阅读说明：本技术 一种组合开关 (Combined switch ) 是由 徐�明 孙宝翔 朱经鹏 孙巨禄 于 2019-09-15 设计创作，主要内容包括：本发明公开了一种组合开关。组合开关,包括第一个开关和第二个开关以及一第一电容,所述第一个开关和所述第二个开关同向串联,所述第二个开关的第二端为所述组合开关的第二输出端,所述第二个开关的第一端与所述第一个开关的第二端串联,所述第一个开关的第一端为所述组合开关的第一输出端,所述第一电容并联在所述第二个开关的驱动控制端与所述第一个开关的第一端,所述第一个开关和所述第二个开关为可控开关。本发明的组合开关为可控组合开关,为所述第一个开关的门极驱动端提供驱动信号即可控制所述组合开关的开通和关断。(The invention discloses a combination switch. The combined switch comprises a first switch, a second switch and a first capacitor, wherein the first switch and the second switch are connected in series in the same direction, the second end of the second switch is a second output end of the combined switch, the first end of the second switch is connected with the second end of the first switch in series, the first end of the first switch is a first output end of the combined switch, the first capacitor is connected with a driving control end of the second switch and the first end of the first switch in parallel, and the first switch and the second switch are controllable switches. The combined switch is a controllable combined switch, and the on and off of the combined switch can be controlled by providing a driving signal for the gate driving end of the first switch.)

1. A combination switch is characterized by comprising a first switch, a second switch and a first capacitor, wherein the first switch and the second switch are connected in series in the same direction, the second end of the second switch is a second output end of the combination switch, the first end of the second switch is connected with the second end of the first switch in series, the first end of the first switch is a first output end of the combination switch, the first capacitor is connected with a driving control end of the second switch and the first end of the first switch in parallel, and the first switch and the second switch are controllable switches.

2. The combination switch of claim 1, wherein the combination switch comprises N switches and N-1 first capacitors, the switches are connected in series in the same direction, the N-1 first capacitor is connected in parallel between the gate of the nth switch and the first terminal of the N-1 switch, N is a natural number not less than 2, and N is a natural number greater than 1 but not greater than N.

3. A combination switch as claimed in claim 2, in which a second capacitor is connected in parallel between the first terminal and the second terminal of the nth switch.

4. A combination switch as in claim 2, further comprising a voltage clamp circuit connected in parallel between the drive control terminal and the first terminal of the switch.

5. A combination switch according to claim 4, wherein the voltage clamping circuit is two zener diodes connected in series in opposite directions, the zener diodes having equal reverse breakdown voltages.

6. A power conversion circuit comprising the combination switch of claim 1.

Technical Field

The present invention relates to the field of power supplies, and more particularly to high voltage switches.

Background

In different applications, for example, a 650V withstand voltage class power switch device is required under the condition of 220V ac power grid voltage, and a 1700V withstand voltage class power switch device is required under the condition of 1KV dc power grid bus voltage. In order to achieve higher withstand voltage class of power switching devices, research on breakdown voltage has been started since the 60 s of the 20 th century. A number of edge termination techniques have been developed in succession to effectively increase the breakdown voltage. The voltage class of the power switch device in the current technical level reaches 4500V, but the rated current of the power switch device is only 1A.

There is therefore a need in the art for a controllable switch that can be used in high voltage applications.

Disclosure of Invention

The invention provides the combined switch which is suitable for a high-voltage application environment, the breakdown voltage of the combined switch is improved by using the controllable switches in series connection, the circuit is simple to realize, and the cost is low.

In order to achieve the purpose, the invention adopts the technical scheme that:

a combined switch comprises a first switch, a second switch and a first capacitor, wherein the first switch and the second switch are connected in series in the same direction, the second end of the second switch is a second output end of the combined switch, the first end of the second switch is connected with the second end of the first switch in series, the first end of the first switch is a first output end of the combined switch, the first capacitor is connected with a driving control end of the second switch and the first end of the first switch in parallel, and the first switch and the second switch are controllable switches.

The combined switch comprises N switches and N-1 first capacitors, the switches are connected in series in the same direction, the N-1 first capacitor is connected between the gate pole of the nth switch and the first end of the N-1 switch in parallel, N is a natural number not less than 2, and N is a natural number greater than 1 but not greater than N.

And a second capacitor is connected in parallel between the first end and the second end of the nth switch.

The combination switch further comprises a voltage clamping circuit, wherein the voltage clamping circuit is connected between the drive control end and the first end of the switch in parallel.

The voltage clamping circuit comprises two voltage stabilizing diodes which are connected in series in a reverse direction, and reverse breakdown voltages of the voltage stabilizing diodes are equal.

An electric energy conversion circuit comprises the combination switch.

The technical scheme of the invention is that the low-voltage switches are connected in series to form the combined switch suitable for high-voltage application.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

FIG. 1 is a diagram of an embodiment of the present invention.

FIG. 2 is a diagram of another embodiment of the present invention.

Detailed Description

In order to make the purpose and technical solution of the embodiments of the present invention clearer, the technical solution of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.

The terms "first," "second," "third," and the like (if any) in this description are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the subject matter described herein are, for example, capable of operation in other sequences than those illustrated or otherwise described herein. Further, wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

The invention aims to provide a combined switch, which is formed by connecting switches in series and is applied to an electronic circuit with higher voltage application requirements after being combined.

Fig. 1 shows an embodiment of the present invention, a combination switch Z includes switches Q1, Q2, and Q3 … QN, the switches Q1, Q2, and Q3 … QN are connected in series in the same direction, two ends S and D after being connected in series are output ends of the combination switch Z, and a breakdown voltage of the combination switch Z is equal to a sum of breakdown voltages of the switches Q1, Q2, and Q3 … QN.

A capacitor C1 is connected in parallel between the driving control terminal G2 of the switch Q2 and the second terminal D1 of the switch Q1, and so on, and a capacitor CN-1 is connected in parallel between the driving control terminal GN of the switch QN and the first terminal SN-1 of the switch QN-1. When the combined switch Z is controlled to be switched on, a switching-on signal is loaded at a driving control end G of the switch Q1, the switch Q1 is switched on, the voltage VDS1 at two ends of the switch Q1 is reduced, the capacitor C1 provides charges for a gate capacitor CGS2 of the switch Q2, when the voltage of the CGS2 reaches the switching-on voltage of the switch Q2, the switch Q2 is switched on, the switch Q2 is switched on and then the switch Q3 is switched on through the same working process, and so on until the switch QN is switched on. In order to limit the voltage between the driving control terminal and the first terminal of the switch to be smaller than the breakdown voltage between the driving control terminal and the first terminal of the switch, referring to fig. 2, the present invention connects a voltage clamp circuit 2n in parallel between the driving control terminal and the first terminal of the switch, the voltage clamp circuit 2n is connected in parallel between the driving control terminal and the first terminal of the switch, and the voltage clamp circuit 2n limits the voltage between the driving control terminal and the first terminal of the switch to be smaller than the breakdown voltage between the driving control terminal and the first terminal of the switch.

In a preferred embodiment of the present invention, the voltage clamp circuit 22 is two reverse series-connected zener diodes D21 and D22, the reverse breakdown voltages of the zener diodes D21 and D22 are equal, and preferably, the reverse breakdown voltages of the zener diodes D21 and D22 are between 10V and 20V.

When the combined switch Z is controlled to be turned off, a turn-off signal is loaded on a driving control end G of the switch Q1, the switch Q1 is turned off, the voltage of the capacitor C1 is reduced by load current, the switch Q2 is turned off when the voltage of the capacitor C1 is lower than a threshold value, and the like, until the switch QN is turned off. The voltages born by the switches Q1, Q2 and Q3 … QN are related to equivalent capacitors and parallel capacitors thereof, and in order to make the voltages born by the switches Q1, Q2 and Q3 … QN equal and achieve the effect of voltage sharing, capacitors can be connected in parallel between the first ends Sn and the second ends Dn of the switches Q1, Q2 and Q3 … QN to adjust the effect of voltage sharing. For example, the capacitance of the capacitor connected in parallel across Q2 is such that the sum of the capacitance of the output capacitor of Q2 and the capacitance of the capacitor equals the sum of the capacitance of C1 and the capacitance of the output capacitor of switch Q1.

The invention can design a controllable switch with high voltage-resistant grade.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.