CN202748409U - Line power frequency parameter measuring apparatus capable of eliminating power frequency interference - Google Patents

Abstract

Disclosed in the utility model is a line power frequency parameter measuring apparatus capable of eliminating a power frequency interference. The measuring apparatus is characterized in that a power frequency resonance device that is used for eliminating a line power frequency induced voltage is arranged and is formed by series connection of a high voltage capacitor C and a high voltage electric reactor L. A high voltage terminal of the high voltage capacitor is connected with a measured circuit; a low voltage terminal of the high voltage capacitor is grounded; and the resonant frequency is 50 Hz. As for a measurement power supply, a power supply apparatus that can measure a three-phase voltage, a three-phase current, an active loss, a power factor and a frequency and is used for providing a 0 to 520-V measurement power supply with the frequency of 400Hz is employed; three-phase outputs of the measurement power supply are correspondingly connected with three-phase lines in the measured circuit. According to the utility model, when there is high power frequency induced voltage that is no less than 1000 V usually at a measured circuit, the power of other relates circuits that cause the induced voltage at the measured circuit are not needed to be cut simultaneously, thereby avoiding the massive blackout accident.

Description

Can eliminate the circuit power frequency parameter measuring apparatus that power frequency is disturbed

Technical field

The utility model relates to high-tension line power frequency parameter measuring device, and is particularly high for tested high-tension line line-frequency induction voltage, the situation that associated circuit can not have a power failure again.

Background technology

Domestic circuit power frequency parameter measuring apparatus commonly used roughly has two classes at present:

1, conventional method circuit power frequency parameter measuring apparatus, it is with low content of technology, cost is low, easy and simple to handle, but does not have antijamming capability, and the line-frequency induction voltage if any little will affect measuring accuracy, can not measure such as large line-frequency induction voltage.

2, the anti-interference line parameter circuit value measurement mechanism of shift frequency method, its principle of work are to produce 45/55Hz(or 40/60Hz by instrument) the shift frequency measuring-signal, by the measurement the data obtained under twice different frequency, the Computer Processing that carries through instrument obtains power frequency parameter.Its measuring error is ± 3%, anti-power frequency interference performance≤1000V.Have certain scientific and technological content than conventional method, certain antijamming capability is arranged, be improved again but antijamming capability is very difficult, and price is also higher.

Summary of the invention

The utility model is for avoiding the existing weak point of above-mentioned prior art, a kind of circuit power frequency parameter measuring apparatus that power frequency is disturbed of eliminating is provided, so that when test line has higher line-frequency induction voltage (usually being not less than 1000V), other line related that need not to cause test line to produce induced voltage has a power failure simultaneously, in order to avoid cause large-area power-cuts.

The utility model is that the technical solution problem adopts following technical scheme:

The design feature that the utility model can be eliminated the circuit power frequency parameter measuring apparatus of power frequency interference is: the industrial frequency resonance device that is provided for eliminating circuit power frequency induced voltage, described industrial frequency resonance device is to be made of high-voltage capacitor C and high voltage reactor L series connection, with the high pressure termination test line of high-voltage capacitor; With the low pressure end ground connection of high voltage reactor, resonance frequency is 50Hz; Measure the power acquisition supply unit for the measurement power supply that 0 ~ 520V, 400Hz are provided that can measure three-phase voltage, three-phase current, active loss, power factor and frequency, described measurement power supply connects triple-phase line in the test line with three-phase output correspondence.

The design feature that the utility model can be eliminated the circuit power frequency parameter measuring apparatus of power frequency interference also is: test line connects in the following manner:

(1) measuring circuit positive sequence impedance:

With the terminal three-phase short-circuit line short circuit of test line; The three-phase high-voltage end A1 of described industrial frequency resonance device middle-and high-voltage capacitor, B1, C1 measure pair of connecting wires with head end three-phase A, B, the C of test line with three-phase respectively should link to each other the three-phase low-voltage end ground connection of industrial frequency resonance device mesohigh reactor;

The three-phase input end of described supply unit connects 380V, 50Hz AC power, and the sub-a of 400Hz three-phase output end of supply unit, b, c measure pair of connecting wires with three-phase respectively and should be connected;

(2) measuring circuit zero sequence impedance

With the line end three-phase with short-circuit line short circuit and ground connection, circuit head end three-phase short circuit and with the A phase A of industrial frequency resonance device middle-and high-voltage capacitor ₁Terminal connects; The A phase low pressure end of industrial frequency resonance device mesohigh reactor and high-voltage capacitor C be the equal ground connection of low pressure end mutually;

The three-phase input end of supply unit connects 380V, 50Hz AC power, the 400Hz lead-out terminal a of supply unit and lead-out terminal c respectively with the A of industrial frequency resonance device middle-and high-voltage capacitor mutually A1 terminal and C phase C ₁Terminal is corresponding to be connected;

(3) measuring circuit positive sequence electric capacity:

Line end open circuit, the three-phase high-voltage end A1 of described industrial frequency resonance device middle-and high-voltage capacitor, B1, C1 link to each other the three-phase low-voltage end ground connection of industrial frequency resonance device mesohigh reactor with head end triple-phase line A, B, the C of test line with the three-phase test line is corresponding respectively;

The three-phase input end of described supply unit connects 380V, 50Hz AC power, and the 400Hz three-phase output end of supply unit is measured pair of connecting wires with three-phase and should be connected;

(4) measuring circuit zero sequence electric capacity:

Line end open circuit, circuit head end three-phase short circuit also is connected with the A phase A1 terminal of industrial frequency resonance device middle-and high-voltage capacitor; The A phase low pressure end of industrial frequency resonance device mesohigh reactor and high-voltage capacitor C be the equal ground connection of low pressure end mutually;

The three-phase input end of supply unit connects 380V, 50Hz AC power, and the 400Hz lead-out terminal a of supply unit is connected the A phase A1 terminal and the corresponding connection of C phase C1 terminal with industrial frequency resonance device middle-and high-voltage capacitor with lead-out terminal c.

Compared with the prior art, the utility model beneficial effect is embodied in:

1, the utility model at first utilizes the line-frequency induction voltage in the industrial frequency resonance device elimination test line, then adopts intermediate frequency to measure the power measurement line parameter circuit value.For intermediate frequency power supply, the industrial frequency resonance device presents high impedance, and its shunting can be ignored, even can not ignore, the impact of its shunting also can be eliminated by calculating; Again the line parameter circuit value of measuring is converted into power frequency parameter by calculating, can effectively eliminates power frequency and disturb, test process is simple, cost is low.

2, utilize utility model to measure, other line related that need not to cause test line to produce induced voltage has a power failure simultaneously, has avoided large-area power-cuts; Line related comprises: the circuit that sets up with the same bar of test line (or same tower); With test line the circuit of parallel or partial parallel is arranged.

3, the applicable line voltage distribution grade of the utility model is 110kV, 220kV, 500kV.

Description of drawings

Fig. 1 is the wiring diagram that the utility model is used to measure positive sequence impedance;

Fig. 2 is the wiring diagram that the utility model is used to measure zero sequence impedance;

Fig. 3 is the wiring diagram that the utility model is used to measure positive sequence electric capacity;

Fig. 4 is the wiring diagram that the utility model is used to measure zero sequence electric capacity.

Embodiment

The circuit power frequency parameter measuring apparatus that present embodiment can be eliminated the power frequency interference is the industrial frequency resonance device that is provided for eliminating circuit power frequency induced voltage, the industrial frequency resonance device is to be made of high-voltage capacitor C and high voltage reactor L series connection, with the high pressure termination test line of high-voltage capacitor; With the low pressure end ground connection of high voltage reactor, resonance frequency is 50Hz; Measure the power acquisition supply unit for the intermediate frequency measurement power supply that 0 ~ 520V, 400Hz are provided that can measure three-phase voltage, three-phase current, active loss, power factor and frequency.

In the implementation, coil that can high voltage reactor is set to a plurality of centre taps, so that it can be regulated within the specific limits.This is that can there be deviation in the electric capacity of device and inductance value and design load usually, cause resonance frequency to depart from 50Hz, and the centre tap adjusting inductance is set, so that resonance frequency is at 50Hz because during fabrication.

May produce switching overvoltage when considering input or pulling open the industrial frequency resonance device; and then damage industrial frequency resonance device; can be arranged in parallel respectively overvoltage protection device at high-voltage capacitor and the high voltage reactor two ends of industrial frequency resonance device, specifically can adopt Zinc-Oxide Arrester.

Because circuit power frequency induced electricity forms short-channel over the ground, the line-frequency induction voltage in the circuit is down to the line-frequency induction electric current and is flow through the pressure drop that industrial frequency resonance device loop resistance produces.When industrial frequency resonance device loop resistance is very little, this pressure drop will be very little, and in the implementation, when considering to flow through resonance device 20A power current, the power frequency pressure drop is no more than 15V.

In the present embodiment, adopt the 400Hz intermediate frequency power supply of Shenzhen Hua Yuanrui gram HY93 of Electronics Co., Ltd. series as measuring power supply, this measures power supply self with measurement instrument, can be used for measuring output three-phase voltage, three-phase current, active loss, power factor and frequency, specifically select by following technical requirement

Circuit mode: IGB/PWM pulse width modulation; Exchange input: three-phase, 380V, 50Hz/60Hz;

Mode of operation: knob quick adjustment voltage, frequency; Rated capacity: 6kVA;

Output frequency: 50～400Hz; Waveform distortion:＜2%; Frequency stability factor:＜0.1%;

Output phase voltage: low-grade 0～150V, high-grade 0～260V; Load coefficient of stabilization: ± 5%;

Maximum phase current: low-grade 0～16.8A, high-grade 0～8.4A;

Voltage resolution: 0.1V; Frequency resolution: 0.1Hz;

The following 0.001A of electric current resolution: 4A; The above 0.01A of 4A;

The following 0.01W of power resolution: 200W; The above 1W of 200W;

COS Ф resolution: 0.001.

Metering system:

One, carries out power frequency positive sequence impedance Z by Fig. 1 wiring ₁Measurement

1, with the terminal three-phase short-circuit line short circuit of test line, draws respectively three-phase at circuit head end A, B, C and measure wiring; Three-phase is measured three-phase high-voltage end A1, B1, the C1 that wiring connects respectively industrial frequency resonance device middle-and high-voltage capacitor, the three-phase low-voltage end ground connection of industrial frequency resonance device mesohigh reactor; When carrying out the wiring operation, the grounding switch of close circuit head end and line end;

2, the three-phase input end at 400Hz intermediate frequency power supply device connects 380V, 50Hz power frequency AC, opens first grounding switch and the more sub-a of 400Hz three-phase output end, b, the c of supply unit should be connected with three-phase measurement pair of connecting wires respectively.

3, supply unit is boosted to the voltage of setting, reads by the measurement mechanism that carries in the supply unit:

Three-phase voltage, and obtain thus 400Hz test voltage three-phase mean value U;

Three-phase current, and three phase average total current I when obtaining thus test and being U with voltage three-phase mean value ₁

Active loss value P;

4, the grounding switch that closes is prepared next item test wiring;

5, when all items test is finished, the industrial frequency resonance device is linked into the three-phase output end of 400Hz intermediate frequency power supply device, the output voltage values when measuring pressurizes, and reads the three-phase mean value I of industrial frequency resonance device partial current ₂, and calculate by following process and to obtain power frequency positive sequence impedance Z ₁:

I＝I ₁-I ₂cos30°

$Z_1=\frac{P}{3I^2}\×\frac{1}{K}+j\frac{1}{8}\×\sqrt{{\left(\frac{U}{I}\right)}^2-{\left(\frac{P}{3I^2}\right)}^2}$

U: be 400Hz test phase voltage (three-phase mean value), unit: V.

I ₁: the total current during for voltage U (three-phase mean value), unit: A.

I ₂: the industrial frequency resonance device shunting (three-phase mean value) during for voltage U, unit: A.

P: the total active power during for voltage U, unit: W.

K: be 400Hz resistance and 50Hz sensitivity coefficient.

Z ₁: be the power frequency positive sequence impedance, unit: Ω.

Two, carry out power frequency zero sequence impedance Z by Fig. 2 wiring ₀Measurement

1, with the line end three-phase with short-circuit line short circuit and ground connection, circuit head end three-phase A, B, C short circuit and with the A phase A of industrial frequency resonance device middle-and high-voltage capacitor ₁Terminal connects; The A phase low pressure end of industrial frequency resonance device mesohigh reactor and high-voltage capacitor C be the equal ground connection of low pressure end mutually.During wiring, circuit two-terminal-grounding disconnecting link should close; Again grounding switch is pulled open during measurement;

2, the three-phase input end of supply unit connects 380V, 50Hz AC power, after the line-to-ground disconnecting link pulls open, with the A of the 400Hz lead-out terminal a of supply unit and lead-out terminal c and industrial frequency resonance device middle-and high-voltage capacitor A mutually ₁Terminal and C be C mutually ₁Terminal is corresponding to be connected.

3, boost to required voltage, read A phase (or C phase) voltage, electric current and active loss value.

4, the grounding switch that closes is prepared next item test wiring.

5, test at all items, industrial frequency resonance device A is linked into 400Hz intermediate frequency power supply device output terminals A phase mutually, C is connected to 400Hz intermediate frequency power supply device output terminal C phase, C phase electric capacity and reactor junction ground connection mutually.The magnitude of voltage that adds when measuring reads I ₂Value.

Zero sequence impedance calculates:

I=I ₁-I ₂cos30°

$Z_0=\frac{3P}{I^2}\×\frac{1}{K}+j[\frac{1}{8}\×\sqrt{{\left(\frac{3\sqrt{3}U}{I}\right)}^2-{\left(\frac{3P}{I^2}\right)}^2}+\frac{1}{100\mathrm{\πC}}]$

U: be 400Hz test phase voltage, unit: V.

I ₁: be voltage

The time total current, unit: A.

I ₂: be voltage

The time industrial frequency resonance device shunting, unit: A.

P: be voltage

The time total active power, unit: W.

K: be 400Hz resistance and 50Hz sensitivity coefficient.

C: be series capacitance, unit: F.

Z ₀: be the power frequency zero sequence impedance, unit: Ω.

Three, carry out the positive sequence capacitor C by Fig. 3 wiring ₁Measurement:

1, line end three-phase open circuit; Draw respectively three-phase at circuit head end A, B, C and measure wiring; Three-phase is measured three-phase high-voltage end A1, B1, the C1 that wiring connects respectively industrial frequency resonance device middle-and high-voltage capacitor, the three-phase low-voltage end ground connection of industrial frequency resonance device mesohigh reactor; When carrying out the wiring operation, the grounding switch of close circuit head end and line end;

2, the three-phase input end at 400Hz intermediate frequency power supply device connects 380V, 50Hz power frequency AC, opens first grounding switch and the 400Hz three-phase output end of supply unit should be connected with three-phase measurement pair of connecting wires again.

3, boost to required voltage, read three-phase voltage, three-phase current and active loss value.

4, the grounding switch that closes is prepared next item test wiring.

5, test at all items, the industrial frequency resonance device is linked into 400Hz intermediate frequency power supply device output terminal (three-phase), the magnitude of voltage that adds when measuring reads I ₂Value.

Positive sequence electric capacity calculates:

I=I ₁+I ₂

Positive sequence admittance y ₁(S) $y_1=\frac{I}{U}$

The positive sequence electricity is led g ₁(S) $g_1=\frac{P}{3U^2}$

Positive sequence susceptance b ₁(S) $b_1=\sqrt{{y_1}^2-{g_1}^2}$

The positive sequence capacitor C ₁(μ F) $C_1=\frac{b_1}{800\mathrm{\π}}\×{10}^6$

U: be 400Hz test phase voltage (three-phase mean value), unit: V.

I ₁: the total current during for voltage U (three-phase mean value), unit: A.

I ₂: the industrial frequency resonance device reactive-load compensation electric current (three-phase mean value) during for voltage U, unit: A.

P: the total active power during for voltage U, unit: W.

Four, press Fig. 4 wiring and measure the zero sequence capacitor C ₀:

1. the line end three-phase is opened a way; Circuit head end three-phase short circuit and with the A phase A of industrial frequency resonance device middle-and high-voltage capacitor ₁Terminal connects; The A phase low pressure end of industrial frequency resonance device mesohigh reactor and high-voltage capacitor C be the equal ground connection of low pressure end mutually.During wiring, circuit two-terminal-grounding disconnecting link should close; Again grounding switch is pulled open during measurement;

2, the three-phase input end of supply unit connects 380V, 50Hz AC power, after the line-to-ground disconnecting link pulls open, with 400Hz lead-out terminal a, the c of supply unit and the A phase A of industrial frequency resonance device middle-and high-voltage capacitor ₁Terminal and C be C mutually ₁Terminal is corresponding to be connected.

3, boost to required voltage, read A phase (or C phase) voltage, electric current and active loss value.

4, the grounding switch that closes is prepared next item test wiring.

5, test at all items, industrial frequency resonance device A is linked into 400Hz intermediate frequency power supply device output terminals A phase mutually, C is connected to 400Hz intermediate frequency power supply device output terminal C phase, C phase electric capacity and reactor junction ground connection mutually.The magnitude of voltage that adds when measuring reads I ₂Value.

Zero sequence electric capacity calculates:

I＝I ₁+I ₂

Zero sequence admittance y ₀(S) $y_0=\frac{I}{3\sqrt{3}U}$

The zero sequence electricity is led g ₀(S) $g_0=\frac{P}{9U^2}$

Zero sequence susceptance b ₀(S) $b_0=\sqrt{{y_0}^2-{g_0}^2}$

The zero sequence capacitor C ₀(μ F) $C_0=\frac{b_0}{800\mathrm{\π}}\×{10}^6$

U: be 400Hz test phase voltage, unit: V.

I ₁: be voltage

The time total current, unit: A.

I ₂: be voltage

The time industrial frequency resonance device reactive-load compensation electric current, unit: A.

P: be voltage

The time total active power, unit: W.

Claims (2)

1. can eliminate the circuit power frequency parameter measuring apparatus that power frequency is disturbed, it is characterized in that: the industrial frequency resonance device that is provided for eliminating circuit power frequency induced voltage, described industrial frequency resonance device is to be made of high-voltage capacitor C and high voltage reactor L series connection, with the high pressure termination test line of high-voltage capacitor; With the low pressure end ground connection of high voltage reactor, resonance frequency is 50Hz; Measure the power acquisition supply unit for the measurement power supply that 0 ~ 520V, 400Hz are provided that can measure three-phase voltage, three-phase current, active loss, power factor and frequency, described measurement power supply connects triple-phase line in the test line with three-phase output correspondence.

2. according to claim 1ly eliminate the circuit power frequency parameter measuring apparatus that power frequency is disturbed, it is characterized in that test line connects in the following manner:

(1) measuring circuit positive sequence impedance:

With the terminal three-phase short-circuit line short circuit of test line; The three-phase high-voltage end A1 of described industrial frequency resonance device middle-and high-voltage capacitor, B1, C1 measure pair of connecting wires with head end three-phase A, B, the C of test line with three-phase respectively should link to each other the three-phase low-voltage end ground connection of industrial frequency resonance device mesohigh reactor;

The three-phase input end of described supply unit connects 380V, 50Hz AC power, and the sub-a of 400Hz three-phase output end of supply unit, b, c measure pair of connecting wires with three-phase respectively and should be connected;

(2) measuring circuit zero sequence impedance

With the line end three-phase with short-circuit line short circuit and ground connection, circuit head end three-phase short circuit and with the A phase A of industrial frequency resonance device middle-and high-voltage capacitor ₁Terminal connects; The A phase low pressure end of industrial frequency resonance device mesohigh reactor and high-voltage capacitor C be the equal ground connection of low pressure end mutually;

The three-phase input end of supply unit connects 380V, 50Hz AC power, the 400Hz lead-out terminal a of supply unit and lead-out terminal c respectively with the A of industrial frequency resonance device middle-and high-voltage capacitor mutually A1 terminal and C phase C ₁Terminal is corresponding to be connected;

(3) measuring circuit positive sequence electric capacity:

Line end open circuit, the three-phase high-voltage end A1 of described industrial frequency resonance device middle-and high-voltage capacitor, B1, C1 link to each other the three-phase low-voltage end ground connection of industrial frequency resonance device mesohigh reactor with head end triple-phase line A, B, the C of test line with the three-phase test line is corresponding respectively;

The three-phase input end of described supply unit connects 380V, 50Hz AC power, and the 400Hz three-phase output end of supply unit is measured pair of connecting wires with three-phase and should be connected;

(4) measuring circuit zero sequence electric capacity:

Line end open circuit, circuit head end three-phase short circuit also is connected with the A phase A1 terminal of industrial frequency resonance device middle-and high-voltage capacitor; The A phase low pressure end of industrial frequency resonance device mesohigh reactor and high-voltage capacitor C be the equal ground connection of low pressure end mutually;

The three-phase input end of supply unit connects 380V, 50Hz AC power, and the 400Hz lead-out terminal a of supply unit is connected the A phase A1 terminal and the corresponding connection of C phase C1 terminal with industrial frequency resonance device middle-and high-voltage capacitor with lead-out terminal c.

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