阅读说明：本技术 一种开关电源高带宽线性放大电路及其控制方法 (High-bandwidth linear amplification circuit of switching power supply and control method thereof ) 是由 齐欣 刘云涛 李君� 张文庆 黄远 张旌 于 2020-04-24 设计创作，主要内容包括：本发明公开了一种开关电源高带宽线性放大电路及其控制方法,该电路包括主电路和控制电路,主电路包括开关电源、线性电路和负载电路,开关电源与线性电路并联,线性电路与负载电路并联；线性支路包括第二电感、线性调整管和电压源；第二电感与开关电源输出端的一端连接,第二电感另一端与线性调整管的C极连接,线性调整管的E极与电压源的负极连接,电压源的正极与开关电源输出端的另一端连接；控制电路包括用于驱动开关电源的开关电源控制器、功率变换器、线性模块控制器和用于调整线性支路电流的线性模块；功率变换器与开关电源控制器连接,线性模块控制器与线性模块连接。本发明提高了负载电流带宽,实现了电流的正负斜率控制和正负电压输出。(The invention discloses a switching power supply high-bandwidth linear amplification circuit and a control method thereof, wherein the circuit comprises a main circuit and a control circuit, the main circuit comprises a switching power supply, a linear circuit and a load circuit, the switching power supply is connected with the linear circuit in parallel, and the linear circuit is connected with the load circuit in parallel; the linear branch comprises a second inductor, a linear adjusting tube and a voltage source; the second inductor is connected with one end of the output end of the switching power supply, the other end of the second inductor is connected with the C pole of the linear adjusting tube, the E pole of the linear adjusting tube is connected with the negative pole of the voltage source, and the positive pole of the voltage source is connected with the other end of the output end of the switching power supply; the control circuit comprises a switching power supply controller for driving the switching power supply, a power converter, a linear module controller and a linear module for adjusting the current of the linear branch circuit; the power converter is connected with the switching power supply controller, and the linear module controller is connected with the linear module. The invention improves the load current bandwidth and realizes the positive and negative slope control and the positive and negative voltage output of the current.)

1. A high-bandwidth linear amplification circuit of a switching power supply, comprising: a main circuit and a control circuit, the main circuit comprises a switch power supply, a linear circuit and a load circuit,

the switching power supply is connected with a linear circuit in parallel, and the linear circuit is connected with a load circuit in parallel;

the linear branch comprises a second inductor, a linear adjusting tube and a voltage source;

the second inductor is connected with one end of the output end of the switching power supply, the other end of the second inductor is connected with the C pole of the linear adjusting tube, the E pole of the linear adjusting tube is connected with the negative pole of the voltage source, and the positive pole of the voltage source is connected with the other end of the output end of the switching power supply;

the control circuit comprises a switching power supply controller, a power converter, a linear module controller and a linear module;

the power converter is connected with the switching power supply controller, the linear module controller is connected with the linear module, the linear module is connected with the linear branch circuit, the switching power supply controller is used for driving the switching power supply, and the linear module is used for adjusting the current of the linear branch circuit.

2. The switching power supply high-bandwidth linear amplification circuit according to claim 1, wherein the switching power supply comprises a first capacitor, a second capacitor, a first power tube, a second power tube, a third power tube, a fourth power tube and a first inductor;

the first power tube, the second power tube, the third power tube and the fourth power tube form a bridge circuit, two ends of the first capacitor are respectively connected with a C pole of the first power tube and an E pole of the second power tube, a first end of the first inductor is connected with the E pole of the first power tube, a second end of the first inductor is connected with one end of the second capacitor, and the other end of the second capacitor is connected with the C pole of the fourth power tube.

3. The switching power supply high bandwidth linear amplification circuit of claim 1, wherein the load circuit comprises an output inductor and an output resistor, the output inductor being connected in series with the output resistor.

4. The switching power supply high-bandwidth linear amplification circuit according to claim 1, wherein the linear regulator adopts an NPN-type linear regulator, and the linear module adopts an NPN-type triode series power supply structure.

5. The switching power supply high-bandwidth linear amplification circuit according to claim 1, wherein the switching power supply controller adopts a PI structure or a PID structure, and the linear module controller adopts a PI structure.

6. The switching power supply high-bandwidth linear amplification circuit according to claim 1, wherein the control circuit further comprises a filter inductor, a filter capacitor, a compensation branch and a cable distributed inductor, a first end of the filter inductor is connected to one end of the power converter, a second end of the filter inductor is connected to a first end of the cable distributed inductor, a second end of the cable distributed inductor is connected to the load circuit, a first end of the filter capacitor is connected to a second end of the filter inductor, the other end of the filter capacitor is connected to the other end of the power converter, the filter capacitor is connected to the compensation branch in parallel, and the linear module is connected to the second end of the cable distributed inductor.

7. The switching power supply high-bandwidth linear amplification circuit according to claim 6, wherein the compensation branch is provided with a compensation capacitor and a compensation resistor, and the compensation capacitor and the compensation resistor are connected in series.

8. The switching power supply high-bandwidth linear amplification circuit according to claim 1 or 6, wherein the control circuit is further provided with a bias current setting end, and the bias current setting end is used for inputting a bias current in a positive direction to the switching power supply controller.

9. The control method of the high-bandwidth linear amplifying circuit of the switching power supply according to any one of claims 1 to 8, comprising the steps of:

inputting a positive bias current to the switching power supply controller, and outputting the positive bias current by the power converter;

the linear module controller adjusts the linear circuit control current after detecting the bias current in the positive direction;

and detecting the load current of the load circuit, the control current of the linear module controller and the control circuit of the switching power supply controller, calculating to obtain the high-frequency component of the input signal, and performing current regulation compensation by the linear module.

Technical Field

The invention relates to the technical field of power electronics, in particular to a high-bandwidth linear amplification circuit of a switching power supply and a control method thereof.

Background

The technology meets the requirement of high-bandwidth dynamic tracking precision of a radio frequency tuning bias current source in a China spallation neutron source project of national major scientific engineering. The foreign similar power supply adopts a linear power supply scheme, a large number of triodes are used for being output in parallel, and the amplification effect of the triodes is utilized to linearly amplify a small current signal output by the control circuit so as to realize large current output. The output bandwidth of the linear power supply can be made higher, but the whole machine is large in size and low in efficiency; the switching power supply works in a high-frequency on/off state, has small volume and high conversion efficiency, but has low output bandwidth, and the index requirement of the output bandwidth is difficult to achieve by only adopting the switching power supply.

Disclosure of Invention

In order to overcome the defects and shortcomings of the prior art, the invention provides the high-bandwidth linear amplification circuit of the switching power supply and the control method thereof.

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

the invention provides a high-bandwidth linear amplification circuit of a switching power supply, which comprises: a main circuit and a control circuit, the main circuit comprises a switch power supply, a linear circuit and a load circuit,

the switching power supply is connected with a linear circuit in parallel, and the linear circuit is connected with a load circuit in parallel;

the linear branch comprises a second inductor, a linear adjusting tube and a voltage source;

the second inductor is connected with one end of the output end of the switching power supply, the other end of the second inductor is connected with the C pole of the linear adjusting tube, the E pole of the linear adjusting tube is connected with the negative pole of the voltage source, and the positive pole of the voltage source is connected with the other end of the output end of the switching power supply;

the control circuit comprises a switching power supply controller, a power converter, a linear module controller and a linear module;

the power converter is connected with the switching power supply controller, the linear module controller is connected with the linear module, the linear module is connected with the linear branch circuit, the switching power supply controller is used for driving the switching power supply, and the linear module is used for adjusting the current of the linear branch circuit.

As a preferred technical solution, the switching power supply includes a first capacitor, a second capacitor, a first power tube, a second power tube, a third power tube, a fourth power tube, and a first inductor;

the first power tube, the second power tube, the third power tube and the fourth power tube form a bridge circuit, two ends of the first capacitor are respectively connected with a C pole of the first power tube and an E pole of the second power tube, a first end of the first inductor is connected with the E pole of the first power tube, a second end of the first inductor is connected with one end of the second capacitor, and the other end of the second capacitor is connected with the C pole of the fourth power tube.

As a preferred technical solution, the load circuit includes an output inductor and an output resistor, and the output inductor is connected in series with the output resistor.

As a preferred technical scheme, the linear adjusting tube is an NPN-type linear adjusting tube, and the linear module is an NPN-type triode series power supply structure.

As a preferred technical solution, the switching power supply controller adopts a PI structure or a PID structure, and the linear module controller adopts a PI structure.

As a preferred technical solution, the control circuit is further provided with a filter inductor, a filter capacitor, a compensation branch and a cable distributed inductor, wherein a first end of the filter inductor is connected with one end of the power converter, a second end of the filter inductor is connected with a first end of the cable distributed inductor, a second end of the cable distributed inductor is connected with the load circuit, one end of the filter capacitor is connected with a second end of the filter inductor, the other end of the filter capacitor is connected with the other end of the power converter, the filter capacitor is connected with the compensation branch in parallel, and the linear module is connected with the second end of the cable distributed inductor.

As a preferred technical scheme, the compensation branch is provided with a compensation capacitor and a compensation resistor, and the compensation capacitor and the compensation resistor are connected in series.

As a preferable technical solution, the control circuit is further provided with a bias current setting end, and the bias current setting end is used for inputting a bias current in a positive direction to the switching power supply controller.

The invention also provides a control method of the high-bandwidth linear amplification circuit of the switching power supply, which comprises the following steps:

inputting a positive bias current to the switching power supply controller, and outputting the positive bias current by the power converter;

the linear module controller adjusts the linear circuit control current after detecting the bias current in the positive direction;

and detecting the load current of the load circuit, the control current of the linear module controller and the control circuit of the switching power supply controller, calculating to obtain the high-frequency component of the input signal, and performing current regulation compensation by the linear module.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the invention adopts the characteristic that the current sources are added in parallel to be equal to the algebraic sum of the output current values of the current sources and the linear circuit, and adopts the switching power supply and the linear circuit to be connected in parallel, thereby solving the technical problems of low efficiency and large volume when the linear circuit is directly adopted to output large current, and achieving the technical effects of improving the efficiency and reducing the volume output current.

(2) The invention adopts a parallel structure of the switching power supply and the linear circuit, the system bandwidth is determined by the high value of the switching power supply and the linear circuit, the technical problem that the bandwidth of the switching power supply cannot exceed the switching frequency is solved, and the technical requirements of high bandwidth and high tracking precision are met.

(3) According to the invention, the voltage source S1 is combined with the NPN type linear adjusting tube in the linear circuit, so that the technical problem that the positive and negative voltage output can only be realized by combining two complementary pair tubes in the traditional linear circuit is solved, the effect of controlling the rising and falling edge waveforms is achieved, the positive and negative slope control of the current and the positive and negative voltage output are realized, and the effect of two-quadrant work is finally achieved.

(4) The invention adopts the hybrid control technology of adding the linear circuit after the switching power supply, solves the problem of bandwidth allocation of the switching power supply and the linear circuit when the switching power supply and the linear circuit are matched, achieves the aim of automatically allocating dynamic current, and realizes the control effect of improving the system bandwidth after adding the external control circuit on the premise of not changing the original control scheme.

Drawings

Fig. 1 is a schematic diagram of a main circuit of a high-bandwidth linear amplification circuit of a switching power supply in the embodiment;

fig. 2 is a block diagram of a control circuit of the high-bandwidth linear amplifying circuit of the switching power supply of the embodiment;

fig. 3 is a block diagram of an equivalent control circuit of the switching power supply high-bandwidth linear amplification circuit after high-frequency signals are superimposed on the control circuit;

fig. 4 is a schematic diagram of a bandwidth test result of the high-bandwidth linear amplifying circuit of the switching power supply of the embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.