CN210142978U - Three-phase rectifying and filtering soft start circuit - Google Patents

Abstract

The utility model discloses a soft start circuit of three-phase rectification filtering, including rectification filter circuit, start control circuit and electric capacity voltage detection circuit, rectification filter circuit's output links to each other with electric capacity voltage detection circuit, electric capacity voltage detection circuit's output links to each other with start control circuit, and this circuit adopts electric capacity voltage detection and increases time delay control, is fit for large capacity electric capacity soft start. High working reliability and strong anti-interference capability. The effect of preventing surge current is effectively played. Stable and reliable operation and long service life. The current rises smoothly in the starting process, and the EMC is better. The selected common components are easy to purchase and have short supply period.

Description

Three-phase rectifying and filtering soft start circuit

Technical Field

The utility model belongs to the technical field of switching power supply circuit, concretely relates to soft start-up circuit of three-phase rectification filtering.

Background

In the design of a high-power switching power supply, a three-phase rectification and capacitance filtering circuit is often adopted in an input part. At the moment when the three-phase power supply is switched on, a large instantaneous surge current can be formed because the initial voltage of the capacitor is zero. The peak current value can reach hundreds of amperes, which can cause overcurrent protection tripping of the circuit breaker, fuse blowing, ablation damage of contacts of a closing switch and abnormal closing of the switching power supply. Therefore, the loop impedance needs to be increased at the moment of closing to limit the capacitor charging current, and when the capacitor voltage approaches the AC voltage, the capacitor voltage is reduced or the bypass impedance enters a normal working state to achieve the purpose of soft start. The commonly used soft start circuit includes: a power thermistor circuit, an SCRR circuit with power-off detection, a circuit composed of a relay and a resistor, a timing circuit, and the like.

SUMMERY OF THE UTILITY MODEL

The utility model aims at solving the problem that exists on the above-mentioned prior art, provide a three-phase rectification filtering soft start circuit, this circuit adopts the circuit that contactor and resistance constitute and has increased time delay relay, can realize the purpose of soft start betterly to effectively guarantee switching power supply normally closes a floodgate.

In order to achieve the above purpose, the utility model adopts the following technical scheme: a three-phase rectifying and filtering soft start circuit comprises a rectifying and filtering circuit, a startup control circuit and a capacitor voltage detection circuit, wherein the output end of the rectifying and filtering circuit is connected with the capacitor voltage detection circuit, the output end of the capacitor voltage detection circuit is connected with the startup control circuit, the rectifying and filtering circuit comprises a resistor R1, a resistor R2, a resistor R3, a resistor R6, a resistor R7, a rectifier V1, a capacitor C1 and a capacitor C2, an AC380V three-phase power supply port is respectively connected with the input end of a rectifying bridge V1 through resistors R1, R2 and R3, the output end of the rectifying bridge V1 charges capacitors C1 and C2 through an inductor L1, the resistor R1, the resistor R2 and the resistor R3 are connected in parallel, the capacitor C1 and the capacitor C2 are connected in series, the resistor R2 is connected in parallel, and the capacitor C2 is connected in parallel.

The positive end of the capacitor voltage detection circuit is connected with the common end of resistors R8 and R9 through resistors R18, R16, R15, R14, R13 and R12, the other end of the resistor R9 is connected with the negative electrode of a polar capacitor C5 through a diode GRE2, the other end of the resistor R8 is connected with the negative electrode of a polar capacitor C5 through a resistor R10, two ends of the resistor R10 are connected with a capacitor C5 in parallel and then are sent to the input end of a solid-state switch S2, the output end of the solid-state switch S2 is connected with a resistor R11 and a capacitor C6 to form a resistance-capacitance absorption loop, the L port of a power supply AC220V is connected with the common end of a KT coil and a KT normally-open contact through a solid-state switch S2, the other end of the KT coil is connected with the N port of the power supply AC 220.

Direct-current voltage is input into an XT6+ port and an XT 6-port of the starting control circuit, a solid-state switch S1 is controlled, a K1 coil is conducted to be closed, soft starting is started, and the XT6+ port is connected with an XT 6-port through a current-limiting resistor R5 and a diode GRE 1; an XT6+ port is connected with an XT 6-port through resistors R4 and R6, two ends of the resistor R6 are connected with a capacitor C3 in parallel and then are sent to an input end of a solid-state switch S1, and an output end of the solid-state switch S1 is connected with the resistor R7 and the capacitor C4 to form a resistance-capacitance absorption loop; the L port of the power AC220 is connected with one end of a K1 coil through a solid-state switch S1, and the other end of the K1 coil is connected with the N port of the power AC 220.

As a further improvement of the three-phase rectifying and filtering soft start circuit of the utility model, the model of the solid-state switch S1 is G3MB-202 PL.

Advantageous effects

The utility model discloses a three-phase rectification filtering soft start circuit adopts the circuit that contactor and resistance constitute and has increased time delay relay. The circuit has the following advantages: the capacitor voltage detection is adopted, and delay control is added, so that the method is suitable for large-capacity capacitor soft start. High working reliability and strong anti-interference capability. The effect of preventing surge current is effectively played. Stable and reliable work and long service life (more than 20000 starting tests). The current rises smoothly in the starting process, and the EMC is better. The selected common components are easy to purchase and have short supply period.

Drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic diagram of the three-phase rectifying and filtering soft start circuit of the present invention;

FIG. 2 is a schematic diagram of a capacitor voltage detection circuit according to the present invention;

fig. 3 is a schematic diagram of the switch-on control circuit of the present invention.

Detailed Description

In order to make the technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

As shown in the figure: the embodiment of the utility model discloses three-phase rectification filtering soft start circuit, including rectification filter circuit, start control circuit and electric capacity voltage detection circuit, rectification filter circuit's output links to each other with electric capacity voltage detection circuit, electric capacity voltage detection circuit's output links to each other with start control circuit, and the circuit of this scheme adopts the circuit that contactor and resistance constitute and has increased time delay relay. The circuit adopts capacitor voltage detection and adds delay control, and is suitable for large-capacity capacitor soft start. High working reliability and strong anti-interference capability. The effect of preventing surge current is effectively played. The working is stable and reliable, the service life is long, the starting test is more than 20000 times, the current smoothly rises in the starting process, and the EMC is better.

The rectifying and filtering circuit comprises a resistor R1, a resistor R2, a resistor R3, a resistor R6, a resistor R7, a rectifier V1, a capacitor C1 and a capacitor C2, an AC380V three-phase power supply port is connected with the input end of a rectifying bridge V1 through resistors R1, R2 and R3 respectively, the output end of the rectifying bridge V1 charges the capacitors C1 and C2 through an inductor L1, the resistors R1, R2 and a resistor R3 are connected in parallel, the capacitor C1 and the capacitor C2 are connected in series, the resistor R6 is connected in parallel with the capacitor C1, and the resistor R7 is connected in parallel with the capacitor C2.

The positive end of the capacitor voltage detection circuit is connected with the common end of the resistors R8 and R9 through resistors R18, R16, R15, R14, R13 and R12, the other end of the resistor R9 is connected with the negative electrode of the polar capacitor C5 through a light-emitting diode GRE2, the other end of the resistor R8 is connected with the negative electrode of the polar capacitor C5 through a resistor R10, two ends of the resistor R10 are connected with the capacitor C5 in parallel and then are sent to the input end of a solid-state switch S2, the output end of the solid-state switch S2 is connected with a resistor R11 and a capacitor C6 to form a resistance-capacitance absorption loop, the L port of a power supply AC220V is connected with the common end of a KT normally open coil and the KT time delay closing instant disconnection contact through a solid-state switch S2, the other end of the KT coil is connected with the N port of the power.

The starting control circuit inputs direct-current voltage into an XT6+ port and an XT 6-port, controls a solid-state switch S1, switches on a K1 coil to be closed, and starts soft start, wherein the XT6+ port is connected with an XT 6-port through a current-limiting resistor R5 and a light-emitting diode GRE 1; an XT6+ port is connected with an XT 6-port through resistors R4 and R6, two ends of the resistor R6 are connected with a capacitor C3 in parallel and then are sent to an input end of a solid-state switch S1, and an output end of the solid-state switch S1 is connected with the resistor R7 and the capacitor C4 to form a resistance-capacitance absorption loop; the L port of the power AC220 is connected with one end of a K1 coil through a solid-state switch S1, and the other end of the K1 coil is connected with the N port of the power AC 220. In the scheme, the model of the solid-state switch S1 is G3MB-202 PL.

The above description is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments, and although the present invention has been disclosed with the preferred embodiments, it is not limited to the present invention, and any skilled person in the art can make some modifications or equivalent changes without departing from the technical scope of the present invention.

Claims (2)

1. The utility model provides a soft start circuit of three-phase rectification filtering, includes rectification filter circuit, start control circuit and electric capacity voltage detection circuit, rectification filter circuit's output links to each other with electric capacity voltage detection circuit, electric capacity voltage detection circuit's output links to each other its characterized in that with start control circuit: the rectifying and filtering circuit comprises a resistor R1, a resistor R2, a resistor R3, a resistor R6, a resistor R7, a rectifier V1, a capacitor C1 and a capacitor C2, an AC380V three-phase power port is respectively connected with the input end of a rectifying bridge V1 through resistors R1, R2 and R3, the output end of the rectifying bridge V1 charges capacitors C1 and C2 through an inductor L1, the resistor R1, the resistor R2 and a resistor R3 are connected in parallel, the capacitor C1 and the capacitor C2 are connected in series, the resistor R6 is connected in parallel with the capacitor C1, and the resistor R7 is connected in parallel with the capacitor C2;

the positive end of the capacitor voltage detection circuit is connected with the common ends of resistors R8 and R9 through resistors R18, R16, R15, R14, R13 and R12, the other end of the resistor R9 is connected with the negative electrode of a polar capacitor C5 through a diode GRE2, the other end of the resistor R8 is connected with the negative electrode of a polar capacitor C5 through a resistor R10, two ends of the resistor R10 are connected with a capacitor C5 in parallel and then are sent to the input end of a solid-state switch S2, the output end of the solid-state switch S2 is connected with a resistor R11 and a capacitor C6 to form a resistance-capacitance absorption loop, the L port of a power supply AC220V is connected with the common end of a KT coil and a KT normally-open contact through a solid-state switch S2, the other end of the KT coil is connected with the N port of the power supply AC 220;

direct-current voltage is input into an XT6+ port and an XT 6-port of the starting control circuit, a solid-state switch S1 is controlled, a K1 coil is conducted to be closed, soft starting is started, and the XT6+ port is connected with an XT 6-port through a current-limiting resistor R5 and a diode GRE 1; an XT6+ port is connected with an XT 6-port through resistors R4 and R6, two ends of the resistor R6 are connected with a capacitor C3 in parallel and then are sent to an input end of a solid-state switch S1, and an output end of the solid-state switch S1 is connected with the resistor R7 and the capacitor C4 to form a resistance-capacitance absorption loop; the L port of the power AC220 is connected with one end of a K1 coil through a solid-state switch S1, and the other end of the K1 coil is connected with the N port of the power AC 220.

2. The three-phase rectifying, filtering and soft-starting circuit as claimed in claim 1, wherein said solid state switch S1 is model G3MB-202 PL.

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