Direct current circuit breaker based on energy storage transfer of fuse

Abstract

Disclose a kind of DC circuit breaker based on fuse energy storage transfer, transfer branch series energy storage capacitor C is connected in parallel on high-speed mechanical switch HSS, energy storage branch and fuse FUSE are connected in parallel, energy dissipation branch and high-speed mechanical switch HSS are connected in parallel, when breaking current, fuse FUSE is fused when the current through DC circuit breaker exceeds the action value of fuse, the voltage across the circuit breaker is charged to energy storage capacitor C through diode D, while high-speed mechanical switch HSS receives the signal of breaking, the contact of high-speed mechanical switch HSS is pulled apart, after energy storage capacitor C is charged to predetermined voltage, thyristor T is opened, energy storage capacitor C is discharged through inductance L, thyristor T and the break of high-speed mechanical HSS to form discharge circuit, so that the break current of high-speed mechanical switch HSS is zero-crossing, after current zero-crossing, the break arc of high-speed mechanical switch HSS is extinguished.

Description

Technical Field

[0001] This invention relates to the field of DC circuit breakers, and in particular to a DC circuit breaker based on fuse energy storage transfer. Background Technology

[0002] As the scale and capacity of DC power systems continue to grow, the challenges posed by short-circuit fault currents are also increasing. Circuit breakers are typically used as the primary protection device; however, due to the diverse forms of short-circuit faults in DC systems, and the characteristics of DC short-circuit faults such as rapid rise rates and the absence of zero-crossing points, directly using DC circuit breakers for short-circuit protection presents certain difficulties. Currently, technical solutions for DC circuit breakers include mechanical circuit breakers, solid-state circuit breakers, and hybrid circuit breakers. Traditional mechanical or hybrid circuit breakers require pre-charged capacitors or power electronics, resulting in high costs, large sizes, and difficulties in large-scale application.

[0003] The information disclosed in the background section is only intended to enhance the understanding of the background of the present invention, and therefore may contain information that does not constitute prior art known to those skilled in the art in this country. Summary of the Invention

[0004] To address the shortcomings or defects of the existing technology, the present invention aims to provide a DC circuit breaker based on fuse energy storage transfer. The voltage generated by the rapid melting of the fuse charges the energy storage capacitor. The energy stored in the capacitor is released, forming a reverse current. This reverse current flows through a high-speed mechanical switch, creating a zero-crossing point for the main current branch. The reverse recovery voltage after the zero-crossing causes the surge arrester in the energy dissipation circuit to operate, and the energy is released through the energy dissipation circuit, thereby achieving rapid interruption.

[0005] The objective of this invention is achieved through the following technical solutions.

[0006] A DC circuit breaker based on fuse energy storage and transfer includes an output terminal A1, an output terminal A2, a main current branch, an energy storage branch, a transfer branch, and an energy dissipation branch. The main current branch consists of a fuse (FUSE) and a high-speed mechanical switch (HSS). The energy storage branch consists of a diode (D) and an energy storage capacitor (C). The transfer branch consists of an inductor (L) and a thyristor (T). The energy dissipation branch consists of a surge arrester (MOV). The energy storage capacitor (C) is connected in series with the transfer branch and in parallel with the high-speed mechanical switch (HSS). The energy storage branch and the fuse (FUSE) are connected in parallel, and the energy dissipation branch and the high-speed mechanical switch (HSS) are connected in parallel.

[0007] Under normal system current-carrying conditions, the system current flows into port A1, passes through the fuse, then flows out through port A2 via the high-speed mechanical switch. When the current reverses, the system current flows into port A2 and out through port A1. The high-speed mechanical switch HSS closes, and no current flows through the energy storage branch, transfer branch, and energy dissipation branch.

[0008] When interrupting the current, the fuse (FUSE) blows when the current through the DC circuit breaker exceeds the fuse's operating value. The voltage across the circuit breaker charges the energy storage capacitor (C) through diode D. Simultaneously, the high-speed mechanical switch (HSS) receives a trip signal, and its contacts open. After the energy storage capacitor (C) is charged to the predetermined voltage, the thyristor (T) turns on. The energy storage capacitor (C) discharges through the inductor (L), thyristor (T), and the break point of the high-speed mechanical switch (HSS), forming a discharge circuit. The discharge current is opposite to the current in the main current branch, causing the break point current of the high-speed mechanical switch (HSS) to cross zero. After the current crosses zero, the arc at the break point of the high-speed mechanical switch (HSS) is extinguished. When the transient recovery voltage across the break point reaches the operating voltage of the surge arrester (MOV), the surge arrester (MOV) completes its operation and dissipates energy. The remaining voltage on the energy storage capacitor (C) is discharged through the energy dissipation circuit, and a voltage is established across the main current branch, ending the interruption.

[0009] In the aforementioned DC circuit breaker based on fuse energy storage transfer, the high-speed mechanical switch HSS is an anti-parallel diode device.

[0010] In the aforementioned DC circuit breaker based on fuse energy storage transfer, the high-speed mechanical switch (HSS) is a vacuum high-speed mechanical switch based on electromagnetic repulsion, a vacuum mechanical switch driven by a high-speed motor, or a vacuum high-speed mechanical switch driven by explosion.

[0011] In the aforementioned DC circuit breaker based on fuse energy storage transfer, the thyristor T is a unidirectional semi-controlled device, which is a single device or combination of the following devices: GTO, thyristor, and IGBT.

[0012] In the aforementioned DC circuit breaker based on fuse energy storage and transfer, the energy dissipation circuit includes one or more of the following devices: line-type metal oxide surge arrester, gapless line-type metal oxide surge arrester, fully insulated composite jacket metal oxide surge arrester, and detachable surge arrester.

[0013] In the aforementioned DC circuit breaker based on fuse energy storage transfer, the energy storage branch includes a single energy storage capacitor or a commutation energy storage circuit composed of an energy storage capacitor and multiple diodes.

[0014] In the aforementioned DC circuit breaker based on fuse energy storage transfer, the fuse includes one or more of the following devices: plug-in fuse, screw-type fuse, enclosed fuse, and self-resetting fuse.

[0015] Compared to traditional mechanical and hybrid circuit breakers, this invention offers advantages such as lower cost, no need for pre-storage, and no need for current detection. This invention can interrupt DC short-circuit current.

[0016] The above description is merely an overview of the technical solution of the present invention. In order to make the technical means of the present invention clearer and more understandable, so that those skilled in the art can implement it according to the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more obvious and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0017] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0018] In the attached diagram:

[0019] Figure 1 This is a topology diagram of a DC circuit breaker based on fuse energy storage transfer according to an embodiment of the present invention;

[0020] Figures 2(a) to 2(d) A schematic diagram of the working structure of a DC circuit breaker based on fuse energy storage transfer according to an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of a bidirectional energy storage and bidirectional interruption structure of a DC circuit breaker based on fuse energy storage transfer according to an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the break-end follow current structure of a DC circuit breaker based on fuse energy storage transfer according to an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of a dual-capacitor energy storage bidirectional interruption structure of a DC circuit breaker based on fuse energy storage transfer according to an embodiment of the present invention.

[0024] The present invention will be further explained below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0025] The following will refer to the appendix. Figures 1 to 5Specific embodiments of the invention will be described in more detail below. While specific embodiments of the invention are shown in the accompanying drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0026] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.

[0027] To facilitate understanding of the embodiments of the present invention, the following will provide further explanation and description with reference to the accompanying drawings and several specific embodiments, and the accompanying drawings do not constitute a limitation on the embodiments of the present invention.

[0028] Figure 1 This is a schematic diagram of a DC circuit breaker based on fuse energy storage transfer according to an embodiment of the present invention. The embodiment of the present invention will be combined with... Figure 1 Please provide a detailed explanation.

[0029] The DC circuit breaker includes an output terminal A1, an output terminal A2, a main current branch, an energy storage branch, a transfer branch, and an energy dissipation branch. The main current branch consists of a fuse (FUSE) and a high-speed mechanical switch (HSS). The energy storage branch consists of a diode (D) and an energy storage capacitor (C). The transfer branch consists of an inductor (L) and a thyristor (T). The energy dissipation branch consists of a surge arrester (MOV). The energy storage capacitor (C) is connected in series with the transfer branch and in parallel with the high-speed mechanical switch (HSS). The energy storage branch and the fuse (FUSE) are connected in parallel, and the energy dissipation branch and the high-speed mechanical switch (HSS) are connected in parallel.

[0030] Under normal system current-carrying conditions, the system current flows into port A1, passes through the fuse, then flows out through port A2 via the high-speed mechanical switch. When the current reverses, the system current flows into port A2 and out through port A1. The high-speed mechanical switch HSS closes, and no current flows through the energy storage branch, transfer branch, and energy dissipation branch.

[0031] When interrupting the current, the fuse (FUSE) blows when the current through the DC circuit breaker exceeds the fuse's operating value. The voltage across the circuit breaker charges the energy storage capacitor (C) through diode D. Simultaneously, the high-speed mechanical switch (HSS) receives a trip signal, and its contacts open. After the energy storage capacitor (C) is charged to the predetermined voltage, the thyristor (T) turns on. The energy storage capacitor (C) discharges through the inductor (L), thyristor (T), and the break point of the high-speed mechanical switch (HSS), forming a discharge circuit. The discharge current is opposite to the current in the main current branch, causing the break point current of the high-speed mechanical switch (HSS) to cross zero. After the current crosses zero, the arc at the break point of the high-speed mechanical switch (HSS) is extinguished. When the transient recovery voltage across the break point reaches the operating voltage of the surge arrester (MOV), the surge arrester (MOV) completes its operation and dissipates energy. The remaining voltage on the energy storage capacitor (C) is discharged through the energy dissipation circuit, and a voltage is established across the main current branch, ending the interruption.

[0032] In a preferred embodiment of the DC circuit breaker based on fuse energy storage transfer, the high-speed mechanical switch HSS is a vacuum high-speed mechanical switch based on electromagnetic repulsion, a vacuum mechanical switch based on high-speed motor drive, or a vacuum high-speed mechanical switch based on explosion drive.

[0033] In the preferred embodiment of the DC circuit breaker based on fuse energy storage transfer, the thyristor T is a unidirectional semi-controlled device, which is a single device or combination of the following devices: GTO, thyristor, IGBT.

[0034] In a preferred embodiment of the DC circuit breaker based on fuse energy storage transfer, the energy dissipation circuit includes one or more of the following devices: line-type metal oxide surge arrester, gapless line-type metal oxide surge arrester, fully insulated composite jacket metal oxide surge arrester, and detachable surge arrester.

[0035] In a preferred embodiment of the DC circuit breaker based on fuse energy transfer, the energy storage branch includes a single energy storage capacitor or a commutation energy storage circuit composed of an energy storage capacitor and multiple diodes.

[0036] In a preferred embodiment of the DC circuit breaker based on fuse energy transfer, the fuse includes one or more of the following devices: plug-in fuse, screw-type fuse, enclosed fuse, and self-resetting fuse.

[0037] In a preferred embodiment of the DC circuit breaker based on fuse energy storage transfer, the high-speed mechanical switch HSS is connected in parallel with a diode device.

[0038] In one embodiment, Figure 1This invention provides a topology diagram of a DC circuit breaker based on fuse energy storage transfer, consisting of a main current branch, an energy storage branch, a transfer branch, and an energy dissipation branch. The transfer branch is connected in series with the energy storage capacitor of the energy storage branch and in parallel with a high-speed switch. The energy storage branch is connected in parallel with the fuse, and the energy dissipation branch is also connected in parallel with the high-speed switch. The main current branch consists of the fuse and the high-speed mechanical switch. The energy storage branch consists of a diode and an energy storage capacitor. The transfer branch consists of an inductor and a thyristor. The energy dissipation branch consists of a surge arrester.

[0039] Under normal system current-carrying conditions, the system current flows in from port A1, passes through the fuse, enters the main circuit of the circuit breaker, and then flows out from port A2. When the current is reversed, it flows in from port A2 and then out from port A1. At this time, the high-speed switch on the main circuit is closed. No current flows through the energy storage branch, transfer branch, or energy dissipation branch.

[0040] During current interruption, the fuse blows when the current through the DC circuit breaker exceeds its tripping value. The voltage across the circuit breaker charges the energy storage capacitor C through the diode. Simultaneously, the high-speed mechanical switch receives a tripping signal and its contacts open. After the energy storage capacitor is charged to the predetermined voltage, the thyristor T turns on, and the energy storage capacitor C discharges through the discharge circuit formed by the inductor L, the thyristor, and the high-speed mechanical break. The discharge current is opposite to the main circuit current, causing the current at the high-speed switch break to cross zero. After the current crosses zero, the arc at the mechanical switch break extinguishes. When the transient recovery voltage across the break reaches the surge arrester's tripping voltage, the surge arrester completes its operation and energy dissipation. The remaining voltage on the capacitor is discharged through the energy dissipation circuit, and a voltage is established across the main circuit, ending the interruption.

[0041] The circuit breaker described in this embodiment Figures 2(a) to 2(d) This is a schematic diagram of its structure during operation.

[0042] As shown in Figure 2(a), under normal system operation, current flows through the fuse and the closed high-speed mechanical switch in the main circuit.

[0043] As shown in Figure 2(b), when a short-circuit fault occurs or a trip command is received from the upper level, the fuse blows first, and the current flows through diode D, energy storage capacitor C, and high-speed mechanical switch. During this process, the energy storage capacitor is charged by the fault current. At the same time, the contacts of the high-speed mechanical switch open, generating an electric arc.

[0044] As shown in Figure 2(c), when the voltage of the energy storage capacitor reaches the threshold, the thyristor T turns on, and the energy storage capacitor C discharges through the discharge circuit formed by the inductor L, the thyristor and the high-speed mechanical break. The discharge current is opposite to the main circuit current, causing the high-speed switch break current to cross zero.

[0045] As shown in Figure 2(d), when the voltage on the transfer branch capacitor reaches the conduction voltage of the surge arrester on the energy dissipation branch, the remaining energy is discharged through the surge arrester, and the current is transferred to the dissipation branch.

[0046] In another embodiment of the magnetically controlled oscillating circuit breaker: the high-speed mechanical switch HSS is a vacuum high-speed mechanical switch based on electromagnetic repulsion, a vacuum mechanical switch driven by a high-speed motor, or a vacuum high-speed mechanical switch driven by explosion.

[0047] In another embodiment of the circuit breaker, the thyristor device T is a unidirectional semi-controlled device, which can be a single device or a combination of the following devices: GTO, thyristor, IGBT.

[0048] like Figure 3 As shown, in one embodiment of the circuit breaker, the energy storage capacitor can store energy bidirectionally and discharge bidirectionally, enabling bidirectional interruption.

[0049] like Figure 4 As shown, in one embodiment of the circuit breaker, an anti-parallel diode is added to the high-speed mechanical switch to prevent the current from flowing in reverse through the break point after the main circuit crosses zero.

[0050] like Figure 5 As shown, in one embodiment of the circuit breaker, the energy storage branch uses two capacitors for energy storage, enabling bidirectional interruption. Further, the positive terminal of one capacitor is connected to diode D, and the negative terminal is connected to one end of a thyristor and another diode; the positive terminal of the other capacitor is connected to the other end of another diode and the other end of a thyristor; and the other capacitor is connected to diode D.

[0051] Although embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments and application fields described above. The specific embodiments described above are merely illustrative and instructive, and not restrictive. Those skilled in the art can make many other forms based on the guidance of this specification and without departing from the scope of protection of the claims of the present invention, and all of these are within the scope of protection of the present invention.

Claims

1. A DC circuit breaker based on fuse energy storage transfer, characterized in that: The DC circuit breaker includes an output terminal A1, an output terminal A2, a main current branch, an energy storage branch, a transfer branch, and an energy dissipation branch. The main current branch consists of a fuse (FUSE) and a high-speed mechanical switch (HSS). The energy storage branch consists of a diode (D) and an energy storage capacitor (C). The transfer branch consists of an inductor (L) and a thyristor (T). The energy dissipation branch consists of a surge arrester (MOV). The energy storage capacitor (C) is connected in series with the transfer branch and in parallel with the high-speed mechanical switch (HSS). The energy storage branch and the fuse (FUSE) are connected in parallel, and the energy dissipation branch and the high-speed mechanical switch (HSS) are connected in parallel. Under normal system current-carrying conditions, the system current flows into port A1, passes through the fuse, then flows out through port A2 via the high-speed mechanical switch. When the current reverses, the system current flows into port A2 and out through port A1. The high-speed mechanical switch HSS closes, and no current flows through the energy storage branch, transfer branch, and energy dissipation branch. When interrupting the current, the fuse (FUSE) blows when the current through the DC circuit breaker exceeds the fuse's operating value. The voltage across the circuit breaker charges the energy storage capacitor (C) through diode D. Simultaneously, the high-speed mechanical switch (HSS) receives a trip signal, and its contacts open. After the energy storage capacitor (C) is charged to the predetermined voltage, the thyristor (T) turns on. The energy storage capacitor (C) discharges through the inductor (L), thyristor (T), and the break point of the high-speed mechanical switch (HSS), forming a discharge circuit. The discharge current is opposite to the current in the main current branch, causing the break point current of the high-speed mechanical switch (HSS) to cross zero. After the current crosses zero, the arc at the break point of the high-speed mechanical switch (HSS) is extinguished. When the transient recovery voltage across the break point reaches the operating voltage of the surge arrester (MOV), the surge arrester (MOV) completes its operation and dissipates energy. The remaining voltage on the energy storage capacitor (C) is discharged through the energy dissipation branch, and a voltage is established across the main current branch, ending the interruption.

2. The DC circuit breaker based on fuse energy storage transfer according to claim 1, characterized in that: The high-speed mechanical switch incorporates an anti-parallel diode to prevent the current from flowing in the opposite direction through the break point after the main circuit crosses zero.

3. The DC circuit breaker based on fuse energy storage transfer according to claim 1, characterized in that: The high-speed mechanical switch HSS is a vacuum high-speed mechanical switch based on electromagnetic repulsion or a vacuum high-speed mechanical switch based on explosion drive.

4. The DC circuit breaker based on fuse energy storage transfer according to claim 1, characterized in that: The thyristor T is a unidirectional semi-controlled device.

5. The DC circuit breaker based on fuse energy storage transfer according to claim 1, characterized in that: The energy dissipation branch includes one or more of the following devices: line-type metal oxide surge arresters and fully insulated composite-jacketed metal oxide surge arresters.

6. The DC circuit breaker based on fuse energy storage transfer according to claim 1, characterized in that: The energy storage branch includes a commutation energy storage circuit composed of an energy storage capacitor and multiple diodes.

7. The DC circuit breaker based on fuse energy storage transfer according to claim 1, characterized in that: The fuse includes one or more of the following devices: plug-in fuse, screw-in fuse, enclosed fuse, and self-resetting fuse.

Images