Dc solid state air gap with shunt multi-pole switch

Abstract

A unidirectional direct current (DC) switching circuit includes a disconnect switch and an interrupt circuit connected in series with the disconnect switch. The interrupt circuit includes a parallel connection of a current steering branch, a bypass power electronics branch, a gate drive branch, and an energy absorption branch. The current steering branch includes a multi-throw switch configured for operation in a first position for establishing a first electrical connection between the current steering branch and a load and a second position for establishing a second electrical connection that turns off the bypass power electronics branch.

Description

Technical Field

[0001] This disclosure generally relates to DC solid-state switching circuits, and more specifically, to a DC switching circuit including a solid-state auxiliary air gap having multiple-throw switches connected in parallel. Background Technology

[0002] In today's electricity distribution, the vast majority of electrical applications use alternating current (AC) power. The ever-increasing power output of renewable energy and energy storage systems necessitates high-voltage direct current (DC) switching and protection devices. In recent years, 600 VDC, 1000 VDC, and 1500 VDC have been used in applications such as electric vehicle charging, battery storage, and utility-scale solar power generation. Switching and interrupting at these high voltage levels becomes increasingly difficult due to the absence of zero-crossing points compared to AC systems. Techniques based on power electronics have been proposed for these high-voltage DC systems because the interruption of power electronic devices is independent of zero-crossing points.

[0003] Voltage systems utilizing power-based electronics have been developed, employing solid-state power electronics to open and close circuits and solid-state auxiliary air gaps. However, as voltage increases, especially at 1500 VDC, the choice of main power electronics becomes limited, and these devices are typically designed for higher voltage systems, resulting in high cost and structural complexity. Furthermore, while constructing solid-state auxiliary air gaps is efficient, they are still designed to be driven by low-voltage control signals. Consequently, isolation between the high-voltage system voltage and the low-voltage control signal becomes challenging. Summary of the Invention

[0004] According to a non-limiting embodiment, a unidirectional direct current (DC) switching circuit includes an isolating switch and an interrupt circuit connected in series with the isolating switch. The interrupt circuit includes a parallel connection of a current-directing branch, a bypass power electronics branch, a gate drive branch, and an energy absorption branch. The current-directing branch includes a multi-throw switch configured to operate in a first position and a second position. The first position establishes a first electrical connection between the current-directing branch and a load, and the second position establishes a second electrical connection that turns off the bypass power electronics branch.

[0005] According to another non-limiting embodiment, a bidirectional direct current (DC) switching circuit includes a main current path, an isolating switch, a forward current interruption subcircuit, a reverse current interruption subcircuit, and a multi-break switch. The main current path includes a voltage source segment and a load segment and is configured to supply load current to the load. The isolating switch is configured to selectively open or close the air gap between the voltage source and the voltage source segment. The forward current interruption subcircuit includes a forward current input connected to both the isolating switch and the voltage source segment, and the reverse current interruption subcircuit includes a reverse current input connected to the load segment. The multi-break switch is configured to operate in a first position and a second position, the first position connecting the voltage source segment and the load segment to establish the main current path, and the second position establishing a connection that shuts off one or both of the forward and reverse current interruption subcircuits.

[0006] According to another non-limiting embodiment, a method is provided for interrupting current supplied to a load connected to a direct current (DC) solid-state switching circuit. The method includes: supplying load current to the load through a main current path comprising a voltage source segment and a load segment; and operating an isolating switch to selectively open or close an air gap between the voltage source and the voltage source segment. The method further includes: operating a multiple-break switch in a first position that connects the voltage source segment and the load segment to establish a main current path; and operating the multiple-break switch in a second position that connects a forward current interruption sub-circuit and a reverse current interruption sub-circuit to establish a current bypass path that interrupts the main current path. Attached Figure Description

[0007] To gain a more complete understanding of this disclosure and its advantages, reference will now be made to the following description taken in conjunction with the accompanying drawings, wherein similar reference numerals denote similar objects.

[0008] Figure 1 A DC unidirectional switching circuit according to a non-limiting embodiment of the present disclosure is shown, the DC unidirectional switching circuit including an interrupt circuit that implements a solid-state auxiliary air gap having multiple-throw switches in parallel;

[0009] Figure 2 It shows Figure 1 A DC unidirectional switching circuit that operates under normal conditions to deliver current to the load;

[0010] Figure 3 The diagram shows the operation in a state where the multi-throw switch is adjusted to generate an electric arc. Figure 1 A DC unidirectional switching circuit in which the electric arc turns on the solid-state switching component;

[0011] Figure 4A DC unidirectional switching circuit is shown that directs current through a current bypass path, which is established when the solid-state switching component is turned on.

[0012] Figure 5 A DC unidirectional switching circuit is shown that directs current through an energy absorption path established after a multi-throw switch turns off the solid-state switching components; and

[0013] Figure 6 The diagram shows a DC unidirectional switching circuit after the disconnecting switch has been disconnected to isolate the interrupt circuit and load from the voltage source;

[0014] Figure 7 A DC unidirectional switching circuit according to another non-limiting embodiment of the present disclosure is shown, the DC unidirectional switching circuit including an interrupt circuit that implements a solid-state auxiliary air gap having multiple-throw switches in parallel;

[0015] Figure 8 A DC bidirectional switching circuit according to another non-limiting embodiment of the present disclosure is shown, the DC bidirectional switching circuit including an interrupt circuit that implements a forward current interrupt sub-circuit and a reverse current interrupt sub-circuit activated using a multi-breakpoint switch;

[0016] Figure 9 It shows Figure 8 A DC bidirectional switching circuit that operates under normal conditions to deliver current to the load in the positive direction;

[0017] Figure 10 A DC bidirectional switching circuit is shown operating in a state where a multi-break switch is adjusted to generate an electric arc, which turns on a first solid-state switching component.

[0018] Figure 11 A DC bidirectional switching circuit is shown that directs current in the positive direction through a first current bypass path, which is established when a first solid-state switching component is turned on.

[0019] Figure 12 A DC bidirectional switching circuit is shown that directs current along a first direction through an energy absorption path, which is established after a multi-break switch turns off a first solid-state switching component.

[0020] Figure 13 The diagram shows a DC bidirectional switching circuit after the isolating switch has been disconnected to isolate the interrupt circuit and load from the voltage source.

[0021] Figure 14 This illustrates a DC bidirectional switching circuit operating in normal conditions to deliver current in the reverse direction;

[0022] Figure 15 A DC bidirectional switching circuit is shown operating in a state where a multi-break switch is adjusted to generate an electric arc, which turns on a second solid-state switching component.

[0023] Figure 16 A DC bidirectional switching circuit is shown that directs current in the reverse direction through a second current bypass path, which is established when the second solid-state switching component is turned on.

[0024] Figure 17 A DC bidirectional switching circuit is shown that directs current in the reverse direction through an energy absorption path, which is established after a multi-break switch turns off a second solid-state switching component.

[0025] Figure 18 This illustrates a DC bidirectional switching circuit after the isolating switch has been disconnected to isolate the interrupt circuit and load from the voltage source; and

[0026] Figure 19 A flowchart is shown illustrating a method for interrupting the current supplied to a load connected to a DC solid-state switching circuit. Detailed Implementation

[0027] Now, various techniques related to providing systems and methods for DC switching circuits including solid-state auxiliary air gaps with parallel multi-throw switches are described with reference to the accompanying drawings. Throughout this specification, similar reference numerals denote similar elements. The drawings discussed below, as well as the various embodiments used in this patent document to describe the principles of this disclosure, are for illustrative purposes only and should not be construed as limiting the scope of this disclosure in any way. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitably arranged device. It should be understood that functions described as being performed by certain system elements may be performed by multiple elements. Similarly, for example, an element may be configured to perform functions described as being performed by multiple elements. Numerous inventive teachings of this application will be described with reference to non-limiting exemplary embodiments.

[0028] To aid in understanding the embodiments, principles, and features of this disclosure, the embodiments, principles, and features of this disclosure will be described below with reference to implementations in illustrative embodiments. In particular, the embodiments, principles, and features of this disclosure will be described in the context of a DC switching circuit including a solid-state auxiliary air gap with parallel multi-throw switches. However, the embodiments of this disclosure are not limited to use in the described apparatus or method.

[0029] The components and materials described below that constitute various embodiments are intended to be illustrative and not limiting. Many suitable components and materials that perform the same or similar functions as the materials described herein are intended to be covered within the scope of embodiments of this disclosure.

[0030] Below, refer to this... Figures 1 to 19 This description includes these and other embodiments of a DC switching circuit according to the present disclosure, comprising a solid-state auxiliary air gap having multiple-throw switches connected in parallel. Similar reference numerals used in the drawings identify similar or identical elements in the various views. The drawings are not necessarily drawn to scale.

[0031] Now refer to Figure 1 A unidirectional DC solid-state switching circuit 100 according to a non-limiting embodiment of the present disclosure is shown. The unidirectional DC solid-state switching circuit 100 includes a solid-state auxiliary air gap having multiple-throw switches connected in parallel. The unidirectional DC switching circuit 100 includes an isolating switch 110 and an interrupt circuit 115 connected in series with the isolating switch 110. The isolating switch 110 is configured to selectively enable a voltage source (see [link to documentation]). Figure 2 The air gap between the interrupt circuit 115 and the interrupt circuit 115 is either opened or closed.

[0032] Interruption circuit 115 includes a parallel connection of current-guiding branch 120, bypass power electronics branch 122, gate drive branch 124, and energy absorption branch 126. Current-guiding branch 120 includes a parallel multi-throw switch 125, which is connected in parallel with, for example, the bypass power electronics branch 122, gate drive branch 124, and energy absorption branch 126. The multi-throw switch 125 is configured to operate in a first position and a second position. The first position establishes a first electrical connection between current-guiding branch 120 and load 104, and the second position establishes a second electrical connection that interrupts the connection between current-guiding branch 120 and load 104 and turns off bypass power electronics branch 122. According to a non-limiting embodiment, the multi-throw switch 125 is a double-throw switch 125, which includes a first terminal (T1) connected to the disconnect switch 110, a second terminal (T2) configured to establish an electrical connection with the load 104, and a third terminal (T3) connected to the gate drive branch 124.

[0033] The bypass power electronic branch 122 includes a power electronic component (Q1) 127 connected in series with a voltage setting component (RVa) 128. The power electronic component 127 can be implemented using various solid-state semiconductor devices or transistors, including, but not limited to, insulated-gate bipolar transistors (IGBTs) and metal-oxide-semiconductor field-effect transistors (MOSFETs).

[0034] The voltage setting component (RVa) 128 includes a first terminal (e.g., a collector terminal) connected to the power electronic component 127. A second terminal of the voltage setting component (RVa) 128 is connected to the gate drive branch 124, the current guiding branch 120, and the energy absorption branch 126. The voltage setting component (RVa) 128 includes, but is not limited to, transient voltage suppression diodes, Zener diodes, resistors, and rheostats such as metal oxide varistors (MOVs). The voltage setting component (RVa) 128 is configured to clamp the voltage present on the bypass power electronic branch 122. The voltage setting component 128 can be selected with operating specifications that allow the power electronic component 127 to operate within a target voltage range that avoids overvoltage damage and / or thermal stress while still applying a voltage amount sufficient to turn on the power electronic component 127.

[0035] The gate drive branch 124 includes a series connection of a resistor (R1) 130, a diode (D1) 132, and a Zener diode (Z1) 134. The resistor (R1) 130 includes a first terminal, which is connected to the first terminal of the voltage setting component (RVa) 128, the current guiding branch 120, and the energy absorption branch 126. The second terminal of the resistor (R) 130 is connected to the anode of the diode (D1) 132.

[0036] Zener diode (Z1) 134 includes a cathode that is connected to both a multi-throw switch (e.g., third terminal T3) and the cathode of diode (D1). The anode of Zener diode (Z1) 134 is connected to both a power electronic component 127 (e.g., the emitter terminal) and a multi-throw switch (e.g., second terminal T2). According to a non-limiting embodiment, a gate resistor 136 may be connected between the gate drive branch 124 and the power electronic component 127. For example, a first terminal of the gate resistor 136 may be connected to a first power electronic component 127 (e.g., a gate terminal), and a second terminal of the gate resistor 136 may be connected to both the cathode of diode (D1) 132, the cathode of Zener diode (Z1) 134, and the multi-throw switch 125 (e.g., third terminal T3).

[0037] Energy absorption branch 126 includes an energy absorption device 160 having a first terminal connected to a disconnect switch 110, a multi-throw switch 125 (e.g., first terminal T1), a first terminal of a resistor 130, and a first terminal of a voltage setting component (RVa) 128. A second terminal of energy absorption branch 126 is connected to the multi-throw switch 125 (e.g., second terminal T3), the anode of a Zener diode 134, and a power electronic component 127 (e.g., emitter). The energy absorption device 160 can be implemented using various components, including but not limited to transient voltage suppressor (TVS) diodes, metal-oxide-semiconductor rheostats (MOVs), and snubber circuits.

[0038] Now refer to Figures 2 to 6 The operation of the unidirectional DC solid-state switch circuit 100 will be described according to one or more non-limiting embodiments of this disclosure. Figure 2 The diagram shows the DC unidirectional circuit 100 connected to a voltage source 101 and operating under normal conditions. Accordingly, the guide branch 120 supplies current to the load 104 via a closed disconnect switch 110 and a multi-throw switch 125 adjusted to its first position (e.g., connecting terminals T1 and T2 together).

[0039] Go to Figure 3 The diagram illustrates a DC unidirectional switching circuit 100 following the adjustment of a multi-throw switch 125 from its first position (e.g., connecting terminals T1 and T2) to its second position (connecting terminals T2 and T3) to activate an interrupt circuit 115. The initial adjustment of the multi-throw switch 125 (e.g., between T1 and a movable switch plate connected to T2) generates an arc 123 with an arc voltage that continues to guide current through the guide branch 120.

[0040] To extinguish the arc 123, current is diverted to a bypass power electronic branch 122, which establishes a bypass current path based on the operating state of the power electronic component (Q1) 127. For example, when the threshold voltage Vge (e.g., the voltage between the gate (g) and emitter (e)) is below a specific ON voltage threshold for the power electronic component (Q1) 127, the power electronic component (Q1) 127 is in an OFF state. Accordingly, when no arc 123 is generated, no voltage is applied to the gate (g), thereby turning off the power electronic component (Q1) 127.

[0041] As described here, the arc voltage generated when the multi-throw switch 125 is adjusted to its second position is used to turn on the power electronic component (Q1) 127. For example, when the multi-throw switch 125 is initially adjusted from its first position (e.g., moved away from terminal T1), a voltage drop (e.g., 15V-20V) is generated. This voltage drop applies a voltage to the gate drive branch 124 and (e.g., through the gate resistor 136) to the gate (g), which increases as the switch plate moves closer to terminal T3 to establish the second position of the switch. Once the arc voltage exceeds this voltage threshold (Vge), the power electronic component (Q1) 127 is turned on, and the gate drive branch becomes conductive. As the arc 123 intensifies, the gate voltage (e.g., the voltage across the gate resistor 136) reaches a voltage level that turns on the Zener diode 134. When turned on, the Zener diode 134 maintains the voltage threshold (Vge) at a target level to avoid damaging the power electronic component (Q1) 127.

[0042] According to embodiments of this disclosure, although an arc 123 may establish a voltage between the gate and emitter, current may not yet have been switched to the bypass power electronic branch 122 because the initial voltage level is below the threshold voltage (Vge) of the power electronic component (Q1) 127. That is, the bypass power electronic branch 122 can only conduct current after the arc voltage is greater than the voltage drop on the bypass power electronic branch 124 (e.g., the sum of the clamping voltage established by the voltage setting component (RVa) 128 and the voltage drop of the power electronic component (Q1) 127 after receiving current).

[0043] Go to Figure 4 This diagram illustrates a DC unidirectional switching circuit 100 that directs current through a current bypass path established when power electronic component (Q1) 127 is turned on. As described herein, a voltage setting component (RVa) 128 is configured to clamp the voltage present on the bypass power electronic branch 122. Accordingly, the clamping voltage drop on the bypass power electronic branch 122 maintains the gate voltage (e.g., the voltage across the gate resistor 136) at a level above a threshold voltage (Vge) so that power electronic component (Q1) 127 remains on after the arc 123 is extinguished, without damaging power electronic component (Q1) 127. If, for example, the bypass power electronic branch 122 only contains power electronic component (Q1) 127 and the voltage setting component (RVa) 128 is omitted, the gate voltage will drop to a low level, and no current will be directed or only a very small amount of current will be directed. In addition, power electronic component (Q1) 127 will be subjected to high thermal stress and may fail.

[0044] Now refer to Figure 5The diagram illustrates a DC unidirectional switching circuit 100 that directs current through an energy absorption branch 126 once the power electronic component (Q1) 127 is turned off. According to a non-limiting embodiment, the multi-throw switch 125 eventually reaches its second position, establishing an electrical connection between the third terminal T3 and the second terminal T2, which short-circuit the gate of the power electronic component (Q1) 127. Accordingly, the threshold voltage (Vge) is set to 0V (or substantially 0V), causing the power electronic component (Q1) 127 to turn off and forcing current to flow into the energy absorption branch 126. The energy absorption branch 126 delivers current to an energy absorption device 160, where the energy of the current is dissipated, ultimately reducing the current level to zero amperes (0A).

[0045] According to a non-limiting embodiment, the value of the gate resistor 136 can be selected to control the turn-off rate of the power electronic component (Q1) 127. For example, reducing the value of the gate resistor 136 will reduce the time spent turning off the power electronic component (Q1) 127. However, as a trade-off, reducing the value of the gate resistor 136 will result in a lower voltage drop and a higher voltage level applied to the gate of the power electronic component (Q1) 127. Accordingly, the value of the gate resistor 136 can be selected based on the voltage source and load requirements to be used with the unidirectional DC solid-state switch circuit 100.

[0046] Go to Figure 6 The diagram illustrates a DC unidirectional switching circuit 100 after disconnecting the isolating switch 110. Accordingly, the interrupt circuit 115 and the load 104 are electrically isolated from the voltage source 101. Depending on the application of the DC unidirectional switching circuit 100, the isolating switch 110 can be disconnected before, during, or after the current interruption performed by the interrupt circuit 115 described above (e.g., manually).

[0047] Figure 7 A DC unidirectional switching circuit 100 according to another non-limiting embodiment of the present disclosure is shown. For example, the DC unidirectional switching circuit 100 can be extended by adding additional bypass power electronic branches 122a to 122n and / or additional energy absorption branches 126a to 126n. Accordingly, the DC unidirectional switching circuit 100 can be designed to handle higher current levels that different loads 104 may require. Although shown... Figure 7 The DC unidirectional switching circuit 100 shown has two bypass power electronic branches 122a, 122b and two energy absorption branches 126a, 126b, but additional bypass power electronic branches and / or additional energy absorption branches 126a, 126b can be implemented without departing from the scope of the invention.

[0048] Now refer to Figure 8 This illustration shows a DC bidirectional switching circuit 200 including an interrupt circuit 215 according to a non-limiting embodiment of the present disclosure. The DC bidirectional switching circuit 200 includes a main current path 202, an isolating switch 210, a forward current interruption sub-circuit 220, and a reverse current interruption sub-circuit 240. The main current path 202 includes a connection for connecting to a voltage source 201 (see [link to documentation]). Figure 9 The voltage source section 206 and the load section 208 for connecting to the load 204 are included. The disconnecting switch 210 is connected in series with the voltage source section 206 and is configured to selectively open or close the air gap between the voltage source 201 and the main current path 202.

[0049] The forward current interruption subcircuit 220 is connected to the disconnect switch 210 and the voltage source section 206 via the forward current input terminal 222. The forward current interruption subcircuit 220 includes a forward bypass power electronic branch 224 and a forward gate drive branch 226 connected in parallel with the forward bypass power electronic branch 224. The forward bypass power electronic branch 224 includes a first power electronic component (Qf1) 227, which is connected in series with a first voltage setting component (RVfa) 228. According to various non-limiting embodiments, the first power electronic component 227 includes, but is not limited to, IGBTs and MOSFETs.

[0050] The first voltage setting component (RVfa) 228 includes a first terminal connected to the forward current input terminal 222 and a second terminal connected to the first power electronic component 227 (e.g., the collector terminal). The first voltage setting component (RVfa) 228 is configured to clamp a voltage present on the forward bypass power electronic branch 224. The first voltage setting component (RVfa) 228 includes, but is not limited to, transient voltage suppression diodes, Zener diodes, resistors, and rheostats such as metal oxide rheostats (MOVs).

[0051] The forward gate drive branch 226 includes a series connection of a first resistor (Rf1) 230, a first diode (Df1) 232, and a first Zener diode (Zf1) 234. The first resistor (Rf1) 230 includes a first terminal that is connected to both a first terminal of the first voltage setting component (RVfa) 228 and a forward current input terminal 222. A second terminal of the first resistor (Rf1) 230 is connected to the anode of the first diode (Df1) 232. The anode of the first diode (Df1) 232 is further connected to a first power electronic component 227 (e.g., an emitter terminal). According to a non-limiting embodiment, a first gate resistor 236 may be connected between the forward gate drive branch 226 and the first power electronic component 227. For example, the first terminal of the first gate resistor 236 may be connected to the first power electronic component 227 (e.g., a gate terminal), and the second terminal may be connected to both the cathode of the first diode (Df1) 232 and the cathode of the first Zener diode (Zf1) 234.

[0052] The reverse current interruption subcircuit 240 includes a reverse current input terminal 242, which is connected to both the load segment 208 and the load 204. The reverse current interruption subcircuit 240 includes a reverse bypass power electronic branch 243 and a reverse gate drive branch 244 connected in parallel with the reverse bypass power electronic branch 243. The reverse bypass power electronic branch 243 includes a second power electronic component (Qr1) 245 connected in series with a second voltage setting component (RVra) 247. According to one or more non-limiting embodiments, the second power electronic component (Qr1) 245 includes, but is not limited to, IGBTs and MOSFETs.

[0053] The second voltage setting component (RVra) 247 includes a first terminal connected to the reverse current input terminal 242 and a second terminal connected to a second power electronic component 245 (e.g., a collector terminal). The second voltage setting component (RVra) 247 is configured to clamp a voltage present on the reverse bypass power electronic branch 243. According to one or more non-limiting embodiments, the second voltage setting component (RVra) 247 includes, but is not limited to, transient voltage suppression diodes, Zener diodes, resistors, and rheostats such as metal oxide rheostats (MOVs).

[0054] The reverse gate drive branch 244 includes a series connection of a second resistor (Rr1) 246, a second diode (Dr1) 248, and a second Zener diode (Zr1) 250. The second resistor (Rr1) 246 includes a first terminal that is connected to both the first terminal of the second voltage setting component (RVra) 247 and the reverse current input terminal 242. A second terminal of the second resistor (Rr1) 246 is connected to the anode of the second diode (Dr1) 248. The second Zener diode (Zr1) 250 includes a cathode connected to the cathode of the second diode (Dr1) 248. The anode of the second Zener diode (Zr1) 250 is connected to a second power electronic device 245 (e.g., an emitter terminal). According to a non-limiting embodiment, a second gate resistor 252 may be connected between the reverse gate drive branch 244 and the second power electronic component (Qr1) 243. For example, the first terminal of the second gate resistor 252 can be connected to the second power electronic component 245 (e.g., the gate terminal), and the second terminal can be connected together with the cathode of the second diode (Dr1) 248 and the cathode of the second Zener diode (Zf1) 250.

[0055] Energy absorption device 260 includes a first terminal connected to disconnect switch 210, voltage source segment 206, and forward current interruption subcircuit 220. A second terminal of energy absorption device 260 is connected to reverse current interruption subcircuit 240, load segment 208, and load 204. As described herein, energy absorption device 260 is configured to absorb and dissipate the energy of the current supplied thereto. Energy absorption device 260 can be implemented using various components, including, but not limited to, transient voltage suppression (TVS) diodes, metal-oxide-semiconductor (MOV) rheostats, and snubber circuits.

[0056] The multi-break switch (SW2) 270 can be adjusted between a first position and a second position. The first position connects the voltage source segment 206 to the load segment 208 to establish a main current path 202. The second position connects the forward current interruption sub-circuit 220 and the reverse current interruption sub-circuit 240 to establish a current bypass path that interrupts the main current path 202 and shuts off one or both of the forward current interruption sub-circuit 220 and the reverse current interruption sub-circuit 240. According to a non-limiting embodiment, the multi-break switch 270 is a double-break switch, including a first terminal (T1), a second terminal (T2), a third terminal (T3), and a further terminal (T4). The first terminal (T1) is connected to the voltage source segment 206. The second terminal (T2) is connected to the load segment 208. The third terminal (T3) is connected to the forward current interruption sub-circuit 220. The fourth terminal (T4) is connected to the reverse current interruption sub-circuit 240. When operating in the first position, the multi-break switch 270 connects the first and second terminals T1 and T2 together to direct the load current through the main current path 202. When operating in the second position, the multi-break switch connects the third and fourth terminals (T3 and T4) together to direct the load current through the current bypass path and into the load segment 208.

[0057] Now refer to Figures 9 to 18 The operation of a DC bidirectional solid-state switch circuit 200 according to one or more non-limiting embodiments of the present disclosure will be described. Figure 9 A DC bidirectional switching circuit 200 is shown operating under normal conditions. Under normal conditions, the isolating switch 210 is closed and the multi-break switch 270 is in the first position to establish the main current path 202 and supply current to the load 204 in the positive direction.

[0058] Go to Figure 10 This illustrates a DC bidirectional switching circuit 200 after adjusting a multi-break switch 270 from a first position to a second position to activate interrupt circuit 215. During the initial adjustment of the multi-break switch 270, a first arc 223a is drawn from the first terminal T1, and a second arc 223b is drawn from the second terminal T2. As described herein, the first arc 223a generates a positive voltage drop on the positive gate drive branch 226, while the second arc 223b generates a negative voltage drop on the reverse gate drive branch 244. As described herein, this positive voltage drop turns the second power electronic component 245 on. However, the negative voltage drop applies a negative voltage to the gate of the second power electronic component 245, which turns it off (e.g., prevents it from conducting). Accordingly, as... Figure 11 As shown, current is guided in the positive direction through the first current bypass path established when the first solid-state switch component is turned on.

[0059] Reference Figure 12This illustrates a DC bidirectional switching circuit 200 that guides current in the positive direction along an energy absorption path. As described here, an energy absorption path is established after the multi-break switch 270 reaches its second position and short-circuits the first power electronic component 227, thereby turning it off. Accordingly, the energy absorption device 260 absorbs and dissipates the energy of the current until the current level eventually drops to 0A.

[0060] exist Figure 13 The diagram shows a DC bidirectional switching circuit 200 after disconnecting the isolating switch 210. Accordingly, the interrupt circuit 215 and the load 204 are electrically isolated from the voltage source 201. Depending on the application of the DC bidirectional switching circuit 200, the isolating switch 210 can be disconnected before, during, or after the current interruption performed by the interrupt circuit 215 described above.

[0061] Go to Figure 14 The diagram illustrates a DC bidirectional switching circuit 200 operating in normal conditions to deliver current in the reverse direction. For example, when the DC bidirectional switching circuit 200 is connected in a reverse connection scenario (e.g., when voltage source 201 is connected to the DC bidirectional switching circuit 200 in reverse), a reverse current direction may occur.

[0062] exist Figure 15 In the reverse connection scenario, the multi-break switch 270 is adjusted from its second position to its first position. Accordingly, the reverse gate drive branch 244 operates to turn on the second power electronic component (Qr1) 245 based on the positive voltage applied by the arc 223b, while the negative voltage applied to the positive gate drive branch 226 by the arc 223a keeps the first power electronic component 227 (Qf1) off. Once the arc voltage of the arc 223b exceeds the threshold voltage (Vge) of the second power electronic component (Qr1) 245, then... Figure 16 As shown, current is delivered along the second bypass current path.

[0063] Go to Figure 17 Current is delivered in the reverse direction along the energy absorption path. In this reverse connection scenario, after the multi-break switch 270 reaches its first position and short-circuits the second power electronic component 245, thereby turning it off, an energy absorption path is established. Accordingly, the energy absorption device 260 absorbs and dissipates the energy of the current until the current level eventually decreases to 0A.

[0064] Reference Figure 18The diagram illustrates a DC bidirectional switching circuit 200 after disconnecting the isolating switch 210. Accordingly, the interrupt circuit 215 and the load 204 are electrically isolated from the reverse-connected voltage source 201. Depending on the application of the DC bidirectional switching circuit 200, the isolating switch 210 can be disconnected before, during, or after the current interruption performed by the interrupt circuit 215 described above (e.g., manually).

[0065] Now go to Figure 19 The flowchart illustrates a method for interrupting the current supplied to a load connected to a DC solid-state switching circuit 100, which includes a solid-state auxiliary air gap with a multi-throw switch 125 connected in parallel. The method begins at operation 1900, and at operation 1902, the interrupting circuit 115 operates in a normal state, with the multi-throw switch 125 in a first position. At operation 1904, current is supplied to the load 104 through an isolating switch 110 operating in a closed position and the multi-throw switch 125 operating in the first position. At operation 1906, the multi-throw switch 125 is adjusted to a second position to generate an electric arc 123. At operation 1908, the electric arc 123 turns on a solid-state power electronic component 127 to establish a bypass current path 122, and at operation 1910, current is directed through the bypass current path 122. At operation 1912, the multi-throw switch 125 reaches the second position, which turns off the solid-state power electronic component 127 to establish an energy absorption path 126. At operation 1914, current is directed through energy absorption path 126 and delivered to energy absorption device 160, where energy is absorbed and dissipated. At operation 1916, disconnecting switch 110 is disconnected to isolate interrupt circuit 115 and load 104 from voltage source 101, and the process ends at operation 1918.

[0066] As described herein, various non-limiting embodiments and techniques provide a DC switching circuit including a solid-state auxiliary air gap with multiple-throw switches connected in parallel. Non-limiting embodiments provide a unidirectional DC switching circuit for guiding current in the forward direction and a bidirectional DC switching circuit for guiding current in either the forward or reverse direction. One or more non-limiting embodiments of the DC switching circuit described herein can be used as a stand-alone disconnect switch, or paired with a fuse device as a fusible disconnect switch, or used as an air gap for a DC switching circuit.

[0067] While embodiments of this disclosure have been described in an exemplary form, it will be apparent to those skilled in the art that many modifications, additions, and deletions may be made therein without departing from the spirit and scope of this disclosure and its equivalents as described in the appended claims.

[0068] The embodiments, along with their various features and advantages, are described more fully with reference to the non-limiting embodiments illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known starting materials, processing techniques, components, and apparatus are omitted to avoid unnecessarily obscuring the embodiments in detail. However, it should be understood that the detailed descriptions and specific examples, while pointing to preferred embodiments, are for illustrative purposes only and not as limitations. Various substitutions, modifications, additions, and / or rearrangements within the spirit and / or scope of the inventive concept upon which these are based will become apparent to those skilled in the art from this disclosure.

[0069] As used herein, the terms “comprising,” “including,” “containing,” “having,” “possessing,” or any other variation thereof are intended to cover non-exclusive inclusion. For example, a process, article, or apparatus that comprises a list of elements is not necessarily limited to those elements but may include other elements not expressly listed or inherent to such a process, article, or apparatus.

[0070] Furthermore, any examples or descriptions given herein should not be construed in any way as limiting, defining, or explicitly defining any terms used with it. Rather, these examples or descriptions should be considered as descriptions of a particular embodiment and are merely illustrative. Those skilled in the art will understand that any terms used with these examples or descriptions will cover other embodiments, whether given with them or not, or elsewhere in the specification, and all such embodiments are intended to be included within the scope of that term or these terms.

[0071] In the foregoing description, this disclosure has been described with reference to specific embodiments. However, those skilled in the art will understand that various modifications and changes can be made without departing from the scope of this disclosure. Accordingly, the specification and drawings should be considered illustrative rather than restrictive, and all such modifications are intended to be included within the scope of this disclosure.

[0072] Although the invention has been described with reference to specific embodiments thereof, these embodiments are merely illustrative and not intended to limit the invention. The description of the embodiments of the invention illustrated herein is not intended to be exhaustive or to limit the invention to the specific forms disclosed herein (in particular, the inclusion of any particular embodiment, feature, or function is not intended to limit the scope of the invention to that embodiment, feature, or function). Rather, the specification is intended to describe illustrative embodiments, features, or functions to provide background for those skilled in the art to understand the invention, and not to limit the invention to any of the specifically described embodiments, features, or functions. While specific embodiments and examples of the invention have been described herein for illustrative purposes only, various equivalent modifications can be made within the spirit and scope of the invention, as will be recognized and understood by those skilled in the art. As noted, these modifications can be made to the invention in accordance with the foregoing description of the embodiments illustrated herein, and these modifications should be included within the spirit and scope of the invention. Therefore, although the invention has been described herein with reference to specific embodiments thereof, the foregoing disclosure is intended to include a degree of freedom to make modifications, various alterations, and substitutions, and it should be understood that in some instances, some features of embodiments of the invention will be used without corresponding use of other features, without departing from the scope and spirit of the invention as set forth. Therefore, many modifications can be made to adapt specific situations or materials to the essential scope and spirit of the invention.

[0073] The phrases "in one embodiment," "in an embodiment," or "in a specific embodiment," or similar terms appearing in various places throughout this specification, do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of any particular embodiment can be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications can be made to the embodiments described and shown herein in accordance with the teachings herein, and such variations and modifications should be considered as part of the spirit and scope of the invention.

[0074] Numerous specific details, such as examples of components and / or methods, are provided in the description herein to provide a comprehensive understanding of embodiments of the invention. However, those skilled in the art will recognize that embodiments can be practiced without one or more of these specific details, or can be practiced using other means, systems, components, methods, parts, materials, components, and / or the like. In other instances, well-known structures, components, systems, materials, or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the invention. While the invention has been described by way of specific embodiments, this is not intended to limit the invention, nor is it intended to limit the invention to any particular embodiment, and those skilled in the art will recognize that additional embodiments are readily understood and are part of the invention.

[0075] It should also be understood that, depending on the needs of a particular application, one or more of the elements depicted in the figures / attached drawings may be implemented in a more separate or integrated form, or may even be removed or made unavailable in some cases.

[0076] The benefits, other advantages, and solutions to problems have been described above with reference to specific embodiments. However, these benefits, advantages, solutions to problems, and any components that may cause any benefit, advantage, or solution to appear or become more significant should not be construed as critical, essential, or necessary features or components.

Claims

1. A unidirectional direct current (DC) switching circuit, comprising: Disconnecting switch; as well as An interrupt circuit connected in series with the disconnecting switch includes a parallel connection of a current guiding branch, a bypass power electronics branch, a gate driving branch, and an energy absorption branch. The current-directing branch includes a multi-throw switch configured to operate in a first position and a second position. The first position is used to establish a first electrical connection between the current-directing branch and the load, and the second position is used to establish a second electrical connection that shuts off the bypass power electronic branch.

2. The unidirectional DC switching circuit according to claim 1, wherein: The bypass power electronic branch includes power electronic components connected in series with the voltage setting component; and The gate drive branch includes a series connection of a resistor, a diode, and a Zener diode.

3. The unidirectional DC switching circuit according to claim 2, wherein: The resistor includes: a first terminal connected to the first terminal of the voltage setting component, the current guiding branch, and the energy absorption branch; and a second terminal connected to the anode of the diode; and The Zener diode includes a cathode that is connected to both the multi-throw switch and the cathode of the diode, and an anode that is connected to both the power electronic component and the multi-throw switch.

4. The unidirectional DC switching circuit according to claim 3, wherein, The voltage setting component includes: a first terminal connected to the power electronic component; and a second terminal connected together with the gate drive branch, the current guide branch and the energy absorption branch.

5. The unidirectional DC switching circuit according to claim 4, wherein, The energy absorption branch includes an energy absorption device having a first terminal that is connected to the first terminal of the disconnect switch, the multi-throw switch, the resistor, and the first terminal of the voltage setting component, and a second terminal that is connected to the anode of the multi-throw switch, the Zener diode, and the power electronic component.

6. The unidirectional DC switching circuit according to claim 5, wherein, The multi-throw switch includes: a first terminal connected to the disconnecting switch; a second terminal connected to both the second terminal of the energy absorption device and the anode of the Zener diode; and a third terminal connected to both the cathode of the diode and the cathode of the Zener diode.

7. The unidirectional DC switching circuit according to claim 2, wherein, The power electronic components include transistors.

8. The unidirectional DC switching circuit according to claim 2, wherein, The voltage setting component includes one or a combination of transient voltage suppression diodes, Zener diodes, resistors, and rheostats.

9. A bidirectional direct current (DC) switching circuit, comprising: A main current path, configured to supply load current to a load, the main current path including a voltage source segment and a load segment; A disconnecting switch configured to selectively open or close the air gap between the voltage source and the voltage source segment; A forward current interruption sub-circuit, the forward current interruption sub-circuit including a forward current input terminal that is connected to both the isolating switch and the voltage source segment; A reverse current interruption sub-circuit, the reverse current interruption sub-circuit including a reverse current input terminal connected to the load segment; as well as A multi-break switch is configured to operate in a first position and a second position, wherein the first position connects the voltage source segment to the load segment to establish the main current path, and the second position establishes a connection to shut down one or both of the forward current interruption subcircuit and the reverse current interruption subcircuit.

10. The bidirectional DC switching circuit according to claim 9, further comprising an energy absorption device, the energy absorption device comprising: The first terminal that is connected together with the disconnecting switch, the voltage source segment, and the positive current interruption sub-circuit; And a second terminal that is connected together with the reverse current interruption sub-circuit and the load segment.

11. The bidirectional DC switching circuit according to claim 10, wherein: The forward current interruption sub-circuit includes a forward bypass power electronic branch and a forward gate drive branch connected in parallel with the forward bypass power electronic branch. as well as The reverse current interruption sub-circuit includes a reverse bypass power electronic branch and a reverse gate drive branch connected in parallel with the reverse bypass power electronic branch.

12. The bidirectional DC switching circuit according to claim 11, wherein: The forward bypass power electronic branch includes a first power electronic component connected in series with the first voltage setting component; and The reverse bypass power electronic branch includes a second power electronic component connected in series with the second voltage setting component.

13. The bidirectional DC switching circuit according to claim 12, wherein: The first voltage setting component includes a first terminal connected to the positive current input terminal and a second terminal connected to the first power electronic component; as well as The second voltage setting component includes a first terminal connected to the reverse current input terminal and a second terminal connected to the second power electronic component.

14. The bidirectional DC switching circuit according to claim 13, wherein: The forward gate drive branch includes a series connection of a first resistor, a first diode, and a first Zener diode; and The reverse gate drive branch includes a second resistor, a second diode, and a second Zener diode connected in series.

15. The bidirectional DC switching circuit according to claim 14, wherein, The multi-break switch includes: Connected to the first terminal of the voltage source segment; Connect to the second terminal of the load segment; The third terminal connected to the positive gate drive branch; and The fourth terminal is connected to the reverse gate drive branch.

16. The bidirectional DC switching circuit according to claim 15, wherein, The multi-break switch selectively operates in a first position and a second position. In the first position, the first terminal is connected to the second terminal to establish the main current path. In the second position, the third terminal is connected to the fourth terminal to connect the forward current interruption subcircuit to the reverse current interruption subcircuit.

17. A method for interrupting current supplied to a load connected to a direct current (DC) solid-state switching circuit, the method comprising: Load current is supplied to the load through a main current path that includes a voltage source section and a load section; Operate the disconnect switch to selectively open or close the air gap between the voltage source and the voltage source segment; as well as The multi-break switch is operated in a first position and a second position. In the first position, the voltage source segment is connected to the load segment to establish the main current path. In the second position, the forward current interruption sub-circuit and the reverse current interruption sub-circuit are connected to establish a current bypass path that interrupts the main current path.

18. The method according to claim 17, wherein, Manually adjust the multi-break switch to the first position and the second position.

19. The method according to claim 18, wherein, An initial adjustment of the multi-break switch generates an electric arc with an arc voltage, which continues to guide the load current through a current-guiding branch, wherein the current-guiding branch establishes an electrical connection between the current-guiding branch and the load.

20. The method according to claim 19, wherein, The forward current interruption subcircuit includes a forward current input terminal connected to both the disconnecting switch and the voltage source segment, and the reverse current interruption subcircuit includes a reverse current input terminal connected to the load segment.

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