CN210578246U

CN210578246U - Switch driving circuit and multi-level cascade power unit device using same

Info

Publication number: CN210578246U
Application number: CN201921805164.6U
Authority: CN
Inventors: 徐元龙; 彭国平; 史奔; 段博; 孟庆良
Original assignee: Guangdong Anpu Electric Power Technology Co ltd
Current assignee: Guangdong Anpu Electric Power Technology Co ltd
Priority date: 2019-10-24
Filing date: 2019-10-24
Publication date: 2020-05-19
Anticipated expiration: 2029-10-24

Abstract

The utility model discloses a switch drive circuit and use its many level cascade power unit device, its characterized in that, including charge switch K1, the linear discharge subassembly of energy storage, drive coil L1 and controllable switch Q2; an external power supply is electrically connected with the energy storage linear discharging assembly through the charging switch K1 to form a charging loop; the driving coil L1 can drive an external bypass contact switch K2, the controllable switch Q2 can be switched on and off according to an external control signal, the driving coil L1 is connected with the controllable switch Q2 in series to form a series branch, and the series branch is connected with the energy storage linear discharge assembly to form a power supply loop. By reasonably controlling the controllable switch Q2, the reliable closing of the bypass can be realized. And simultaneously, the utility model discloses the design of simplifying reduces design cost, has very high reliability and practicality.

Description

Switch driving circuit and multi-level cascade power unit device using same

Technical Field

The utility model relates to a drive circuit field, in particular to switch drive circuit and use its many level cascade power unit device.

Background

Multilevel cascade topology, such as reactive compensation, frequency converter, direct current distribution network, etc., is widely applied in the medium and high voltage power grid field, such as electric power, rail transit and new energy field. In order to ensure safe and reliable operation of the multilevel cascade device, a bypass function needs to be designed. When a certain cascaded power unit fails, the bypass function inside the power unit bypasses the failed unit, so that failure expansion is avoided, normal operation of equipment is maintained, and greater economic loss is avoided.

However, in the current bypass switch driving circuit of the multilevel cascade power unit, a switching power supply is mostly adopted as the power supply. The switching power supply has high working frequency and uses a nonlinear device, so that the noise is large, the conduction is serious, and the generated electromagnetic radiation seriously interferes other electronic circuits to influence the normal work of the switching power supply.

The linear power supply has the advantages of simple structure, no need of additional control, no switching noise and the like, and is particularly suitable for low-power application occasions. But the input voltage range is lower, so that the linear power supply is not suitable for being used in the application occasions of more than 800V, and the output voltage of the linear power supply is also lower. The input voltage of the bypass switch power supply in the cascade multi-level power unit is usually above 1400V, and the output voltage is 220V or 400V.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to solve one of the technical problem that exists among the prior art at least, provide a switch drive circuit, can effectively improve many level cascade power unit's operational reliability.

According to the utility model discloses an aspect provides a switch drive circuit, include:

the charging circuit comprises a charging switch K1 and an energy storage linear discharging assembly, wherein an external power supply is electrically connected with the energy storage linear discharging assembly through the charging switch K1 to form a charging loop;

the driving coil L1 and the controllable switch Q2, the driving coil L1 can drive the external bypass contact switch K2, the controllable switch Q2 can be switched on and off according to an external control signal, the driving coil L1 and the controllable switch Q2 are connected in series to form a series branch, and the series branch is connected with the energy storage linear discharge assembly to form a power supply loop.

Preferably, the driving coil L1 can drive the charging switch K1, and the charging switch K1 is opposite to the on-off state of the external bypass contact switch K2.

Preferably, the energy storage linear discharging assembly comprises an energy storage capacitor C1 and a discharging resistor R3, and the energy storage capacitor C1 is connected in parallel with the discharging resistor R3.

Preferably, the controllable switch Q2 is a thyristor.

Preferably, the charging system further comprises a power supply, the power supply is electrically connected with the energy storage linear discharging assembly through the charging switch K1, and an external power unit is electrically connected with the power supply to charge the charging loop.

Preferably, the power supply is a linear power supply.

Preferably, the linear power supply comprises a current-limiting resistor R1, a voltage stabilizing module, a switching tube Q1, a diode D1 and a resistor R2; one pole of an external power supply is electrically connected with one end of the current-limiting resistor R1 and the input end of the switch tube Q1, the other end of the current-limiting resistor R1 is electrically connected with one end of the voltage stabilizing module and the control end of the switch tube Q1, and the other end of the voltage stabilizing module is electrically connected with the other pole of the external power supply and one end of the charging loop; the output end of the switch tube Q1 is electrically connected to one end of the diode D1, the other end of the diode D1 is electrically connected to one end of the resistor R2, and the other end of the resistor R2 is electrically connected to the other end of the charging loop.

Any one of the technical schemes at least has the following beneficial effects:

when the power unit breaks down or needs to be overhauled, the controllable switch Q2 receives a control conduction signal of an upper stage, the controllable switch Q2 is conducted, and the charging switch K1 is disconnected. The energy storage linear discharge assembly, the driving coil L1 and the conducted controllable switch Q2 form a closed loop, energy stored in the energy storage linear discharge assembly is released through the closed loop, energy and high voltage needed by closing are provided for the driving coil L1, and the driving coil L1 closes and conducts the bypass contact switch K2. The bypass contact switch K2 which is closed and conducted short-circuits the alternating current output end of the power unit which is connected with the bypass contact switch K2 in parallel, and reliable closing of the bypass of the power unit is achieved. And the charging switch K1 is switched off, so that the connection between the external power supply and the rear-stage circuit is cut off, and the power impact on the external power supply is reduced.

By reasonably controlling the controllable switch Q2, the reliable closing of the bypass can be realized. And simultaneously, the utility model discloses the design of simplifying reduces the cost of design, has very high reliability and practicality.

According to the utility model discloses a second aspect provides a many level cascade power unit device, including any of the aforesaid switch drive circuit, bypass contact switch K2 and power unit, the switch drive circuit can drive bypass contact switch K2, bypass contact switch K2 with power unit's alternating current output end is parallelly connected.

Preferably, the power unit further comprises a plurality of cascaded branches, and the plurality of power units are connected end to form the cascaded branches.

Preferably, the device further comprises a cascade module, wherein the cascade branch comprises a plurality of cascade branches, and the plurality of cascade branches are connected to form the cascade module.

Has the advantages that: the bypass switch driving circuit of the multilevel cascade power unit is reasonably controlled, so that reliable closing of the bypass can be realized. And simultaneously, the utility model discloses the design of simplifying reduces the cost of design, has very high reliability and practicality.

Drawings

The present invention will be further described with reference to the accompanying drawings and examples;

fig. 1 is a circuit diagram of an embodiment of a switch driving circuit of the present invention;

FIG. 2 is a circuit diagram of the power unit of the present invention;

fig. 3 is a circuit diagram of another embodiment of the switch driving circuit of the present invention;

fig. 4 is a circuit diagram of the multi-level cascaded power cell apparatus of the present invention.

Detailed Description

This section will describe in detail the embodiments of the present invention, preferred embodiments of the present invention are shown in the attached drawings, which are used to supplement the description of the text part of the specification with figures, so that one can intuitively and vividly understand each technical feature and the whole technical solution of the present invention, but they cannot be understood as the limitation of the protection scope of the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated with respect to the orientation description, such as up, down, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, a plurality of means are one or more, a plurality of means are two or more, and the terms greater than, less than, exceeding, etc. are understood as not including the number, and the terms greater than, less than, within, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, a plurality of means are one or more, a plurality of means are two or more, and the terms greater than, less than, exceeding, etc. are understood as not including the number, and the terms greater than, less than, within, etc. are understood as including the number.

In the description of the present invention, unless there is an explicit limitation, the words such as setting, installation, connection, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in combination with the specific contents of the technical solution.

Referring to fig. 1 and 2, a switch driving circuit is shown, which includes a charging switch K1, an energy storage linear discharging assembly 2, a driving coil L1 and a controllable switch Q2; the external power supply is electrically connected with the energy storage linear discharging assembly 2 through the charging switch K1 to form a charging loop; the driving coil L1 can drive an external bypass contact switch K2, the controllable switch Q2 can be switched on and off according to an external control signal, the driving coil L1 is connected with the controllable switch Q2 in series to form a series branch, and the series branch is connected with the energy storage linear discharging assembly 2 to form a power supply loop.

When the power unit 3 is in fault or needs to be overhauled, the controllable switch Q2 receives a control conducting signal of a higher stage, the energy storage linear discharging assembly 2, the driving coil L1 and the conducted controllable switch Q2 form a closed loop, energy stored in the energy storage linear discharging assembly 2 is released through the closed loop, energy and high voltage required by closing of the driving coil L1 are provided, and the driving coil L1 closes the bypass contact switch K2. The closed conducting bypass contact switch K2 short-circuits the ac output of the power cell 3 connected in parallel with it. When the bypass contact switch K2 is closed, the charging switch K1 is also opened, so that the connection between the power supply 1 and a rear-stage circuit is cut off, and the power impact on the power supply 1 is reduced. The bypass contact switch K2 is self-locking, and the trigger is kept in a closed state, so that the bypass of the power unit 3 is reliably switched on. After the power unit 3 is overhauled, the manual opening bypass contact switch K2 is communicated with the power supply 1 and the rear-stage circuit to prepare for starting charging of the power unit 3 next time.

The present embodiment has a simple structure, a wide input operating voltage range, and a high output voltage, and satisfies the operating voltage requirement of the driving coil L1. By reasonably controlling the controllable switch Q2, the reliable closing of the bypass can be realized. Meanwhile, the simplified design of the embodiment reduces the design cost and has high reliability and practicability.

In one embodiment, the driving coil L1 can also drive the charging switch K1, control the charging switch K1 to be turned on and off, and the charging switch K1 is opposite to the on-off state of the external bypass contact switch K2. This can further simplify the circuit structure and reduce the cost of the present embodiment. Of course, in practical applications, the charging switch K1 may be controlled by another driving coil L1 alone, or alternatively, controlled by an external signal instead of the controllable switch, and is not limited to this.

In one embodiment, the drive coil L1 and the bypass contact switch K2 are integrated into a single electrical component, such as a vacuum contactor or circuit breaker. Of course, it is also possible that the driving coil L1, the bypass contact switch K2, and the charging switch K1 are all integrated on one electric element, without being limited thereto. This can further simplify the circuit structure and reduce the cost of the present embodiment. In addition, the vacuum contactor has the advantages of short closing time, no bounce, no error action and no action rejection, and the working reliability of the embodiment is improved.

Referring to fig. 1, in an embodiment, the energy storage linear discharging assembly 2 includes an energy storage capacitor C1 and a discharging resistor R3, and the energy storage capacitor C1 is connected in parallel with the discharging resistor R3. When the controllable switch Q2 is turned on to release energy, the energy storage capacitor C1 can quickly consume redundant energy through the discharge resistor R3, thereby reducing electromagnetic interference to other circuits. Of course, the energy storage linear discharging assembly 2 may also be composed of a plurality of resistors or energy storage capacitors C1 connected in parallel or in series, but is not limited thereto.

In one embodiment, the controllable switch Q2 is a thyristor. The controllable silicon has the advantages of small volume, high efficiency, long service life and the like.

In one embodiment, the power supply 1 is further included, the power supply 1 is electrically connected to the energy storage linear discharging device 2 through a charging switch K1, and the external power unit 3 is electrically connected to the power supply 1 to charge the charging loop. The power supply 1 is a linear power supply, and may be a nonlinear power supply. The linear power supply comprises a current-limiting resistor R1, a voltage stabilizing module, a switching tube Q1, a diode D1 and a resistor R2; one pole of the external power supply is electrically connected with one end of a current-limiting resistor R1 and the input end of a switch tube Q1, the other end of a current-limiting resistor R1 is electrically connected with one end of a voltage stabilizing module and the control end of a switch tube Q1, and the other end of the voltage stabilizing module is electrically connected with the other pole of the external power supply and one end of a charging loop; the output end of the switching tube Q1 is electrically connected to one end of the diode D1, the other end of the diode D1 is electrically connected to one end of the resistor R2, and the other end of the resistor R2 is electrically connected to the other end of the charging loop. The linear power supply has the advantages of simple structure, no need of additional control, no switching noise and the like.

In one embodiment, the switch Q1 is a mosfet or an igbt, but is not limited thereto. The metal oxide semiconductor field effect transistor or the insulated gate bipolar transistor has the advantages of high withstand voltage, large current and easiness in driving.

In one embodiment, the voltage regulator module includes a voltage regulator tube, a cathode of the voltage regulator tube is electrically connected to the current limiting resistor R1 and the control end of the switch tube Q1, and the other end of the voltage regulator module is an input end and an output end of the linear power supply. Referring to fig. 3, in practical application, the voltage regulator module may also be formed by connecting two or more voltage regulator tubes in series, but is not limited to this. The output voltage of the linear power supply can be improved by connecting a plurality of voltage-stabilizing tubes in series.

In one embodiment, the voltage regulator is a zener diode or a transient suppression diode, but is not limited thereto. The Zener diode or the transient suppression diode has the advantages of high response speed, high transient power, low leakage current, small breakdown voltage deviation, easy control of clamping voltage, no damage limit, small size and the like.

Referring to fig. 1 and 2, there is shown a multilevel cascaded power cell arrangement comprising a switch drive circuit of any of the above, a bypass contact switch K2 and a power cell 3, the switch drive circuit being capable of driving the bypass contact switch K2, the bypass contact switch K2 being connected in parallel with an ac output of the power cell 3.

When the power unit 3 starts charging, the energy storage linear discharging assembly 2 can be charged through the connection of the power supply 1 and the H bridge. After the power unit 3 is started, the power supply 1 supplements the energy lost by the discharge resistor R3 and the energy storage linear discharge assembly 2. At the moment, the energy is small, the heating of the power supply 1 is small, and the design requirement can be met. When the power unit 3 needs to be overhauled, the bypass contact switch K2 short-circuits the ac output terminal of the power unit 3 connected in parallel with the bypass contact switch K2, so that the whole power unit 3 is powered off, and the bypass switch driving circuit of the multilevel cascade power unit connected with the power unit is also powered off completely. The reliability of the whole driving circuit is improved, and the consumption of electric energy is reduced. Of course, in practical applications, the input terminal of the power supply 1 may be connected to other external power sources, but is not limited thereto.

Referring to fig. 4, in an embodiment, the power module further includes a plurality of cascaded branches 4, the plurality of power units 3 are connected end to form the cascaded branches 4, and the plurality of cascaded branches 4 are connected to form the cascaded module 5. In a three-phase power system, three cascade branches 4 are connected to form a cascade module 5, and the cascade module 5 is electrically connected with the three-phase power system. Compared with the prior art, the stability of the three-phase power system is improved. Meanwhile, the embodiment simplifies the design, reduces the cost and has high reliability and practicability. Of course, in practical applications, the cascade circuit 4 may also be applied to a high-voltage static var generator or a medium-voltage frequency converter, but is not limited thereto.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist of the present invention within the knowledge range of those skilled in the art.

Claims

1. A switch drive circuit, comprising:

the charging switch K1 and the energy storage linear discharging component (2), an external power supply is electrically connected with the energy storage linear discharging component (2) through the charging switch K1 to form a charging loop;

the driving coil L1 and the controllable switch Q2 are connected in series, the driving coil L1 can drive the external bypass contact switch K2, the controllable switch Q2 can be switched on and off according to an external control signal, the driving coil L1 and the controllable switch Q2 form a series branch, and the series branch is connected with the energy storage linear discharge assembly (2) to form a power supply loop.

2. The switch driving circuit according to claim 1, wherein the driving coil L1 is capable of driving the charging switch K1, and the charging switch K1 is opposite to the on-off state of the external bypass contact switch K2.

3. A switch driver circuit according to claim 1, wherein the energy storage linear discharge assembly (2) comprises an energy storage capacitor C1 and a discharge resistor R3, and the energy storage capacitor C1 is connected in parallel with the discharge resistor R3.

4. The switch driving circuit as claimed in claim 1, wherein the controllable switch Q2 is a thyristor.

5. The switch driving circuit according to claim 1, further comprising a power supply (1), wherein the power supply (1) is electrically connected to the energy storage linear discharging assembly (2) through the charging switch K1, and an external power unit (3) is electrically connected to the power supply (1) for charging the charging loop.

6. A switch driver circuit according to claim 5, characterized in that the power supply (1) is a linear power supply.

7. The switch driving circuit according to claim 6, wherein the linear power supply comprises a current limiting resistor R1, a voltage stabilizing module, a switch tube Q1, a diode D1 and a resistor R2; one pole of an external power supply is electrically connected with one end of the current-limiting resistor R1 and the input end of the switch tube Q1, the other end of the current-limiting resistor R1 is electrically connected with one end of the voltage stabilizing module and the control end of the switch tube Q1, and the other end of the voltage stabilizing module is electrically connected with the other pole of the external power supply and one end of the charging loop; the output end of the switch tube Q1 is electrically connected to one end of the diode D1, the other end of the diode D1 is electrically connected to one end of the resistor R2, and the other end of the resistor R2 is electrically connected to the other end of the charging loop.

8. A multilevel cascaded power cell arrangement comprising a switch driving circuit according to any of claims 1 to 7, a bypass contact switch K2 and a power cell (3), the switch driving circuit being capable of driving the bypass contact switch K2, the bypass contact switch K2 being connected in parallel with the ac output of the power cell (3).

9. The multilevel cascaded power cell device according to claim 8, further comprising a plurality of cascaded branches (4), wherein the plurality of power cells (3) are connected end to form the cascaded branches (4).

10. A multilevel cascaded power cell arrangement according to claim 9, further comprising a cascaded block (5), wherein said cascaded branches (4) are plural, and a plurality of said cascaded branches (4) are connected to form said cascaded block (5).