled current to flow through the electrical components.

[0007] This disclosure relates to a method for controlling the internal power flow of an AC electrical system, the AC electrical system including an AC power supply, electrical components, and a power converter having a primary side, wherein the primary side of the power converter is electrically coupled to the AC power supply via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units, wherein each of the plurality of units includes an AC-to-DC converter having a first AC portion electrically coupled to the primary side of the plurality of units, or an AC-to-AC converter having a first AC portion electrically coupled to the primary side of the plurality of units, the method comprising: obtaining at least one electrical parameter of the AC electrical system; and based on the obtained at least one electrical parameter... The system generates a control signal for each of the plurality of units; and controls the internal power flow of the AC electrical system by adjusting the voltage on the primary side of the plurality of units based on the generated control signal, such that the voltage difference between the voltage of the AC power supply and the sum of the voltages on the primary side of the plurality of units causes a controlled current to flow through the electrical component, wherein adjusting the voltage on the primary side of the plurality of units includes adjusting the amplitude and phase of the voltage on the primary side of the plurality of units by controlling the first AC section of the AC to DC converter based on the generated control signal, or by controlling the first AC section of the AC to AC converter based on the generated control signal, and wherein the sum of the amplitudes of the voltages on the primary side of the plurality of units is greater than the amplitude of the voltage of the AC power supply.

[0008] Various embodiments may preferably implement the following features:

[0009] Preferably, the sum of the voltage amplitudes on the primary side of the plurality of units is at least 10% greater than the voltage amplitude of the AC power supply.

[0010] Preferably, the sum of the voltage amplitudes on the primary side of the plurality of units is at least 25% greater than the voltage amplitude of the AC power supply.

[0011] Preferably, the sum of the voltage amplitudes on the primary side of the multiple units is at most 33% greater than the voltage amplitude of the AC power supply.

[0012] Preferably, the sum of the voltage amplitudes on the primary side of the multiple units is at most 30% greater than the voltage amplitude of the AC power supply.

[0013] Preferably, the sum of the voltage amplitudes on the primary side of the multiple units is at most 25% greater than the voltage amplitude of the AC power supply.

[0014] Preferably, controlling these internal power flows includes controlling the power flow of the power converter, particularly the power flow of each of the plurality of units. More preferably, controlling these internal power flows includes controlling the portion of each of the plurality of units that interfaces with the power supply, as well as the remainder of each of the plurality of units.

[0015] Preferably, the plurality of units includes corresponding plurality of unit converters, wherein the primary side of the plurality of units is electrically coupled to the corresponding plurality of unit converters, and in particular, two ports of the corresponding plurality of unit converters form the primary side of the plurality of units. More preferably, controlling these internal power flows includes or controls the power flow of the corresponding plurality of unit converters. Preferably, the plurality of units includes a secondary side, which is different from the primary side of the plurality of units, and wherein the plurality of units are electrically isolated from each other at the secondary side of the plurality of units.

[0016] Preferably, the power system is a DC system, the power supply is a DC power supply, and each of the plurality of units includes a DC-to-AC converter or a DC-to-DC converter, and a first DC portion of the DC-to-AC converter is electrically coupled to the primary side of the plurality of units, or a first DC portion of the DC-to-DC converter is electrically coupled to the primary side of the plurality of units.

[0017] Preferably, adjusting the voltage on the primary side of the plurality of units includes adjusting the amplitude of the voltage on the primary side of the plurality of units by controlling the first DC section of the DC-to-AC converter based on the generated control signal or by controlling the first DC section of the DC-to-DC converter based on the generated control signal.

[0018] Preferably, particularly when the power system is a DC system, and even more particularly when the electrical system is resistive, the control includes, or controls the internal power flow of the electrical system by adjusting the voltage on the primary side of the plurality of units based on the generated control signal, such that the voltage difference between the voltage of the power supply and the sum of the voltages on the primary side of the plurality of units sets a voltage drop across the electrical component, causing a controlled current to flow through the electrical component.

[0019] Preferably, the electrical system is an AC system, the power supply is an AC power supply, each of the plurality of units includes an AC-to-DC converter or an AC-to-AC converter, and a first AC portion of the AC-to-DC converter is electrically coupled to the primary side of the plurality of units, or a first AC portion of the AC-to-AC converter is electrically coupled to the primary side of the plurality of units.

[0020] Preferably, adjusting the voltage on the primary side of the plurality of units includes adjusting the amplitude and phase of the voltage on the primary side of the plurality of units by controlling the first AC section of the AC-to-DC converter based on the generated control signal or by controlling the first AC section of the AC-to-AC converter based on the generated control signal.

[0021] Preferably, particularly when the power system is an AC system, and even more particularly when the electrical system is inductive and / or capacitive, and optionally resistive, the control includes, or is achieved by, adjusting the voltage on the primary side of the plurality of units based on the generated control signal to control the internal power flow of the electrical system, such that the voltage difference between the voltage of the power supply and the sum of the voltages on the primary side of the plurality of units sets the voltage across the electrical component, inducing a controlled current to flow through the electrical component.

[0022] Preferably, the voltage of the power grid, the voltage of the primary side of the multiple units, the controlled current, and the voltage drop across the electrical components are vectors including amplitude and phase information, and the sum of the voltages of the primary side of the multiple units is a vector sum.

[0023] Preferably, the electrical system further includes a first switch and a second switch, the first switch electrically coupling the power grid in series to the electrical component, the second switch electrically coupling the power grid in parallel to the electrical component.

[0024] Preferably, the method further includes closing one of the first switch and the second switch; and opening the other of the first switch and the second switch.

[0025] Preferably, the electrical component is resistive, or the electrical component is inductive and / or capacitive, and optionally resistive.

[0026] Preferably, at least one electrical parameter obtained is the voltage and / or current of the power supply, electrical components, the primary side of the power converter, or the primary side of multiple units.

[0027] Preferably, the power of at least one of the multiple units flows bidirectionally based on the generated control signal.

[0028] This disclosure also relates to an apparatus for controlling the internal power flow of an electrical system, the electrical system including a power source, electrical components, and a power converter having a primary side, wherein the primary side of the power converter is electrically coupled to the power source via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units, wherein the apparatus includes a processor configured to: obtain at least one electrical parameter of the electrical system; generate a control signal for each of the plurality of units based on the obtained at least one electrical parameter; and control the internal power flow of the electrical system by adjusting the voltage of the primary side of the plurality of units based on the generated control signal, such that the voltage difference between the voltage of the power source and the sum of the voltages of the primary side of the plurality of units causes a controlled current to flow through the electrical components.

[0029] This disclosure also relates to an apparatus for controlling the internal power flow of an AC electrical system, the AC electrical system including an AC power supply, electrical components, and a power converter having a primary side, wherein the primary side of the power converter is electrically coupled to the AC power supply via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units, wherein each of the plurality of units includes an AC-to-DC converter having a first AC portion electrically coupled to the primary side of the plurality of units or an AC-to-AC converter having a first AC portion electrically coupled to the primary side of the plurality of units, wherein the apparatus includes a processor configured to: obtain at least one electrical parameter of the electrical system; based on the obtained... At least one electrical parameter is provided to generate a control signal for each of the plurality of units; and the internal power flow of the AC electrical system is controlled by adjusting the voltage on the primary side of the plurality of units based on the generated control signal, such that the voltage difference between the voltage of the AC power supply and the sum of the voltages on the primary side of the plurality of units causes a controlled current to flow through the electrical component, wherein adjusting the voltage on the primary side of the plurality of units includes adjusting the magnitude and phase of the voltage on the primary side of the plurality of units by controlling a first AC section of the AC-to-DC converter or by controlling a first AC section of the AC-to-AC converter based on the generated control signal, and wherein the sum of the magnitudes of the voltages on the primary side of the plurality of units is greater than the magnitude of the voltage of the AC power supply.

[0030] Preferably, the sum of the voltage amplitudes on the primary side of the multiple units is at least 10% greater than the voltage amplitude of the AC power supply.

[0031] Preferably, the sum of the voltage amplitudes on the primary side of the multiple units is at least 25% greater than the voltage amplitude of the AC power supply.

[0032] Preferably, the processor is further configured to perform a method according to any of the embodiments disclosed herein.

[0033] This disclosure further relates to a system for controlling the internal power flow of an electrical system, wherein the system includes a device according to any embodiment disclosed herein, and the electrical system includes a power supply, electrical components, and a power converter having a primary side, wherein the primary side of the power converter is electrically coupled to the power supply via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units.

[0034] This disclosure further relates to a system for controlling the internal power flow of an AC electrical system, wherein the system includes devices according to any embodiment disclosed herein, and the AC electrical system includes an AC power supply, electrical components, and a power converter having a primary side, wherein the primary side of the power converter is electrically coupled to the power supply via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units, each of the plurality of units including an AC-to-DC converter having a first AC portion electrically coupled to the primary side of the plurality of units or an AC-to-AC converter having a first AC portion electrically coupled to the primary side of the plurality of units.

[0035] The various exemplary embodiments disclosed herein are intended to provide features that will become readily apparent when taken in conjunction with the accompanying drawings and the following description. Exemplary systems, methods, and apparatuses are disclosed herein according to various embodiments. However, it should be understood that these embodiments are presented by way of example and not limitation, and that various modifications may be apparent to those skilled in the art upon reading this disclosure while remaining within the scope of this disclosure.

[0036] Therefore, this disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. Furthermore, the specific order and / or hierarchy of steps in the methods disclosed herein are merely exemplary methods. Based on design preferences, the specific order or hierarchy of steps in the disclosed methods or processes may be rearranged while remaining within the scope of this disclosure. Therefore, those skilled in the art will understand that the methods and techniques disclosed herein present various steps or actions in an exemplary order, and unless otherwise expressly stated, this disclosure is not limited to the specific order or hierarchy presented.

[0037] The following items relate to specific embodiments of this disclosure.

[0038] 1. A method for controlling the internal power flow of an electrical system, the electrical system including a power source, electrical components, and a power converter having a primary side, wherein the primary side of the power converter is electrically coupled to the power source via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units, the method comprising: Obtain at least one electrical parameter of the electrical system; Based on at least one obtained electrical parameter, a control signal is generated for each of the plurality of units; and The internal power flow of the electrical system is controlled by adjusting the voltage on the primary side of the plurality of units based on the generated control signal, such that the voltage difference between the voltage of the power supply and the sum of the voltages on the primary side of the plurality of units causes a controlled current to flow through the electrical components.

[0039] 2. The method of claim 1, wherein the plurality of units includes a secondary side, the secondary side being different from the primary side of the plurality of units, and wherein the plurality of units are electrically isolated from each other at the secondary side of the plurality of units.

[0040] 3. The method as described in item 1 or 2, wherein, The power system is a DC system. The power supply is a DC power supply, and Each of the plurality of units includes a DC-to-AC converter or a DC-to-DC converter, and The first DC portion of the DC-to-AC converter is electrically coupled to the primary side of the plurality of units, or the first DC portion of the DC-to-DC converter is electrically coupled to the primary side of the plurality of units.

[0041] 4. The method as described in item 3, wherein adjusting the voltage on the primary side of the plurality of units includes: The amplitude of the voltage on the primary side of the plurality of units is adjusted by controlling the first DC section of the DC-to-AC converter based on the generated control signal or by controlling the first DC section of the DC-to-DC converter based on the generated control signal.

[0042] 5. The method as described in item 1 or 2, wherein, The electrical system is an AC system. The power source is AC power. Each of the plurality of units includes an AC-to-DC converter or an AC-to-AC converter, and The first AC portion of the AC-to-DC converter is electrically coupled to the primary side of the plurality of units, or the first AC portion of the AC-to-AC converter is electrically coupled to the primary side of the plurality of units.

[0043] 6. The method as described in item 5, wherein adjusting the voltage on the primary side of the plurality of units includes: The amplitude and phase of the voltage on the primary side of the plurality of units are adjusted by controlling the first AC section of the AC-to-DC converter based on the generated control signal or by controlling the first AC section of the AC-to-AC converter based on the generated control signal.

[0044] 7. The method as described in item 5 or 6, wherein, The voltage of the power grid, the voltage on the primary side of the plurality of units, the controlled current, and the voltage drop across the electrical components are vectors including amplitude and phase information, and The sum of the voltages on the primary side of the plurality of units is a vector sum.

[0045] 8. The method as described in any one of items 5 to 7, wherein, The electrical system further includes a first switch and a second switch. The first switch electrically couples the power grid in series to the electrical component. The second switch is electrically coupled to the node between the first switch and the electrical component, and The second switch electrically couples the power grid to the electrical component in parallel.

[0046] 9. The method of claim 8, further comprising: Close one of the first switch and the second switch; and Disconnect the other of the first and second switches.

[0047] 10. The method as described in any one of items 1 to 9, wherein, The electrical component is resistive, or The electrical components are inductive and / or capacitive, and optionally resistive.

[0048] 11. The method of any one of claims 1 to 10, wherein at least one electrical parameter obtained is the voltage and / or current of the power supply, the electrical component, the primary side of the power converter, or the primary side of the plurality of units.

[0049] 12. The method of any one of items 1 to 11, wherein the power of at least one of the plurality of units flows bidirectionally based on the generated control signal.

[0050] 13. An apparatus for controlling the internal power flow of an electrical system, the electrical system including a power source, electrical components, and a power converter having a primary side, wherein the primary side of the power converter is electrically coupled to the power source via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units, wherein the apparatus includes a processor configured to: Obtain at least one electrical parameter of the electrical system; Based on at least one obtained electrical parameter, a control signal is generated for each of the plurality of units; and The internal power flow of the electrical system is controlled by adjusting the voltage on the primary side of the plurality of units based on the generated control signal, such that the voltage difference between the voltage of the power supply and the sum of the voltages on the primary side of the plurality of units causes a controlled current to flow through the electrical components.

[0051] 14. The apparatus of claim 13, wherein the processor is further configured to perform the method according to any one of claims 2 to 12.

[0052] 15. A system for controlling the internal power flow of an electrical system, wherein the system includes the device according to claim 13 or 14, and the electrical system includes a power supply, electrical components, and a power converter having a primary side, wherein the primary side of the power converter is electrically coupled to the power supply via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units.

[0053] The above and other aspects and their embodiments are described in more detail in the accompanying drawings, description and claims. Attached Figure Description

[0054] Figure 1 A flowchart illustrating a method for controlling the internal power flow of an electrical system according to an embodiment of the present disclosure is shown.

[0055] Figure 2a The diagram illustrates a power converter according to an embodiment and a corresponding control method according to an embodiment.

[0056] Figure 2b The diagram illustrates a power converter according to an embodiment and a corresponding control method according to an embodiment.

[0057] Figure 3a The diagram illustrates a power converter according to an embodiment and a corresponding control method according to an embodiment.

[0058] Figure 3bThe diagram illustrates a power converter according to an embodiment and a corresponding control method according to an embodiment.

[0059] Figure 4 The illustration shows an electric system according to an embodiment of the present disclosure.

[0060] Figure 5 The illustration shows a power system according to an embodiment of the present disclosure and its operation according to a control method according to an embodiment of the present disclosure.

[0061] Figure 6 The illustration shows a power system according to an embodiment of the present disclosure and its operation according to a control method according to an embodiment of the present disclosure.

[0062] Figure 7 The illustration shows a power system according to an embodiment of the present disclosure and its operation according to a control method according to an embodiment of the present disclosure.

[0063] Figure 8a The illustration shows an apparatus according to an embodiment of the present disclosure.

[0064] Figure 8b The illustration shows an electrical system according to an embodiment of the present disclosure.

[0065] Figure 8c The illustration shows a system according to an embodiment of the present disclosure.

[0066] In the following, exemplary embodiments of this disclosure will be described. Note that, unless otherwise stated or obvious, some aspects of any of the described embodiments may also be found in some other embodiments. However, for the sake of understanding, each aspect will be described in detail only when first mentioned, and any repeated descriptions of the same aspect will be omitted. Detailed Implementation

[0067] Figure 1 A flowchart illustrating a method for controlling the internal power flow of an electrical system according to an embodiment of the present disclosure is shown. Specifically, Figure 1The flowchart shown relates to a method for controlling the internal power flow of an electrical system, the electrical system including a power supply, electrical components, and a power converter having a primary side, wherein the primary side of the power converter is electrically coupled to the power supply via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units. In an embodiment, the plurality of units includes a secondary side, which is different from the primary side of the plurality of units. In an embodiment, the plurality of units are electrically isolated from each other at the secondary side of the plurality of units. In an embodiment, the electrical component is resistive, or the electrical component is inductive and / or capacitive, and optionally resistive. At S101, at least one electrical parameter of the electrical system is obtained. In an embodiment, the at least one electrical parameter obtained is the voltage and / or current of the power supply, the electrical components, the primary side of the power converter, or the primary side of the plurality of units. At S102, based on the at least one electrical parameter obtained, a control signal is generated for each of the plurality of units. In an embodiment, the control signal is a PWM signal. In an embodiment, each of the plurality of units, particularly at least one of the controllable switching components included therein, is controllable based on a control signal. In an embodiment, each of the plurality of units is or includes a solid-state transformer (SST). At S103, the internal power flow of the electrical system is controlled by adjusting the voltage on the primary side of the plurality of units based on the generated control signal, such that the voltage difference between the voltage of the power supply and the sum of the voltages on the primary side of the plurality of units causes a controlled current to flow through the electrical components.

[0068] In embodiments, controlling the internal power flow includes controlling the power flow of the power converter, particularly the power flow of each of the plurality of units. In a particular embodiment, controlling these internal power flows includes controlling the portion of each of the plurality of units that interfaces with the power supply, as well as the remainder of each of the plurality of units.

[0069] In one embodiment, the plurality of units includes a plurality of corresponding unit converters, wherein the primary side of the plurality of units is electrically coupled to the respective unit converters, and in particular, two ports of the respective unit converters form the primary side of the plurality of units. In a particular embodiment, controlling these internal power flows includes controlling the power flows of the respective unit converters.

[0070] In one embodiment, the plurality of units include a secondary side that is different from the primary side of the plurality of units, and wherein the plurality of units are electrically isolated from each other at the secondary side of the plurality of units.

[0071] In an embodiment, the secondary side of at least one of the multiple units is electrically coupled to a DC load, a DC power supply, or a DC storage element. The DC load may require electrical isolation. The DC load can be any of a battery (particularly a battery for electric vehicles), a distributed energy source, a DC motor, a local energy storage facility (which is, for example, different from a battery, particularly a battery for electric vehicles), etc.

[0072] In an embodiment, the power system is a DC system, the power supply is a DC power supply, and each of the plurality of units includes a DC-to-AC converter or a DC-to-DC converter, and a first DC portion of the DC-to-AC converter is electrically coupled to the primary side of the plurality of units, or a first DC portion of the DC-to-DC converter is electrically coupled to the primary side of the plurality of units.

[0073] In an embodiment, adjusting the voltage on the primary side of the plurality of units includes adjusting the amplitude of the voltage on the primary side of the plurality of units by controlling the first DC section of the DC-to-AC converter based on a generated control signal or by controlling the first DC section of the DC-to-DC converter based on a generated control signal.

[0074] In embodiments, particularly when the power system is a DC system, and even more particularly when the electrical system is resistive, control includes, or by adjusting the voltage on the primary side of the plurality of units based on the generated control signal, controlling the internal power flow of the electrical system such that the voltage difference between the voltage of the power supply and the sum of the voltages on the primary side of the plurality of units sets a voltage drop across the electrical component, causing a controlled current to flow through the electrical component.

[0075] In an embodiment, the electrical system is an AC system, the power supply is an AC power supply, and each of the plurality of units includes an AC-to-DC converter or an AC-to-AC converter, wherein a first AC portion of the AC-to-DC converter is electrically coupled to the primary side of the plurality of units, or a first AC portion of the AC-to-AC converter is electrically coupled to the primary side of the plurality of units.

[0076] In an embodiment, adjusting the voltage on the primary side of the plurality of units includes adjusting the amplitude and phase of the voltage on the primary side of the plurality of units by controlling the first AC section of the AC-to-DC converter based on a generated control signal or by controlling the first AC section of the AC-to-AC converter based on a generated control signal.

[0077] In embodiments, particularly when the power system is an AC system, and even more particularly when the electrical system is inductive and / or capacitive, and optionally resistive, the control includes, or is achieved by, adjusting the voltage on the primary side of the plurality of units based on a generated control signal to control the internal power flow of the electrical system, such that the voltage difference between the voltage of the power supply and the sum of the voltages on the primary side of the plurality of units sets a voltage across the electrical component, inducing a controlled current to flow through the electrical component.

[0078] In the embodiment, the voltage of the power grid, the voltage of the primary side of the plurality of units, the controlled current, and the voltage drop across the electrical components are vectors including amplitude and phase information, and the sum of the voltages of the primary side of the plurality of units is a vector sum.

[0079] In an embodiment, the electrical system further includes a first switch and a second switch, the first switch being electrically coupled in series to the electrical component, the second switch being electrically coupled to the node between the first switch and the electrical component, and the second switch being electrically coupled in parallel to the electrical component.

[0080] In an embodiment, the method further includes closing the first switch and the other of the second switch; and opening the first switch and the other of the second switch.

[0081] In an embodiment, the electrical component is resistive, or the electrical component is inductive and / or capacitive, and optionally resistive.

[0082] In an embodiment, at least one electrical parameter obtained is the voltage and / or current of the power supply, electrical components, the primary side of the power converter, or the primary side of the plurality of units.

[0083] In one embodiment, the power of at least one of the plurality of units flows bidirectionally based on the generated control signal.

[0084] This disclosure also relates to an apparatus for controlling the internal power flow of an electrical system, the electrical system including a power source, electrical components, and a power converter having a primary side, wherein the primary side of the power converter is electrically coupled to the power source via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units, wherein the apparatus includes a processor configured to: obtain at least one electrical parameter of the electrical system; generate a control signal for each of the plurality of units based on the obtained at least one electrical parameter; and control the internal power flow of the electrical system by adjusting the voltage of the primary side of the plurality of units based on the generated control signal, such that the voltage difference between the voltage of the power source and the sum of the voltages of the primary side of the plurality of units causes a controlled current to flow through the electrical components.

[0085] In one embodiment, the processor is further configured to perform a method according to any of the embodiments disclosed herein.

[0086] This disclosure further relates to a system for controlling the internal power flow of an electrical system, wherein the system includes a device according to any embodiment disclosed herein, and the electrical system includes a power supply, electrical components, and a power converter having a primary side, wherein the primary side of the power converter is electrically coupled to the power supply via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units.

[0087] Figure 2a The diagram illustrates a power converter according to an embodiment and a corresponding control method therefor according to an embodiment. Specifically, Figure 2a The diagram illustrates a power converter, specifically a DC-DC power converter 200. The power converter 200 comprises multiple units, more specifically, n units 210, 220, and 2n0, where n is a natural number. The primary side of each of the multiple units 210, 220, and 2n0 is electrically coupled to each other in series, as shown below. Figure 2a As shown in the diagram. Each of the plurality of units 210, 220, and 2n0 includes an electrically isolated DC-DC power converter. The DC-DC power converter includes a DC-AC converter, a transformer, and an AC-DC converter. The DC-AC converter is electrically isolated from the AC-DC converter via a transformer, particularly a single-winding intermediate frequency transformer (MFT), which electrically couples the DC-AC converter to the AC-DC converter. The DC-AC converter and the AC-DC converter each include a first set of controllable switching components and a second set of controllable switching components. Therefore, the power converter 200 can be referred to as an SST with a single-winding MFT. In an embodiment, each of the plurality of units 210, 220, and 2n0 includes a secondary side that is different from its primary side. It should be noted that the power converter 200 is configured with input series and output separation. In other words, the primary side of each of the plurality of units is connected in series to form the series-connected input terminal of the power converter 200, i.e., the primary side of the power converter 200 formed by nodes X and Y, while the secondary side of each of the plurality of units is electrically isolated from each other, thereby forming the discrete output terminal of the power converter 200, i.e., the secondary side of the power converter 200. In embodiments, the secondary side of each of the plurality of units is electrically coupled in series or in parallel to each other. That is, the power converter can be configured as having a series input and a series output or a series input and a parallel output.

[0088] The power converter 200 can be used in a power system. An exemplary power system in which the power converter can be included and controlled is described below.

[0089] The power system can be a DC power system including a DC power supply, which is electrically coupled to the primary side of the power converter 200 via electrical components, particularly resistive components. The power converter 200 is electrically coupled in series to the electrical components at node X. The DC power supply and the electrical components are... Figure 2a The values ​​are omitted in the original text. The voltage and current of the DC power supply are expressed as follows: and The voltage drop across electrical components is expressed as And the voltage at the primary side of each of the multiple units 210, 220 and 2n0 is respectively expressed as and And the current through the electrical components is expressed as It should be noted that Suitable for electrical components connected in series.

[0090] Power converter 200 can be based on Figure 1 The disclosed methods are for control, particularly when configured in power systems as described above. That is, obtaining... , , and / or Based on these signals, control signals are generated for controlling multiple units 210, 220, and 2n0. The control signals may be, or include, first signals, particularly PWM signals, for controlling a first set of controllable switching components in the DC-to-AC converter included in each of the multiple units. The internal power flow of the electrical system is controlled based on the generated control signals. Specifically, this is accomplished by adjusting the voltages on the primary sides of the multiple units 210, 220, and 2n0 based on the generated control signals, particularly by controlling the first set of controllable switching components included in the DC-to-AC converter, such that the voltage difference between the power supply voltage and the sum of the voltages on the primary sides of the multiple units 210, 220, and 2n0 sets a voltage drop across the electrical components, causing a controlled current to flow through the electrical components, particularly to compensate for the voltage difference. That is, this control scheme operates under the following constraints:

[0091] in, and Representing the first of multiple units 210, 220 and 2n0 respectively The current and voltage of each unit. This is illustrated in Figure 201. The first unit in multiple units 210, 220, and 2n0... The corresponding power flow of each unit is given by the following formula:

[0092] Due to this embodiment Since all n units are identical, and Proportional, and through ( The following is given:

[0093] The symbol ~ indicates a proportional relationship. The reference can be provided by any higher-order system. In this way, the power flow of multiple units is controlled. Specifically, the portion of each of the multiple units that interfaces the primary side of the multiple units with the power grid is controlled. In this embodiment, the power flow of the AC-to-DC converter included in each of the multiple units is controlled. The power flow of the multiple units can be the internal power flow of the electrical system.

[0094] Figure 2b The diagram illustrates a power converter according to an embodiment and a corresponding control method therefor according to an embodiment. Figure 2b The power converter 200b shown in the figure has Figure 2a The power converter 200b shown differs in that it includes a multi-winding transformer that electrically isolates the primary side of each of the plurality of units 210b, 220b, and 2n0b from the secondary side of each of the plurality of units 210b, 220b, and 2n0b. Therefore, the power converter 200b can be referred to as an SST with a multi-winding MFT. Figure 2b The remaining aspects of the embodiments shown are the same as those of the embodiments described above. Figure 2a The rest of the aspects are the same. That is, the power converter 200b can be included in a DC power system, wherein a DC power supply is electrically coupled to the primary side of the power converter 200b via electrical components, wherein the power converter 200b includes a plurality of units 210b, 220b and 2n0b, which are electrically coupled to each other at the primary side of each of the plurality of units 210b, 220b and 2n0b. Furthermore, suitable for Figure 2a The method for controlling the internal power of a power system is also applicable to power converter 200b. For the sake of brevity, the same aspects previously set forth in the foregoing sections of this disclosure will not be repeated herein. Those skilled in the art will understand that, in the case of a multi-winding MFT, the control method disclosed herein can compensate for the different natural power flows caused by the different series inductances corresponding to different units of the MFT winding.

[0095] Figure 3a The diagram illustrates a power converter according to an embodiment and a corresponding control method therefor according to an embodiment. Specifically, Figure 3aThe diagram illustrates a power converter, specifically an AC-to-DC power converter 300. The power converter 300 comprises multiple units, more specifically, n units 310, 320, and 3n0, where n is a natural number. The primary side of each of the multiple units 310, 320, and 3n0 is electrically coupled to each other in series, as shown below. Figure 3a As shown in the diagram. Each of the plurality of units 310, 320, and 3n0 includes an AC-to-DC converter electrically coupled to a DC-to-DC power converter. The DC-to-DC power converter includes a DC-to-AC converter, a transformer, and an additional AC-to-DC converter (different from the AC-to-DC converter electrically coupled to the DC-to-DC power converter). Two ports on the DC side of this additional AC-to-DC converter form the output ports of each of the plurality of units 310, 320, and 3n0. The DC-to-AC converter is electrically isolated from the additional AC-to-DC converter by a transformer, particularly a single-winding intermediate frequency transformer (MFT), which electrically couples the DC-to-AC converter to the additional AC-to-DC converter. The DC-to-AC converter and the AC-to-DC converter each include a first set of controllable switching components and a second set of controllable switching components, respectively. Therefore, the power converter 300 can be referred to as an SST with a single-winding MFT. In an embodiment, each of the plurality of units 310, 320, and 3n0 includes a secondary side that is different from its primary side. It should be noted that the power converter 200 is configured with a series input and a discrete output. That is, the primary side of each of the plurality of units is connected in series with each other to form the series-connected input terminal of the power converter 300, i.e., the primary side of the power converter 300 formed by nodes X and Y, while the secondary side of each of the plurality of units is electrically isolated from each other, thereby forming the discrete output terminal of the power converter 300, i.e., the secondary side of the power converter 300. In embodiments, the secondary sides of each of the plurality of units are electrically coupled in series or in parallel with each other. That is, the power converter can be configured with a series input and series output or a series input and parallel output.

[0096] The power converter 200 can be used in a power system. An exemplary power system in which the power converter can be included and controlled is described below.

[0097] The power system may be an AC power system including an AC power source electrically coupled to the primary side of the power converter 300 via electrical components, particularly inductive and / or capacitive components, and optionally resistive components. In an embodiment, the power converter 300 is electrically coupled in series to the electrical components at node X. The AC power source and the electrical components are... Figure 3a The values ​​are omitted in the original text. The voltage and current of the DC power converter are expressed as follows: and The voltage drop across electrical components is expressed as And the voltage at the primary side of each of the multiple units 310, 320 and 3n0 is expressed as follows: and It should be noted that Suitable for electrical components connected in series.

[0098] Power converter 300 can be based on Figure 1 The disclosed methods are for control, particularly when configured in power systems as described above. That is, obtaining... , , and / or And based on these, control signals are generated for controlling multiple units 310, 320, and 3n0. Note the parameters in the AC system. , , and / or It is a vector that includes amplitude and phase information. The control signal can be or includes a first signal, particularly a PWM signal, for controlling the first set of controllable switching components in the AC-to-DC converter included in each of the multiple units. The internal power flow of the electrical system is controlled based on the generated control signal. Specifically, this is accomplished by adjusting the voltage on the primary side of the multiple units 310, 320, and 3n0 based on the generated control signal, particularly by controlling the first set of controllable switching components included in the AC-to-DC converter, such that the voltage difference between the power supply voltage and the sum of the voltages on the primary side of the multiple units 310, 320, and 3n0 sets a voltage drop across the electrical components, which causes a controlled current to flow through the electrical components. That is, this control scheme operates under the following constraints:

[0099] in, and These represent the first, second, and third elements in multiple units 310, 320, and 3n0, respectively. The current and voltage of each unit, and This indicates that the variable X is a complex number (e.g., a compact representation of a 2-dimensional spatial vector, also known as a phasor). This is illustrated in phasor diagram 301. The phasor in multiple elements 310, 320, and 3n0... The corresponding power flow of each unit is given by the following formula:

[0100] Among the symbols This represents the absolute value of the complex number X, which physically represents the amplitude of the signal. X can be either the maximum value or the RMS value. It should be noted that whether X is RMS or the maximum value is independent of the control method described in this paper. express and The phasor angle between them.

[0101] Due to this embodiment Since all n units are identical, and Proportional, and through ( The following is given:

[0102] The symbol ~ indicates a proportional relationship. The reference can be provided by any higher-order system. In this way, the power flow of multiple units is controlled. Specifically, the portion of each of the multiple units that interfaces the primary side of the multiple units with the power grid is controlled. In this embodiment, the power flow of the AC-to-DC converter included in each of the multiple units is controlled. The power flow of the multiple units can be the internal power flow of the electrical system.

[0103] In the embodiments, active power flow is controlled based on measurements of current and / or voltage on the secondary side of multiple units, and / or reactive power flow is controlled based on measurements of voltage and / or current on the primary side of multiple units.

[0104] Figure 3b The diagram illustrates a power converter according to an embodiment and a corresponding control method therefor according to an embodiment. Figure 3b The power converter 300b shown in the figure is... Figure 3a The power converter 300 shown in the diagram differs in that it includes a multi-winding transformer that electrically isolates the primary side of each of the multiple units 310b, 320b, and 3n0b from the secondary side of each of the multiple units 310b, 320b, and 3n0b. Therefore, the power converter 300b can be referred to as an SST with a multi-winding MFT. Figure 3b The remaining aspects of the embodiments shown are the same as those of the embodiments described above. Figure 3a The rest of the aspects are the same. That is, the power converter 300b can be included in an AC power system, wherein the AC power supply is electrically coupled to the primary side of the power converter 300b via electrical components, wherein the power converter 300b includes a plurality of units 310b, 320b and 3n0b, which are electrically coupled to each other at the primary side of each of the plurality of units 310b, 320b and 3n0b. Furthermore, suitable for Figure 3aThe method for controlling the internal power of a power system is also applicable to AC power systems including power converter 300b. For the sake of brevity, the same aspects previously set forth in the foregoing sections of this disclosure will not be repeated herein. Those skilled in the art will understand that, in the case of a multi-winding MFT, the control method disclosed herein is capable of compensating for the different natural power flows caused by the different series inductances corresponding to different units of the MFT winding.

[0105] Figure 4 The illustration depicts an electric power system according to an embodiment of the present disclosure. Specifically, Figure 4 The diagram illustrates an AC power system including an AC power source 401, which is electrically coupled to an AC-to-DC power converter 400 via an inductor 402 connected in series. and This indicates the voltage of AC power supply 401, the current of AC power supply 401, and the voltage across the series-connected inductor 402. The power AC-to-DC converter 400 is... Figure 3a The power converter 300 shown is an embodiment with six units. Those skilled in the art will understand that the power AC-to-DC power converter 400 can be... Figure 3b The embodiment of power converter 300b shown is illustrated in [reference needed]. It should be noted that the AC-to-DC power converter 400 is configured with a series input and discrete output. That is, the primary side of each of the multiple units is connected in series with each other to form the series-connected input of the AC-to-DC power converter, while the secondary side of each of the multiple units is electrically isolated from each other, thereby forming the discrete output of the AC-to-DC power converter. Features of this configuration include: electrical isolation at the output of each unit, individual control of the power flow at each output, only one MFT per power path and a minimal number of power conversion stages, the ability to integrate local PV and storage devices, and high flexibility to add, upgrade, or change units. and These represent the voltages on the primary side of multiple units 410, 420, 430, 440, 450, and 460, respectively. The discrete outputs of the AC-to-DC power converter, i.e., the secondary side of each of the multiple units 410, 420, 430, 440, 450, and 460, are electrically coupled to the corresponding multiple loads 411, 421, 431, 441, 451, and 461. Each of the multiple units is capable of bidirectional power flow, allowing each of the multiple loads 411, 421, 431, 441, 451, and 461 to either draw power from or supply power to the system. Note the parameters in the AC system. , , , and It is a vector that includes amplitude and phase information.

[0106] Figure 5 The illustration shows a power system according to an embodiment of the present disclosure and its operation according to a control method according to an embodiment of the present disclosure. Specifically, Figure 5 The diagram illustrates the following: Figure 1 The method shown is used to perform the operation. Figure 4 The power system shown. It should be noted that, for simplicity, in... Figure 5 The AC power supply 401 and the series-connected inductor 402 are omitted. In this embodiment, the AC power supply 401 is the power grid and only provides active power. Four vehicles 411, 421, 431, and 441 are charged at a nominal power Pn. The fifth unit, electrically coupled to battery 451, only provides reactive power compensation, and photovoltaic device 461 provides power to the AC power system. The corresponding power Pn, Pn, Pn, Pn, 0, and 0.8Pn of each of the multiple units 410, 420, 430, 440, 450, and 460 can be collectively defined as the internal power flow of the electrical system. When according to Figure 1 When operating using the method shown, Figure 5 The power system shown operates according to the constraints of equation (4) and produces the phasors shown in phasor diagram 501. Specifically, it is adjusted based on control signals generated using measurements from the electrical system. and The amplitude and phase. For example, Adjusted to relative The phase difference is 90 degrees. Adjusted to relative The phase difference is 180 degrees, and and Adjusted to relative They are in phase, meaning the phase angle difference between them is 0. This ensures that, in the phasor domain, the voltage difference between the vector sum of the power supply voltage and the voltages on the primary sides of the multiple units 410, 420, 430, 440, 450, and 460 sets the voltage drop across the electrical components. This, in turn, makes the controlled current Flow through electrical components . This represents the vector sum of the voltages on the primary side of multiple units 410, 420, 430, 440, 450, and 460.

[0107] Those skilled in the art will understand that the fifth unit 450 and the sixth unit 460 implement power routing, particularly by ensuring a voltage margin to allow for a phase shift between the AC vectors on the primary side of the units. More specifically, the fifth unit 450 and the sixth unit 460 provide an additional voltage to produce a voltage margin greater than zero, which is defined as... This voltage margin allows for control of additional degrees of freedom, namely, the corresponding phase and amplitude of the voltage at the input side of the unit in the power converter. This is due to the nature of active and reactive power, which are the vertical and horizontal components of the apparent power vector, respectively. If more reactive power is needed while maintaining constant active power, a voltage margin is required to satisfy both requirements simultaneously. According to the definition of voltage margin, without it, the only way to connect to... ,all( All vectors must be collinear. This means that for any vector Ui to not be collinear with any other vector, Ideally, collinearity requires a voltage margin, where i and j are in {1,...,n}. Therefore, it is possible to have different... Different phases of the vector advantageously allow for independent power flow control for each cell. The corresponding phase and amplitude of the control voltage enable the power direction in the control unit to be controlled individually, which in turn enables power cycling between cells.

[0108] In the event that at least one of the multiple units becomes uncontrollable and / or disabled, for example due to maintenance, temporary disabling, failure, etc., the system can continue to operate by operating a power converter with a reduced number of controllable units based on the method according to any embodiment disclosed herein, i.e., the power flow is controlled. However, when this situation results in a voltage margin equal to or less than zero, the corresponding phase and amplitude of the voltage at the input side of the unit in the power converter may no longer be controllable. Therefore, the power converter may be unable to route power between units within the power converter. Thus, the unit in the power converter that results in a voltage margin greater than zero and subsequent additional units can be referred to as (additional) redundant units.

[0109] The voltage margin is greater than zero when the sum of the absolute values ​​of the primary side voltages of the multiple cells is greater than the absolute value of the power supply voltage. Considering vectors, the voltage margin is greater than zero when the sum of the magnitudes of the primary side voltages of the multiple cells is greater than the magnitude of the power supply voltage.

[0110] In this embodiment, the voltage margin is at least 10% of the absolute voltage of the power grid, i.e., .

[0111] In another embodiment, the voltage margin is at least 25% of the absolute voltage of the power grid, i.e., .

[0112] In this embodiment, the voltage margin is at most 33% of the absolute voltage of the power grid, that is, .

[0113] In this embodiment, the voltage margin is at most 30% of the absolute voltage of the power grid, that is, .

[0114] In this embodiment, the voltage margin is at most 25% of the absolute voltage of the power grid, that is, .

[0115] Figure 6 The illustration shows a power system according to an embodiment of the present disclosure and its operation according to a control method according to an embodiment of the present disclosure. Specifically, Figure 6 The diagram illustrates the following: Figure 1 The method shown is used to perform the operation. Figure 4 The power system shown. It should be noted that, for simplicity, in... Figure 6 The AC power supply 401 and the series-connected inductor 402 are omitted. In this embodiment, the AC power supply 401 is the power grid and only provides reactive power. The first three vehicles 411, 421, and 431 are charged at nominal power Pn, the fourth vehicle 441 provides nominal power Pn to the system, the unit with battery 451 provides nominal power Pn to the system, and the photovoltaic device 461 provides power Pn to the system. The corresponding power Pn, Pn, Pn, Pn, Pn, and Pn of each of the multiple units 410, 420, 430, 440, 450, and 460 can be collectively defined as the internal power flow of the electrical system. When according to Figure 1 When operating using the method shown, Figure 6 The power system shown operates according to the constraints of equation (4) and produces the phasors shown in phasor diagram 601. Specifically, it is adjusted based on control signals generated using measurements from the electrical system. and The amplitude and phase. For example, and Adjusted to relative Phase difference degree, and and Adjusted to relative Phase difference It is known that the adjusted primary-side voltage of each cell can have any phase difference with any other voltage other than the power supply voltage. This allows the voltage difference between the power supply voltage and the vector sum of the primary-side voltages of the multiple cells 410, 420, 430, 440, 450, and 460 in the phasor domain to set the voltage across the electrical components. This, in turn, causes the controlled current to... Flow through electrical components Therefore, the internal power flow of the electrical system is controlled.

[0116] Those skilled in the art will understand that reactive power from the grid can be used to generate current vectors in the appropriate direction to achieve active power circulation between units. The reactive and active power from the grid are caused by the sum of the unit voltages. However, the circulation between units is not controlled from the grid side. This is achieved by different controllers that set the active power setpoint for balancing purposes. That is, all... The vector sum provides the total voltage vector of the converter, which is used to control the active and reactive power entering the grid. Above this, each U... i The amplitude and phase are controlled to achieve internal power flow control. It should also be noted that reactive power injection into the grid may be undesirable and may not be allowed to exceed a certain level. (See reference...) Figure 5 The principles and requirements for explaining power routing (i.e., power cycling between cells) also apply to... Figure 6 Examples of implementations.

[0117] Figure 7 The illustration shows a power system according to an embodiment of the present disclosure and its operation according to a control method according to an embodiment of the present disclosure. Specifically, Figure 7 The diagram illustrates an AC power system including an AC power supply 701, which is electrically coupled to a power converter 700 via a series-connected inductor 702. The power converter 700 can be an AC-to-DC power converter, specifically power converter 300 or 300b, or an AC-to-AC power converter. The power converter 700 comprises six units. The AC voltage on the primary side of each of the six units is represented by six corresponding voltage sources 710, 720, 730, 740, 750, and 760. The voltages of these six voltage sources 710, 720, 730, 740, 750, and 760 are respectively represented as follows: and For simplicity, the remainder of the power converter 700 is omitted herein. The system further includes a first switch 703 and a second switch 704, wherein the first switch 703 electrically couples the power grid in series to the electrical component, i.e., the inductor 702, and the second switch 704 electrically couples the first switch 703 to the node between the first switch 703 and the electrical component 702. The second switch 704 electrically couples the power grid (i.e., AC power supply) 701 in parallel to the electrical component 702. In an embodiment, one of the first switch 703 and the second switch 704 is closed, and the other of the first switch 703 and the second switch 704 is closed. Opening and closing occur simultaneously or with a predetermined time delay between them. Specifically, when the first switch 703 is open (i.e., electrically decoupled) and the second switch 704 is closed (i.e., electrically coupled), the AC power supply does not provide power to the system. In this embodiment, a loop, ring, or island is formed, comprising six voltage sources 710, 720, 730, 740, 750, and 760, the electrical component 702, and the second switch 704. The circuit operates in such a way that loads, power supplies, and / or storage devices electrically coupled to the secondary side of multiple units (which combine to form six voltage sources 710, 720, 730, 740, 750, and 760) participate in power balancing operations. Those skilled in the art will understand that the electrical system can be configured differently to achieve power isolation and form a circuit or loop without a power source but including power converters and electrical components.

[0118] In the following text, it is assumed that the power converter 700 is as follows: Figure 6 The AC-to-DC power converter 400 configured in the system has the same load and power flow, i.e., the first three vehicles 411, 421, and 431 are charged at nominal power, the fourth vehicle 441 provides nominal power to the system, the unit with battery 451 provides nominal power to the system, and the photovoltaic device 461 provides power to the system. In this case, even when the AC grid 701 is disconnected from the power converter 700, the constraints of equation (4) can be followed. Figure 1 The method shown controls the electrical system. The resulting phasor parameters are shown in phasor diagram 701. Specifically, the control signal is adjusted based on the measurement results of the electrical system. and The amplitude and phase. For example, and Adjusted to the phase difference relative to the reference signal degree, and and Adjusted to the phase difference relative to the reference signal This ensures that, in the phasor domain, the voltage difference between the voltage of the power supply and the vector sum of the voltages on the primary sides of the multiple units 410, 420, 430, 440, 450, and 460 sets the voltage across the electrical components. This, in turn, causes the controlled current to... Flow through electrical components Therefore, the internal power flow of the electrical system is controlled.

[0119] Figure 8a The illustration shows a device according to an embodiment of the present disclosure. Specifically, Figure 8a The device 810 shown is for controlling the internal power flow of an electrical system 800, which includes a power supply 820, electrical components 830, and a power converter 840 having a primary side, wherein the primary side of the power converter 840 is electrically coupled to the power supply 820 via the electrical components 830, wherein the power converter 840 includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units, wherein the device 810 includes a processor configured to: obtain at least one electrical parameter of the electrical system 800; generate a control signal for each of the plurality of units based on the obtained at least one electrical parameter; and control the internal power flow of the electrical system 800 by adjusting the voltage of the primary side of the plurality of units based on the generated control signal, such that the voltage difference between the voltage of the power supply 820 and the sum of the voltages of the primary side of the plurality of units causes a controlled current to flow through the electrical components 830.

[0120] In one embodiment, the processor is further configured to perform a method according to any of the embodiments disclosed herein.

[0121] In one embodiment, the device further includes a communication unit configured to receive at least one electrical parameter of an electrical system, and wherein the communication unit is configured to transmit the received at least one electrical parameter to a processor for further processing.

[0122] Figure 8b The diagram illustrates an electrical system according to an embodiment of the present disclosure. Specifically, the electrical system 820 includes a power supply 821, an electrical component 822, and a power converter 823 having a primary side, wherein the primary side of the power converter 823 is electrically coupled to the power supply 821 via the electrical component 822, and wherein the power converter 823 includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units.

[0123] Figure 8c The illustration shows a system according to an embodiment of the present disclosure. In particular, system 800 relates to a system for controlling the internal power flow of an electrical system 820. System 800 includes device 810 and electrical system 820.

[0124] In one embodiment, the system further includes at least one sensing unit configured to sense at least one electrical parameter of the electrical system. In another embodiment, the at least one sensing unit is communicatively coupled to a communication unit. In yet another embodiment, the at least one sensing unit transmits the sensed electrical parameter to the communication unit.

[0125] In an embodiment, the electrical system is an AC system, the power supply is an AC power supply, each of the plurality of units includes an AC-to-DC converter or an AC-to-AC converter, and a first AC portion of the AC-to-DC converter is electrically coupled to the primary side of the plurality of units, or a first AC portion of the AC-to-AC converter is electrically coupled to the primary side of the plurality of units.

[0126] In an embodiment, adjusting the voltage on the primary side of the plurality of units includes adjusting the amplitude and phase of the voltage on the primary side of the plurality of units by controlling the first AC section of the AC-to-DC converter based on a generated control signal or by controlling the first AC section of the AC-to-AC converter based on a generated control signal.

[0127] In one embodiment, the sum of the voltage amplitudes on the primary side of the plurality of units is greater than the voltage amplitude of the AC power supply.

[0128] In one embodiment, the sum of the voltage amplitudes on the primary side of the plurality of units is at least 10% greater than the voltage amplitude of the AC power supply.

[0129] In one embodiment, the sum of the voltage amplitudes on the primary side of the plurality of units is at least 25% greater than the voltage amplitude of the AC power supply.

[0130] While various embodiments of this disclosure have been described above, it should be understood that these embodiments are presented by way of example only and not by way of limitation. Similarly, various figures may depict exemplary architectures or configurations provided to enable those skilled in the art to understand the exemplary features and functionality of this disclosure. However, those skilled in the art should understand that this disclosure is not limited to the illustrated exemplary architectures or configurations, but can be implemented using various alternative architectures and configurations. Furthermore, as those skilled in the art will understand, one or more features of one embodiment may be combined with one or more features of another embodiment described herein. Therefore, the breadth and scope of this disclosure should not be limited by any of the exemplary embodiments described above.

[0131] It should also be understood that any reference to elements in this document using names such as "first," "second," etc., generally does not restrict the number or order of those elements. Rather, these names may be used in this document as a convenient way to distinguish two or more elements or instances of elements. Therefore, referring to the first and second elements does not imply that only two elements can be used, or that the first element must somehow precede the second element.

[0132] Furthermore, those skilled in the art will understand that information and signals can be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, and symbols (e.g., possibly mentioned in the above description) can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0133] Those skilled in the art will further understand that any of the various illustrative logic blocks, units, processors, devices, circuits, methods, and functions described in conjunction with the aspects disclosed herein can be implemented by electronic hardware (e.g., digital implementation, analog implementation, or a combination of both), firmware, various forms of program or design code containing instructions (which may be referred to herein as "software" or "software unit" for convenience), or any combination of these technologies.

[0134] To clearly illustrate this interchangeability of hardware, firmware, and software, various illustrative components, blocks, units, circuits, and steps have been described above generally according to their functions. Whether such functionality is implemented as hardware, firmware, or software, or a combination of these technologies, depends on the specific application and design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in various ways for each specific application, but such implementation decisions will not lead to a departure from the scope of this disclosure. According to various embodiments, processors, devices, components, circuits, structures, machines, units, etc., can be configured to perform one or more functions described herein. The terms "configured to" or "configured for" as used herein with respect to a specified operation or function refer to processors, devices, components, circuits, structures, machines, units, etc., physically constructed, programmed, and / or arranged to perform the specified operation or function.

[0135] Furthermore, those skilled in the art will understand that the various illustrative methods, logic blocks, units, devices, components, and circuits described herein can be implemented within or executed by an integrated circuit (IC) that may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices or any combination thereof. Logic blocks, units, and circuits may further include antennas and / or transceivers for communication with various components within a network or device. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other suitable configuration to perform the functions described herein. If implemented in software, these functions may be stored as one or more instructions or code on a computer-readable medium. Therefore, the steps of the methods or algorithms disclosed herein can be implemented as software stored on a computer-readable medium.

[0136] Computer-readable media include computer storage media and communication media, including any medium capable of transferring computer programs or code from one place to another. Storage media can be any available medium that is accessible to a computer. By way of example and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disc storage devices, magnetic disk storage devices or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer.

[0137] Additionally, memory or other storage devices and communication components may be employed in the embodiments of this disclosure. It should be understood that, for clarity, the above description has referenced various functional units and processors in the embodiments of this disclosure. However, it will be apparent that any suitable functional distribution among different functional units, processing logic elements, or domains may be used without departing from this disclosure. For example, functions illustrated to be performed by a separate processing logic element or controller may be performed by the same processing logic element or controller. Therefore, references to specific functional units are merely references to suitable means for providing the described functions and do not represent a strict logical or physical structure or organization.

[0138] Various modifications to the embodiments described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not intended to be limited to the embodiments shown, but is intended to be consistent with the maximum scope of the novel features and principles disclosed herein, as described in the claims.

Claims

1. A method for controlling the internal power flow of an AC electrical system, the AC electrical system comprising an AC power supply, electrical components, and a power converter having a primary side, wherein, The primary side of the power converter is electrically coupled to the AC power supply via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units, wherein each of the plurality of units includes an AC-to-DC converter having a first AC portion electrically coupled to the primary side of the plurality of units or an AC-to-AC converter having a first AC portion electrically coupled to the primary side of the plurality of units, the method comprising: Obtain at least one electrical parameter of the AC electrical system; Based on at least one obtained electrical parameter, a control signal is generated for each of the plurality of units; and The internal power flow of the AC electrical system is controlled by adjusting the voltage on the primary side of the plurality of units based on the generated control signal, such that the voltage difference between the voltage of the AC power supply and the sum of the voltages on the primary side of the plurality of units causes a controlled current to flow through the electrical components. The adjustment of the primary-side voltage of the plurality of units includes adjusting the amplitude and phase of the primary-side voltage of the plurality of units by controlling the first AC section of the AC-to-DC converter based on the generated control signal, or by controlling the first AC section of the AC-to-AC converter based on the generated control signal. The sum of the voltage amplitudes on the primary side of the plurality of units is greater than the voltage amplitude of the AC power supply.

2. The method of claim 1, wherein, The sum of the voltage amplitudes on the primary side of the plurality of units is at least 10%, preferably 25%, greater than the voltage amplitude of the AC power supply, and / or The sum of the voltage amplitudes on the primary side of the plurality of units is at most 33%, preferably 30%, and more preferably 25% greater than the voltage amplitude of the AC power supply.

3. The method as described in claim 1 or 2, wherein, The plurality of units include a secondary side, which is different from the primary side of the plurality of units, and wherein the plurality of units are electrically isolated from each other at the secondary side of the plurality of units.

4. The method according to any one of claims 1 to 3, wherein, The voltage of the power grid, the voltage on the primary side of the plurality of units, the controlled current, and the voltage drop across the electrical components are vectors including amplitude and phase information, and The sum of the voltages on the primary side of the plurality of units is a vector sum.

5. The method according to any one of claims 1 to 4, wherein, The AC electrical system further includes a first switch and a second switch. The first switch electrically couples the power grid in series to the electrical component. The second switch is electrically coupled to the node between the first switch and the electrical component, and The second switch electrically couples the power grid to the electrical component in parallel.

6. The method of claim 5, further comprising: Close one of the first switch and the second switch; as well as Disconnect the other of the first and second switches.

7. The method according to any one of claims 1 to 6, wherein, The electrical component is resistive, or The electrical components are inductive and / or capacitive, and optionally resistive.

8. The method according to any one of claims 1 to 7, wherein, At least one electrical parameter obtained is the voltage and / or current of the AC power supply, the electrical component, the primary side of the power converter, or the primary side of the plurality of units.

9. The method according to any one of claims 1 to 8, wherein, The power of at least one of the plurality of units flows bidirectionally based on the generated control signal.

10. A device for controlling the internal power flow of an AC electrical system, said AC electrical system comprising an AC power supply, electrical components, and a power converter having a primary side, wherein, The primary side of the power converter is electrically coupled to the AC power supply via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units, wherein each of the plurality of units includes an AC-to-DC converter having a first AC portion electrically coupled to the primary side of the plurality of units or an AC-to-AC converter having a first AC portion electrically coupled to the primary side of the plurality of units, wherein the device includes a processor configured to: Obtain at least one electrical parameter of the AC electrical system; Based on at least one obtained electrical parameter, a control signal is generated for each of the plurality of units; and The internal power flow of the AC electrical system is controlled by adjusting the voltage on the primary side of the plurality of units based on the generated control signal, such that the voltage difference between the voltage of the AC power supply and the sum of the voltages on the primary side of the plurality of units causes a controlled current to flow through the electrical components. The adjustment of the primary-side voltage of the plurality of units includes adjusting the amplitude and phase of the primary-side voltage of the plurality of units by controlling the first AC section of the AC-to-DC converter based on the generated control signal, or by controlling the first AC section of the AC-to-AC converter based on the generated control signal. The sum of the voltage amplitudes on the primary side of the plurality of units is greater than the voltage amplitude of the AC power supply.

11. The device as claimed in claim 10, wherein, The processor is further configured to perform the method according to any one of claims 2 to 9.

12. A system for controlling the internal power flow of an AC electrical system, wherein, The system includes the device as claimed in claim 10 or 11, and the AC electrical system includes an AC power supply, electrical components, and a power converter having a primary side, wherein the primary side of the power converter is electrically coupled to the AC power supply via the electrical components, wherein the power converter includes a plurality of units electrically coupled in series to each other at the primary side of the plurality of units, each of the plurality of units including an AC-to-DC converter having a first AC portion electrically coupled to the primary side of the plurality of units or an AC-to-AC converter having a first AC portion electrically coupled to the primary side of the plurality of units.

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