Control of internal power flow in electrical systems

Abstract

This disclosure relates to a method for controlling the internal power flow of an AC electrical system comprising an AC 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 AC power source via the electrical components, and the power converter comprises a plurality of cells, each of which is electrically coupled in series with respect to the primary side of the plurality of cells, and each of the plurality of cells comprises an AC-DC converter having a first AC portion electrically coupled to the primary side of the plurality of cells, or an AC-AC converter having a first AC portion electrically coupled to the primary side of the plurality of cells, wherein the method comprises obtaining at least one electrical parameter of the AC electrical system and controlling the control signal of each of the plurality of cells based on the obtained at least one electrical parameter The method comprises generating a signal and controlling the internal power flow of an AC electrical system by adjusting the primary voltages of the multiple cells based on the generated signal so that the voltage difference between the voltage of the AC power supply and the sum of the primary voltages of the multiple cells produces a controlled current through electrical components, wherein adjusting the primary voltages of the multiple cells includes adjusting the magnitude and phase of the primary voltages of the multiple cells by controlling a first AC portion of an AC-DC converter based on the generated signal, or by controlling a first AC portion of an AC-AC converter based on the generated signal, and wherein the sum of the magnitudes of the primary voltages of the multiple cells is greater than the magnitude of the voltage of the AC power supply.

Description

[Technical Field]

[0001] This disclosure relates to methods, devices, and systems for controlling internal power flows in electrical systems. [Background technology]

[0002] As technology advances, electric vehicles (EVs) are equipped with increasing battery capacity and faster charging speeds (for example, DC fast charging power is also needed to reach 350kW-600kW). Therefore, the voltage platform for new EVs is shifting from 400V to 800V-1kV. This indicates that in the coming years, different charging infrastructures with different battery voltage platforms and / or charging power levels will likely be required. However, due to limited available installation space, such as highway rest stops, service stations, and gas stations, it is not practical to install different separate chargers to meet the changing requirements.

[0003] Therefore, it is desirable to develop a modular, reconfigurable power converter that can deliver power to EVs at different voltages and power levels, preferably corresponding to different charging ports, but within a single power converter. Such power converters are sometimes called multiplex power converters. Furthermore, it is even more desirable for EV charging infrastructure (EVCI) to flexibly connect automotive batteries with bidirectional flow capabilities, along with other loads and power sources.

[0004] Such desirable modularity and reconfigurability of a power converter can be achieved by stacking multiple cells within the power converter. However, this does not fully satisfy the above requirements without proper control, particularly power control of the active power flow in each of the stacked cells to handle voltage balance, flexibly route the associated power, and respond quickly to any new reconfiguration requests from the existing EV situation. For this purpose, solid-state transformers (SSTs) may be used, especially for their controllability. In particular, AC / DC-based (or DC / DC with one bulky AC / DC) modular cells equipped with SSTs may be used. On the AC side, it is often necessary to control both active and reactive power, which can be a challenge when complete flexibility is required for individual cells.

[0005] Therefore, there is a need to improve methods, devices, and systems for controlling the internal power flow of an electrical system to allow flexibility to follow P,Q setpoints in various ways, in particular, while maintaining voltage balance at the individual output ports of the cells contained in the power converter, and further rerouting power as required by the EV battery, which can be charged or discharged for possible support when circumstances require. [Overview of the project] [Means for solving the problem]

[0006] A method for controlling an internal power flow of an 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, the power converter includes a plurality of cells electrically coupled in series with each other at the primary sides of the plurality of cells, the method includes obtaining at least one electrical parameter of the electrical system, generating a control signal for each of the plurality of cells based on the obtained at least one electrical parameter, and adjusting the voltage at the primary sides of the plurality of cells based on the generated control signals such that a voltage difference between the voltage of the power source and the sum of the voltages at the primary sides of the plurality of cells causes a controlled current to flow through the electrical components, thereby controlling the internal power flow of the electrical system.

[0007] The present disclosure is a method for controlling the internal power flow of an AC electrical system comprising an AC 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 AC power source via the electrical components, the power converter comprises a plurality of cells electrically coupled in series with each other at the primary side of the plurality of cells, and each of the plurality of cells comprises an AC-DC converter having a first AC portion electrically coupled to the primary side of the plurality of cells, or an AC-AC converter having a first AC portion electrically coupled to the primary side of the plurality of cells, the method comprising 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 adjusting the voltage at the primary side of the plurality of cells based on the generated control signals such that a voltage difference between the voltage of the AC power source and the sum of the voltages at the primary side of the plurality of cells causes a controlled current to flow through the electrical components, thereby controlling the internal power flow of the AC electrical system, adjusting the voltage at the primary side of the plurality of cells comprising controlling the first AC portion of the AC-DC converter based on the generated control signals, or controlling the first AC portion of the AC-AC converter based on the generated control signals, to adjust the magnitude and phase of the voltage at the primary side of the plurality of cells, and wherein the sum of the magnitudes of the voltages at the primary side of the plurality of cells is greater than the magnitude of the voltage of the AC power source.

[0008] Various embodiments may preferably implement the following features. Preferably, the sum of the magnitudes of the voltages at the primary side of the plurality of cells is at least 10% greater than the magnitude of the voltage of the AC power source.

[0009] Preferably, the sum of the magnitudes of the voltages at the primary side of the plurality of cells is at least 25% greater than the magnitude of the voltage of the AC power source.

[0010] Preferably, the sum of the primary voltages of multiple cells is greater than the voltage of the AC power supply by up to 33%.

[0011] Preferably, the sum of the primary voltages of multiple cells is greater than the voltage of the AC power supply by up to 30%.

[0012] Preferably, the sum of the primary voltages of multiple cells is greater than the voltage of the AC power supply by up to 25%.

[0013] Preferably, controlling the internal power flow includes, or controls, the power flow of the power converter, particularly the power flow of each of the multiple cells. More preferably, controlling the internal power flow includes, or controls, the portion of each of the multiple cells that interfaces with the power source and the remaining portion of each of the multiple cells.

[0014] Preferably, each of the multiple cells comprises multiple cell converters, and the primary side of each of the multiple cells is electrically coupled to each of the multiple cell converters, in particular, the two ports of each of the multiple cell converters form the primary side of the multiple cells. More preferably, controlling the internal power flow includes, or controls, the power flow of each of the multiple cell converters. Preferably, each of the multiple cells comprises a secondary side different from the primary side of the multiple cells, and the multiple cells are galvanically isolated from each other on their secondary sides.

[0015] Preferably, the power system is a DC system, the power supply is a DC power supply, each of the plurality of cells comprises a DC-AC converter or a DC-DC converter, and the first DC portion of the DC-AC converter is electrically coupled to the primary side of the plurality of cells, or the first DC portion of the DC-DC converter is electrically coupled to the primary side of the plurality of cells.

[0016] Preferably, adjusting the primary voltage of multiple cells includes adjusting the magnitude of the primary voltage of multiple cells by controlling a first DC portion of a DC-AC converter based on a generated control signal, or by controlling a first DC portion of a DC-DC converter based on a generated control signal.

[0017] Preferably, especially when the power system is a DC system, and more specifically when the electrical system is resistive, the control includes, or controls, the internal power flow of the electrical system by adjusting the primary side voltages of the multiple cells based on a generated control signal, such that the voltage difference between the voltage of the power supply and the sum of the primary side voltages of the multiple cells causes a controlled current to flow through the electrical components.

[0018] Preferably, the electrical system is an AC system, the power supply is an AC power supply, each of the plurality of cells comprises an AC-DC converter or an AC-AC converter, and the first AC portion of the AC-DC converter is electrically coupled to the primary side of the plurality of cells, or the first AC portion of the AC-AC converter is electrically coupled to the primary side of the plurality of cells.

[0019] Preferably, adjusting the primary voltages of multiple cells includes adjusting the magnitude and phase of the primary voltages of multiple cells by controlling a first AC portion of an AC-DC converter based on a generated control signal, or by controlling a first AC portion of an AC-AC converter based on a generated control signal.

[0020] Preferably, particularly when the power system is an AC system, and more specifically when the electrical system is inductive and / or capacitive and optionally resistive, controlling involves or controls the internal power flow of the electrical system by setting the voltage across the electrical components, adjusting the primary side voltages of the multiple cells based on a generated control signal such that the voltage difference between the voltage of the power supply and the sum of the primary side voltages of the multiple cells induces a controlled current flow through the electrical components.

[0021] Preferably, the voltage of the power grid, the primary side voltages of multiple cells, the controlled current, and the voltage drop across electrical components are vectors containing magnitude and phase information, and the sum of the primary side voltages of multiple cells is a vector sum.

[0022] Preferably, the electrical system further comprises a first switch and a second switch, the first switch electrically coupling the power grid in series with the electrical components, the second switch electrically coupling the nodes between the first switch and the electrical components, and the second switch electrically coupling the power grid in parallel with the electrical components.

[0023] 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.

[0024] Preferably, the electrical component is resistive, or the electrical component is inductive and / or capacitive, and optionally resistive.

[0025] Preferably, the acquired electrical parameter is the voltage and / or current of the primary side of a power supply, electrical component, power converter, or multiple cells.

[0026] Preferably, the power from at least one of the multiple cells flows bidirectionally based on the generated control signal.

[0027] The disclosure also relates to a device for controlling the internal power flow of an electrical system comprising 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, and the power converter comprises a plurality of cells, the plurality of cells being electrically coupled in series with each other on the primary side, and the device comprises a processor configured to control the internal power flow of the electrical system by acquiring at least one electrical parameter of the electrical system, generating a control signal for each of the plurality of cells based on the acquired at least one electrical parameter, and adjusting the voltages on the primary sides of the plurality of cells based on the generated control signals such that the voltage difference between the voltage of the power supply and the sum of the primary side voltages of the plurality of cells produces a controlled current through the electrical components.

[0028] The disclosure also relates to a device for controlling the internal power flow of an AC electrical system comprising an AC 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 AC power source via the electrical components, and the power converter comprises a plurality of cells, each of which is electrically coupled in series with respect to the primary side of the plurality of cells, and each of the plurality of cells comprises an AC-DC converter having a first AC portion electrically coupled to the primary side of the plurality of cells, or an AC-AC converter having a first AC portion electrically coupled to the primary side of the plurality of cells, and the device acquires at least one electrical parameter of the AC electrical system and generates a control signal for each of the plurality of cells based on the acquired at least one electrical parameter. The device comprises a processor configured to control the internal power flow of an AC electrical system by adjusting the primary voltages of a plurality of cells based on a generated control signal, such that the voltage difference between the voltage of an AC power supply and the sum of the primary voltages of a plurality of cells produces a controlled current through an electrical component, wherein adjusting the primary voltages of a plurality of cells includes adjusting the magnitude and phase of the primary voltages of a plurality of cells by controlling a first AC portion of an AC-DC converter based on a generated control signal, or by controlling a first AC portion of an AC-AC converter based on a generated control signal, and the sum of the magnitudes of the primary voltages of the plurality of cells is greater than the magnitude of the voltage of an AC power supply.

[0029] Preferably, the sum of the primary voltages of multiple cells is at least 10% greater than the voltage of the AC power supply.

[0030] Preferably, the sum of the primary voltages of multiple cells is at least 25% greater than the voltage of the AC power supply.

[0031] Preferably, the processor is further configured to perform a method according to any one of the embodiments disclosed herein.

[0032] The disclosure further relates to a system for controlling the internal power flow of an electrical system, comprising a device according to any one embodiment disclosed herein, wherein the electrical system comprises a power source, electrical components, and a power converter having a primary side, the primary side of the power converter being electrically coupled to the power source via the electrical components, and the power converter comprising a plurality of cells, the primary sides of which are electrically coupled in series with each other.

[0033] The disclosure further relates to a system for controlling the internal power flow of an AC electrical system, comprising a device according to any one embodiment disclosed herein, wherein the AC electrical system comprises an AC power source, electrical components, and a power converter having a primary side, the primary side of which is electrically coupled to the AC power source via the electrical components, and the power converter comprises a plurality of cells, each of which is electrically coupled in series with respect to the primary side of which is which, and each of which is an AC-DC converter having a first AC portion electrically coupled to the primary side of which is which, or an AC-AC converter having a first AC portion electrically coupled to the primary side of which is which.

[0034] The various exemplary embodiments of the Disclosure disclosed herein are intended to provide features that will be readily apparent by referring to the following description in conjunction with the accompanying drawings. Exemplary systems, methods, and devices are disclosed herein according to various embodiments. However, it will be understood that these embodiments are presented as examples and not as limitations, and it will be apparent to those skilled in the art who have read this disclosure that various modifications to the disclosed embodiments can be made while remaining within the scope of this disclosure.

[0035] Therefore, this disclosure is not limited to the exemplary embodiments and uses described and shown herein. Furthermore, the specific order and / or hierarchy of steps in the methods disclosed herein is merely an exemplary approach. Based on design preferences, the specific order or hierarchy of steps in the disclosed methods or processes can be rearranged while remaining within the scope of this disclosure. Accordingly, those skilled in the art will understand that the methods and techniques disclosed herein present various steps or operations in a sample order, and that this disclosure is not limited to the specific order or hierarchy presented unless otherwise specified.

[0036] The following items refer to specific embodiments of this disclosure. 1. A method for controlling the internal power flow of an electrical system comprising 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, and the power converter comprises a plurality of cells, the plurality of cells being electrically coupled in series with each other at the primary sides, and the method Obtaining at least one electrical parameter of the electrical system, Based on at least one acquired electrical parameter, generate control signals for each of the multiple cells, The internal power flow of an electrical system is controlled by adjusting the primary voltages of multiple cells based on a generated control signal, such that the voltage difference between the power supply voltage and the sum of the primary voltages of multiple cells generates a controlled current through the electrical components. Methods that include...

[0037] 2. The method according to item 1, wherein the plurality of cells have a secondary side different from the primary side of the plurality of cells, and the plurality of cells are galvanically insulated from each other on the secondary side of the plurality of cells.

[0038] 3. The power system is a DC system. The power supply is a DC power supply. Each of the multiple cells is equipped with a DC-AC converter or a DC-DC converter, and The first DC portion of a DC-AC converter is electrically coupled to the primary side of multiple cells, or the first DC portion of a DC-DC converter is electrically coupled to the primary side of multiple cells. The method described in item 1 or 2.

[0039] 4. Adjusting the primary voltage of multiple cells Adjusting the magnitude of the primary side voltage of multiple cells by controlling the first DC portion of a DC-AC converter based on the generated control signal, or by controlling the first DC portion of a DC-DC converter based on the generated control signal. The method described in item 3, including the method described in item 3.

[0040] 5. The electrical system is an AC system. The power supply is AC power. Each of the multiple cells is equipped with an AC-DC converter or an AC-AC converter, and The first AC portion of the AC-DC converter is electrically coupled to the primary side of multiple cells, or the first AC portion of the AC-AC converter is electrically coupled to the primary side of multiple cells. The method described in item 1 or 2.

[0041] 6. Adjusting the primary voltage of multiple cells Adjusting the magnitude and phase of the primary voltages of multiple cells by controlling the first AC portion of an AC-DC converter based on the generated control signal, or by controlling the first AC portion of an AC-AC converter based on the generated control signal. The method described in item 5, including the method described in item 5.

[0042] 7. The voltage of the power grid, the primary side voltage of multiple cells, the controlled current, and the voltage drop across electrical components are vectors containing magnitude and phase information, and The sum of the primary voltages of multiple cells is a vector sum. The method described in item 5 or 6.

[0043] 8. The electrical system further comprises a first switch and a second switch, The first switch electrically connects the power grid to the electrical components in series. The second switch is electrically coupled to the node between the first switch and the electrical component, and The second switch electrically connects the power grid to the electrical components in parallel. The method described in any one of items 5-7.

[0044] 9. Closing either the first switch or the second switch, Opening the other of the first switch and the second switch The method described in item 8, further including the method described in item 8.

[0045] 10. Are the electrical components resistive, or An electrical component is inductive and / or capacitive, and optionally resistive. The method described in any one of items 1 through 9.

[0046] 11. The method according to any one of items 1 to 10, wherein at least one of the obtained electrical parameters is the voltage and / or current on the primary side of a power supply, electrical component, power converter, or multiple cells.

[0047] 12. The method according to any one of items 1 to 11, wherein the power of at least one of the multiple cells flows bidirectionally based on the generated control signal.

[0048] 13. A device for controlling the internal power flow of an electrical system comprising 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, and the power converter comprises a plurality of cells, the plurality of cells being electrically coupled in series with each other on their primary sides, and the device is Obtain at least one electrical parameter of the electrical system, Based on the acquired electrical parameter, a control signal is generated for each of the multiple cells, and The internal power flow of an electrical system is controlled by adjusting the primary voltages of multiple cells based on a generated control signal, so that the voltage difference between the power supply voltage and the sum of the primary voltages of multiple cells generates a controlled current through the electrical components. A device equipped with a processor configured in such a way.

[0049] 14. The device described in item 13, wherein the processor is further configured to perform the method described in any one of items 2 through 12.

[0050] 15. A system for controlling the internal power flow of an electrical system, comprising the device described in item 13 or 14, wherein the electrical system comprises a power source, electrical components, and a power converter having a primary side, the primary side of the power converter being electrically coupled to the power source via the electrical components, and the power converter comprising a plurality of cells, the primary sides of which are electrically coupled in series with each other.

[0051] The above and other embodiments, as well as their implementations, are described in more detail in the drawings, description, and claims. [Brief explanation of the drawing]

[0052] [Figure 1] A flowchart of a method for controlling the internal power flow of an electrical system according to one embodiment of the present disclosure is shown. [Figure 2a] Figure 2a) shows a power converter according to one embodiment and a corresponding control method according to one embodiment. [Figure 2b] Figure 2b) shows a power converter according to one embodiment and a corresponding control method according to one embodiment. [Figure 3a] Figure 3a) shows a power converter according to one embodiment and a corresponding control method according to one embodiment. [Figure 3b]Figure 3b) shows a power converter according to one embodiment and a corresponding control method according to one embodiment. [Figure 4] This disclosure shows a power system according to one embodiment. [Figure 5] This disclosure shows a power system according to one embodiment of this disclosure and its operation according to a control method according to one embodiment of this disclosure. [Figure 6] This disclosure shows a power system according to one embodiment of this disclosure and its operation according to a control method according to one embodiment of this disclosure. [Figure 7] This disclosure shows a power system according to one embodiment of this disclosure and its operation according to a control method according to one embodiment of this disclosure. [Figure 8a] Figure 8a) shows a device according to one embodiment of the present disclosure. [Figure 8b] Figure 8b) shows an electrical system according to one embodiment of the present disclosure. [Figure 8c] Figure 8c) shows a system according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0053] The following describes exemplary embodiments of this disclosure. Note that some aspects of any one of the embodiments described may also be found in some other embodiments unless otherwise specified or obvious. However, for the sake of clarity, each aspect is described in detail only when first mentioned, and repeated descriptions of the same aspect are omitted.

[0054] Figure 1 shows a flowchart of a method for controlling the internal power flow of an electrical system according to one embodiment of the present disclosure. In particular, the flowchart shown in Figure 1 relates to a method for controlling the internal power flow of an electrical system comprising 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, and the power converter comprises a plurality of cells, the plurality of cells being electrically coupled in series with each other on their primary sides. In one embodiment, the plurality of cells have a secondary side different from the primary side of the plurality of cells. In one embodiment, the plurality of cells are galvanically isolated from each other on their secondary sides. In one embodiment, the electrical components are resistive, or the electrical components are inductive and / or capacitive and optionally resistive. In S101, at least one electrical parameter of the electrical system is acquired. In one embodiment, the acquired at least one electrical parameter is the voltage and / or current of the power source, the electrical components, the primary side of the power converter, or the primary side of the plurality of cells. In S102, a control signal for each of the plurality of cells is generated based on the acquired at least one electrical parameter. In one embodiment, the control signal is a PWM signal. In one embodiment, each of the plurality of cells, in particular at least one controllable switching component contained therein, is controllable based on the control signal. In one embodiment, each of the plurality of cells is or comprises a solid-state transformer (SST). In S103, the internal power flow of the electrical system is controlled by adjusting the primary-side voltages of the plurality of cells based on the generated control signal, such that the voltage difference between the voltage of the power supply and the sum of the primary-side voltages of the plurality of cells produces a controlled current through the electrical components.

[0055] In one embodiment, controlling the internal power flow includes, or controls, the power flow of the power converter, particularly the power flow of each of the multiple cells. In a particular embodiment, controlling the internal power flow includes, or controls, the portion of each of the multiple cells that interfaces with the power source and the remaining portion of each of the multiple cells.

[0056] In one embodiment, each of the multiple cells comprises multiple cell converters, and the primary side of each of the multiple cells is electrically coupled to each of the multiple cell converters, in particular, the two ports of each of the multiple cell converters form the primary side of the multiple cells. In a particular embodiment, controlling the internal power flow includes, or controls, the power flow of each of the multiple cell converters.

[0057] In one embodiment, the plurality of cells have a secondary side that is different from the primary side of the plurality of cells, and the plurality of cells are galvanically insulated from each other on the secondary side of the plurality of cells.

[0058] In one embodiment, the secondary side of at least one of the multiple cells is electrically coupled to a DC load, DC power source, or DC storage element. The DC load may require galvanic isolation. The DC load may be any one of the following: a battery, particularly an electric vehicle battery, a distributed energy resource, a DC motor, or a local energy storage facility (e.g., a battery, particularly an electric vehicle battery).

[0059] In one embodiment, the power system is a DC system, the power supply is a DC power supply, each of the plurality of cells comprises a DC-AC converter or a DC-DC converter, and the first DC portion of the DC-AC converter is electrically coupled to the primary side of the plurality of cells, or the first DC portion of the DC-DC converter is electrically coupled to the primary side of the plurality of cells.

[0060] In one embodiment, adjusting the primary voltage of multiple cells includes adjusting the magnitude of the primary voltage of multiple cells by controlling a first DC portion of a DC-AC converter based on a generated control signal, or by controlling a first DC portion of a DC-DC converter based on a generated control signal.

[0061] In one embodiment, particularly when the power system is a DC system, and more specifically when the electrical system is resistive, the control includes, or controls, the internal power flow of the electrical system by adjusting the primary side voltages of the multiple cells based on a generated control signal, such that the voltage difference between the voltage of the power supply and the sum of the primary side voltages of the multiple cells causes a controlled current to flow through the electrical components.

[0062] In one embodiment, the electrical system is an AC system, the power supply is an AC power supply, each of the plurality of cells comprises an AC-DC converter or an AC-AC converter, and the first AC portion of the AC-DC converter is electrically coupled to the primary side of the plurality of cells, or the first AC portion of the AC-AC converter is electrically coupled to the primary side of the plurality of cells.

[0063] In one embodiment, adjusting the primary voltage of multiple cells includes adjusting the magnitude and phase of the primary voltage of multiple cells by controlling a first AC portion of an AC-DC converter based on a generated control signal, or by controlling a first AC portion of an AC-AC converter based on a generated control signal.

[0064] In one embodiment, particularly when the power system is an AC system, and more specifically when the electrical system is inductive and / or capacitive and optionally resistive, controlling includes, or controls, the internal power flow of the electrical system by adjusting the primary side voltages of multiple cells based on a generated control signal, such that the voltage difference between the voltage of the power supply and the sum of the primary side voltages of multiple cells induces a controlled current flow through the electrical components.

[0065] In one embodiment, the voltage of the power grid, the primary voltages of multiple cells, the controlled current, and the voltage drop across electrical components are vectors containing magnitude and phase information, and the sum of the primary voltages of multiple cells is a vector sum.

[0066] In one embodiment, the electrical system further comprises a first switch and a second switch, the first switch electrically coupling the power grid in series with the electrical components, the second switch electrically coupling the nodes between the first switch and the electrical components, and the second switch electrically coupling the power grid in parallel with the electrical components.

[0067] In one embodiment, 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.

[0068] In one embodiment, the electrical component is resistive, or the electrical component is inductive and / or capacitive, and optionally resistive.

[0069] In one embodiment, the acquired electrical parameter is the voltage and / or current of a power supply, an electrical component, the primary side of a power converter, or the primary side of multiple cells.

[0070] In one embodiment, power from at least one of the multiple cells flows bidirectionally based on the generated control signal.

[0071] The disclosure also relates to a device for controlling the internal power flow of an electrical system comprising 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, and the power converter comprises a plurality of cells, the plurality of cells being electrically coupled in series with each other on the primary side, and the device comprises a processor configured to control the internal power flow of the electrical system by acquiring at least one electrical parameter of the electrical system, generating a control signal for each of the plurality of cells based on the acquired at least one electrical parameter, and adjusting the voltages on the primary sides of the plurality of cells based on the generated control signals such that the voltage difference between the voltage of the power supply and the sum of the primary side voltages of the plurality of cells produces a controlled current through the electrical components.

[0072] In one embodiment, the processor is further configured to perform a method according to any one of the embodiments disclosed herein.

[0073] The disclosure further relates to a system for controlling the internal power flow of an electrical system, comprising a device according to any one embodiment disclosed herein, wherein the electrical system comprises a power source, electrical components, and a power converter having a primary side, the primary side of the power converter being electrically coupled to the power source via the electrical components, and the power converter comprising a plurality of cells, the primary sides of which are electrically coupled in series with each other.

[0074] Figure 2a) shows a power converter according to one embodiment and a corresponding control method according to one embodiment. In particular, Figure 2a) shows a power converter, in particular a DC-DC power converter 200. The power converter 200 comprises a plurality of cells, more specifically n cells 210, 220, and 2n0, where n is a natural number. The primary sides of each of the plurality of cells 210, 220, and 2n0 are electrically coupled in series with each other, as shown in Figure 2a). Each of the plurality of cells 210, 220, and 2n0 comprises a galvanically isolated DC-DC power converter. The DC-DC power converter comprises a DC-AC converter, a transformer, and an AC-DC converter. The DC-AC converter is galvanically isolated from the AC-DC converter by a transformer, in particular a single-winding medium-wave transformer (MFT), which electrically couples the DC-AC converter to the AC-DC converter. The DC-AC converter and the AC-DC converter each comprise a first set of controllable switching components and a second set of controllable switching components. Therefore, the power converter 200 may be referred to as an SST having a single-winding MFT. In one embodiment, each of the plurality of cells 210, 220, and 2n0 has a secondary side distinct from its primary side. It should be noted that the power converter 200 is configured as an input-series output isolation. That is, the primary sides of each of the plurality of cells are connected in series with each other to form the series input of the power converter 200, i.e., the primary side of the power converter 200 formed by nodes X and Y, and the secondary sides of each of the plurality of cells are galvanically isolated from each other to form the isolated output of the power converter 200, i.e., the secondary side of the power converter 200. In one embodiment, the secondary sides of each of the plurality of cells are electrically coupled in series or in parallel with each other. That is, the power converter may be configured as input-series output-series or input-series output-parallel.

[0075] The power converter 200 may be used in a power system. An exemplary power system that may include and be controlled by the power converter is described below.

[0076] The power system may be a DC power system comprising a DC power source 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. In FIG. 2a), the DC power source and the electrical components are omitted. The voltage and current of the DC power source are represented as U ,

[0078] , and I g respectively, the voltage drop of the electrical component is represented as U r and the voltage at the primary side of each of the plurality of cells 210, 220, 2n0 is represented as U1, U2, and U n respectively, and the current passing through the electrical component is represented as I r It should be noted that for the electrically connected electrical components, I g =I r applies.

[0077] When the power converter 200 is configured in a power system particularly as described above, it may be controlled according to the method disclosed in FIG. 1. That is, U g , I g , U r , U1, U2, and / or U n are obtained, and based on these, control signals for controlling the plurality of cells 210, 220, 2n0 are generated. The control signal may be, or may include, a first signal, particularly a PWM signal, for controlling a first set of controllable switching components included in the DC-AC converters of each of the plurality of cells. The internal power flow of the electrical system is controlled based on the generated control signals. Specifically, this is to set the voltage drop of the electrical component, and the voltage difference between the voltage of the power source and the sum of the voltages at the primary sides of the plurality of cells 210, 220, and 2n0 causes a controlled current to pass through the electrical component. Particularly, by adjusting the voltages at the primary sides of the plurality of cells 210, 220, and 2n0 based on the generated control signals so as to compensate for the voltage difference, particularly by controlling a first set of controllable switching components included in the DC-AC converters. That is, such a control method operates under the following constraints.

[0078]

number

[0079] In the formula, I i and U i These represent the current and voltage of the i-th cell among the multiple cells 210, 220, and 2n0, respectively. This is shown in Figure 201. The corresponding power flow of the i-th cell among the multiple cells 210, 220, and 2n0 is given by:

[0080]

number

[0081] I i However, in this embodiment, it is the same for all n cells, so P i U i It is proportional to, and as follows I g (I i =I g It is given by ).

[0082]

number

[0083] In the equation, the sign ~ indicates a proportional relationship. g The reference can be provided by any higher-order system. This controls the power flow of multiple cells. Specifically, the portion of each of the multiple cells that interfaces the primary side of the multiple cells with the power grid is controlled. In this embodiment, the power flow of the AC-DC converter contained in each of the multiple cells is controlled. The power flow of the multiple cells may also be the internal power flow of the electrical system.

[0084] Figure 2b) shows a power converter according to one embodiment and a corresponding control method thereof according to one embodiment. The power converter 200b shown in Figure 2b) differs from the power converter 200 shown in Figure 2a) in that the power converter 200b includes a multi-winding transformer that galvanically isolates the primary side of each of the multiple cells 210b, 220b, and 2n0b from the secondary side of each of the multiple cells 210b, 220b, and 2n0b. Therefore, the power converter 200b may be called an SST with a multi-winding MFT. The remaining aspects of the embodiment shown in Figure 2b) are the same as those of the embodiment in Figure 2a). That is, the power converter 200b may be included in a DC power system in which a DC power source is electrically coupled to the primary side of the power converter 200b via electrical components, and the power converter 200b includes a multiple of cells 210b, 220b, and 2n0b that are electrically coupled to each other on the primary side of each of the multiple cells 210b, 220b, and 2n0b. Furthermore, the method for controlling the internal power of the power system applied to Figure 2a) may also be similarly applied to the power converter 200b. For brevity, the same embodiments described above, which were previously detailed in the preceding parts of this disclosure, will not be repeated herein. In the case of a multi-winding MFT, it will be understood by those skilled in the art that the control method disclosed herein allows for compensation of different natural power flows caused by different series inductances of the MFT windings corresponding to different cells.

[0085] Figure 3a) shows a power converter according to one embodiment and a corresponding control method according to one embodiment. In particular, Figure 3a) shows a power converter, specifically an AC-DC power converter 300. The power converter 300 comprises a plurality of cells, more specifically n cells 310, 320, and 3n0, where n is a natural number. The primary sides of each of the plurality of cells 310, 320, and 3n0 are electrically coupled in series with each other, as shown in Figure 3a). Each of the plurality of cells 310, 320, and 3n0 comprises an AC-DC converter electrically coupled to the DC-DC power converter. The DC-DC power converter comprises a DC-AC converter, a transformer, and a further AC-DC converter, different from the AC-DC converter, electrically coupled to the DC-DC power converter. The two DC-side ports of the further AC-DC converter form the output ports of each of the plurality of cells 310, 320, and 3n0. The DC-AC converter is galvanically isolated from the further AC-DC converter by a transformer, particularly a monowinding medium-wave transformer (MFT), which electrically couples the DC-AC converter to a further AC-DC converter. The DC-AC converter and the AC-DC converter each comprise a first set and a second set of controllable switching components. Thus, the power converter 300 may be referred to as an SST with a monowinding MFT. In one embodiment, each of the plurality of cells 310, 320, and 3n0 has a secondary side distinct from its primary side. It should be noted that the power converter 200 is configured as an input-series-output isolation. That is, the primary sides of each of the plurality of cells are connected in series with each other to form the series input of the power converter 300, i.e., the primary side of the power converter 300 formed by nodes X and Y, and the secondary sides of each of the plurality of cells are galvanically isolated from each other to form the isolated output of the power converter 300, i.e., the secondary side of the power converter 300. In one embodiment, the secondary sides of each of the multiple cells are electrically coupled to one another in series or in parallel. That is, the power converter may be configured as input series, output series, or input series, output parallel.

[0086] The power converter 200 may be used in a power system. An exemplary power system that may include and be controlled by the power converter is described below.

[0087] The power system may be an AC power system comprising an AC power supply electrically coupled to the primary side of the power converter 300 via electrical components, particularly inductive and / or capacitive, and optionally resistive components. In one embodiment, the power converter 300 is electrically coupled in series with the electrical components at node X. In Figure 3a), the AC power supply and electrical components are omitted. The voltage and current of the DC power converter are U, respectively. g and I g It is expressed as, and the voltage drop across electrical components is U f Represented as such, the voltages on the primary side of each of the multiple cells 310, 320, and 3n0 are U1, U2, and U, respectively. n It is expressed as follows: In series-connected electrical components, I g =I r Please note that this applies.

[0088] The power converter 300 may be controlled according to the method disclosed in Figure 1, especially when it is configured in the power system described above. That is, U g , I g , U r , U1, U2, and / or U f The parameters U in the AC system are acquired, and based on these, control signals are generated to control multiple cells 310, 320, and 3n0. g , I g , U r , U1, U2, and / or U fHowever, it should be noted that it is a vector containing magnitude and phase information. The control signal may be, or may include, a first signal, particularly a PWM signal, for controlling a first set of controllable switching components contained in each of the AC-DC converters of the multiple cells. The internal power flow of the electrical system is controlled based on the generated control signal. Specifically, this is done by controlling a first set of controllable switching components contained in the AC-DC converter, particularly by adjusting the primary voltages of the multiple cells 310, 320, and 3n0 based on the generated control signal, such that the voltage difference between the voltage of the power supply and the sum of the primary voltages of the multiple cells 310, 320, and 3n0, which sets the voltage drop of the electrical components, produces a controlled current through the electrical components. That is, such a control scheme operates under the following constraints:

[0089]

number

[0090]

number

[0091]

number

[0092] In the equation, the sign ~ indicates proportionality. g The reference can be provided by any higher-order system. This controls the power flow of multiple cells. Specifically, the portion of each of the multiple cells that interfaces the primary side of the multiple cells with the power grid is controlled. In this embodiment, the power flow of the AC-DC converter contained in each of the multiple cells is controlled. The power flow of the multiple cells may also be the internal power flow of the electrical system.

[0093] In one embodiment, the active power flow is controlled based on measured current and / or voltage values ​​on the secondary side of multiple cells, and / or the reactive power flow is controlled based on measured voltage and / or current values ​​on the primary side of multiple cells.

[0094] Figure 3b) shows a power converter according to one embodiment and a corresponding control method according to one embodiment. The power converter 300b shown in Figure 3b) differs from the power converter 300 shown in Figure 3a) in that the power converter 300b includes a multi-winding transformer that galvanically isolates the primary side of each of the multiple cells 310b, 320b, and 3n0b from the secondary side of each of the multiple cells 310b, 320b, and 3n0b. Therefore, the power converter 300b may be called an SST having a multi-winding MFT. The remaining aspects of the embodiment shown in Figure 3b) are the same as those of the embodiment in Figure 3a). That is, the power converter 300b may be included in an AC power system in which an AC power source is electrically coupled to the primary side of the power converter 300b via electrical components, and the power converter 300b includes a multiple of cells 310b, 320b, and 3n0b that are electrically coupled to each other on the primary side of each of the multiple cells 310b, 320b, and 3n0b. Furthermore, the method for controlling the internal power of the power system applied to Figure 3a) may also be applied to an AC power system equipped with a power converter 300b. For brevity, the same embodiments described above, which were previously detailed in the preceding parts of this disclosure, will not be repeated herein. In the case of a multi-winding MFT, it will be understood by those skilled in the art that the control method disclosed herein allows for compensation of different natural power flows caused by different series inductances of the MFT windings corresponding to different cells.

[0095] Figure 4 shows a power system according to one embodiment of the present disclosure. In particular, Figure 4 shows an AC power system comprising an AC power supply 401 electrically coupled to an AC-DC power converter 400 via a series-connected inductor 402. grid , I grid , and U filterThis represents the voltage of the AC power supply 401, the current of the AC power supply 401, and the voltage across the series-connected inductor 402. The AC-DC power converter 400 is one embodiment of the power converter 300 shown in Figure 3a), having six cells. It will be understood by those skilled in the art that the AC-DC power converter 400 may also be one embodiment of the power converter 300b shown in Figure 3b). Note that the AC-DC power converter 400 is configured as input-series output isolation. That is, the primary sides of each of the multiple cells are connected in series with each other to form the series input of the AC-DC power converter, and the secondary sides of each of the multiple cells are galvanically isolated from each other, thereby forming the isolated output of the AC-DC power converter. Features of this configuration include galvanic isolation of all cell outputs, separate power flow control of all outputs, only one MFT and minimal power conversion stage per power path, the ability to integrate local PV and storage, and high flexibility in adding, upgrading, or changing cells. U1, U2, U3, U4, U5, and U6 represent the primary voltages of the multiple cells 410, 420, 430, 440, 450, and 460, respectively. The isolated outputs of the AC-DC power converter, i.e., the secondary sides of each of the multiple cells 410, 420, 430, 440, 450, and 460, are electrically coupled to the multiple loads 411, 421, 431, 441, 451, and 461, respectively. Each of the multiple cells is capable of bidirectional power flow, so that each of the multiple loads 411, 421, 431, 441, 451, and 461 can draw power from or supply power to the system. The above parameter U in the AC system grid , I grid , U filter Note that U1, U2, U3, U4, U5, and U6 are vectors containing magnitude and phase information.

[0096] Figure 5 shows a power system according to one embodiment of the present disclosure and its operation according to a control method according to one embodiment of the present disclosure. In particular, Figure 5 shows the power system shown in Figure 4 in operation according to the method shown in Figure 1. Note that in Figure 5, for simplification, the AC power supply 401 and the series-connected inductor 402 are omitted. In this embodiment, the AC power supply 401 is a power grid providing purely active power, four automobiles 411, 421, 431, and 441 are charged with nominal power Pn, a fifth cell electrically coupled to battery 451 provides only reactive power compensation, and a photovoltaic unit 461 powers the AC power system. The powers Pn, Pn, Pn, Pn, 0, and 0.8Pn passing through each of the multiple cells 410, 420, 430, 440, 450, and 460 may be collectively defined as the internal power flow of the electrical system. When operating according to the method shown in Figure 1, the power system shown in Figure 5 operates according to the constraint of equation (4), and the phasor quantities shown in phasor diagram 501 are obtained. Specifically, the magnitudes and phases of U1, U2, U3, U4, U5, and U6 are adjusted based on control signals generated using measurements of the electrical system. For example, U5 is U grid It is adjusted so that the phase is shifted by 90 degrees relative to U6, grid U1, U2, U3, and U4 are adjusted to be 180 degrees out of phase with respect to U grid They are adjusted to be in phase, i.e., the phase angle difference between them is 0. This is because the voltage difference in the phasor region between the power supply voltage and the vector sum of the primary side voltages of multiple cells 410, 420, 430, 440, 450, and 460 is the voltage drop U of the electrical components. filter This sets the controlled current I grid is an electrical component L filter This is done so that the current flows through it. U_sst_equivalent represents the vector sum of the primary-side voltages of multiple cells 410, 420, 430, 440, 450, and 460.

[0097] It will be understood by those skilled in the art that the fifth cell 450 and the sixth cell 460 enable power routing by ensuring a voltage margin that allows for a phase shift between the AC vectors of the primary side cells in particular. More specifically, the fifth cell 450 and the sixth cell 460 are greater than zero,

[0098]

number

[0099] It provides an additional voltage that constitutes a voltage margin, defined as such. Such a voltage margin allows for further degrees of freedom, namely, control over the phase and amplitude of the respective voltages at the input side of the cells within 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 a constant active power, a voltage margin is necessary to satisfy both requirements. If there is no voltage margin, then according to the definition of voltage margin, everything (

[0100]

number

[0101] (The vectors must be collinear) but simply

[0102]

number

[0103] This makes it possible to connect to any vector U. i However, any other

[0104]

number

[0105] This means that a voltage margin is necessary for (i and j to be within {1, ..., n}) to be not ideally collinear.

[0106]

number

[0107] The ability to have different phases for the vectors advantageously allows for independent power flow control of each cell. By controlling the respective phases and amplitudes of the voltages, it becomes possible to individually control the power direction within each cell, thereby enabling power circulation between cells.

[0108] If at least one of the cells becomes uncontrollable, and / or disabled, for example due to maintenance, temporary deactivation, malfunction, etc., the system may continue to operate by operating a power converter with a reduced number of controllable cells, i.e., power flow is controlled, based on the method according to any one of the embodiments disclosed herein. However, if the voltage margin becomes zero or less in such a case, it may become impossible to control the phase and amplitude of each voltage on the input side of the cells in the power converter. As a result, the power converter may be unable to route power between the cells in the power converter. Therefore, cells in the power converter and subsequent additional cells that make the voltage margin greater than zero may be referred to as (additional) redundant cells.

[0109] The voltage margin is greater than 0 if the sum of the absolute values ​​of the primary voltages of multiple cells is greater than the absolute value of the power supply voltage. When considering vectors, the voltage margin is greater than 0 if the sum of the magnitudes of the primary voltages of multiple cells is greater than the magnitude of the power supply voltage.

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

[0111]

number

[0112] In another embodiment, the voltage margin is at least 25% of the absolute voltage of the power grid, i.e.,

[0113]

number

[0114] In one embodiment, the voltage margin is 33% of the absolute voltage of the power grid, i.e.,

[0115]

number

[0116] In one embodiment, the voltage margin is 30% of the absolute voltage of the power grid, i.e.,

[0117]

number

[0118] In one embodiment, the voltage margin is 25% of the absolute voltage of the power grid, i.e.,

[0119]

number

[0120] Figure 6 shows a power system according to one embodiment of the present disclosure and its operation according to a control method according to one embodiment of the present disclosure. In particular, Figure 6 shows the power system shown in Figure 4 in operation according to the method shown in Figure 1. Note that in Figure 6, for simplification, the AC power supply 401 and the series-connected inductor 402 are omitted. In this embodiment, the AC power supply 401 is a power grid that provides purely reactive power, the first three vehicles 411, 421, and 431 are charged with nominal power Pn, the fourth vehicle 441 provides nominal power Pn to the system, the cell with battery 451 provides nominal power Pn to the system, and the photovoltaic unit 461 provides power Pn to the system. Each power Pn, Pn, Pn, Pn, Pn, and Pn passing through each of the multiple cells 410, 420, 430, 440, 450, and 460 may be defined collectively as the internal power flow of the electrical system. When operating according to the method shown in Figure 1, the power system shown in Figure 6 operates according to the constraint of equation (4), and the phasor quantities shown in phasor diagram 601 are obtained. Specifically, the magnitudes and phases of U1, U2, U3, U4, U5, and U6 are adjusted based on control signals generated using measurements of the electrical system. For example, U4, U5, and U6 are U grid The phase is adjusted so that it is shifted by θ4, 5, and 6 degrees relative to U1, U2, and U3, U grid -θ 1,2,3 (For example, θ 1,2,3 =90-θ 4,5,6 The phase is adjusted to be shifted by ). It is known that the adjusted primary voltage of each cell may have any phase difference with any other voltage that is different from the power supply voltage. This is because the voltage difference in the phasor region between the power supply voltage and the vector sum of the primary voltages of the multiple cells 410, 420, 430, 440, 450, and 460 is the voltage U across the electrical components. filter Set it, and then the controlled current I grid electrical component L filter This is done in a way that guides the power flow in a certain direction. Therefore, the internal power flow of the electrical system is controlled.

[0121] It is understood by those skilled in the art that reactive power from the power grid can be useful in generating current vectors in the appropriate direction to enable active power circulation between cells. Reactive and active power from the power grid are induced by the sum of the cell voltages. However, the circulation between cells is not controlled from the power grid side. This is a different controller that sets active power setpoints for the purpose of balancing. That is, all

[0122]

number

[0123] The vector sum of each U provides the total voltage vector of the converter, which is used to control active and reactive power into the power grid. i The magnitude and phase are also controlled to achieve internal power flow control. It should also be noted that reactive power injection into the power grid may be undesirable and may not be permissible beyond a certain point. The principles of power routing, i.e., power circulation between cells, and the requirements described with reference to Figure 5, also apply to the embodiment in Figure 6.

[0124] Figure 7 shows a power system according to one embodiment of the present disclosure and its operation according to a control method according to one embodiment of the present disclosure. In particular, Figure 7 shows an AC power system comprising an AC power supply 701 electrically coupled to a power converter 700 via a series-connected inductor 702. The power converter 700 may be an AC-DC power converter, in particular power converter 300 or 300b, or an AC-AC power converter. The power converter 700 comprises six cells. The AC voltage on the primary side of each of the six cells is represented by six voltage sources 710, 720, 730, 740, 750, and 760. The voltages of the six voltage sources 710, 720, 730, 740, 750, and 760 are represented as U1, U2, U3, U4, U5, and U6, respectively. The rest of the power converter 700 is omitted here for simplicity. The system further comprises a first switch 703 and a second switch 704, the first switch 703 electrically coupling the power grid in series with an electrical component, namely an inductor 702, and the second switch 704 electrically coupling to a node between the first switch 703 and the electrical component 702. The second switch 704 electrically coupling the power grid, namely an AC power source 701, in parallel with the electrical component 702. In one 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. The opening and closing are performed simultaneously or with a set time delay between them. In particular, when the first switch 703 is opened, i.e. electrically discoupled, and the second switch 704 is closed, i.e. electrically coupled, the AC power source does not supply power to the system. In such embodiments, a loop, ring, or island is formed comprising six voltage sources 710, 720, 730, 740, 750, and 760, an electrical component 702, and a second switch 704. The loop operates such that loads, power sources, and / or storage means electrically coupled to the secondary side of multiple cells that combine to form the six voltage sources 710, 720, 730, 740, 750, and 760 participate in power balancing operation.The electrical system may have different configurations, such as achieving power isolation and forming loops or rings without power sources, but it will be understood by those skilled in the art that it includes power converters and electrical components.

[0125] Hereinafter, the power converter 700 is assumed to be an AC-DC power converter 400 configured as shown in Figure 6, and to have 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 is supplying nominal power to the system, the cell with battery 451 is supplying nominal power to the system, and the photovoltaic unit 461 is supplying power to the system. In this case, even if the AC power grid 701 is disconnected from the power converter 700, the electrical system may be controlled according to the method shown in Figure 1, subject to the constraints of equation (4). The resulting phasor parameters are shown in phasor diagram 701. Specifically, the magnitudes and phases of U1, U2, U3, U4, U5, and U6 are adjusted based on control signals generated using measurements of the electrical system. For example, U1, U2, and U3 are θ with respect to the reference signal 1,2,3 The phase is adjusted to shift by θ, and U4, U5, and U6 are θ relative to the reference signal. 4,5,6 The phase is adjusted to shift by 1 degree. This is because the voltage difference in the phasor region between the power supply voltage and the vector sum of the primary side voltages of multiple cells 410, 420, 430, 440, 450, and 460 corresponds to the voltage U across the electrical components. filter Set it, and then the controlled current I grid electrical component L filter This is done in a way that guides the power flow in a certain direction. Therefore, the internal power flow of the electrical system is controlled.

[0126] Figure 8a) shows a device according to one embodiment of the present disclosure. In particular, the device 810 shown in Figure 8a) is a device 810 for controlling the internal power flow of an electrical system 800 comprising a power supply 820, an electrical component 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 component 830, and the power converter 840 comprises a plurality of cells, the plurality of cells being electrically coupled in series with each other on their primary sides, and the device 810 comprises a processor configured to control the internal power flow of the electrical system 800 by acquiring at least one electrical parameter of the electrical system 800, generating a control signal for each of the plurality of cells based on the acquired at least one electrical parameter, and adjusting the primary side voltages of the plurality of cells based on the generated control signals such that the voltage difference between the voltage of the power supply 820 and the sum of the primary side voltages of the plurality of cells produces a controlled current through the electrical component 830.

[0127] In one embodiment, the processor is further configured to perform a method according to any one of the embodiments disclosed herein.

[0128] In one embodiment, the device further comprises a communication unit configured to receive at least one electrical parameter of an electrical system, and the communication unit configured to transmit the received at least one electrical parameter to a processor for further processing.

[0129] Figure 8b) shows an electrical system according to one embodiment of the present disclosure. In particular, the electrical system 820 comprises a power supply 821, an electrical component 822, and a power converter 823 having a primary side, the primary side of which is electrically coupled to the power supply 821 via the electrical component 822, and the power converter 823 comprises a plurality of cells, the plurality of which are electrically coupled in series with each other on the primary side.

[0130] Figure 8c) shows a system according to one 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 comprises a device 810 and an electrical system 820.

[0131] In one embodiment, the system further comprises at least one sensing unit, the at least one sensing unit configured to sense at least one electrical parameter of an electrical system. In one embodiment, the at least one sensing unit is communicatively coupled to a communication unit. In one embodiment, the at least one sensing unit transmits the sensed at least one electrical parameter to the communication unit.

[0132] In one embodiment, the electrical system is an AC system, the power supply is an AC power supply, each of the plurality of cells comprises an AC-DC converter or an AC-AC converter, and the first AC portion of the AC-DC converter is electrically coupled to the primary side of the plurality of cells, or the first AC portion of the AC-AC converter is electrically coupled to the primary side of the plurality of cells.

[0133] In one embodiment, adjusting the primary voltage of multiple cells includes adjusting the magnitude and phase of the primary voltage of multiple cells by controlling a first AC portion of an AC-DC converter based on a generated control signal, or by controlling a first AC portion of an AC-AC converter based on a generated control signal.

[0134] In one embodiment, the sum of the primary voltages of multiple cells is greater than the voltage of the AC power supply.

[0135] In one embodiment, the sum of the primary voltages of multiple cells is at least 10% greater than the voltage of the AC power supply.

[0136] In one embodiment, the sum of the primary voltages of multiple cells is at least 25% greater than the voltage of the AC power supply.

[0137] While various embodiments of this disclosure have been described above, it should be understood that they are presented only as examples and not as limitations. Similarly, various diagrams may depict exemplary architectures or configurations provided to enable those skilled in the art to understand the exemplary features and functions of this disclosure. However, such persons will understand that this disclosure is not limited to the exemplary architectures or configurations shown and can be implemented using various alternative architectures and configurations. Furthermore, as will be understood by those skilled in the art, one or more features of one embodiment can 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.

[0138] Furthermore, it should be understood that any references to elements in this specification using names such as "first," "second," etc., do not generally limit the quantity or order of those elements. Rather, these names can be used in this specification as a convenient means of distinguishing two or more elements or examples of elements. Thus, references to first and second elements do not mean that only two elements can be employed, nor that the first element must in some way precede the second element.

[0139] Furthermore, those skilled in the art will understand that information and signals can be represented using any of the various different scientific and technological methods. For example, data, instructions, commands, information, signals, bits, and symbols that may be referenced in the above description may be represented by voltage, electric current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0140] Those skilled in the art will further recognize that any of the various exemplary logic blocks, units, processors, means, circuits, methods, and functions described in connection with the embodiments disclosed herein can be implemented by various forms of programs or design code incorporating electronic hardware (e.g., digital implementations, analog implementations, or a combination of both), firmware, instructions (which may be referred to herein as “software” or “software units” for convenience), or any combination thereof.

[0141] To clearly demonstrate this compatibility of hardware, firmware, and software, various exemplary components, blocks, units, circuits, and steps are generally described above with respect to their functions. Whether such functions are 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. A person skilled in the art can implement the described functions in various ways for specific applications, but such implementation decisions do not deviate 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 of the functions described herein. The terms “configured to” or “configured for” as used herein with respect to a specified operation or function mean a processor, device, component, circuit, structure, machine, unit, etc., that is physically built, programmed and / or positioned to perform the specified operation or function.

[0142] Furthermore, those skilled in the art will understand that the various exemplary methods, logic blocks, units, devices, components, and circuits described herein can be implemented or carried out within an integrated circuit (IC) which 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 device, or any combination thereof. The logic blocks, units, and circuits may further include antennas and / or transceivers for communicating with various components within a network or device. While a general-purpose processor may be a microprocessor, in alternative examples, the processor may be any conventional processor, controller, or state machine. The processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors working with a DSP core, or any other suitable configuration for carrying out the functions described herein. When implemented in software, the functions may be stored on a computer-readable medium as one or more instructions or code. Therefore, the steps of the methods or algorithms disclosed herein can be implemented as software stored on a computer-readable medium.

[0143] Computer-readable media include both computer storage media and communication media, which include any media that can enable the transmission of computer programs or code from one place to another. Storage media can be any available media that a computer can access. Such computer-readable media, but not limited to, include RAM, ROM, EEPROM, CD-ROM or other optical disk storage devices, magnetic disk storage devices or other magnetic storage devices, or any other media that a computer can access and which can be used to store desired program code in the form of instructions or data structures.

[0144] Furthermore, embodiments of this disclosure may employ memory or other storage devices, as well as communication components. For clarity, it will be understood that the above description refers to embodiments of this disclosure with reference to different functional units and processors. However, it will be clear that any appropriate distribution of functions between different functional units, processing logic elements, or domains may be used without prejudice to this disclosure. For example, a function shown to be performed by a separate processing logic element or controller may be performed by the same processing logic element or controller. Thus, references to specific functional units are not intended to indicate a strict logical or physical structure or organization, but merely to refer to appropriate means for providing the described functions.

[0145] Various modifications to the implementations described herein will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other implementations without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the implementations shown herein, but should be given the broadest scope consistent with the novel features and principles disclosed herein, as set forth in the following claims.

Claims

1. A method for controlling the internal power flow of an 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, and the power converter comprises a plurality of cells, each of which is electrically coupled in series with respect to the primary side of the plurality of cells, and each of the plurality of cells comprises an AC-DC converter having a first AC portion electrically coupled to the primary side of the plurality of cells, or an AC-AC converter having a first AC portion electrically coupled to the primary side of the plurality of cells, and the method is To obtain at least one electrical parameter of the AC electrical system, Based on the acquired at least one electrical parameter, a control signal is generated for each of the plurality of cells. The internal power flow of the AC electrical system is controlled by adjusting the voltages on the primary sides of the plurality of cells based on the generated control signal, such that the voltage difference between the voltage of the AC power supply and the sum of the primary side voltages of the plurality of cells generates a controlled current through the electrical components. Includes, Adjusting the voltage on the primary side of the plurality of cells includes adjusting the magnitude and phase of the voltage on the primary side of the plurality of cells by controlling the first AC portion of the AC-DC converter based on the generated control signal, or by controlling the first AC portion of the AC-AC converter based on the generated control signal, and The sum of the magnitudes of the primary voltages of the plurality of cells is greater than the magnitude of the voltage of the AC power supply. method.

2. The sum of the magnitudes of the primary voltages of the plurality of cells is greater than the magnitude of the voltage of the AC power supply by at least 10%, preferably 25%, and / or The sum of the magnitudes of the primary voltages of the plurality of cells is greater than the magnitude of the voltage of the AC power supply by a maximum of 33%, preferably 30%, and more preferably 25% of the magnitude of the voltage of the AC power supply. The method according to claim 1.

3. The method according to claim 1 or 2, wherein the plurality of cells have a secondary side different from the primary side of the plurality of cells, and the plurality of cells are galvanically insulated from each other on the secondary side of the plurality of cells.

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

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

6. Closing either the first switch or the second switch, Opening the other of the first switch and the second switch The method according to claim 5, further comprising:

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

8. The method according to any one of claims 1 to 7, wherein the 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 cells.

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

10. A device for controlling the internal power flow of an 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, and the power converter comprises a plurality of cells, each of which is electrically coupled in series with respect to the primary side of the plurality of cells, and each of the plurality of cells comprises an AC-DC converter having a first AC portion electrically coupled to the primary side of the plurality of cells, or an AC-AC converter having a first AC portion electrically coupled to the primary side of the plurality of cells, and the device is, Obtain at least one electrical parameter of the AC electrical system, Based on the acquired at least one electrical parameter, a control signal is generated for each of the plurality of cells, and The internal power flow of the AC electrical system is controlled by adjusting the voltages on the primary sides of the plurality of cells based on the generated control signal, such that the voltage difference between the voltage of the AC power supply and the sum of the primary side voltages of the plurality of cells generates a controlled current through the electrical components. Equipped with a processor configured as follows: Adjusting the voltage on the primary side of the plurality of cells includes adjusting the magnitude and phase of the voltage on the primary side of the plurality of cells by controlling the first AC portion of the AC-DC converter based on the generated control signal, or by controlling the first AC portion of the AC-AC converter based on the generated control signal, and The sum of the magnitudes of the primary voltages of the plurality of cells is greater than the magnitude of the voltage of the AC power supply. device.

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

12. A system for controlling the internal power flow of an AC electrical system, comprising the device according to claim 10 or 11, wherein the AC electrical system comprises 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, and the power converter comprises a plurality of cells, each of which is electrically coupled in series with respect to the primary side of the plurality of cells, wherein each of the plurality of cells is an AC-DC converter having a first AC portion electrically coupled to the primary side of the plurality of cells, or an AC-AC converter having a first AC portion electrically coupled to the primary side of the plurality of cells.

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