Circuit interrupting device

Abstract

A circuit interrupting device (20) comprises: first and second terminals (22, 24) for connection, in use, to a respective electrical circuit or network (34); a current conducting limb comprising first, second and third current conducting limb portions connected in series succession between the first and second terminals (22, 24), the first current conducting limb portion comprising a first switching element (36), the second current conducting limb portion comprising a second switching element (38), the third current conducting limb portion comprising a third switching element (40), each switching element (36, 38, 40) being configured to be switchable to selectively permit and prevent the flow of current (46) in the respective current conducting limb portion; first and second current bypass paths (28, 30), the first current bypass path (28) being connected across the first and second current conducting limb portions, the second current bypass path (30) being connected across the second and third current conducting limb portions; and a controller (32) configured to selectively control the switching of the switching elements (36, 38, 40) to control the flow of current (46) between the first and second terminals (22, 24) such that: (i) in a first operating mode of the circuit interrupting device (20, 120, 220), current (46) is permitted to flow through the first, second and third current conducting limb portions and is prevented from flowing through the current bypass paths (28, 30); and (ii) in a second operating mode of the circuit interrupting device (20, 120, 220), current (46) is prevented from flowing through the first and third current conducting limb portions and is permitted to flow through the current bypass paths (28, 30) so as to reverse the direction of current (46) flowing through the second current conducting limb portion.

Description

Technical Field

[0001] The present invention relates to a circuit interruption device, a circuit interruption assembly, a method of operating the circuit interruption device, and a method of operating the circuit interruption assembly, preferably for use in medium- and high-voltage applications. Background Technology

[0002] Circuit breakers are known to be used to disconnect electrical equipment from either or both AC and DC electrical networks to prevent uncontrolled fault currents from flowing through the equipment. However, conventional AC circuit breakers have slow response times and therefore cannot interrupt fault currents before they rise beyond unacceptable limits, while conventional high-speed DC circuit breakers have insufficient current and voltage ratings for use in power transmission networks. Furthermore, after the original fault has been cleared, a considerable amount of time is spent reclosing the circuit breaker, thus adding further delay before normal operation of the electrical equipment can be restored. Summary of the Invention

[0003] According to a first aspect of the present invention, a circuit interruption device is provided, comprising:

[0004] The first and second terminals are used for connection to the corresponding electrical circuit or network during use;

[0005] A current conduction branch includes a first current conduction branch section, a second current conduction branch section, and a third current conduction branch section connected in series between a first terminal and a second terminal. The first current conduction branch section includes a first switching element, the second current conduction branch section includes a second switching element, and the third current conduction branch section includes a third switching element. Each switching element is configured to be switched to selectively allow and block the flow of current in the corresponding current conduction branch section.

[0006] A first current bypass path and a second current bypass path, wherein the first current bypass path is connected across a first current conduction branch portion and a second current conduction branch portion, and the second current bypass path is connected across a second current conduction branch portion and a third current conduction branch portion; and

[0007] A controller configured to selectively control the switching of switching elements to control the flow of current between a first terminal and a second terminal, such that:

[0008] (i) In the first operating mode of the circuit interruption device, current is permitted to flow through the first current conduction branch, the second current conduction branch, and the third current conduction branch, but is prevented from flowing through the current bypass path; and

[0009] (ii) In the second operating mode of the circuit interruption device, current is blocked from flowing through the first current conduction branch and the third current conduction branch, but is allowed to flow through the current bypass path so as to reverse the direction of the current flowing through the second current conduction branch.

[0010] During normal operation, the circuit interrupter operates in its first operating mode to allow current to flow freely between the first and second terminals, thereby permitting the operation of the associated electrical circuit or network. However, in certain circumstances, it may be necessary to interrupt the flow of current in the associated electrical circuit or network. Such circumstances may include, but are not limited to, faults or other abnormal operating conditions in the electrical circuit or network that cause high fault currents, shutdowns in the electrical circuit or network, and repairs, testing, or maintenance of the electrical circuit or network.

[0011] The arrangement of the current bypass path and current conduction branch between the first and second terminals of the circuit interruption device of the present invention enables the control of the switching element to create an alternative current path for the current flowing between the first and second terminals, so that the current flow through the second switching element is temporarily reversed to force the current to zero, thereby achieving the turn-off of the second switching element. This further facilitates the limitation or interruption of the current flowing through the circuit interruption device.

[0012] The configuration of the circuit interruption device of the present invention is advantageous because it requires fewer switching components than conventional circuit interruption devices to perform the function of limiting or interrupting current, thus providing a relative reduction in size, weight, cost and conduction losses.

[0013] In an embodiment of the invention, the controller may be configured to selectively control the switching of the switching element to control the flow of current between the first terminal and the second terminal, such that in a third operating mode of the circuit interruption device, current is blocked from flowing through the second current conduction branch portion, while being allowed to flow through the first current conduction branch portion, the third current conduction branch portion, and the current bypass path.

[0014] In the third operating mode, the circuit interruption device is operated so that the current flowing between the first terminal and the second terminal can bypass the second current conduction branch, which is part of the current limiting or interruption function of the circuit interruption device.

[0015] In another embodiment of the invention, the first current bypass path may include a first energy storage device, and / or the second current bypass path may include a second energy storage device. The provision of the first energy storage device in the first current bypass path and / or the second energy storage device in the second current bypass path enables the current flowing through one or more current bypass paths to charge the energy storage device, thereby providing a reverse voltage opposing the flow of current through the one or more current bypass paths, thus enhancing the current limiting or interruption capability of the circuit interruption device.

[0016] In another embodiment of the invention, the circuit interruption device may include a third current bypass path connected across the first and second terminals, the third current bypass path including a third energy storage device. The provision of the third energy storage device in the third current bypass path not only enables the current flowing through the third current bypass path to charge the third energy storage device to provide a reverse voltage against the flow of current through the third current bypass path, thus enhancing the current limiting or interruption capability of the circuit interruption device, but also reduces the overall energy storage device requirements of the circuit interruption device, thus providing cost, size, and weight savings.

[0017] The energy storage device may be any device capable of storing and releasing energy to selectively provide voltage, such as a capacitor, fuel cell, or battery.

[0018] Optionally, the circuit interruption device may include a first energy dissipation or absorption device connected across the second current conduction branch. The controller may be configured to selectively control the switching of the switching elements to control the flow of current between the first and second terminals, such that in a fourth operating mode of the circuit interruption device, current is blocked from flowing through the second current conduction branch and the current bypass path, while being permitted to flow through the first and third current conduction branches and the first energy dissipation or absorption device.

[0019] In the fourth operating mode, the circuit interruption device enables the first energy dissipation or absorption device to absorb energy to limit the voltage of the second current conduction branch, thereby limiting the total voltage of the circuit interruption device to an acceptable value.

[0020] More preferably, the circuit interruption device may include at least one of the following:

[0021] ●A second energy dissipation or absorption device connected across the first and second terminals;

[0022] ●A third energy dissipation or absorption device connected across the first current bypass path;

[0023] • A fourth energy dissipation or absorption device connected across the second current bypass path;

[0024] ●A fifth energy dissipation or absorption device connected to the first switching element in the first current conduction branch section;

[0025] • The sixth energy dissipation or absorption device is connected to the third switching element in the third current conduction branch section.

[0026] The circuit interruption device includes one, some, or all of a second, third, fourth, fifth, and sixth energy dissipation or absorption device to absorb energy, thereby limiting the total voltage of the circuit interruption device to an acceptable value.

[0027] Each energy dissipation or absorption device may take the form of a resistive element (preferably a nonlinear resistive element, such as a metal oxide surge arrester) or an energy storage device.

[0028] Each of the first and third switching elements can be, but is not limited to, an electronic switching element. Examples of electronic switching elements include gate-off thyristors (GTOs), field-effect transistors (FETs), metal-oxide-semiconductor field-effect transistors (MOSFETs), injection-enhanced gate transistors (IEGTs), integrated gate-commutated thyristors (IGCTs), dual-mode insulated-gate transistors (BIGTs), or any other self-commutated semiconductor device. Each electronic switching element can be a switching element based on a wide-bandgap material or a switching element based on silicon semiconductors. Examples of wide-bandgap materials include, but are not limited to, silicon carbide, boron nitride, gallium nitride, and aluminum nitride.

[0029] The second switching element can be, but is not limited to, a mechanical switching element. Examples of mechanical switching elements include vacuum switching elements or gas-insulated switching elements, such as SF6-insulated switching elements.

[0030] Each of the first and third switching elements can be a unidirectional switching element. Alternatively, each of the first and third switching elements can be a bidirectional switching element. A bidirectional switching element can be or may include a pair of anti-parallel connected switching devices.

[0031] This invention can be applied to both DC and AC circuit interruption devices. A DC circuit interruption device can be any device capable of interrupting direct current flow in a DC circuit or network. Such a DC circuit interruption device can be, but is not limited to, a DC circuit breaker. An AC circuit interruption device can be any device capable of interrupting alternating current flow (including sub-cycle and non-zero current interruption) in an AC circuit or network. Such an AC circuit interruption device can be, but is not limited to, an AC circuit breaker.

[0032] According to a second aspect of the invention, a circuit interruption assembly is provided, comprising at least one circuit interruption device connected in series with at least one isolator, wherein the circuit interruption device or each circuit interruption device is according to any one of the first aspects of the invention and the embodiments described above.

[0033] The features and advantages of the circuit interruption device and its embodiments of the first aspect of the present invention, with necessary modifications, are applied to the circuit interruption assembly and its embodiments of the second aspect of the present invention.

[0034] After the circuit interrupter is operated, residual current may continue to flow through it, potentially causing unnecessary heating of one or more components. The isolator or each isolator may be operated to isolate the circuit interrupter from one or more electrical circuits or networks to prevent the flow of residual current.

[0035] According to a third aspect of the invention, a circuit interruption assembly is provided, comprising a plurality of circuit interruption devices, each circuit interruption device being according to any one of the first aspects of the invention and the embodiments described above, wherein each controller of the circuit interruption device is configured to control the switching of a switching element of the corresponding circuit interruption device, such that the circuit interruption devices initiate the same operating mode at the same time or at different times.

[0036] The features and advantages of the circuit interruption device and its embodiments of the first aspect of the present invention, with necessary modifications, are applied to the circuit interruption assembly and its embodiments of the third aspect of the present invention.

[0037] Configuring circuit interruption devices and controllers in this manner offers several benefits, including but not limited to:

[0038] ● Achieve a reduction in the physical size and weight of the circuit interruption assembly;

[0039] • Implement a modular design approach for circuit interruption assemblies that can be applied to different circuit interruption requirements;

[0040] ● Provides built-in redundancy to improve the availability of current limiting or interrupt functions;

[0041] ●Permitted to operate one or more individual circuit interruption devices in service for routine testing purposes;

[0042] ● Optimization of the current limiting or interruption function properties of circuit interruption assemblies;

[0043] ● Coordinate the operation of circuit interruption devices to provide a wide range of current limiting or interruption functions.

[0044] In embodiments of the present invention, at least one of the multiple circuit interruption devices may have the same or different voltage rating as at least one other circuit interruption device of the multiple circuit interruption devices.

[0045] In embodiments of the invention employing one or more energy storage devices, at least one of the multiple circuit interruption devices may have the same or different energy storage device ratings as at least one other interruption device of the multiple interruption devices.

[0046] The voltage ratings of the circuit interruption device and / or the energy storage device ratings can be optimized to provide not only cost, size, and weight savings, but also to achieve specific current limiting or interruption functions.

[0047] According to a fourth aspect of the present invention, a method for operating a circuit interruption device is provided, the circuit interruption device comprising:

[0048] The first and second terminals are used for connection to the corresponding electrical circuits or networks during use;

[0049] A current conduction branch includes a first current conduction branch section, a second current conduction branch section, and a third current conduction branch section continuously connected in series between a first terminal and a second terminal. The first current conduction branch section includes a first switching element, the second current conduction branch section includes a second switching element, and the third current conduction branch section includes a third switching element. Each switching element is configured to selectively allow and block the flow of current in its respective current conduction branch section.

[0050] A first current bypass path and a second current bypass path, wherein the first current bypass path is connected across a first current conduction branch portion and a second current conduction branch portion, and the second current bypass path is connected across a second current conduction branch portion and a third current conduction branch portion.

[0051] The method includes the following steps:

[0052] In the first operating mode of the circuit interruption device, the switching of the switching element is selectively controlled such that the flow of current between the first terminal and the second terminal is permitted to flow through the first current conduction branch, the second current conduction branch, and the third current conduction branch, while being blocked from flowing through the current bypass path; and

[0053] In the second operating mode of the circuit interruption device, the switching of the switching element is selectively controlled such that current is blocked from flowing through the first current conduction branch and the third current conduction branch, while being allowed to flow through the current bypass path, so as to reverse the direction of the current flowing through the second current conduction branch.

[0054] The features and advantages of the circuit interruption device and its embodiments of the first aspect of the present invention, with necessary modifications, are applied to the method and its embodiments of the fourth aspect of the present invention.

[0055] The method of the fourth aspect of the present invention may include the following steps: selectively controlling the switching of a switching element in a third operating mode of the circuit interruption device such that current is blocked from flowing through the second current conduction branch portion, while being allowed to flow through the first current conduction branch portion, the third current conduction branch portion, and the current bypass path.

[0056] In the method of the fourth aspect of the present invention, the first current bypass path may include a first energy storage device, and / or the second current bypass path may include a second energy storage device.

[0057] In a fourth aspect of the invention, the circuit interruption device may include a third current bypass path connected across a first terminal and a second terminal, the third current bypass path including a third energy storage device.

[0058] In a method of a fourth aspect of the invention, the circuit interruption device may include a first energy dissipation or absorption device connected across a second current conduction branch portion, and the method may include the steps of selectively controlling the switching of a switching element in a fourth operating mode such that current is blocked from flowing through the second current conduction branch portion and the current bypass path, while being permitted to flow through the first current conduction branch portion and the third current conduction branch portion and the first energy dissipation or absorption device.

[0059] In the method of the fourth aspect of the present invention, the circuit interruption device may include at least one of the following:

[0060] A second energy dissipation or absorption device connected across the first and second terminals;

[0061] • A third energy dissipation or absorption device connected across the first current bypass path;

[0062] • A fourth energy dissipation or absorption device connected across the second current bypass path;

[0063] • A fifth energy dissipation or absorption device to which the first switching element in the first current conduction branch is connected;

[0064] • The sixth energy dissipation or absorption device is connected to the third switching element in the third current conduction branch section.

[0065] In the method of the fourth aspect of the present invention, each of the first and third switching elements may be a unidirectional switching element, or each of the first and third switching elements may be a bidirectional switching element.

[0066] According to a fifth aspect of the invention, a method is provided for operating a circuit interruption assembly, the circuit interruption assembly including at least one circuit interruption device connected in series with at least one isolator, wherein the circuit interruption device is according to any one of the first aspects of the invention and the embodiments described above, the method comprising the steps of: operating the circuit interruption device according to any one of the fourth aspects of the invention and the embodiments described above, followed by the step of opening the isolator.

[0067] The features and advantages of the circuit interruption assembly and its embodiments of the second aspect of the present invention, with necessary modifications, are applied to the method and its embodiments of the fifth aspect of the present invention.

[0068] According to a sixth aspect of the invention, a method for operating a circuit interruption assembly is provided, the circuit interruption assembly comprising a plurality of circuit interruption devices, each circuit interruption device being according to any one of the first aspect of the invention and the embodiments described above, wherein the method comprises the following steps:

[0069] According to the method of the fourth aspect of the invention and any of the embodiments described above, each circuit interruption device is operated; and the switching of the switching elements of each circuit interruption device is selectively controlled such that the circuit interruption devices initiate the same operating mode at the same time or at different times.

[0070] The features and advantages of the circuit interruption assembly and its embodiments of the third aspect of the present invention, with necessary modifications, are applied to the method and its embodiments of the sixth aspect of the present invention.

[0071] Preferably, multiple circuit interruption devices are connected in series.

[0072] In the method of the sixth aspect of the invention, at least one of the multiple circuit interruption devices may have the same or different voltage rating as at least one other circuit interruption device of the multiple circuit interruption devices.

[0073] In the method of the sixth aspect of the invention, at least one of the multiple circuit interruption devices may have the same or different energy storage device rating as at least one other interruption device of the multiple interruption devices.

[0074] In the context of describing the connection of two electrical components, elements, or parts, the terms "across" and "in parallel" are used interchangeably. For example, if an electrical component is connected across another electrical component, then the electrical component is connected in parallel with the other electrical component.

[0075] It will be understood that the controller can be implemented as a single control unit or multiple control units. For example, the controller may include multiple control units, each configured to control a corresponding switching element of a circuit interruption device. Each control unit may be configured to communicate with at least one other control unit via a telecommunications link.

[0076] In embodiments employing multiple controllers, the controllers may be implemented as individual controllers or as part of the same control system. Each controller may be configured to communicate with at least one other controller via a telecommunications link. When the controllers are implemented as part of the same control system, each controller may be configured to communicate with a central controller via a telecommunications link.

[0077] It will be understood that the terms “first” and “second” used in this patent specification are intended only to help distinguish similar features (e.g., first terminal and second terminal, first current conduction branch portion, second current conduction branch portion and third current conduction branch portion, first operating mode, second operating mode, third and fourth operating modes, etc.) and are not intended to indicate the relative importance of one feature to another, unless otherwise specified.

[0078] Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples, and alternatives set forth in the foregoing paragraphs and claims and / or the following description and drawings, and in particular their individual features, may be employed independently or in any combination. That is, all embodiments and all features of any embodiment may be combined in any manner and / or combination unless such features are incompatible. The applicant reserves the right to accordingly modify any originally filed claim or to file any new claim, including the right to modify any originally filed claim to depend on any feature of any other claim and / or incorporate any feature of any other claim, although not originally claimed in that manner. Attached Figure Description

[0079] Preferred embodiments of the invention will now be described by way of non-limiting example, with reference to the following figures, in which:

[0080] Figure 1 A circuit interruption device according to a first embodiment of the present invention is shown;

[0081] Figures 2a to 2f Illustration Figure 1 The current interruption operation of the circuit interruption device;

[0082] Figures 3a to 3c Illustration Figure 1 The electrical behavior of the circuit interruption device during current interruption operation;

[0083] Figure 4 A circuit interruption device according to a second embodiment of the present invention is shown; and

[0084] Figure 5 A circuit interruption assembly according to a third embodiment of the invention is shown.

[0085] The accompanying drawings are not necessarily to scale, and some features and views in the drawings are shown to scale or in schematic form for clarity and simplicity. Detailed Implementation

[0086] The circuit interruption device according to the first embodiment of the present invention Figure 1 It is shown in the figure and is usually specified by reference number 20.

[0087] The circuit interruption device 20 is a circuit breaker that includes first and second terminals 22 and 24, a current conduction branch, a first energy dissipation or absorption device 26, a first current bypass path and second current bypass paths 28 and 30, and a controller 32. In use, the first and second terminals 22, 24 are connected to corresponding DC electrical circuits or networks 34.

[0088] The current conduction branch includes a first current conduction branch section, a second current conduction branch section, and a third current conduction branch section, which are continuously connected in series between the first terminal and the second terminals 22 and 24. The first, second, and third current conduction branch sections each include a first switching element 36, a second switching element 38, and a third switching element 40, respectively. In this way, each switching element 36, 38, and 40 is configured to be switchable to selectively allow and block the flow of current in its respective current conduction branch section.

[0089] Each of the first and third switching elements 36, 40 is a low-voltage bidirectional electronic switching element having parallel-connected energy dissipation or absorption devices 37, 41, such as nonlinear resistors and / or surge arresters. The second switching element 38 is a high-voltage mechanical switching element. Non-limiting examples of electronic and mechanical switching elements are described in other parts of this specification. It is contemplated that in other embodiments of the invention, each of the first and third electronic switching elements may include multiple electronic switching devices (e.g., electronic switching devices connected in series and / or in parallel), and / or the second mechanical switching element may include multiple mechanical switches (e.g., mechanical switches connected in series and / or in parallel).

[0090] The first energy dissipation or absorption device 26 is connected across the second current conduction branch. The first energy dissipation or absorption device 26 takes the form of a zinc oxide surge arrester, but in other embodiments it may take the form of another type of resistive element.

[0091] A first current bypass path 28 is connected across the first and second current conduction branches. A second current bypass path 30 is connected across the second and third current conduction branches. The first and second current bypass paths 28 and 30 respectively include a first energy storage device and second energy storage devices 42 and 44. Each energy storage device 42 and 44 is a capacitor, but in other embodiments it may take the form of another type of device capable of storing and releasing energy to selectively provide voltage, such as a fuel cell or a battery.

[0092] The controller 32 is configured (e.g., programmed) to selectively open and close each switching element 36, 38, 40 to control the flow of current in the corresponding current conduction branch, and thereby control the flow of current between the first terminal and the second terminals 22, 24.

[0093] Figure 1 The operation reference for the circuit interruption device 20 Figures 2a to 2f and Figures 3a to 3c The description is as follows.

[0094] During normal operation, the circuit interruption device 20 is operated in the first operating mode by closing the first, second, and third switching elements 36, 38, and 40, allowing current 46 to flow through the first, second, and third current conduction branches, while preventing it from flowing through the current bypass paths 28 and 30. Figure 2a As shown, this allows current 46 to flow freely between the first terminal and the second terminals 22, 24, thereby permitting the normal operation of the associated DC electrical circuit or network 34.

[0095] There may be a requirement to interrupt the flow of current in the associated DC electrical circuit or network 34 under certain circumstances (such as a fault or other abnormal operating condition that causes a high fault current in the DC electrical circuit or network 34, a shutdown of the DC electrical circuit or network 34, and repair, testing or maintenance of the DC electrical circuit or network 34).

[0096] like Figure 2bAs shown, the second mechanical switching element 38 is then opened, which causes an electric arc 48 to be induced between the contacts of the second mechanical switching element 38. The presence of the electric arc 48 means that the current 46 continues to flow through the first current conduction branch, the second current conduction branch, and the third current conduction branch between the first terminal and the second terminals 22, 24.

[0097] After sufficient separation gap is achieved between the contacts of the second mechanical switching element 38, the first electronic switching element and the third electronic switching elements 36 and 40 are opened in the second operating mode of the circuit interruption device 20. The time between the opening of the second mechanical switching element 38 and the opening of the first electronic switching element and the third electronic switching elements 36 and 40 is kept as short as possible to minimize arc corrosion of the contacts of the second mechanical switching element 38.

[0098] Therefore, in such Figure 2c In the second operating mode shown, current 46 is blocked from flowing through the first and third current conduction branches, causing current 46 to flow through capacitors 42 and 44 in the current bypass paths 28 and 30. Due to the configuration of the current bypass paths 28 and 30, the direction of current 46 flowing through the second mechanical switching element 38 is reversed, thus forcing zero current in the second mechanical switching element 38 and thereby allowing the arc 48 in the second mechanical switching element 38 to be extinguished. The time required to achieve the forced current to zero is determined by the voltage ratings of the first and third electronic switching elements 36 and 40, and the capacitance values ​​of the first and second capacitors 42 and 44.

[0099] exist Figure 2d In the third operating mode of the circuit interruption device 20 shown, the current flowing through capacitors 42 and 44 will create a corresponding voltage across each capacitor of capacitors 42 and 44, which, once reaching the voltage rating of the nonlinear resistors or surge arresters 37 and 41 connected in parallel in the first and third current conduction branches, will cause the current 46 flowing between the first and second terminals 22 and 24 to flow through the two parallel circuits. Additionally or alternatively, in Figure 2d In the third operating mode of the circuit interruption device 20 shown, the controlled closing of the first and third electronic switching elements 36 and 40 allows the current 46 flowing between the first terminal and the second terminals 22 and 24 to flow through two parallel circuits. The first parallel circuit includes a first current conduction branch and a second current bypass path 30. The second parallel circuit includes a third current conduction branch and a first current bypass path 28. Simultaneously, the current 46 continues to be blocked from flowing through the second current conduction branch.

[0100] The first and second capacitors 42 and 44 are charged by the flow of current 46 through two parallel circuits, such that each capacitor 42 and 44 provides a reverse voltage against the flow of current 46 through the respective parallel circuit. In this way, the combined first and second capacitors 42 and 44 can be charged to provide a sufficiently high reverse voltage to stop the flow of current 46 between the first and second terminals 22 and 24. During this period, the rate of change of voltage across the second mechanical switching element 38 is determined by the capacitance values ​​of the first and second capacitors 42 and 44 and the amplitude of the current 46 flowing between the first and second terminals 22 and 24, and can be set to a value suitable for the capability of the contacts of the second mechanical switching element 38.

[0101] Following the third operating mode Figure 2e The circuit interruption device 20 shown in the diagram has a fourth operating mode in which the first and third electronic switching elements 36, 40 are closed to allow current to flow through them, or are opened to allow current to flow through corresponding parallel-connected nonlinear resistors or surge arresters 37, 41, and the second mechanical switching element 38 remains open. In this fourth operating mode, current 46 is prevented from flowing through the second current conduction branch and current bypass paths 28, 30 due to the open second mechanical switching element 38 and the charged first and second capacitors 42, 44, while current 46 is allowed to flow through the first and third current conduction branches and the first energy dissipation or absorption device 26. This allows the first energy dissipation or absorption device 26 to absorb energy to limit the voltage of the second current conduction branch, and thereby limit the total voltage of the circuit interruption device 20 to an acceptable value.

[0102] Figure 2f This shows the state of the circuit interruption device 20 when the current 46 is successfully interrupted.

[0103] Figure 3a Figures a, b, c, d, and e respectively illustrate the variation in the contact voltage 100 of the second mechanical switching element 38 (Figure a), the variation in the contact current 102 of the second mechanical switching element 38 (Figure b), the variation in the current 104 flowing between the first terminal and the second terminals 22, 24 (Figure c), and the variation in the voltage and current 106, 108 of each electronic switching element 36, 40 (Figure d), as well as the variation in... Figure 1 The change in voltage 110 of each capacitor 42, 44 during the opening of the circuit interruption device 20 (Figure e). Figure 3b Charts a, b, and c correspond to Figure 3a Charts a, b, and c, but based on an expanded timescale. Figure 3c Charts a and b correspond Figure 3aand Figure 3b Charts a and b, but based on a further expanded timescale.

[0104] from Figures 3a to 3c It can be seen that the reduction of the current 110 flowing between the first terminal and the second terminals 22 and 24 of the circuit interruption device 20 is achieved by the combination of opening the second mechanical switch element 38, opening the first electronic switch element and the third electronic switch elements 36 and 40, and charging the capacitors 42 and 44 to provide a reverse voltage.

[0105] therefore, Figure 1 The circuit interruption device 20 is configured to provide current limiting or interruption functionality by controlling switching elements 36, 38, 40 and using passive components 42, 44 to create alternative current paths for the current 46 flowing between the first terminal and the second terminals 22, 24 (which forces the current to zero and thereby enables the second mechanical switching element 48 to be turned off). Figure 1 Such a configuration of the circuit interrupt device 20 requires fewer switching components than conventional circuit interrupt devices to perform the function of limiting or interrupting current, thus providing a relative reduction in size, weight, cost and conduction losses.

[0106] The circuit interruption device according to the second embodiment of the present invention... Figure 4 It is shown in the figure and is usually specified by reference number 120. Figure 4 The circuit interrupt device 120 is structurally and operationally similar to... Figure 1 The circuit interruption device 20 is similar, and similar features share the same reference numerals.

[0107] Figure 4 Circuit interruption device 120 and Figure 1 The difference between the circuit interruption device 20 and the circuit interruption device 20 is that, Figure 4 The circuit interruption device 120 includes a third current bypass path connected across the first and second terminals 22, 24. The third current bypass path 50 includes a third energy storage device 52, which is a capacitor, but in other embodiments may take the form of another type of device capable of storing and releasing energy to selectively provide voltage, such as a fuel cell or a battery.

[0108] During the operation of the circuit interruption device 120 to stop the flow of current between the first and second terminals 22, 24, current 46 flows through the third current bypass path 50 to charge the third capacitor 52, thereby providing a reverse voltage against the flow of current between the first and second terminals 22, 24. Including the third capacitor 52 alongside the first and second capacitors 42, 44 in the circuit interruption device 120 has the following effects: reducing the overall capacitance requirement of the circuit interruption device 120, thus providing cost, size, and weight savings.

[0109] Figure 1 and Figure 4 The circuit interruption device 20, 120 may include at least one of the following:

[0110] A second energy dissipation or absorption device connected across the first and second terminals 22, 24;

[0111] • A third energy dissipation or absorption device connected across the first current bypass path 28;

[0112] ●A fourth energy dissipation or absorption device connected across the second current bypass path 30.

[0113] Each of the second, third, and fourth energy dissipation or absorption devices takes the form of a zinc oxide surge arrester, but in other embodiments may take the form of a different type of resistive element.

[0114] The circuit interruption devices 20 and 120 include one, some, or all of a second, third, and fourth energy dissipation or absorption device to absorb energy and limit the total voltage of the circuit interruption devices 20 and 120 to an acceptable value.

[0115] exist Figure 1 and Figure 4 In either of the circuit interruption devices 20 and 120, it may be required that one or each surge arrester 26 be set to a value that causes residual current flow when the circuit interruption device is turned on, which may result in unacceptable heating of the one or each surge arrester 26. Connecting the circuit interruption devices 20 and 120 in series with at least one isolator enables the operation of the one or each isolator to isolate the circuit interruption devices 20 and 120 from one or more DC electrical circuits or networks 34 to prevent the flow of residual current.

[0116] Higher voltage ratings for circuit interruption devices 20, 120 can be achieved by increasing the voltage ratings of their individual components. An alternative is to use two or more circuit interruption devices 20, 120 connected in series, each configured to have a voltage rating less than the total required voltage rating.

[0117] According to the third embodiment of the present invention, the voltage interruption assembly 54 is in Figure 5 As shown in the image.

[0118] The circuit interruption assembly 54 includes a plurality of circuit interruption devices connected in series, each of which is generally designated by reference numeral 220. Each circuit interruption device 220 is structurally and operationally similar to... Figure 1 or Figure 4 The circuit interruption devices 20 and 120 are similar, and similar features share the same reference numerals. In the illustrated embodiment, the circuit interruption assembly 54 includes three circuit interruption devices 220, but in other embodiments, it may include a different number of multiple circuit interruption devices.

[0119] At least one of the multiple circuit interruption devices 220 may have the same or different voltage rating as at least one other circuit interruption device of the multiple circuit interruption devices 220. At least one of the multiple circuit interruption devices 220 may have the same or different energy storage device rating as at least one other interruption device of the multiple circuit interruption devices 220.

[0120] Each controller 32 of the circuit interruption device 220 is configured to control the switching of the corresponding switching elements 36, 38, 40 of the circuit interruption device 220, such that the circuit interruption devices 220 initiate the same operating mode at the same time or at different times. For example, one or more circuit interruption devices 220 having relatively low voltage ratings and relatively high capacitance ratings can be operated to initially limit the flow of high current, followed by operation of one or more other circuit interruption devices 220 having higher voltage ratings and lower capacitance ratings to further limit or stop the current flow reduced by the initial restriction on current flow.

[0121] Figure 1 The configuration of the circuit interruption assembly 54 provides several benefits, such as:

[0122] • The total voltage rating and capacitance value of capacitors 42, 44, and 52 can be reduced in order to reduce the physical size and weight of the circuit interruption assembly 54;

[0123] • When configuring the circuit interruption assembly 54, a modular design approach can be adopted to meet different circuit interruption requirements. For example, the number of circuit interruption devices 220 can be set according to the voltage rating of the associated DC electrical circuit or network 34;

[0124] ● The circuit interruption assembly 54 may have one or more redundant circuit interruption devices 220, thus providing built-in redundancy to improve the availability of current limiting or interruption functions;

[0125] ● The circuit interruption assembly 54 includes multiple circuit interruption devices 220, which allow one or more individual circuit interruption devices 220 to operate in service for routine testing purposes without eliminating current limiting or the availability of interruption functionality.

[0126] ● The ratings of individual components of each circuit interruption device 220 can be designed to optimize the current limiting or interruption function of the circuit interruption assembly 54.

[0127] ● The operation of the circuit interruption device 220 can be coordinated, for example, in terms of timing, to provide a wide range of current limiting or interruption functions, such as:

[0128] ο Modify the profile of the current 46 flowing between the first terminal and the second terminals 22, 24 in order to, for example, modify any associated transient overvoltages;

[0129] The current 46 flowing between the first terminal and the second terminals 22, 24 is temporarily limited rather than interrupted to allow fault location to be identified;

[0130] In the event of a fault operation, the current limiting or interruption operation is aborted.

[0131] The above embodiments of the invention have been described with reference to DC circuit interruption devices; however, it will be appreciated that the above embodiments of the invention can be applied to AC circuit interruption devices with necessary modifications. Such AC circuit interruption devices are configured to conduct and interrupt alternating current flow. This is achieved by constructing each of the first and third switching elements as a bidirectional switching element. For example, each of the first and third switching elements may be configured as or comprise a pair of anti-parallel connected switching devices.

[0132] Unless the context otherwise indicates, the preference and options of a given aspect, feature, or parameter of the invention should be regarded as any and all preferences and options in combination with all other aspects, features, and parameters of the invention being disclosed.

Claims

1. A circuit interruption device, comprising: The first terminal and the second terminal (22, 24) are used for connection to the corresponding electrical circuit or network (34) in use; A current conduction branch includes a first current conduction branch portion, a second current conduction branch portion, and a third current conduction branch portion connected in series between the first terminal and the second terminal (22, 24). The first current conduction branch portion includes a first switching element (36), the second current conduction branch portion includes a second switching element (38), and the third current conduction branch portion includes a third switching element (40). Each switching element (36, 38, 40) is configured to be switchable to selectively allow and block the flow of current (46) in the corresponding current conduction branch portion. A first current bypass path and a second current bypass path (28, 30), wherein the first current bypass path (28) is connected across the first current conduction branch portion and the second current conduction branch portion, and the second current bypass path (30) is connected across the second current conduction branch portion and the third current conduction branch portion; and A controller (32) configured to selectively control the switching of the switching elements (36, 38, 40) to control the flow of current (46) between the first terminal and the second terminal (22, 24), such that: (i) In the first operating mode of the circuit interruption device, the current (46) is permitted to flow through the first current conduction branch, the second current conduction branch and the third current conduction branch, but is prevented from flowing through the current bypass path (28, 30). as well as (ii) In the second operating mode of the circuit interruption device, the current (46) is blocked from flowing through the first current conduction branch and the third current conduction branch, but is allowed to flow through the current bypass path (28, 30) so as to reverse the direction of the current (46) flowing through the second current conduction branch.

2. The circuit interruption device as claimed in claim 1, wherein, The controller (32) is configured to selectively control the switching of the switching elements (36, 38, 40) to control the flow of current (46) between the first terminal and the second terminal (22, 24), such that in the third operating mode of the circuit interruption device, the current (46) is blocked from flowing through the second current conduction branch portion, but is allowed to flow through the first current conduction branch portion and the third current conduction branch portion and the current bypass path (28, 30).

3. The circuit interruption device as described in any of the preceding claims, wherein, The first current bypass path (28) includes a first energy storage device (42), and / or the second current bypass path includes a second energy storage device (44).

4. The circuit interruption device according to any one of claims 1-2, comprising a third current bypass path (50) connected across the first terminal and the second terminal (22, 24), the third current bypass path (50) comprising a third energy storage device (52).

5. The circuit interruption device according to any one of claims 1-2, comprising a first energy dissipation or absorption device (26) connected across the second current conduction branch portion, wherein the controller (32) is configured to selectively control the switching of the switching elements (36, 38, 40) to control the flow of current (46) between the first terminal and the second terminal (22, 24), such that in a fourth operating mode of the circuit interruption device, the current (46) is blocked from flowing through the second current conduction branch portion and the current bypass path (28, 30), but is permitted to flow through the first current conduction branch portion and the third current conduction branch portion and the first energy dissipation or absorption device (26).

6. The circuit interruption device according to any one of claims 1-2, comprising at least one of the following: ● A second energy dissipation or absorption device connected across the first terminal and the second terminal (22, 24); ●A third energy dissipation or absorption device connected across the first current bypass path (28); ●A fourth energy dissipation or absorption device connected across the second current bypass path (30); • A fifth energy dissipation or absorption device connected to the first switching element across the first current conduction branch; • A sixth energy dissipation or absorption device connected to the third switching element across the third current conduction branch.

7. The circuit interruption device according to any one of claims 1-2, wherein, Each of the first switching element and the third switching element (36, 40) is a unidirectional switching element, or each of the first switching element and the third switching element (36, 40) is a bidirectional switching element.

8. A circuit interruption assembly comprising at least one circuit interruption device connected in series with at least one isolator, wherein the at least one circuit interruption device is in accordance with any of the preceding claims.

9. A circuit interruption assembly (54) comprising a plurality of circuit interruption devices, each circuit interruption device according to any one of claims 1 to 7, wherein each controller (32) of the circuit interruption device is configured to control the switching of the switching element (36, 38, 40) of the corresponding circuit interruption device, such that the circuit interruption devices initiate the same operating mode at the same time or at different times.

10. The circuit interruption assembly (54) as claimed in claim 9, wherein, At least one of the plurality of circuit interruption devices has the same or different voltage rating as at least one other circuit interruption device of the plurality of circuit interruption devices.

11. The circuit interruption assembly (54) as claimed in claim 9 or claim 10, wherein, The first current bypass path (28) includes a first energy storage device (42), and / or the second current bypass path includes a second energy storage device (44), wherein at least one of the plurality of circuit interruption devices has the same or different energy storage device ratings as at least one other circuit interruption device of the plurality of circuit interruption devices.

12. The circuit interruption assembly (54) of claim 9 or claim 10, comprising a third current bypass path (50) connected across the first terminal and the second terminal (22, 24), the third current bypass path (50) comprising a third energy storage device (52), wherein, At least one of the plurality of circuit interruption devices has the same or different energy storage device rating as at least one other circuit interruption device of the plurality of circuit interruption devices.

13. A method of operating a circuit interruption device, the circuit interruption device comprising: The first terminal and the second terminal (22, 24) are used for connection to the corresponding electrical circuit or network (34) in use; A current conduction branch includes a first current conduction branch portion, a second current conduction branch portion, and a third current conduction branch portion connected in series between the first terminal and the second terminal (22, 24). The first current conduction branch portion includes a first switching element (36), the second current conduction branch portion includes a second switching element (38), and the third current conduction branch portion includes a third switching element (40). Each switching element (36, 38, 40) is configured to be switchable to selectively allow and block the flow of current (46) in the corresponding current conduction branch portion. as well as A first current bypass path and a second current bypass path (28, 30), wherein the first current bypass path (28) is connected across the first current conduction branch portion and the second current conduction branch portion, and the second current bypass path (30) is connected across the second current conduction branch portion and the third current conduction branch portion. The method includes the following steps: In the first operating mode of the circuit interruption device, the switching of the switching elements (36, 38, 40) is selectively controlled such that the flow of current (46) between the first terminal and the second terminal (22, 24) is permitted to flow through the first current conduction branch, the second current conduction branch and the third current conduction branch, while being blocked from flowing through the current bypass path (28, 30). as well as In the second operating mode of the circuit interruption device, the switching elements (36, 38, 40) are selectively controlled such that the current (46) is blocked from flowing through the first current conduction branch and the third current conduction branch, but is allowed to flow through the current bypass path (28, 30), so as to reverse the direction of the current (46) flowing through the second current conduction branch.

14. The method of claim 13, comprising the step of selectively controlling the switching of the switching elements (36, 38, 40) in a third operating mode of the circuit interruption device such that the current (46) is blocked from flowing through the second current conduction branch portion, but is permitted to flow through the first current conduction branch portion and the third current conduction branch portion and the current bypass path (28, 30).

15. A method of operating a circuit interruption assembly, the circuit interruption assembly comprising at least one circuit interruption device connected in series with at least one isolator, the at least one circuit interruption device according to any one of claims 1 to 7, the method comprising the steps of: operating the at least one circuit interruption device according to the method of claim 13 or claim 14, followed by the step of opening the at least one isolator.

16. A method of operating a circuit interruption assembly (54), the circuit interruption assembly (54) comprising a plurality of circuit interruption devices, each circuit interruption device according to any one of claims 1 to 7, wherein the method comprises the following steps: Operate each circuit interruption device according to the method of claim 13 or claim 14; and The switching elements (36, 38, 40) of each circuit interruption device are selectively controlled so that the circuit interruption devices initiate the same operating mode at the same time or at different times.

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