Protection methods for electricity collection systems

Abstract

This disclosure relates to a method for protecting a power collection system having a power grid electrically coupled to an electrical branch, wherein the electrical branch comprises a plurality of switches for connecting or disconnecting the electrical branch at each location on the electrical branch, and distributed energy sources are electrically coupled to nodes on the electrical branch. The method includes detecting a fault on the electrical branch based on monitored voltage and / or current on the electrical branch; restricting the flow of power from the electrical branch to the power grid based on the detection of the fault; adjusting the voltage and / or current on the electrical branch based on the detection of the fault; determining the fault location based on the adjusted voltage and / or current on the electrical branch; and disconnecting a portion of the power collection system based on the determined fault location. This disclosure also relates to the respective controllers and systems.

Description

Technical Field

[0001] Technical Field The present disclosure relates to a method, a controller, and an electrical collection system for protecting an electrical collection system.

Background Art

[0002] Background In a power collection system that supplies power from distributed energy resources (DERs) to a power grid, faults cause many problems. A conventional solution for fault removal is to install a DC circuit breaker to interrupt the path through which power flows. However, such a solution not only increases the power loss during operation but is also cost-ineffective.

[0003] FIG. 1a) shows a conventional medium voltage DC (MVDC) system for a wind power plant application. In FIG. 1a), power is supplied from a wind turbine to the power grid via a power converter and a bus that electrically couples the wind turbine to the power grid. In particular, a grid AC / DC converter is electrically coupled to the power grid via a point of common coupling (PCC) and to the MVDC bus, and converts the flow of power between the MVDC bus and the power grid. Each wind turbine includes a generator and a galvanic isolator. Such a system can alternatively or additionally include any other DERs such as photovoltaic (PV) panels and battery energy storage devices (BESs) for smooth power output. FIG. 1b) shows a simplified block diagram of a conventional power collection system. In such an MVDC system, short circuit faults cause many problems, and conventional fault removal solutions increase power loss and are not cost-effective.

[0004] Therefore, there is a need to improve a method, a controller, and an electrical collection system for protecting an electrical collection system. [Overview of the project] [Means for solving the problem]

[0005] overview This disclosure relates to a method for protecting a power collection system having a power grid electrically coupled to an electrical branch, wherein the electrical branch comprises a plurality of switches for connecting or disconnecting the electrical branch at each location on the electrical branch, and distributed energy sources are electrically coupled to nodes on the electrical branch, and the method includes detecting a fault on the electrical branch based on monitored voltage and / or current of the electrical branch, restricting the flow of power from the electrical branch to the power grid based on the detection of the fault, adjusting the voltage and / or current on the electrical branch based on the detection of the fault, determining the location of the fault based on the adjusted voltage and / or current on the electrical branch, and disconnecting a portion of the power collection system based on the determined location of the fault.

[0006] In one embodiment, the restriction means, or includes, restricting the flow of power from an electrical branch to the power grid, particularly by controlling a bidirectional power valve that electrically couples the electrical branch to the power grid.

[0007] In one embodiment, the adjustment further includes injecting a predetermined current into an electrical branch, particularly by controlling a galvanic isolator that electrically couples a distributed energy source to a node, and determining the fault location based on the adjusted current.

[0008] In one embodiment, the method further includes restricting the flow of power from the distributed energy source to the node, in particular by controlling a galvanic isolator that electrically couples the distributed energy source to the node, before disconnecting.

[0009] In one embodiment, disconnecting means disconnecting or including disconnecting at least two of a plurality of switches when it is determined that the fault location is at a branch between at least two switches.

[0010] In one embodiment, at least two of the multiple switches are adjacent to each other and have nodes located particularly between at least two switches.

[0011] In one embodiment, the two ends of an electrical branch are electrically coupled to a bidirectional power valve and further electrically coupled to the power grid to form a loop, and power flows from a distributed energy source to the power grid.

[0012] In one embodiment, the method further includes restarting a power collection system after disconnection by enabling the flow of power from the power grid to distributed energy sources, in particular by controlling a bidirectional power valve that electrically couples the power grid to an electrical branch.

[0013] The disclosure also relates to a controller for protecting a power collection system having a power grid electrically coupled to an electrical branch, wherein the electrical branch comprises a plurality of switches for connecting or disconnecting the electrical branch at each location on the electrical branch, distributed energy sources are electrically coupled to nodes on the electrical branch, and the controller is configured to detect a fault on the electrical branch based on the monitored voltage and / or current of the electrical branch, to restrict the flow of power from the electrical branch to the power grid based on the detection of the fault, to adjust the voltage and / or current on the electrical branch based on the detection of the fault, to determine the location of the fault based on the adjusted voltage and / or current on the electrical branch, and to disconnect a portion of the power collection system based on the determined location of the fault.

[0014] In one embodiment, the controller is further configured to perform a method according to any one of the embodiments disclosed herein.

[0015] The disclosure further relates to a power collection system comprising a power grid electrically coupled to electrical branches, wherein the electrical branches comprise a plurality of switches for connecting or disconnecting the electrical branches at each location on the electrical branches, and distributed energy sources are electrically coupled to nodes on the electrical branches.

[0016] In one embodiment, the power collection system further comprises a controller according to any one of the embodiments disclosed herein.

[0017] A method according to any one of the embodiments disclosed herein can advantageously monitor and / or estimate quantities of an industrial asset, such as operational performance, operating status, or information regarding external conditions or adjacent systems. One particular quantity to monitor and / or estimate is the health status of an industrial asset, which makes it possible to understand the degradation of the asset, predict its remaining useful life (RUL), and derive operational, maintenance, and repair decisions. The information thus obtained can be used to inform human operators, managers, or stakeholders, to support their operational or other decisions, or to partially or fully automate the operation of the asset.

[0018] Various exemplary embodiments of this disclosure 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 by various embodiments. However, it should 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.

[0019] Therefore, the present disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. Further, the specific order and / or hierarchy of steps in the methods disclosed herein are merely exemplary approaches. Based on design preferences, the specific order or hierarchy of steps of the disclosed methods or processes can be rearranged while remaining within the scope of the present disclosure. Thus, those skilled in the art will understand that the methods and techniques disclosed herein present various steps or operations in a sample order, and the present disclosure is not limited to the specific order or hierarchy presented, unless otherwise specified.

[0020] Exemplary embodiments of the present disclosure will be described below. Note that some aspects of any one of the described embodiments may be found in some other embodiments as well, unless otherwise specified or not obvious. However, for better understanding, each aspect will be described in detail only when it is first mentioned, and repeated descriptions of the same aspect will be omitted.

[0021] The above and other aspects and their embodiments will be described in more detail in the drawings, the description, and the claims.

Brief Description of the Drawings

[0022] [Figure 1a)] Shows a conventional power grid. [Figure 1b)] Shows a simplified diagram of a conventional power grid. [Figure 2] Shows a flowchart of a method according to an embodiment of the present disclosure. [Figure 3a)] Shows a power collection system according to an embodiment of the present disclosure under normal operating conditions. [Figure 3b)] Shows a power collection system according to an embodiment of the present disclosure under a fault condition. [Figure 3c)] Shows a power collection system according to an embodiment of the present disclosure under a fault condition. [Figure 3d)] Shows a power collection system according to an embodiment of the present disclosure under a fault condition. [Figure 3e)] Shows a power collection system according to an embodiment of the present disclosure during a fault location determination process. [Figure 4] Shows a flowchart of a method according to an embodiment of the present disclosure. [Figure 5] Shows a flowchart of a fault location determination method according to an embodiment of the present disclosure. [Figure 6a)] Shows a bidirectional power valve according to an embodiment of the present disclosure during startup or restart processes. [Figure 6b)] Shows a bidirectional power valve according to an embodiment of the present disclosure after startup or restart processes. [Figure 6c)] Shows a bidirectional power valve according to an embodiment of the present disclosure during normal operating conditions. [Figure 7] Shows a power collection system according to an embodiment of the present disclosure. [Figure 8a)] Shows a controller for a power collection system according to an embodiment of the present disclosure. [Figure 8b)] Shows a power collection system according to an embodiment of the present disclosure.

Best Mode for Carrying Out the Invention

[0023] Detailed Description of the Disclosure FIG. 2 shows a flowchart of a method according to an embodiment of the present disclosure. In particular, it is a method for protecting a power collection system comprising a power grid electrically coupled to an electrical branch, the electrical branch comprising a plurality of switches for connecting or disconnecting the electrical branch at respective positions on the electrical branch, and a distributed energy source being electrically coupled to a node on the electrical branch. The electrical collection system can equivalently be referred to as a power collection system.

[0024] In S201, a fault on an electrical branch is detected based on the monitored voltage and / or current of the electrical branch. The monitored voltage and / or current can be measured at any location on the electrical branch, in particular at any one of the locations of multiple switches. Detection may be based on at least one of the voltage and / or current measured at any location on the electrical branch, in particular at any one of the voltage and / or current measured at any one of the locations of multiple switches. Detection may further be based on any other electrical or physical parameters of the electrical collection system and / or any components contained therein.

[0025] In S202, based on the detection of a fault, the flow of power from the electrical branch to the power grid is restricted. The term “restrict” may be semantically equivalent to other terms such as “alter,” “reduce,” “block,” and “interrupt,” and it will be understood by those skilled in the art that they can therefore be used interchangeably. In one embodiment, restricting is or includes controlling a bidirectional power valve, which electrically connects the electrical branch to the power grid. In one embodiment, restricting is performed after S201 and / or before S203. Restricting may also be performed if it is determined that no fault has occurred, for example, if the fault detection yielded a false negative response.

[0026] In S203, based on the detection of a fault, the voltage and / or current on the electrical branch are adjusted. The term “adjust” may be semantically equivalent to other terms such as “set” or “control,” and it will be understood by those skilled in the art that they can therefore be used interchangeably. In one embodiment, adjusting is or includes injecting a predetermined current into the electrical branch, particularly by controlling a galvanic isolator, which electrically couples a distributed energy source (DER) to the node. The term “distributed energy source” refers to any decentralized power source, e.g., a generator, or a power reserve, e.g., a battery. In one embodiment, adjusting is performed after S202 and / or before S204.

[0027] In S204, the fault location is determined based on the regulated voltage and / or current on the electrical branch. The regulated voltage and / or current can be measured at any location on the electrical branch, in particular at any one of the locations of the multiple switches. The fault location may also be a fault range, and the fault is located within the fault range. In one embodiment, the fault range is determined by the regulated voltage and / or current measured at at least two different locations on the electrical branch, in particular at at least two different locations where two different switches of the multiple switches are located, and the fault range is between at least two different switches of the multiple switches. In one embodiment, determining the fault location is based on regulating the current on the electrical branch.

[0028] In S205, a portion of the electrical collection system is disconnected based on the determined fault location. In one embodiment, disconnecting means disconnecting or including at least two of a plurality of switches when it is determined that the fault location is located at a branch between at least two switches.

[0029] In one embodiment, the method further includes restricting the flow of power from a distributed energy source to a node. This restriction may be performed after S203 and / or before S205. This restriction may be, or include, controlling a galvanic isolator, which electrically couples the distributed energy source to the node.

[0030] In one embodiment, the method further includes reactivating a power collection system by enabling the flow of power from the power grid to distributed energy sources. Reactivation may occur after S205. In one embodiment, enabling includes controlling or controlling bidirectional power valves that electrically couple the power grid to electrical branches.

[0031] In one embodiment, at least two of the multiple switches are adjacent to each other and have nodes located particularly between at least two switches.

[0032] In one embodiment, the two ends of an electrical branch are electrically coupled to a bidirectional power valve that forms a loop, and the bidirectional power valve is further electrically coupled to the power grid via a power converter, so that power flows from the distributed energy source to the power grid. The loop may be a ring main unit.

[0033] In one embodiment, multiple switches connect electrical branches at their respective positions, particularly under normal operating conditions. In another embodiment, at least one of the multiple switches disconnects an electrical branch at its respective position, particularly under normal operating conditions.

[0034] In this specification, the term "disconnector" may be used interchangeably with the term "switch."

[0035] Figures 3a) to 3e) illustrate an electricity collection system according to an embodiment of the present disclosure operating based on an exemplary method disclosed herein. In particular, the electricity collection system 300 comprises a power grid 310 electrically coupled to an electrical branch 330, the electrical branch 330 comprising a plurality of switches 331, 332, 333, 334, 335, and 336 for connecting or disconnecting the electrical branch 330 at each location on the electrical branch 330, and distributed energy sources (i.e., generators 350) in Figures 3a) to 3e) electrically coupled to nodes on the electrical branch 330. The nodes are located on the electrical branch between a second switch 331 and a third switch 332 of the plurality of switches 331, 332, 333, 334, 335, and 336. For clarity, only some of the switches, 331, 332, 333, 334, 335, and 336, are referenced by their reference numerals in Figures 3a) to 3e), and the numbering begins at the top of the electrical branch 330, which has one of its two ends electrically coupled to bus 321, and increases along the branch toward the other end of the two ends of the branch. Bus 321 may be one of an electrical interconnect, an electrical bus, an electrical busbar, and a PCC. A set of two consecutive switches containing a node to which a DER is electrically coupled can be called a pair of consecutive switches. For example, the second switch 331 and the third switch 332 are a pair of consecutive switches. Power converter 311 electrically couples the power grid 310 to a bidirectional power valve 360, which is further electrically coupled to bus 321, to which both ends of the electrical branch 330 are electrically coupled. SST 340 electrically couples the DER to a node in the electrical branch 330.

[0036] Figure 3a) shows a power collection system according to one embodiment of the present disclosure under normal operating conditions. The term “normal operating conditions” refers to operating conditions without abnormalities and / or operating conditions after startup or restart. For example, an abnormality may be a failure in an electrical branch, such as a short circuit. For example, an abnormality may be a failure in any of the electrical components included in the power collection system. Under normal operating conditions, a number of switches 331, 332, 333, 334, 335, and 336 connect the electrical branch 330 at their respective locations. Under normal operating conditions, the power generated by the generator 350 is supplied to the power grid 310 via the SST 340, bus 321, bidirectional power valve 360, and power 311. Under normal operating conditions, the bidirectional power valve 360 ​​is controlled to function as a one-way power valve, allowing only the flow of power from the electrical branch 330 to the power grid 310. It will be understood by those skilled in the art that the generated power may be supplied to another DER, such as a BES, electrically coupled to the electrical branch. In one embodiment, the BES is controlled to supply power to an electrical branch. Under normal operating conditions, a fault on the electrical branch 330 is detected based on the monitored voltage and / or current of the electrical branch. The method described above may be one embodiment of S201. Such fault detection may be repeated. When a fault on an electrical branch is detected, the power collection system 300 performs the following method according to one embodiment of the present disclosure, as shown in Figure 3b).

[0037] Figure 3b) shows a power collection system according to one embodiment of the present disclosure under a fault condition. For example, according to S201, a fault (shown with lightning in Figures 3b) to 3e) occurs in an electrical branch between the third switch 332 and the fourth switch 333 of a plurality of switches 331, 332, 333, 334, 335, and 336. When the fault is detected, the flow of power between the electrical branch 330 and the power grid 310 is restricted by controlling the bidirectional power valve 360. Note that the exact location of the fault on the electrical branch may not be determined at this stage, but merely detecting the occurrence of a fault may suffice. The method described above may be one embodiment of S202. Once the flow of power between the electrical branch 330 and the power grid 310 is restricted, the current on the electrical branch 330 can be adjusted by controlling the SST 340 to inject a predetermined current into the electrical branch 330. The method described above may be one embodiment of S203. Next, the location of the fault is determined based on the adjusted current on the electrical branch 330. The method described above may be one embodiment of S204. While the method described above is being performed, the switches 331, 332, 333, 334, 335, and 336 are connecting the electrical branch 330 at their respective locations. Once the fault location is determined, the power collection system 300 performs the following method according to one embodiment of the present disclosure, as shown in Figure 3c).

[0038] Figure 3c) shows a power collection system according to one embodiment of the present disclosure under a fault. When it is determined that the fault location is between the second switch 331 and the third switch 332 of a plurality of switches 331, 332, 333, 334, 335, and 336, the flow of power from the generator 350 to the electrical branch 330 is restricted by controlling the SST 340. While the method described above is being performed, the plurality of switches 331, 332, 333, 334, 335, and 336 are connecting the electrical branch 330 at their respective locations. Next, as shown in Figure 3d), a fault point isolation method according to one embodiment of the present disclosure is performed.

[0039] Figure 3d) shows a power collection system according to one embodiment of the present disclosure under fault conditions. When it is determined that the fault is located between the third switch 332 and the fourth switch 333, and the flow of power from the generator 350 to the electrical branch 330 is controlled, a portion of the electrical branch is disconnected by opening the third switch 332 and the fourth switch 333, i.e., by disconnecting the electrical branch 330 at the respective locations of the third switch 332 and the fourth switch 333. In this embodiment, for illustrative purposes, the two switches closest to the fault location (i.e., the third switch 332 and the fourth switch 333) are disconnected to isolate the fault, but it will be understood by those skilled in the art that, as long as the fault is within a selected combination of at least two switches, it is possible to disconnect any portion of the electrical branch by controlling any combination of at least two switches of the plurality of switches 331, 332, 333, 334, 335, and 336 for the same purpose. For example, the third switch 332 and the seventh switch 334 may be controlled to disconnect a portion of the electrical branch between them. The method described above may be one embodiment of S205.

[0040] Figure 3e) shows a power collection system according to one embodiment of the present disclosure during a fault location process. In particular, Figure 3e) shows one embodiment of the method shown in S204 or Figure 3b). When the bidirectional power valve 360 ​​restricts the flow of power between the electrical branch 330 and the power grid and the current on the electrical branch 330 is regulated, the regulated current in the electrical branch 330 flows toward the fault location between the third switch 332 and the fourth switch 333. By defining any current direction as the positive direction 380, the current direction can be observed at multiple measurement points, for example, at the respective locations of multiple switches 331, 332, 333, 334, 335, and 336. Furthermore, when the DER injects current into the electrical branch 330 at multiple locations along the conduction path, starting from any location on the electrical branch, the current accumulates along the path toward the fault location. Thus, the fault location can be identified between a first measurement point that records the maximum current in the positive current direction and a second measurement point that records the maximum current in the negative current direction. The method shown in Figure 4 can be implemented in combination with the electricity collection systems shown in Figures 3a) to 3e).

[0041] Figure 4 shows a flowchart of a method according to one embodiment of the present disclosure. In S401, a periodic protective inspection is performed. In S402, an MVDC fault is determined. S402 may be equivalent to S201. In S403, further action is determined based on the fault occurrence determined in S402. If no fault is detected, the method jumps to another process (S404). In one embodiment, the other process in S404 may include fault detection in S402. If a fault is detected, the SST is controlled to output a preset current to adjust the electrical branch current (S406). In one embodiment, before S406, the flow of power between the power grid and the electrical branch is restricted. Next, in S407, a fault location process is performed and repeatedly checked until the fault location is determined (S408). In one embodiment, after a predetermined number of iterations or a predetermined period, the loop formed by S407, S408, and the negative result of S408 is interrupted, and the method jumps to another block, for example, S409. In the same embodiment, after a predetermined number of iterations or a predetermined period of time, the fault point may be determined as a predetermined location on the electrical branch. Blocks S405-S408 may correspond to the method shown in the system shown in Figure 3b). Once the fault location is determined, the SST controlled in S406 is blocked to restrict the flow of power between the grid and the node (S409). S409 may correspond to the method shown in the system shown in Figure 3c). Next, the fault point is isolated by opening an adjacent switch (S410). S410 may correspond to the method shown in the system shown in Figure 3d). In S411, the system enters a restart process. S411 may correspond to the method shown in the system shown in Figure 3e). The terms “restart” or “reoperation” refer to the operation of controlling the relevant components included in the system to return to normal operation, particularly after protective measures have been applied, such as disconnecting a portion of the electrical branch.

[0042] Figure 5 shows a flowchart of a fault location determination method according to one embodiment of the present disclosure. The method shown in Figure 5 may be an embodiment of the fault location determination in S407 or the method shown in Figure 3e). When an MVDC fault is detected, the current on the electrical branch can be adjusted as shown in Figure 3b). In S503, the adjustment current is measured at each of the multiple switches on the electrical branch. The measured adjustment current is classified into a first group of disconnectors (S504) located at each position where the current flows in a specified positive direction, and a second group of disconnectors (S505) located at each position where the current flows in a specified negative direction, according to the current direction in S502. The numbering (count order) of the disconnectors that record the maximum current value in the first and second groups is identified in S506 and S507, respectively. Next, in S508, the location of the fault area is identified by the numbers of the two disconnectors with the maximum current. In S509, the fault area and the numbers of the two adjacent disconnectors are output for further processing or signal generation.

[0043] Figures 6a) to 6c) illustrate power collection systems according to embodiments of the present disclosure in various processes and states. Power collection system 600 is a simplified diagram of power collection system 300 shown in Figures 3a) to 3e). That is, the power grid 610, power converter 620, bidirectional power valve 630, bus 640, electrical branch 650, SST 660, and generator 670 in Figures 6a) to 6c) correspond to the power grid 310, power converter 311, power valve 360, bus 321, electrical branch 330, SST 340, and generator 350 shown in Figures 3a) to 3e), respectively. In one embodiment, the power converter 620 and / or SST 660 enable bidirectional power transmission. The bidirectional power valve 630 comprises a first branch having a first plurality of diodes and a second branch having a second diode in antiparallel to the first plurality of diodes, the second branch further comprising a switch for connecting or disconnecting the second branch at a position following the second diode in the direction of the current flowing through the second diode when the second diode is forward biased. It will be understood by those skilled in the art that the first branch of the bidirectional power valve may have only one diode.

[0044] Figure 6a) shows a power collection system according to one embodiment of the present disclosure during a startup or restart process. During the startup or restart process, a switch included in the second branch is closed to allow the flow of power from the power grid 610 to the generator 670 through the second branch of the bidirectional power valve 630. After such a startup or restart process, power flows through the first branch as shown in Figure 6b). Figure 6b) shows a power collection system according to one embodiment of the present disclosure after a startup or restart process. After such a startup or restart process, power is supplied from the generator 670 to the power grid 610 through the first branch included in the bidirectional power valve 630. Note that the switch in the second branch included in the bidirectional power valve 630 may still be connected to the second branch. Figure 6c) shows a power collection system according to one embodiment of the present disclosure in a normal operating state. Under normal operating conditions, the switch in the second branch included in the bidirectional power valve 630 disconnects the second branch, and power is supplied from the generator 670 to the power grid 610 via the first branch included in the bidirectional power valve 630.

[0045] Figure 7 shows a power collection system according to one embodiment of the present disclosure. In particular, the power collection system comprises the system shown in Figures 3a) to 3e), and further comprises a controller and a plurality of intelligent electronic devices (IEDs). The controller is configured to perform a method according to any one of the embodiments disclosed herein. The controller may be further configured to communicate, in particular bidirectionally, with any one of the components included in the system. In one embodiment, the controller receives or acquires measured values ​​and / or signals and generates control signals and / or communication signals based on the received or acquired measured values ​​and / or signals. Each of the plurality of IEDs may be a voltage and / or current sensor, or may include a current sensor. Each of the plurality of IEDs may be positioned at each of the switches included in the electrical branch to connect and disconnect the electrical branch at each of the respective locations. It will be understood by those skilled in the art that the number of plurality of IEDs may differ from the number of switches. The controller may be configured to control the plurality of switches. The plurality of IEDs may be configured to control the plurality of switches. The grid AC / DC converter may be a modular multilevel converter (MMC) having full bridge cells as shown in Figure 7, or it may include an MMC. The MMC may have m full bridge cells in its branch. In one embodiment, m is given as follows:

[0046]

number

[0047] Figure 8a) shows a controller for a power collection system according to one embodiment of the present disclosure. Controller 810 may be the controller shown in Figure 7. In one embodiment, controller 810 is further configured to perform a method according to any one of the embodiments disclosed herein. The controller 810 is a controller for protecting a power collection system 800 which comprises a power grid 820 electrically coupled 823 to an electrical branch 830, the electrical branch 830 comprising a plurality of switches 840 for connecting or disconnecting the electrical branch 830 at each location of the electrical branch 830, and distributed energy sources 850 which are electrically coupled 835 to nodes on the electrical branch 830, and the controller is configured to detect a fault on the electrical branch 830 based on the monitored voltage and / or current of the electrical branch 830, to restrict the flow of power from the electrical branch 830 to the power grid 820 based on the detection of a fault, to adjust the voltage and / or current on the electrical branch 830 based on the detection of a fault, to determine the location of the fault based on the adjusted voltage and / or current on the electrical branch 830, and to disconnect a portion of the power collection system 800 based on the determined location of the fault.

[0048] Figure 8b) shows a power collection system according to one embodiment of the present disclosure. The power collection system 800 is a power collection system comprising a power grid 820 electrically coupled 823 to an electrical branch 830, the electrical branch 830 comprising a plurality of switches 840 for connecting or disconnecting the electrical branch 830 at each location on the electrical branch 830, distributed energy sources 850 electrically coupled to nodes on the electrical branch 830, and the power collection system 800 further comprises a controller according to any one of the embodiments disclosed herein.

[0049] 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 figures may illustrate exemplary architectures or configurations provided to enable those skilled in the art to understand the exemplary features and functions of this disclosure. However, such those skilled in the art will understand that this disclosure is not limited to the illustrated exemplary architectures or configurations 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.

[0050] Furthermore, it should be understood that any reference to elements in this specification using designations such as “first,” “second,” etc., does 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 used, or that the first element must in some way precede the second element.

[0051] Furthermore, those skilled in the art will understand that information and signals can be represented using any of the various different techniques and methods. For example, data, instructions, commands, information, signals, bits, and symbols that can be mentioned throughout the above description can be represented by voltage, electric current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0052] Those skilled in the art will further understand that any of the various exemplary logic blocks, units, processors, means, circuits, methods, and functions described in relation to the embodiments disclosed herein can be implemented by electronic hardware (e.g., digital implementations, analog implementations, or a combination of both), firmware, various forms of programs or design code incorporating instructions (which may be referred to herein as “software” or “software units” for convenience), or any combination of these technologies.

[0053] To clearly demonstrate this compatibility with hardware, firmware, and software, various exemplary components, blocks, units, circuits, and steps are generally described above in relation to their functions. Whether such functions are implemented as hardware, firmware, software, or a combination of these technologies depends on the specific application and the design constraints imposed on the overall system. A person skilled in the art may implement the described functions in various ways for each specific application, but such implementation decisions should not be construed as departing 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 for” or “configured to” as used herein in relation to a specified operation or function refer to a processor, device, component, circuit, structure, machine, unit, etc., that is physically constructed, programmed and / or positioned to perform the specified operation or function.

[0054] 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 in, or performed by, 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 performing the functions described herein. When implemented in software, the functions may be stored as one or more instructions or codes 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.

[0055] Computer-readable media include both computer storage media and communication media, which include any media that can enable the transfer of computer programs or code from one location to another. Storage media can be any available media that can be accessed by a computer. 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 can be used to store desired program code in the form of instructions or data structures and can be accessed by a computer.

[0056] Furthermore, embodiments of this disclosure may utilize memory or other storage devices, as well as communication components. For clarity, it will be understood that the above description has illustrated embodiments of this disclosure with reference to different functional units and processors. However, it will be apparent that any suitable set of functionalities 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 suitable means for providing the described functionality.

[0057] Various modifications to the embodiments described herein will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the embodiments 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 protecting a power collection system comprising a power grid electrically coupled to an electrical branch, wherein the electrical branch comprises a plurality of switches for connecting or disconnecting the electrical branch at each location on the electrical branch, and distributed energy sources are electrically coupled to nodes on the electrical branch, and the method is Detecting the occurrence of a fault on the electrical branch based on the monitored voltage and / or current of the electrical branch, Based on the detection of the occurrence of a fault, the flow of power from the electrical branch to the power grid is restricted, Based on the detection of the occurrence of a fault, the voltage and / or current on the electrical branch are adjusted, Determining the fault location based on the adjusted voltage and / or current on the electrical branch, Based on the determined fault location, a portion of the electrical collection system is disconnected. Methods that include...

2. The method according to claim 1, wherein the restriction means, in particular, restricting or limiting the flow of power from the electrical branch to the power grid by controlling a bidirectional power valve that electrically connects the electrical branch to the power grid.

3. The adjustment further includes injecting a predetermined current into the electrical branch by controlling a galvanic isolator that electrically couples the distributed energy source to the node, The method according to claim 1 or 2, wherein the fault location is determined based on the adjusted current.

4. The method according to any one of claims 1 to 3, further comprising restricting the flow of power from the distributed energy source to the node, in particular by controlling the galvanic isolator that electrically couples the distributed energy source to the node, before the aforementioned disconnection.

5. The method according to any one of claims 1 to 4, wherein the disconnection is to disconnect or include disconnecting at least two of the plurality of switches when it is determined that the fault location is in the branch between at least two of the switches.

6. The method according to claim 5, wherein at least two of the plurality of switches are adjacent to each other and have the node located between the at least two switches.

7. The two ends of the aforementioned electrical branch are electrically coupled to a bidirectional power valve and further electrically coupled to the power grid to form a loop. The method according to any one of claims 1 to 6, wherein electricity flows from the distributed energy source to the power grid.

8. After the aforementioned disconnection, the flow of power from the power grid to the distributed energy source is enabled, in particular by controlling the bidirectional power valve that electrically connects the power grid to the electrical branch. The method according to any one of claims 1 to 7, further comprising restarting the force collection system by means of the method.

9. A controller for protecting a power collection system comprising a power grid electrically coupled to an electrical branch, wherein the electrical branch comprises a plurality of switches for connecting or disconnecting the electrical branch at each location on the electrical branch, distributed energy sources are electrically coupled to nodes on the electrical branch, and the controller, Based on the monitored voltage and / or current of the electrical branch, a fault is detected on the electrical branch. Based on the detection of the fault, the flow of power from the electrical branch to the power grid is restricted. Based on the detection of the fault, the voltage and / or current on the electrical branch are adjusted. The fault location is determined based on the adjusted voltage and / or current on the aforementioned electrical branch, Based on the determined fault location, a portion of the electrical collection system is disconnected. A controller configured in such a way.

10. The controller according to claim 9, further configured to perform the method described in any one of claims 2 to 8.

11. A power collection system comprising a power grid electrically coupled to an electrical branch, wherein the electrical branch comprises a plurality of switches for connecting or disconnecting the electrical branch at each location on the electrical branch, distributed energy sources electrically coupled to nodes on the electrical branch, and the power collection system further comprises the controller according to claim 9 or 10.

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