CN202600025U - Scalable vector graphics (SVG) power unit body direct current voltage detection circuit - Google Patents

Abstract

The utility model provides a scalable vector graphics (SVG) power unit body direct current voltage detection circuit which comprises a resistance voltage division circuit, a filter circuit, a follower circuit and a voltage frequency conversion circuit, wherein the resistance voltage division circuit, the filter circuit, the follower circuit and the voltage frequency conversion circuit are sequentially connected. After the resistance voltage division circuit reduces to-be-detected direct current voltage; the voltage is inputted into the filter circuit which absorbs higher harmonic component in voltage signals; after being stabilized by the follower circuit, the voltage is inputted into the voltage frequency conversion circuit to be converted into pulse signals; the frequency of the pulse signals is in direct proportion to the to-be-detected direct current voltage; and the size of the direct current voltage is reflected through the frequency of the pulse signals. According to the SVG power unit body direct current voltage detection circuit, the to-be-detected direct current voltage is converted to the pulse signals, the frequency of the pulse signals is in direct proportion to the amplitude of the voltage, and the size of the direct current voltage is reflected through the pulse signals, so isolation of high voltage and low voltage is effectively achieved, good voltage detection effect is achieved, meanwhile the manufacturing process is simple, and manufacturing cost is low.

Description

SVG power cell body DC voltage testing circuit

Technical field

The utility model relates to electric and electronic technical field, is specifically related to a kind of testing circuit of SVG power cell body DC voltage.

Background technology

Chain type SVG (static reacance generator) is every to be in series by some identical power cell bodies, for being maintained in covering device stable operation, must carry out real-time sampling to the DC voltage of each power cell body.The technical scheme that generally adopts at present is divided into two kinds: 1) adopt Hall element directly to measure; 2) isolate through linear optical coupling behind the electric resistance partial pressure.These two kinds of technological means all can be converted into higher DC voltage lower DC voltage, and can realize that high-low pressure effectively isolates, but the Hall element price is very high, is unfavorable for improving competitiveness of product; Be segmentation between the linear zone of linear optical coupling, and the linearity receives the influence of humiture bigger, the linearity also changes easily after the long-time running.

The utility model content

The purpose of the utility model is to overcome the shortcoming and defect of prior art, and a kind of SVG power cell body DC voltage testing circuit is provided, and can effectively realize the high and low pressure isolation, has good assay.

The purpose of the utility model realizes through following technical scheme:

A kind of SVG power cell body DC voltage testing circuit; Comprise the resistor voltage divider circuit, filtering circuit, follow circuit and the voltage-frequency change-over circuit that connect successively; After said resistor voltage divider circuit reduces DC voltage to be detected; Input absorbs the filtering circuit of the higher harmonic components in the voltage signal, at input voltage-frequency change-over circuit after the follow circuit voltage stabilizing voltage is changed into pulse signal.

Scheme according to above-mentioned the utility model; This circuit is converted into the pulse signal that frequency is directly proportional with voltage magnitude with measured DC voltage; The size that reflects DC voltage through the frequency of pulse signal; Effectively the realization high and low pressure is isolated simultaneously, has good detection effect and effectively realizes high pressure, low pressure isolation simultaneously, has good detection effect.

Therein among embodiment; Above-mentioned resistor voltage divider circuit comprises the resistance in series that is connected and composed by two above resistance series connection; Two input ends of said resistor voltage divider circuit are respectively the two ends of said resistance in series; And any input end grounding of said resistor voltage divider circuit; The output terminal of said resistor voltage divider circuit is arranged on the series connection intermediate point of any two adjacent resistors, and output voltage equals resistance sum that input voltage (being voltage to be detected) multiply by the resistance between output terminal and the ground again divided by the resistance sum of all resistance that are connected in series, because the resistance sum of the resistance between output terminal and the ground is less than the resistance sum of all resistance in seriess like this; Therefore, resistor voltage divider circuit has been reduced to lower output voltage with higher input voltage.

Therein among embodiment; Above-mentioned filtering circuit comprises the RC low-pass filter circuit; Said RC low-pass filter circuit comprises resistance and the direct earth capacitance that is connected with the output terminal of this RC low-pass filter circuit; The other end of resistance is connected with the input end of this RC low-pass filter circuit, the higher hamonic wave signal of RC low-pass filter circuit in can well the filtering d. c. voltage signal.

Description of drawings

Fig. 1 is the block diagram of the SVG power cell body DC voltage testing circuit of the utility model embodiment;

Fig. 2 is the circuit diagram of the SVG power cell body DC voltage testing circuit of the utility model one concrete example.

Embodiment

Below in conjunction with embodiment and accompanying drawing the utility model is set forth in detail, but the embodiment of the utility model is not limited thereto.

Embodiment

Referring to shown in Figure 1; Block diagram for the SVG power cell body DC voltage testing circuit of the utility model embodiment; SVG power cell body DC voltage testing circuit among this embodiment comprises resistor voltage divider circuit 101, filtering circuit 102, follow circuit 103 and the voltage-frequency change-over circuit 104 that connects successively; After said resistor voltage divider circuit 101 reduces DC voltage to be detected; Input absorbs the filtering circuit 102 of the higher harmonic components in the voltage signal, at input voltage-frequency change-over circuit after follow circuit 103 voltage stabilizings 104 voltage is changed into pulse signal.

Scheme according to above-mentioned the utility model; Make through resistor voltage divider circuit 101 and to reduce to lower d. c. voltage signal than higher d. c. voltage signal to be detected; Filtering circuit 102 absorbs the higher harmonic components in the d. c. voltage signals, and follow circuit 103 is guaranteed the stability of d. c. voltage signal, and voltage-frequency change-over circuit 104 is converted into pulse signal with d. c. voltage signal; The frequency of this pulse signal is directly proportional with DC voltage to be detected; Therefore can go out the size of d. c. voltage signal to be measured through the frequency response of pulse signal, effectively realize high pressure, low pressure isolation simultaneously, have good detection effect.

Among embodiment, referring to shown in Figure 2, resistor voltage divider circuit 201 comprises the resistance in series that is connected and composed by two above resistance series connection therein; The number of resistance in series and the resistance of each resistance can be decided according to specific requirement; But want two just can play the dividing potential drop effect at least, the situation shown in Fig. 2 is resistance R 1, resistance R 2, resistance R 3, the resistance R 4 formation resistance in series that is connected in series; Two input ends of resistor voltage divider circuit 201 are respectively the two ends of said resistance in series; These two input ends are promptly in resistance R 1 side of resistance in series shown in Fig. 2 and resistance R 4 sides of resistance in series, and any input end grounding of resistor voltage divider circuit 201, in this implements, are resistance R 4 side joint ground; The output terminal of resistor voltage divider circuit 201 is arranged on the series connection intermediate point of any two adjacent resistors; But adopting the purpose of resistor voltage divider circuit 201 is to transfer the higher output voltage of SVG power cell body to lower output voltage, and according to the principle of bleeder circuit, the resistance of the resistance that low-pressure side is corresponding is more little; The voltage of low-pressure side is also just more little; Therefore, what provide in this embodiment is that output terminal is connected between resistance R 3 and the resistance R 4, and output voltage equals resistance sum that input voltage (being voltage to be detected) multiply by resistance R 4 again divided by the resistance sum (the resistance sums of resistance R 1, resistance R 2, resistance R 3, resistance R 4 these four resistance) of all resistance that are connected in series like this; Because the resistance sum of the resistance between output terminal and the ground is less than the resistance sum of all resistance in seriess; Therefore, resistor voltage divider circuit 201 has been reduced to lower output voltage with higher input voltage, and the embodiment of the utility model is not limited to situation shown in Fig. 2.

Therein among embodiment; Referring to shown in Figure 2; Filtering circuit 202 comprises the RC low-pass filter circuit, and this RC low-pass filter circuit comprises resistance R 5 and the direct earth capacitance C1 that is connected with the output terminal of this RC low-pass filter circuit, and the other end of resistance R 5 is connected with the input end of this RC low-pass filter circuit; The higher hamonic wave signal of RC low-pass filter circuit in can well the filtering d. c. voltage signal, the embodiment of the utility model is not limited to situation shown in Fig. 2.

In order better to understand the utility model, specifically be exemplified as the principle of work that example is introduced the utility model in detail with one below.

Concrete example

Referring to shown in Figure 2; The circuit diagram of the SVG power cell body DC voltage testing circuit of concrete for this reason example; It comprises resistor voltage divider circuit 201, filtering circuit 202, follow circuit 203 and the voltage-frequency change-over circuit 204 that connects successively; The VFC (Voltage Frequency Converter) of mark is a voltage to frequency converter in voltage-frequency change-over circuit 204; What adopt in this concrete example is this model of VFC32, is not limited to this model in the practical application, and DC voltage to be detected is that direct current supports capacitor C in the chain type SVG power cell body _DcThe voltage U at two ends _Dc, divider resistance R ₁, R ₂, R ₃, R ₄Capacitor C is supported with direct current in the series connection back _DcParallel connection, resistor voltage divider circuit 201 is with U _DcBe reduced to U ₁, shown in (1):

$U_1=\frac{R_4}{R_1+R_2+R_3+R_4}\×U_{\mathrm{dc}}---\left(1\right)$

Filtering circuit 202 absorbs higher hamonic waves, to the not influence of fundametal compoment of voltage signal, can think output voltage U ₂With input voltage U ₁Equate, shown in (2):

u ₂＝U ₁ (2)

Follow circuit 203 burning voltage signals, output voltage U ₃With input voltage U ₂Equate, shown in (3):

U ₃＝U ₂ (3)

Voltage-frequency change-over circuit 204 converts voltage signal into pulse signal, the frequency of pulse signal and input voltage signal U ₃Amplitude be directly proportional, shown in (4):

$F=\frac{{\mathrm{<figure-callout\; id="3"\; label="U"\; filenames="HDA00001708050300012.png"\; state="\{\{state\}\}">U</figure-callout>}}_3}{7500R_7{C}_2}---\left(4\right)$

Comprehensive above-mentioned formula (1), formula (2), formula (3) and formula (4) can obtain DC voltage U to be detected _DcWith the relation of pulse signal frequency F, shown in (5):

$F=\frac{U_{\mathrm{dc}}}{7500R_7{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA00001708050300012.png"\; state="\{\{state\}\}">C</figure-callout>}}_2}\&times;\frac{R_4}{R_1+R_2+R_3+R_4}---\left(5\right)$

Under the situation that circuit parameter is confirmed, the value of resistance and electric capacity is definite value, can be with formula 5 arrangements:

F＝K×U _dc (6)

Wherein:

$K=\frac{R_4}{7500R_7{C}_2(R_1+R_2+R_3+R_4)}---\left(7\right)$

Shown in (6), through the related testing circuit of the utility model, with DC voltage U to be detected _DcBe converted into pulse signal, the frequency F of pulse signal and DC voltage U to be detected _DcBe directly proportional.

The above embodiment has only expressed several kinds of embodiments of the utility model, and it describes comparatively concrete and detailed, but can not therefore be interpreted as the restriction to the utility model claim.Should be pointed out that for the person of ordinary skill of the art under the prerequisite that does not break away from the utility model design, can also make some distortion and improvement, these all belong to the protection domain of the utility model.Therefore, the protection domain of the utility model patent should be as the criterion with accompanying claims.

Claims (3)

1. SVG power cell body DC voltage testing circuit; It is characterized in that; Comprise the resistor voltage divider circuit, filtering circuit, follow circuit and the voltage-frequency change-over circuit that connect successively; After said resistor voltage divider circuit reduced DC voltage to be detected, input absorbed the filtering circuit of the higher harmonic components in the voltage signal, at input voltage-frequency change-over circuit after the follow circuit voltage stabilizing voltage was changed into pulse signal.

2. SVG power cell body DC voltage testing circuit according to claim 1; It is characterized in that; Said resistor voltage divider circuit comprises the resistance in series that is connected and composed by two above resistance series connection; Two input ends of said resistor voltage divider circuit are respectively the two ends of said resistance in series, and any input end grounding of said resistor voltage divider circuit, and the output terminal of said resistor voltage divider circuit is arranged on the series connection intermediate point of any two adjacent resistors.

3. SVG power cell body DC voltage testing circuit according to claim 1 and 2; It is characterized in that; Said filtering circuit comprises the RC low-pass filter circuit; Said RC low-pass filter circuit comprises resistance and the direct earth capacitance that is connected with the output terminal of this RC low-pass filter circuit, and the other end of resistance is connected with the input end of this RC low-pass filter circuit.

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