阅读说明：本技术 一种利用igbt或mos管的ac-ac变换器及其控制方法 (AC-AC converter using IGBT or MOS tube and control method thereof ) 是由 王德斌 王康 于 2019-01-22 设计创作，主要内容包括：本发明公开了一种利用IGBT或MOS管的AC-AC变换器及其控制方法,包括：电连接交流输出端的控制电路,所述控制电路电连接2(两)个并联的IGBT模块,分别为第一IGBT模块和第二IGBT模块；所述第一和第二IGBT模块每个模块均与两个串联的二极管并联；所述IGBT模块包含两个串联的IGBT开关管及其反向并联的二极管；所述第一和第二IGBT模块的输出端为第一输出端和第二输出端；所述第一输出端串联电感,还包括电容,电容的一端连接电感和负载的一端,另一端连接第二输出端和负载的另一端。本发明由于去掉了现有技术中由交流进行整流变成直流的电路,采用AC-AC的主电路控制模式,减少了电能转换流程,从而提高了电源变换效率,减少了电子元器件,降低了生产成本,且缩小了变换器的体积。(The invention discloses an AC-AC converter using IGBT or MOS tube and a control method thereof, comprising the following steps: the control circuit is electrically connected with the alternating current output end, and the control circuit is electrically connected with 2 (two) IGBT modules which are connected in parallel and are respectively a first IGBT module and a second IGBT module; each of the first and second IGBT modules is connected in parallel with two diodes connected in series; the IGBT module comprises two series-connected IGBT switching tubes and diodes which are connected in parallel in an opposite direction; the output ends of the first IGBT module and the second IGBT module are a first output end and a second output end; the first output end is connected with the inductor in series and further comprises a capacitor, one end of the capacitor is connected with one end of the inductor and one end of the load, and the other end of the capacitor is connected with the second output end and the other end of the load. The invention eliminates the circuit that the alternating current is rectified into the direct current in the prior art, and adopts the AC-AC main circuit control mode, thereby reducing the electric energy conversion flow, improving the power conversion efficiency, reducing the electronic components, reducing the production cost and reducing the volume of the converter.)

1. An AC-AC converter using an IGBT or MOS transistor, comprising: the control circuit is electrically connected with the alternating current output end and is electrically connected with two parallel IGBT modules which are a first IGBT module and a second IGBT module respectively; the first and second IGBT modules are each connected in parallel with two series-connected diodes, wherein the first IGBT module is connected in parallel with D1 and D2, and the second IGBT module is connected in parallel with D3 and D4 diodes; the IGBT module comprises two series-connected IGBT switching tubes and anti-parallel diodes thereof, wherein the first IGBT module comprises Q1 and Q2 switching tubes, and the second IGBT module comprises Q3 and Q4 switching tubes; the output ends of the first IGBT module and the second IGBT module are a first output end and a second output end; the first output end is connected with an inductor in series; the capacitor is connected with one end of the inductor and one end of the load, and the other end of the capacitor is connected with the second output end and the other end of the load.

2. An AC-AC converter using IGBT or MOS transistor according to claim 1, wherein said two series IGBT switch transistors are connected in parallel with two series diodes, and there is a connection point between the first output terminal and both IGBT transistor and diode.

3. An AC-AC converter using IGBT or MOS transistor according to claim 2, characterized in that said first and second IGBT modules are symmetrically connected.

4. An AC-AC converter using IGBT or MOS transistor according to claim 3, characterized in that Q1 is the same as Q3, and Q2 is the same as Q4.

5. The AC-AC converter using IGBT or MOS transistor according to claim 4, wherein the switching frequency of Q1 and Q3 is 20KHZ, and the switching frequency of Q2 and Q4 is 50 HZ.

6. An AC-AC converter using IGBT or MOS transistor according to any one of claims 1-5, characterized in that the IGBT module can be replaced by MOS transistor.

7. The method as claimed in any one of claims 1 to 5, wherein the relative potential of L, N two phase lines at the AC output terminal is determined by the control circuit, when the L line potential is higher than the N line potential, Q2 is turned off and Q4 is turned on; on the contrary, when the L line potential is lower than the N line potential, Q2 is turned on, and Q4 is turned off.

8. The method as claimed in claim 7, wherein the switching frequency of Q2, Q4 is 50Hz, and is synchronized with the phase line potential variation.

9. The method as claimed in claim 7, wherein the switching frequency of Q1, Q3 is 20KHZ, and the control circuit performs PWM modulation according to the output power.

Technical Field

The invention relates to the technical field of power electronics, in particular to an AC-AC converter and a control method thereof.

Background

With the large-scale application of electric energy in the industrial and civil fields, various power change devices such as switching power supplies and frequency converters, which use single-phase electricity and three-phase electricity as initial energy supply modes, are being used greatly. However, in some special application fields of electric power, an electric energy conversion mode of firstly rectifying and then inverting is still uniformly adopted, so that the overall input power factor of the electric equipment is low, and the power supply conversion efficiency is not high.

Disclosure of Invention

Based on the technical problems in the background art, the invention develops a method for adjusting output power or converting output current according to an alternating current-alternating current mode aiming at the problems that the overall input power factor of electric equipment is low and the power conversion efficiency is not high due to the mode of converting electric energy according to alternating current-direct current-alternating current in the prior art, so that the input power factor of the electric equipment can be greatly improved, the pollution of the electric equipment to a power grid is reduced, and the conversion efficiency of the electric equipment can be effectively improved.

The invention relates to an AC-AC converter using IGBT or MOS tube, comprising: the control circuit is electrically connected with the alternating current output end and is electrically connected with two parallel IGBT modules which are a first IGBT module and a second IGBT module respectively; the first and second IGBT modules are each connected in parallel with two series-connected diodes, wherein the first IGBT module is connected in parallel with D1 and D2, and the second IGBT module is connected in parallel with D3 and D4 diodes; the IGBT module comprises two series-connected IGBT switching tubes and anti-parallel diodes thereof, wherein the first IGBT module comprises Q1 and Q2 switching tubes, and the second IGBT module comprises Q3 and Q4 switching tubes; the output ends of the first IGBT module and the second IGBT module are a first output end and a second output end; the first output end is connected with an inductor in series; the capacitor is connected with one end of the inductor and one end of the load, and the other end of the capacitor is connected with the second output end and the other end of the load.

Furthermore, the two series-connected IGBT switching tubes are connected with the two series-connected diodes in parallel, and connection points are arranged between the first output end and the two IGBT switching tubes and between the two diodes.

Further, the first IGBT module and the second IGBT module are symmetrically connected.

Further, Q1 is the same as Q3, and Q2 is the same as Q4.

Further, the switching frequency of the Q1 and the Q3 is 20KHZ, and the switching frequency of the Q2 and the Q4 is 50 HZ.

Further, the IGBT module can be replaced by an MOS tube.

The invention also provides a control method of the converter, which comprises the following steps:

the control circuit judges the relative potential of L, N phase lines at the AC output end, when the potential of the L line is higher than that of the N line, Q2 is closed, and Q4 is conducted; on the contrary, when the L line potential is lower than the N line potential, Q2 is turned on, and Q4 is turned off.

Further, the switching frequency of the Q2 and the Q4 is 50HZ, and is synchronous with the potential change of the phase line; the switching frequency of Q1 and Q3 is 20KHZ, and PWM modulation is performed by the control circuit according to the output power. Obviously, in the whole circuit, Q2, Q4 function as blocking and freewheeling, similar to the freewheeling diodes in the chopper circuit; q1, Q3 act as chopping, with the magnitude of its on duty cycle acting to regulate the magnitude of the output power, and Q1 and Q3 only act when the phase line to which they are connected is at a relatively high potential.

The invention has the beneficial effects that:

the invention eliminates the electronic components in the process of rectifying alternating current into direct current in the prior art, reduces the production cost and reduces the volume of the converter. In addition, the invention only has the through loss of two PN junctions, the power factor is approximate to 1, and the loss is obviously reduced compared with the traditional mode.

The invention adopts the AC-AC main circuit control mode, reduces the electric energy conversion flow, thereby improving the power conversion efficiency, reducing electronic components, reducing the production cost and reducing the volume of the converter.

Drawings

FIG. 1 is a diagram of a main circuit for power conversion according to AC-DC-AC power usage in the prior art;

FIG. 2 is a schematic diagram of the main circuit of a single-phase AC-AC converter using IGBT or MOS according to the present invention;

FIG. 3 is a schematic diagram of the main circuit of the three-phase AC-AC converter of the present invention using IGBT or MOS;

FIG. 4 is a sine graph of electronic speed regulation using thyristors in the prior art;

FIG. 5 is a sinogram of an electronic governor using the present invention;

fig. 6 is a schematic diagram of electronic speed regulation using the present invention.

Detailed Description

The present invention will be further illustrated with reference to the following specific examples.