CN105353290A - Detection circuit for judging on-off state of channel in alternating-current solid-state power controller - Google Patents

Abstract

The invention relates to a detection circuit for judging the on-off state of a channel in an alternating-current solid-state power controller. The detection circuit is applied to the power distribution devices of airborne equipment. The detection circuit is mainly composed of a voltage sampling circuit unit, a voltage following circuit unit and an alternating-current voltage effective value conversion circuit unit. The detection circuit of the invention has the advantages of simple circuit structure, high integration degree, high reliability and high detection accuracy, and can assist in preventing false positives.

Description

A kind of testing circuit for judging channel switch state in alternating current solid-state power controller

Technical field

The present invention relates to solid-state power controller SSPC, particularly a kind of testing circuit for judging channel switch state in alternating current solid-state power controller.

Background technology

Solid-state power controller SSPC (Solid-StatePowerController) is a kind of Intellectualized Switchgear of gauge tap break-make in solid state distribution system; it is indispensable power distribution equipment in airborne equipment; its function comprises the opening of load, turns off; on off state is uploaded, current value is uploaded, overcurrent protection etc.; it have contactless, without electric arc, noiseless, response is fast, electromagnetic interference (EMI) is little, the life-span is long, reliability is high and be convenient to the advantages such as computer long-distance control, current widespread use in flight sequencing.Wherein, upload about on off state, first need to judge SSPC switch opening state in advance, and then just can upload.And current testing circuit structure relative complex, using discrete electronic devices and components more, integrated level is not high, reliability is lower slightly, accuracy of detection is slightly poor, have the possibility that there is wrong report.

Summary of the invention

The object of the invention is to solve prior art Problems existing, a kind of testing circuit for judging channel switch state in alternating current solid-state power controller provided.

To achieve these goals, technical scheme of the present invention is achieved in that a kind of testing circuit for judging channel switch state in alternating current solid-state power controller, in the power distribution equipment of airborne equipment, includes,

Voltage sampling circuit unit, it has the first resistance, the second resistance and the 3rd resistance, first termination SSPC AC power input end of described first resistance, the first end of the second resistance described in second termination of described first resistance, the first end of the 3rd resistance described in second termination of described second resistance, the second termination SSPC AC power output terminal of described 3rd resistance;

Voltage follower circuit unit, it has the 4th resistance, 5th resistance, 6th resistance, 7th resistance and voltage follower, the first end of described 4th resistance connects the second end of described first resistance and the first end of described second resistance respectively, second end of described 4th resistance connects the described first end of the 7th resistance and the inverting input of described voltage follower respectively, the first end of described 5th resistance connects the second end of described second resistance and the first end of described 3rd resistance respectively, second end of described 5th resistance connects the described first end of the 6th resistance and the normal phase input end of described voltage follower respectively, the output terminal of voltage follower described in second termination of described 7th resistance, and,

Alternating voltage RMS-DC converter circuit unit, it has RMS conversion device, the output terminal of voltage follower and the second end of described 7th resistance described in the high impedance input termination of described RMS conversion device, described RMS conversion device the AD conversion mouth of output termination control processor CPU.

As a kind of preferred version of the testing circuit for judging channel switch state in alternating current solid-state power controller, positive supply termination first positive voltage terminal of described RMS conversion device, the first end of average capacitance termination first electric capacity of described RMS conversion device, the negative power end of described RMS conversion device and the second end of described first electric capacity all connect the first negative voltage side, the first end of described very effectively output terminal filter capacitor termination second electric capacity of converter, the output terminal of RMS conversion device described in second termination of described second electric capacity, the first end of Low ESR input termination the 3rd electric capacity of described RMS conversion device, second end of described 3rd electric capacity and the equal ground connection of common port of described RMS conversion device.

Compared with prior art, the present invention at least has the following advantages: circuit structure is simple, and integrated level is high, and reliability is high, accuracy of detection is slightly high, prevents wrong report.

Accompanying drawing explanation

Fig. 1 is the electrical block diagram of one embodiment of the invention.

Embodiment

Below in conjunction with drawings and Examples, the present invention is elaborated.

Refer to Fig. 1, shown in figure is a kind of testing circuit for judging channel switch state in alternating current solid-state power controller.Wherein, exchange SSPC on-off circuit to form primarily of SSPC AC power input end POWERIN, the first switching tube MOS1, second switch pipe MOS2, the 8th resistance R8 and SSPC AC power output terminal POWEROUT.

Described testing circuit mainly contains voltage sampling circuit unit, voltage follower circuit unit and alternating voltage RMS-DC converter circuit unit composition.

Described voltage sampling circuit unit has the first resistance R1, the second resistance R2 and the 3rd resistance R3.SSPC AC power input end POWERIN described in first termination of described first resistance R1, the first end of the second resistance R2 described in second termination of described first resistance R1, the first end of the 3rd resistance R3 described in second termination of described second resistance R2, SSPC AC power output terminal POWEROUT described in second termination of described 3rd resistance R3.

Described voltage follower circuit unit has the 4th resistance R4, the 5th resistance R5, the 6th resistance R6, the 7th resistance R7 and voltage follower U1.The first end of described 4th resistance R4 connects second end of described first resistance R1 and the first end of described second resistance R2 respectively, second end of described 4th resistance R4 connects the first end of described 7th resistance R7 and the inverting input of described voltage follower U1 respectively, the first end of described 5th resistance R5 connects second end of described second resistance R2 and the first end of described 3rd resistance R3 respectively, second end of described 5th resistance R5 connects the first end of described 6th resistance R6 and the normal phase input end of described voltage follower U1 respectively, the output terminal of voltage follower U1 described in second termination of described 7th resistance R7.The gain of described voltage follower U1 is regulated by the size of described 7th resistance R7.

Described alternating voltage RMS-DC converter circuit unit has RMS conversion device U2.In the present embodiment, described RMS conversion device U2 system adopts AD736.The high impedance input end VIN of described RMS conversion device U2 connects the output terminal of described voltage follower U1 and second end of described 7th resistance R7, described RMS conversion device U2 output terminal OUTPUT connect the AD conversion mouth of control processor CPU, positive power source terminal+the VS of described RMS conversion device U2 meets the first positive voltage terminal VCC, the average capacitance end CAV of described RMS conversion device U2 connects the first end of the first electric capacity, negative power end-the VS of described RMS conversion device U2 and the second end of described first electric capacity all meet the first negative voltage side VEE, the output terminal filter capacitor end CF of described very effectively converter connects the first end of the second electric capacity, the output terminal OUTPUT of RMS conversion device U2 described in second termination of described second electric capacity, the Low ESR input end CC of described RMS conversion device U2 connects the first end of the 3rd electric capacity, second end of described 3rd electric capacity and the equal ground connection GND of common port COM of described RMS conversion device U2.

Be not difficult to find out, the voltage U c of the output terminal of described voltage follower U1 calculates by following:

$\frac{Ua-\frac{R6}{R5+R6}\×Ub}{R4}=\frac{\frac{R6}{R5+R6}\×Ub-Uc}{R7}$

Wherein, the voltage at the first end place of the described second resistance R2 of Ua system, the voltage at the second end place of the described second resistance R2 of Ub system.

As R4=R5=R6=R7,

$Ua-\frac{1}{2}Ub=\frac{1}{2}Ub-Uc$

Therefore: Uc=Ub-Ua

The voltage at voltage U b-Ua i.e. described second resistance R2 two ends.

If have load and switch is not opened time, the voltage at described second resistance R2 two ends is that AC power input voltage Uin (115VAC/400Hz) divides by described first resistance R1, described second resistance R2, described 3rd resistance R3 the voltage be pressed on described second resistance R2.That is,

$\begin{array}{c}Uc=Ub-Ua=-\frac{R2}{R1+R2+R3}\×Iin\\ =-\frac{R2}{R1+R2+R3}\×115V\end{array}$

If have load and switch is opened time, the voltage at described second resistance R2 two ends is described first switching tube MOS1, conduction voltage drop on described 8th resistance R8 and described second switch pipe MOS2 divides by described first resistance R1, described second resistance R2, described 3rd resistance R3 the voltage be pressed on described second resistance R2.The conduction voltage drop of switch generally can at about 450mV, that is,

$Uc=Ub-Ua=-\frac{R2}{R1+R2+R3}\×450mV$

If time non-loaded, do not have electric current to flow through from SSPC AC power input end POWERIN to SSPC AC power output terminal POWEROUT, described second resistance R2R2 two ends pressure drop is 0, that is, Uc=0V.

According to above-mentioned, the output voltage of the output terminal of described RMS conversion device U2 also has corresponding three kinds of different outputs in varied situations.Described control processor CPU can contrast according to the output voltage values collected from described RMS conversion device U2 and default set-point, thus judges three kinds of states of switch.These three kinds of states are respectively: have load switch not open, have load switch to open with non-loaded.It should be noted that, those skilled in the art can in conjunction with above-mentioned and through simply calculating default set-point corresponding to three kinds of states, seldom repeat at this.

Below only have expressed embodiments of the present invention, it describes comparatively concrete and detailed, but can not therefore be construed as limiting the scope of the patent.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection domain of patent of the present invention should be as the criterion with claims.

Claims (3)

1., for judging a testing circuit for channel switch state in alternating current solid-state power controller, in the power distribution equipment of airborne equipment, it is characterized in that, including,

Voltage sampling circuit unit, it has the first resistance, the second resistance and the 3rd resistance, first termination SSPC AC power input end of described first resistance, the first end of the second resistance described in second termination of described first resistance, the first end of the 3rd resistance described in second termination of described second resistance, the second termination SSPC AC power output terminal of described 3rd resistance;

Voltage follower circuit unit, it has the 4th resistance, 5th resistance, 6th resistance, 7th resistance and voltage follower, the first end of described 4th resistance connects the second end of described first resistance and the first end of described second resistance respectively, second end of described 4th resistance connects the described first end of the 7th resistance and the inverting input of described voltage follower respectively, the first end of described 5th resistance connects the second end of described second resistance and the first end of described 3rd resistance respectively, second end of described 5th resistance connects the described first end of the 6th resistance and the normal phase input end of described voltage follower respectively, the output terminal of voltage follower described in second termination of described 7th resistance, and,

Alternating voltage RMS-DC converter circuit unit, it has RMS conversion device, the output terminal of voltage follower and the second end of described 7th resistance described in the high impedance input termination of described RMS conversion device, described RMS conversion device the AD conversion mouth of output termination control processor CPU.

2. a kind of testing circuit for judging channel switch state in alternating current solid-state power controller according to claim 1, it is characterized in that, positive supply termination first positive voltage terminal of described RMS conversion device, the first end of average capacitance termination first electric capacity of described RMS conversion device, the negative power end of described RMS conversion device and the second end of described first electric capacity all connect the first negative voltage side, the first end of described very effectively output terminal filter capacitor termination second electric capacity of converter, the output terminal of RMS conversion device described in second termination of described second electric capacity, the first end of Low ESR input termination the 3rd electric capacity of described RMS conversion device, second end of described 3rd electric capacity and the equal ground connection of common port of described RMS conversion device.

3. a kind of testing circuit for judging channel switch state in alternating current solid-state power controller according to claim 1 and 2, it is characterized in that, described RMS conversion device system adopts AD736, and described voltage follower system adopts Linear Tech (Linear) two-way zero shift operational amplifier LTC2051.