阅读说明：本技术 一种开关直流电源电路 (switching DC power supply circuit ) 是由 张斌 于 2019-11-13 设计创作，主要内容包括：本发明提供了一种开关直流电源电路,包括输入单元、整流滤波电路、逆变电路、PWM控制电路、高频变压器、以及输出单元,输入单元连接三相电网,三相电网电压经整流滤波得到的520VDC平滑直流电压供给逆变电路,PWM控制电路输出控制信号,驱动高频变压器初级产生高频脉冲电压,变压器次级电压整流滤波后向负载提供能量,得到输出纹波小的稳定直流电压,最后通过输出单元输出。本发明与传统的可控硅整流器和线性电源相比,高效高频开关直流电源使用效率高,稳压稳流瞬态响应指标先进,输出波形平滑,具有省电、质量稳定且容易控制的特点。(The invention provides switch direct current power supply circuits, which comprise an input unit, a rectification filter circuit, an inverter circuit, a PWM control circuit, a high-frequency transformer and an output unit, wherein the input unit is connected with a three-phase power grid, 520VDC smooth direct current voltage obtained by rectifying and filtering the voltage of the three-phase power grid is supplied to the inverter circuit, the PWM control circuit outputs a control signal to drive the primary of the high-frequency transformer to generate high-frequency pulse voltage, the secondary voltage of the transformer provides energy to a load after rectification and filtering to obtain stable direct current voltage with small output ripples, and finally the stable direct current voltage is output through the output unit.)

The switching direct-current power supply circuit is characterized by comprising an input unit, a rectification filter circuit, an inverter circuit, a PWM (pulse-width modulation) control circuit, a high-frequency transformer and an output unit, wherein the input unit is connected with a three-phase power grid, 520VDC smooth direct-current voltage obtained by rectifying and filtering the voltage of the three-phase power grid is supplied to the inverter circuit, the PWM control circuit outputs a control signal to drive a primary side of the high-frequency transformer to generate high-frequency pulse voltage, the rectification filter of the secondary voltage of the transformer provides energy to a load, stable direct-current voltage with small output ripples is obtained, and the stable direct-current voltage is.

2. The switch DC power supply circuit according to claim 1, wherein the output unit is further connected to a feedback loop, the feedback loop is connected to the PWM control circuit, the feedback loop includes but is not limited to a voltage stabilizing circuit, a current limiting circuit, a constant current circuit, and a constant voltage circuit, so as to stabilize the output.

3. The switching DC power supply circuit according to claim 1, further comprising a protection circuit having over-temperature, over-current, over-voltage and short-circuit protection functions, the protection circuit being connected to the PWM control circuit.

4. The kinds of switch DC power supply circuit of claim 1, wherein the rectification filter circuit comprises a rectification unit, a surge protection unit, a power factor correction unit, and a filter unit.

5. The switching DC power supply circuit according to claim 1, wherein the inverter circuit includes a high power IGBT module.

6. The kinds of switch DC power supply circuit of claim 1, wherein the PWM control circuit comprises a comparator circuit and an operational amplifier circuit.

7. The kinds of switch DC power supply circuit of claim 1, wherein the inverter circuit is a full-bridge inverter circuit.

8. The switching DC power supply circuit according to claim 1, further comprising a temperature acquisition circuit connected to the inverter circuit, the high frequency transformer, and the high frequency rectification filter circuit, and transmitting the acquired data to the PWM control circuit.

9. The switch DC power supply circuit according to claim 5, further comprising a driving unit, wherein the PWM control circuit drives the power module in the inverter circuit through the isolation driver.

10. The kinds of switch DC power supply circuit of claim 1, further comprising a display unit, wherein the PWM control circuit displays the control result through the display unit.

Technical Field

The invention belongs to the field of switching power supplies, and particularly relates to switching direct-current power supply circuits.

Background

The switching power supply is an electric energy conversion device composed of a duty ratio controlled switching circuit, used for AC-DC or DC-DC electric energy conversion, the core of the switching power supply is a power electronic switching circuit, according to the requirement of the load to the output voltage stabilization or current stabilization characteristic of the power supply, the switching circuit is controlled by using feedback control current and a duty ratio control method.

Disclosure of Invention

In view of the above, the present invention is directed to provide switching dc power circuits to improve the utilization efficiency and reliability stability.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

switch DC power supply circuit comprises an input unit, a rectification filter circuit, an inverter circuit, a PWM control circuit, a high frequency transformer and an output unit, wherein the input unit is connected with a three-phase power grid, the 520VDC smooth DC voltage obtained by the three-phase power grid voltage through rectification filter is supplied to the inverter circuit, the PWM control circuit outputs a control signal to drive the high frequency transformer to generate a high frequency pulse voltage, the transformer secondary voltage is rectified and filtered to provide energy to a load, a stable DC voltage with small output ripple is obtained, and finally the stable DC voltage is output through the output unit.

Further , the output unit is further connected to a feedback loop that is connected to the PWM control circuit, the feedback loop including, but not limited to, a voltage stabilizing circuit, a current limiting circuit, a constant current circuit, and a constant voltage circuit, so that the output is stabilized.

, it also includes a protection circuit with over-temperature, over-current, over-voltage and short circuit protection function, which is connected with the PWM control circuit.

Further , the rectifying-filtering circuit includes a rectifying unit, a surge protection unit, a power factor correction unit, and a filtering unit.

Further , the inverter circuit includes a high power IGBT module.

Further , the PWM control circuit includes a comparator circuit and an operational amplifier circuit.

And , the inverter circuit is a full-bridge inverter circuit.

And , the intelligent power supply further comprises a temperature acquisition circuit, wherein the temperature acquisition circuit is connected with the inverter circuit, the high-frequency transformer and the high-frequency rectification filter circuit and transmits acquired data to the PWM control circuit.

And , the inverter circuit further comprises a driving unit, and the PWM control circuit drives the power module in the inverter circuit through the isolation driver.

And , a display unit is also included, and the PWM control circuit displays the control result through the display unit.

Compared with the prior art, the switch direct-current power supply circuits have the following advantages:

(1) the invention adopts low-loss high-frequency magnetic core, imported high-speed IGBT soft switching technology and rectifier elements, so that the heat loss of power supply conversion is small, and the efficiency is high;

(2) the power factor correction unit can reduce the interference of harmonic waves to a power grid;

(3) the power supply anti-surge circuit and the soft start circuit reduce the impact of power supply start on a power grid;

(4) the invention utilizes the comparison and operational amplification circuit to control the feedback loop, so that the control precision is higher;

(5) the invention makes the output voltage and current adjustable within the rated output range through the PWM control circuit;

(6) the invention adopts the high-efficiency full-bridge conversion circuit, so that the power of the power supply is larger and more stable;

(7) the invention is provided with the protection circuit, so that the power supply is safer and more reliable in working.

Drawings

The accompanying drawings, which form a part hereof , are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, an illustrative embodiment of the invention and the description of the invention for purposes of explanation and not limitation, of the invention, wherein:

fig. 1 is a schematic diagram of a circuit principle of kinds of switching dc power supplies according to an embodiment of the present invention.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings for convenience in describing the invention and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are not to be construed as limiting the invention.

In the description of the present invention, it should be noted that unless otherwise specifically stated or limited, the terms "mounted," "connected," and "connected" are used to mean, for example, either fixedly or removably connected or physically connected, mechanically or electrically connected, directly or indirectly connected through an intermediary, or communicating between two elements.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in figure 1, the invention provides kinds of switch DC power supply circuits, which mainly comprise a rectifier filter circuit, a bridge type conversion circuit, a PWM control circuit, a constant voltage and constant current circuit, a protection circuit and the like.

After the three-phase power grid voltage passes through a power switch, the 520VDC smooth direct-current voltage obtained by rectification, surge prevention, power factor correction and filtering is supplied to an inverter circuit. The inverter circuit mainly comprises a high-power IGBT module. When the PWM output control signal drives the power module to drive the primary of the high-frequency transformer to generate high-frequency pulse voltage through the isolation driver, the secondary voltage of the transformer provides energy to the load after rectification and filtering, and stable direct-current voltage with small output ripple waves is obtained.

The output end is respectively connected with feedback loops of constant voltage, constant current, voltage limiting and the like. When the power supply works in a voltage stabilizing state, the voltage stabilizing circuit plays a role, when the output voltage is increased or decreased, the sampling voltage is compared with the reference voltage through a voltage comparator inside the voltage stabilizing circuit, the error signal voltage of the sampling voltage is added to the PWM control circuit, the PWM output pulse width is correspondingly changed, and therefore the purpose of stabilizing the output voltage is achieved, and if the load current is too high, the current limiting circuit works, and the output current is limited within a current limiting set value. Similarly, when the power supply operates in a constant current state, the constant current circuit functions to stabilize the output current within a set value, and when the load changes into a constant voltage state, the constant voltage circuit clamps the output voltage at a voltage limiting value.

The constant voltage and constant current state is automatically switched according to the load condition.

The power supply has a constant voltage and constant current output function, the output voltage and the output current can be continuously adjusted from approximately 0 to the maximum value, and the maximum output current can be set in a constant voltage mode; the maximum output voltage can be set in the constant current mode and can be switched with each other. The power supply has complete protection functions and has over-temperature, over-current, over-voltage and short-circuit protection functions. In the constant voltage output mode, when the overvoltage set value is exceeded, the output is disconnected. In the constant current output mode, when the output voltage exceeds a constant current output value, the output voltage is reduced, and the output current is kept stable.

When abnormal conditions, such as input phase loss, output overvoltage, overcurrent, overheating and the like, generate protection signals to be applied to the protection control circuit, and the protection circuit outputs voltages to be applied to the PWM circuit to enable the PWM circuit to stop outputting, so that the purpose of protecting the power supply is achieved.

Compared with the traditional silicon controlled rectifier and linear power supply, the high-efficiency high-frequency switching direct-current power supply has the characteristics of high use efficiency, advanced voltage and current stabilization transient response index, smooth output waveform, power saving, stable quality and easiness in control.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.