CN107846211A - The composite switch of primary path inline solid state switch - Google Patents

Abstract

The present invention proposes a hybrid switch circuit, a switch, a switch system and a control method for a solid-state switch connected in series in a main path. The hybrid switch circuit includes a mechanical switch branch, a main solid-state switch branch, and an energy absorption branch. wherein, the main solid state switch branch includes one or more solid state switches in series; the mechanical switch branch includes a mechanical switch and a solid state switch; the solid state switch includes a forward circuit and a reverse circuit, and the forward circuit and the The reverse circuit shares a controllable switch circuit and an anti-parallel diode. The hybrid switch circuit, switch, switch system and control method of the present invention have the characteristics of convenient control and fast switch, simple structure and reliable performance.

Description

Hybrid switch with solid-state switches in series in the main path

technical field

The invention relates to the technical field of power electronics, in particular to a hybrid switch circuit and a switch device in which a main path is connected in series with a solid-state switch.

Background technique

At present, mechanical switching devices are generally used to control the on-off of electric power. With the widespread use of switchgear in various industries, the requirements for switches are now getting higher and higher.

The diode is a common electronic component that is also used in switches. The most common function of a diode is to only allow current to flow in a single direction, that is, from the anode (also known as the positive pole) to the cathode (also known as the negative pole), and to block the current in the reverse direction. Due to this characteristic of diodes, they are widely used in electronic circuits. Diodes are now used in a variety of circuits, such as clipping circuits and switching circuits. The existing diode switch circuit is shown in Fig. 1 . However, such diode switching circuits are generally suitable for DC circuits and cannot be controlled.

Contents of the invention

In order to solve the above technical problems, the present invention provides a reliable and highly stable hybrid switching circuit, a switching device, and a power switching protection system in which the main path is connected in series with solid-state switches.

The invention provides a hybrid switch circuit in which the main path is connected in series with a solid-state switch, which is characterized in that:

The hybrid switching circuit includes a mechanical switching branch, a main solid state switching branch, and an energy absorbing branch, wherein,

a main solid state switch branch comprising one or more series connected solid state switches;

The mechanical switch branch includes a mechanical switch and a state switch;

The solid-state switch includes a forward circuit and a reverse circuit, and the forward circuit and the reverse circuit share a controllable switch circuit and an anti-parallel diode.

Further, the controllable switch circuit includes a power electronic switch.

Further, the power electronic switch is any one of thyristor, IGBT, IGCT or GTO.

Further, the mechanical switch branch, the main solid state switch branch and the energy absorbing branch are connected in parallel.

Further, the forward circuit includes a first diode and a third diode, the cathode of the first diode is connected to the first end of the controllable switch circuit, and the third diode The anode of is connected to the second end of the controllable switch circuit;

The reverse circuit includes a second diode and a fourth diode, the cathode of the second diode is connected to the first end of the controllable switch circuit, and the anode of the fourth diode is connected to the first end of the controllable switch circuit. The second end of the controllable switch circuit is connected.

Further, the energy absorbing branch includes a lightning arrester.

The present invention also provides a switch circuit control method, which is applied to the hybrid switch circuit of the main channel series solid-state switch as described above, characterized in that,

Control the main solid-state switch branch to conduct, and the solid-state switch in the mechanical switch branch to turn off;

The mechanical switch in the mechanical switch branch is controlled to open, and the main solid state switch branch is controlled to open.

Further, when the contact gap of the mechanical switch in the mechanical switch branch can withstand the transient recovery voltage, the main solid state switch branch is controlled to be disconnected.

The present invention also provides a switch circuit control method, which is applied to the hybrid switch circuit of the main channel series solid-state switch as described above, characterized in that,

controlling the main solid state switch branch to conduct;

controlling the mechanical switch of the mechanical switch branch to be closed, and controlling the solid-state switch of the mechanical switch branch to be turned on;

The main solid state switch branch is controlled to open.

The present invention also provides an automatic transfer switch device, which is characterized in that the automatic transfer switch device includes a main transfer switch part and a standby transfer switch part, wherein,

The main switch part includes three hybrid switching circuits of the main channel series solid-state switches as described above, which are respectively used in the A-phase, B-phase, and C-phase branches of the three-phase electricity;

The standby switch part includes three hybrid switching circuits of the above-mentioned main path series solid-state switches, which are respectively used in the A-phase, B-phase, and C-phase branches of the three-phase electricity.

The present invention also provides a power switching protection system, characterized in that,

The power protection switching system includes:

Working power and backup power;

The automatic transfer switch device as described above, the main transfer switch part in the automatic transfer switch device is connected to the working power supply, and the standby transfer switch part is connected to the backup power supply;

A monitoring system for monitoring the working status of the working power supply and/or the backup power supply;

The control and protection system controls the opening of the main transfer switch part and/or the standby transfer switch part in the automatic transfer switch device according to the switch circuit control method described above, and/or controls the switch circuit according to the above switch circuit control method The main diverter switch part and/or the standby diverter switch part in the automatic transfer switch device are switched on.

Further, the monitoring system is also used to send the information of the working state to the control and protection system, and the control and protection system controls the automatic transfer switch device between the main transfer switch part and the backup switch according to the information. Switch between toggle switch widgets.

Further, the monitoring system also detects the closing and opening states of the automatic transfer switch, and feeds back information about the states to the control and protection system. .

The hybrid switch circuit, switch and power switch protection system of the present invention have the characteristics of convenient control and fast switching, simple structure and reliable performance.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

FIG. 1 shows a schematic structural diagram of a diode switch circuit in the prior art;

Fig. 2 shows the schematic structural diagram of the hybrid switch circuit of the main channel series solid-state switch of the embodiment of the present invention;

Fig. 3 shows a schematic structural diagram of a hybrid automatic transfer switch device with a main path connected in series with a solid-state switch according to an embodiment of the present invention;

Fig. 4 shows a schematic structural diagram of a dual power supply redundant power supply system according to an embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The changeover switch of the present invention adopts a hybrid switch circuit in which a solid-state switch is connected in series on the main path. The embodiment of the present invention takes the switch circuit as an example for illustration, but those skilled in the art should realize that, without departing from the basic inventive concept of the present invention, all devices that can realize circuit on and off, such as a switch and a circuit breaker, Switching circuits, components, parts, equipment, systems, etc. can all realize the present invention, and all of these belong to the protection scope of the present invention.

As shown in FIG. 2, the switching circuit includes a mechanical switching branch, a main solid state switching branch, and an energy absorbing branch. The main solid-state switch branch includes one or more solid-state switches as the main solid-state switch, and multiple solid-state switches are connected in series. The branch where the main solid-state switch is located in FIG. solid-state switch, but it does not mean that the branch where the solid-state switch is located is electrically disconnected; the mechanical switch branch includes a mechanical switch and a solid-state switch as an auxiliary solid-state switch; the solid-state switch includes a forward circuit and a reverse circuit, and the The forward circuit and the reverse circuit share a controllable switch circuit and an anti-parallel diode.

The solid state switches in the main solid state switch branch comprise a plurality of diodes D1, D2, D3, D4, D5 and power electronic switches. The cathode of the diode D1 is connected to the first end of the electronic power switch, the cathode of the diode D2, and the cathode of the diode D5; the anode of the diode D4 is connected to the second end of the electronic power switch, the anode of the diode D3, and the anode of the diode D5; the anode of the diode D1 The anode is connected to the cathode of the diode D4, and the anode of the diode D2 is connected to the cathode of the diode D3. The controllable switch circuit also has a diode D5 connected in antiparallel with it, providing reverse flow capability for the controllable switch.

When the power electronic switch is turned on, the diode D1, the power electronic switch, and the diode D3 form a path, the forward current enters the path from the anode of the diode D1, and flows out from the cathode of the diode D3; the diode D2, the power The electronic switch and the diode D4 form a path through which the reverse current enters from the anode of the diode D2 and flows out from the cathode of the diode D4.

When the power electronic switch is turned off, current cannot pass through the solid-state switch circuit based on the diode hybrid bridge due to the characteristic of the diode that only allows current to flow in one direction. Thus, in case of opening the power electronic switch, the current is cut off.

The power electronic switch can be selected from thyristor, IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor), IGCT (integrated Gate Commutated Thyristors, integrated gate commutated thyristor) or GTO (Gate-Turn-OffThyristor, gate can be closed Any one or more of the thyristor) and the like. The on-off of the solid-state switch circuit based on the diode hybrid bridge can be realized by controlling the on-off of the power electronic switch.

One end of the main solid-state switching branch is connected to one winding of the coupling coil Ls, the other winding of the transformer Ls is in the discharge capacitor circuit, so that the two windings of the transformer Ls make the commutation branch and the coupling The negative voltage circuit is coupled; the coupled negative voltage circuit includes a thyristor S, a discharge capacitor Cs and a coupling coil Ls, and the thyristor S, the discharge capacitor Cs and the second winding of the coupling coil Ls form a loop. At the same time, in order to charge the discharge capacitor Cs, a DC power supply circuit is also provided for the capacitor Cs. The DC power supply circuit includes a resistor Rs, an electric key K, and a direct current power supply DC, wherein one end of the resistor is connected to one end of the capacitor Cs, the other end of the resistor is connected to the electric key K, and the electric key K is connected to the electric key K. One end of the DC power supply is connected, and the other end of the DC power supply is connected to the other end of the capacitor Cs. The energy absorption branch mainly includes a lightning arrester. In the embodiment, a MOV (metal oxide varistor) zinc oxide lightning arrester is used. The lightning protection absorption system absorbs the remaining energy generated during the opening and closing process of the mechanical switch, thereby realizing Overvoltage protection for mechanical switches. The present invention uses the MOV zinc oxide arrester as an exemplary lightning protection absorption system, but it is not limited to the MOV zinc oxide arrester as the lightning protection absorption system. All energy absorption circuits or systems that can absorb the residual energy in the branch circuit can be used in the present invention. The primary solid state switching branch, the secondary solid state switching branch, the mechanical switching branch and the energy absorbing branch are connected in parallel.

When the switch circuit is operating normally to establish a connection between a power source and a load, the mechanical switches in the mechanical switch branch are closed, and the solid-state switches in the mechanical switch branch are turned on; the main solid-state The solid state switch in the switch branch is open, in which state current flows through the mechanical switch branch.

The opening control process of the hybrid switch circuit of the main channel series solid-state switch described in the embodiment is as follows: control the solid-state switch in the main solid-state switch branch to conduct, and disconnect the solid-state switch in the mechanical switch branch, so that The forced current is transferred from the mechanical switch branch to the main solid-state switch branch; when the current transfer is completed, the mechanical switch controlling the mechanical switch branch is turned off, the mechanical switch is zero-crossing and the arc is extinguished, and the mechanical switch When the opening moves until the contact gap can withstand the corresponding transient recovery voltage, the solid state switch in the main solid state switch branch is controlled to be turned off. At this time, the line energy is absorbed by the MOV, and the main switch current drops to zero.

The closing control process of the hybrid switch circuit of the main channel series solid-state switch described in the embodiment is as follows: control the solid-state switch in the main solid-state switch branch to conduct, control the mechanical switch in the mechanical switch branch to close , controlling the solid-state switch in the mechanical switch branch to conduct.

The embodiment also provides a switch component, which adopts the above-mentioned hybrid switch circuit in which the main path is connected in series with solid-state switches. The switching component is used in a three-phase alternating current system, and the circuit of each phase adopts the above-mentioned hybrid switching circuit based on the coupled negative voltage circuit. As shown in Fig. 3, described switching part adopts the hybrid switching circuit of above-mentioned main channel series solid-state switch in A phase, B phase, C phase respectively: A phase, B phase, C phase ( In order to distinguish from the three-phase line of the standby switch, A1, B1, and C1 represent A phase, B phase, and C phase) in the figure) all adopt the above-mentioned hybrid switching circuit of the main channel in series with the solid-state switch; Phase A, Phase B, and Phase C (in order to distinguish from the three-phase lines of the main switch in the figure, A2, B2, and C2 represent phase A, phase B, and phase C) also use the above-mentioned main channel series solid-state switch hybrid switching circuit.

As shown in FIG. 3 , the embodiment also provides an automatic transfer switch device, which includes two above-mentioned switch parts, one of which is a main transfer switch part and the other is a standby transfer switch part. During normal operation, the main switch part is turned on, so that the power supply can supply current to the load through the main switch part; the standby switch part is turned off. When a fault occurs and it is necessary to switch the power supply from the main diverter switch part to the standby diverter switch part, the main diverter switch part is disconnected through the above-mentioned opening control process, and the standby diverter switch part is turned on through the above-mentioned closing control process.

In this embodiment, a dual power supply redundant power supply system is used to illustrate the control and use of the above-mentioned hybrid switching device with solid-state switches connected in series in the main channel. However, it should be clear that the hybrid automatic transfer switch device of the main channel in series with the solid-state switch of the above-mentioned embodiment is not limited to the dual power supply redundant power supply system, the multi-power supply redundant power supply system and general power supply systems such as single power supply, which can use switch The power system and the like can use the hybrid automatic transfer switch device of the main channel series solid-state switch described in the above embodiment.

FIG. 4 is a schematic structural diagram of a dual power supply redundant power supply system according to an embodiment of the present invention. The dual power supply system includes a power supply, a control protection system, an automatic transfer switch device, a load, and a monitoring system composed of monitoring components such as sensors, wherein the power supply includes two sets of power supplies, a working power supply and a backup power supply, and the automatic transfer switch device The main transfer switch part is connected with the working power supply, and the standby transfer switch part is connected with the standby power supply. In the dual power supply redundant power supply system, the main switch part on the working power branch and/or the standby switch part on the backup power branch can use the hybrid automatic switch of the main channel series solid-state switch described in the above embodiment part. In this embodiment, both the switch on the working power supply branch and the switch on the standby power supply branch use the above-mentioned hybrid automatic switch component in which the main path is connected in series with the solid-state switch as an example for illustration.

In the normal power supply state of the dual power supply redundant power supply system, all the switch circuits (that is, the switch circuits on the A, B, and C phase lines) in the main switch parts of the working power supply branch in the automatic transfer switch device are in the In the closed state, the power of the working power supply is provided to the load through the transfer switch device; and all the switch circuits in the backup switch parts of the backup power supply branch in the automatic transfer switch device (that is, A, B, C phase The switching circuits on the line) are all in an off state, and the backup power supply does not provide power to the load.

The monitoring system continuously or periodically monitors the working status of the entire power supply system, such as abnormal conditions in the system: the sensor in the working power supply branch monitors the working status of the working power supply, and the sensor in the backup power supply branch monitors the working status of the backup power supply 1. The sensor in the load branch monitors the working state of the load.

When the monitoring system detects a failure of the working power supply or an excessive voltage drop, it sends a corresponding failure signal to the control and protection system. After the control and protection system receives the signal from the monitoring system indicating that the working power supply has failed, it judges that the working power supply has failed, and needs to switch the power supply from the working power supply to the standby power supply. At this time, the control unit in the control and protection system sends an opening command to the switching part of the working power supply, and sends a closing command to the switching part of the backup power supply, thereby controlling the switching part of the working power supply to disconnect, and controlling the switching part of the backup power supply. The diverter switch part of the power supply is closed to establish an electrical connection between the backup power source and the load, thereby providing power to the load through the backup power box.

During normal operation, all mechanical switches on phase A, phase B and phase C of the main diverter switch part are in the closed state, and the current on each phase line flows through the respective mechanical switches to provide power to the load. When the sensor detects that the working power supply fails, it sends an alarm message to the control and protection system. After receiving the alarm message,

The control unit in the control protection system sends an opening command to the main switch part in the automatic transfer switch device, controls the solid state switch in the main solid state switch branch to conduct, and disconnects the solid state switch in the mechanical switch branch. switch, thereby forcing the current to be transferred from the mechanical switch branch to the main solid-state switch branch; when the current transfer is completed, the mechanical switch controlling the mechanical switch branch is turned off, the mechanical switch is zero-crossing and extinguishes the arc, and the When the mechanical switch opens and moves until the contact gap can bear the corresponding transient recovery voltage, the solid-state switch in the main solid-state switch branch is controlled to be turned off. At this time, the line energy is absorbed by the MOV, and the main switch current drops to zero. At the same time, an opening command is sent to the backup switch part in the automatic transfer switch device, and the main solid-state switch branch in the backup switch part is controlled to conduct; and the mechanical switch branch in the backup switch part is controlled The mechanical switch of the circuit is closed, and at the same time, the solid-state switch of the mechanical switch branch is controlled to be turned on, and the main solid-state switch branch is controlled to be disconnected. The closing process of the backup diverter switch component is completed, so as to realize the closing of the diverter switch device in the backup power supply branch, so that the backup working power supply supplies power to the load.

In the dual power supply redundant power supply system, the process of switching from the standby power supply to the load to the working power supply to the load is the same as the process of switching from the working power supply to the load to the standby power supply to the load similar and will not be repeated here.

After the sensor in the load branch monitors that the load is faulty, it will send the detected fault information to the control and protection system. The control and protection system can close the switching components in the working power branch and the backup power branch according to the fault information, so as to disconnect any power supply from supplying power to the load.

The monitoring system simultaneously detects the switching on-off state, and feeds back state information to the control and protection system to ensure on-off and on-off.

The control and protection system also realizes the control of other contact switches or receives the status information of other contact switches according to the received information, and sends all the received information to the remote computer, and can receive information from the remote computer at the same time, such as controlling the relevant switching switch Open or closed information.

In the embodiment, three-phase alternating current is taken as an example for illustration, but those skilled in the art should realize that, without departing from the basic inventive concept of the present invention, the switching circuit, switching device, system and control method thereof of the present invention It is not limited to the three-phase alternating current for illustrative purposes in the specification, and the switching circuit, switching device, system and control method thereof of the present invention are applicable to systems including but not limited to direct current and alternating current.

It should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, not to limit it. Between the two steps before and after does not necessarily mean that there must be a sequence of execution, as long as the technical problem of the present invention can be solved, and between the two steps before and after does not necessarily mean that the steps not listed in the invention must be excluded. In addition, the main device and the auxiliary device in the specification do not necessarily indicate the main and auxiliary, and the first device and the second device do not necessarily indicate the front and back sequence, which are only used for distinction; similarly, each element and part of the system It does not necessarily imply a direct electrical connection between them, and the description only expresses a logical relationship. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that: they can still modify the technical solutions described in the aforementioned embodiments, or perform equivalent replacements for some of the technical features; and these The modification or replacement does not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (13)

1. A kind of hybrid switch circuit of main channel series solid-state switch, it is characterized in that, The hybrid switching circuit includes a mechanical switching branch, a main solid state switching branch, and an energy absorbing branch, wherein, a main solid state switch branch comprising one or more series connected solid state switches; The mechanical switch branch includes mechanical switches and solid state switches; The solid-state switch includes a forward circuit and a reverse circuit, and the forward circuit and the reverse circuit share a controllable switch circuit and an anti-parallel diode. 2. The hybrid switch circuit according to claim 1, characterized in that, The controllable switching circuit includes a power electronic switch. 3. The hybrid switch circuit according to claim 2, characterized in that, The power electronic switch is any one of thyristor, IGBT, IGCT or GTO. 4. The hybrid switch circuit according to claim 1, characterized in that, The mechanical switching branch, the main solid state switching branch and the energy absorbing branch are connected in parallel. 5. The hybrid switch circuit according to any one of claims 1-4, characterized in that, The forward circuit includes a first diode and a third diode, the cathode of the first diode is connected to the first end of the controllable switch circuit, and the anode of the third diode is connected to the first end of the controllable switch circuit. The second end of the controllable switch circuit is connected; The reverse circuit includes a second diode and a fourth diode, the cathode of the second diode is connected to the first end of the controllable switch circuit, and the anode of the fourth diode is connected to the first end of the controllable switch circuit. The second end of the controllable switch circuit is connected. 6. The hybrid switch circuit according to claim 1, characterized in that, The energy absorbing branch includes a lightning arrester. 7. A switch circuit control method, which is applied to the hybrid switch circuit of the main channel series solid-state switch according to any one of claims 1-6, characterized in that, Control the main solid-state switch branch to conduct, and the solid-state switch in the mechanical switch branch to turn off; The mechanical switch in the mechanical switch branch is controlled to open, and the main solid state switch branch is controlled to open. 8. The switch circuit control method according to claim 7, characterized in that, The main solid state switch branch is controlled to open when the contact gaps of the mechanical switches in the mechanical switch branch can withstand a transient recovery voltage. 9. A switching circuit control method, which is applied to the hybrid switching circuit of the main path series solid-state switch according to any one of claims 1-6, characterized in that, controlling the main solid state switch branch to conduct; controlling the mechanical switch of the mechanical switch branch to be closed, and controlling the solid-state switch of the mechanical switch branch to be turned on; The main solid state switch branch is controlled to open. 10. An automatic transfer switch device, characterized in that, the automatic transfer switch device comprises a main transfer switch part and a backup switch part, wherein, The main switch part comprises three hybrid switching circuits of the main channel series solid-state switch according to any one of claims 1-6, which are respectively used in the A-phase, B-phase, and C-phase branches of three-phase electricity; The spare changeover switch part includes three hybrid switch circuits of main path series solid-state switches according to any one of claims 1-6, which are respectively used in A-phase, B-phase and C-phase branches of three-phase electricity. 11. A power switching protection system, characterized in that, The power protection switching system includes: Working power and backup power; The automatic transfer switch device according to claim 10, wherein the main transfer switch part in the automatic transfer switch device is connected to the working power supply, and the standby transfer switch part is connected to the backup power supply; A monitoring system for monitoring the working status of the working power supply and/or the backup power supply; The control and protection system, according to the switching circuit control method described in any one of claims 7-8, controls the opening of the main transfer switch part and/or the standby transfer switch part in the automatic transfer switch device, and/or according to claim 9 The switch circuit control method controls the switching on of the main switch part and/or the standby switch part in the automatic transfer switch device. 12. The power switching protection system according to claim 11, characterized in that, The monitoring system is also used to send the information of the working state to the control and protection system, and the control and protection system controls the automatic transfer switch device between the main transfer switch part and the standby transfer switch part according to the information. switch between. 13. The power switching protection system according to claim 11 or 12, characterized in that, The monitoring system also detects the closing and opening states of the automatic transfer switch, and feeds back information about the states to the control and protection system.