CN1018027B - Automatic dielectic-loss and capacitance measure instrument for power plants - Google Patents
Automatic dielectic-loss and capacitance measure instrument for power plantsInfo
- Publication number
- CN1018027B CN1018027B CN 88104054 CN88104054A CN1018027B CN 1018027 B CN1018027 B CN 1018027B CN 88104054 CN88104054 CN 88104054 CN 88104054 A CN88104054 A CN 88104054A CN 1018027 B CN1018027 B CN 1018027B
- Authority
- CN
- China
- Prior art keywords
- output
- input
- function piece
- detecting device
- component detecting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Images
Abstract
The present invention relates to an automatic dielectic-loss and capacitance measure instrument for power plant. The present invention is characterized in that an integrated circuit technique is adopted to accurately detect an active component and a reactive component of a measured signal; when the active component is detected, a peak detector and a multiplier are adopted to automatically compensate the reactive component of a signal so as to enhance the accuracy of measuring tgdelta; a divider is adopted to eliminate the influence of the variation of applied voltage; therefore, no matter how much applied voltage is, the automatic dielectic-loss and capacitance measure instrument for power plant can directly read out the tgdelta and C. The present invention is especially suitable for automatically measuring the tgdelta and the C under the condition that power plant runs in an electrified mode.
Description
The present invention relates to the instrument of a kind of automatic measurement power equipment dielectric loss and electric capacity, be applicable to that particularly power equipment measures power under the very little situation of the occasion of Operation of Electric Systems and power factor.
Measure the dielectric loss and the electric capacity of power equipment at present both at home and abroad, the Schering bridges that adopt more, in the extensive employing of China is the QS1 type alternating current bridge that Shanghai Electric Meter Factory is produced, this electric bridge is the electric bridge of manual balance, parameter during according to balance is obtained dielectric loss tangent value tg δ and electric capacity C, with QS1 bridge measurement dielectric loss and electric capacity, its shortcoming is: the balancing troublesome poeration, time-consuming, often the element of operation is out of order easily, the local galvanometric light belt strong at light is difficult to see clearly, in tg δ and the time dependent occasion of C because of can't balance using the QS1 electric bridge, also can't use the QS1 electric bridge under the power equipment charging operation, have a kind of self-balancing bridge circuit the fifties abroad, is to utilize the method for machinery to realize the electric bridge self-poise, and this electric bridge costs an arm and a leg, can not be in electrician trade widespread usage, only used in very special occasion; And, time with the mechanical means automatic adjusting balance is longer, can't use at tg δ and the time dependent occasion of C, though the measuring resistance of many other types is arranged at present both at home and abroad, the electric bridge of inductance and electric capacity or instrument, but, be unwell to the tg δ and the C that measure power equipment because they all are the methods that adopts high-frequency (10KHz or more than) and low-voltage (several hectovolts or following); Because the characteristics of measuring the power equipment dielectric loss are high voltage (10Kv or more than), 50Hz and low power factor (COS θ=sin δ ≈ 0.005～0.06); At present still extensively adopt the QS1 product of this fifties in the electric system, its reason just is: do not find the method that can accurately measure power under the situation of power factor very little (0.005～0.06) automatically as yet, do not find the instrument that can replace the QS1 electric bridge as yet.
The objective of the invention is in order to overcome above-mentioned shortcoming with Schering bridge measurement power equipment dielectric loss and electric capacity, find out measurement power equipment dielectric loss and the new method of electric capacity and the new instrument that can replace the QS1 electric bridge, to improve the operational reliability of electric system.
The present invention adopts new design and application integrated circuit technology, design the automatic measuring instrument of dielectric loss and electric capacity, its ultimate principle is, measure the real component of measured signal respectively, after the idle component of measured signal and the idle component of reference signal, with the real component of measured signal idle component divided by measured signal, get the dielectric loss tangent value, with the idle component of measured signal idle component divided by reference signal, get the electric capacity of test product to be measured, because the power factor very little (0.005～0.06) of measured signal, the present invention adopts automatic compensation to fall the method for the idle component in the measured signal, to realize the accurate measurement of real component.
The present invention compares with the QS1 type alternating current bridge that extensively adopts in electrician trade at present, has in light weightly, and volume is little, measurement range is wide, the accuracy height does not need balancing, directly reading, the influence that reading is not changed by applied voltage, be applicable to the time dependent occasion of tg δ and C, and the advantages such as occasion that are applicable to the power equipment charging operation, in addition, use method of the present invention, the very little power of available common watt meter indicated power factor.
Below in conjunction with drawings and Examples, the present invention is described in further detail.
Fig. 1: power equipment dielectric loss and electric capacity automatic measuring instrument theory diagram.
Fig. 2: the vector plot of the signal that instrument is related.
Fig. 3: the schematic diagram of automatic compensating reactive power component.
Fig. 4: tg δ and C automatic measuring instrument circuit block diagram.
Such as Fig. 1, the present invention is by measured signal converter (1), reference signal converter (2), real component detector (3), idle component detector (4) is with reference to idle component detector (5), division function device (6 and 7), and indicator (8 and 9) forms.
Measured signal converter (1) and reference signal converter (2) can respectively or be made up of RC divider, capacitive divider, resitstance voltage divider, transformer, current-to-voltage converter or amplifier according to the measuring condition of reality simultaneously.
The detection of real component and the detection of idle component all adopt four-quadrant multiplication function piece to finish, and its basic principle is illustrated in conjunction with Fig. 2. Among Fig. 2, establishing U is the voltage that acts on the power equipment, and Uno is the reference voltage that becomes 90 degree with U, and Ix is the electric current that flows through power equipment, and Ic is the idle component of Ix, and Ir is the real component of Ix, and Uxo and Ix same-phase are established
U＝Um·Sinωt
Uxo＝Uxom·sin（ωt+θ）
Uno＝Unom·sin（ωt+π/2）
When detecting idle component, Uxo and Uno are input in the four-quadrant multiplication function piece, then the output of this multiplication function piece is proportional to:
[Cosδ+sin（2ωt+θ）]
After adopting wave filter elimination alternating component, the just remaining DC component that is proportional to Cos δ is because normal power equipment, δ is very little, Cos δ ≈ 1, and the ripple factor of wave filter generally can reach 0.1%, therefore, said method can guarantee to measure the accuracy of idle component.
When detecting real component, if Uxo and U are directly inputted in the multiplication function piece, so, the output of this multiplication function piece at this moment is proportional to:
[Sinδ-Cos（2ωt+θ）]
Since normal power equipment, sin δ ≈ 0.005～0.06, and even therefore at this moment adopt the wave filter elimination alternating component of 0.1% ripple factor, its accuracy of the real component of measuring can not guarantee.
In order to overcome above-mentioned difficulties, among the present invention, during the measuring media loss or when measuring the very little power loss of power factor, not directly Uxo and U to be input in the multiplication function piece, but as Fig. 3, at first the idle component with Uxo compensates, and the method for compensation is, Uxo is amplified KUnom doubly, obtain new vectorial Ux. and Uno is amplified KUxom doubly obtain new vectorial Un, so, Ux and Un amplitude equate, the phase place of Un is identical with Uno, and the phase place of Ux is identical with Uxo; Ux subtracts Un and obtains a new vectorial Unx, then, is input in the four-quadrant multiplication function piece with Unx and U, and the output of this multiplication function piece is proportional to:
(Cosθ)/(Cosδ/2) [Cosδ/2-Cos（2ωt-δ/2）]
Use wave filter elimination alternating component again, promptly obtain the output quantity that is directly proportional with Cos θ because COS δ/2 ≈ 1, adopt 0.1% ripple factor wave filter, can satisfy the requirement of accuracy.
Measuring media when loss is not to represent with power but represent that with tg δ for this reason, the present invention adopts division function device (6) to draw the amount that is directly proportional with tg δ on the general custom.
With reference to the output of idle component detecting device (5), be according to the needs of measuring electric capacity so that idle component divided by the reference idle component after, it is condition that the amount of division function device (7) output can be proportional to the testing capacitance amount
Pointer-type can be adopted, digital or automatic recording instrument according to actual needs in indicator (8) and (9).
Fig. 1 is corresponding with QS1 type alternating current bridge, is the theory diagram of measuring tg δ and C simultaneously; In order to save element, functional block (3), (4), and (5) can have common sparing, if in fact only need to measure real component, or idle component, or when tg δ or C, Fig. 1 can simplify.
Embodiment:
Automatically measure circuit block diagram such as Fig. 4 of tg δ and C simultaneously.Measured signal converter (1) is connected with test product Cx by noninductive resistance R and enlarging function piece (11) is formed, C is the electric capacity of test product Cx, reference signal converter (2) is connected with standard capacitor Cn by noninductive resistance Rn and enlarging function piece (21) is formed, and real component detecting device (3) is made up of functional block (3451), (341), (31), (32), (33), (34), (35) and (36); (3451) reaching (31) is peak detection block, and (341) and (32) are the multiplication function piece.(341) Shu Chu amplitude is the enlarging function piece with the amplitude identical 33 of (32) output, is made of operational amplifier; (341) and the connected mode of (32), the input that guarantees (33) is equivalent to Unx; (33) purpose is that Unx is suitably amplified; (34) be the phase shift function piece, its objective is that its phase place of voltage that makes output is identical with U; (35) be the multiplication function piece; (36) be the filter function piece, the employing operational amplifier constitutes, its objective is only to allow direct current to pass through, the ripple factor 0.1% of wave filter can guarantee the accuracy of measuring, idle component detecting device (4) by functional block (3451), (341), (41), and (42) form; (41) be the multiplication function piece, the output terminal of (341) is received in a pair of input of (41), and purpose is to make the reading of tg δ not be subjected to the influence of applied voltage amplitude; (42) be the filter function piece, adopt amplifier to form, purpose is only to allow direct current to pass through, and ripple factor reaches 0.1% can guarantee the accuracy of measuring.By functional block (3451), (51) and (52) are formed with reference to idle component detecting device (5); (51) be the squarer functional block, (52) are the multiplication function piece, and the effect of these functional blocks is that the reading of electric capacity only is directly proportional with testing capacitance amount C, and irrelevant with applied voltage, division function device (6) is made up of (61) and (62); (61) be divider; (62) be voltage regulator, its effect is that tg δ reading and meter dial are adapted; (62) can be resitstance voltage divider or enlarging function piece according to actual conditions; As unnecessary, (62) can save, and division function device (7) is made up of (71) and (72); (71) be that divider (72) is a voltage regulator; (72) effect is that the scale of the reading of electric capacity C and indicating instrument is adapted; (72), can be resitstance voltage divider or enlarging function piece according to actual conditions; As unnecessary, (72) can save.The value of indicator (8) indication tg δ; The value of indicator (9) indication C; Pointer-type can be adopted, digital or automatic recording type voltage table according to actual needs in indicator (8) and (9).(3451) be the common sparing of (3), (4) and (5).(341) be the common sparing of (3) and (4).
When only needing to measure tg δ automatically, save (51), (52), (71), (72) and (9) among Fig. 4, when only needing to measure C automatically, save (3), (6), (8), (341) and (52), when only needing to measure active power, save (4), (5), (6), (7) and (9); When indicator adopts watt meter, save (35) and (36) again, and watt meter is placed the position that is equivalent to (35); When power factor is very little, not only can not accurately measure power in the past, nor can accurately measure with existing low power-factor wattmeter with common watt meter; Owing to adopt the technology of the illustrated automatic compensating reactive power component of Fig. 3, not only available low power-factor wattmeter is measured, and available common watt meter is measured among the present invention.
Claims (6)
1, power equipment dielectric loss and electric capacity automatic measuring instrument, two indication electric meter (pointer-type are arranged, digital or automatic recording type voltage table), the dielectric loss of an indication power equipment (8), the electric capacity of an indication power equipment (9), feature of the present invention is, by measured signal converter (1), reference signal converter (2), real component detecting device (3) by the realization of four-quadrant functional block, idle component detecting device (4) by the realization of four-quadrant multiplication function piece, with reference to idle component detecting device (5), division function device (6 and 7) and indicator integrated circuit components such as (8 and 9) are formed, the output of measured signal converter (1) is connected to real component detecting device (3) and both a pair of inputs of idle component detecting device (4), the output of reference signal converter (2) has been connected to function component detection device (3), idle component detecting device (4) and with reference to idle component detecting device threes' such as (5) a pair of input, the output of idle component detecting device (4) is connected to both a pair of inputs of division function device (6 and 7), be connected to a pair of input of division function device (7) with reference to the output of idle component detecting device (5), the output of division function device (6) is connected to indicator (8), the output of division function device (7) is connected to indicator (9), real component detecting device (3), idle component detecting device (a 4) and peak detection block (3451) that the three is shared is arranged with reference to idle component detecting device (5), there are function component detection device (3) and idle component detecting device (4) that both shared multiplication function pieces (341) are arranged, the real component detecting device can compensate the idle component in the swap signal automatically, with the irrelevant AC compounent wave filter elimination of measured signal, eliminate the influence of applied voltage variation in real component detecting device and the idle component detecting device to the scale factor of indicator with divider.
2, measuring instrument according to claim 1, it is characterized in that real component detecting device (3), by peak detection block (3451 and 31), multiplication function piece (341,32 and 35), enlarging function piece (33), phase shift function piece (34) and filter function piece (36) are formed, the input of peak detection block (3451) is connected to the output of reference signal converter, the input of peak detection block (31) is connected to the output of measured signal converter, the a pair of input of multiplication function piece (341) is connected to the output of peak detctor (3451), another of multiplier (341) is connected to the output of measured signal converter to input, the a pair of input of multiplier (32) is connected to the output of peak detctor (31), another of multiplier (32) is connected to the output of reference signal converter to input, the amplitude of multiplier (341) output is identical with the amplitude of multiplier (32) output, the poor (U of the output of multiplier (341) and multiplier (32) output
Nx) be input to the input of enlarging function piece (33), the input of phase shift function piece (34) is connected to the output of reference signal converter (2), the a pair of input of multiplication function piece (35) is connected to the output of enlarging function piece (33), another of multiplication function piece (35) is connected to the output of phase shift function piece (34) to input, the output voltage phase place of phase shift function piece (34) is consistent with applied voltage U, the output of multiplication function piece (35) is connected to filter function piece (36), the output of filter function piece (36) is connected to a pair of input of divider (61), and the ripple factor of filter function piece (36) is 0.1%.
3, measuring instrument according to claim 1, it is characterized in that, idle component detecting device (4), by peak detection block (3451), multiplication function piece (341 and 41) and filter function piece (42) are formed, the a pair of input of multiplication function piece (41) is connected to the output of reference signal converter (2), another of multiplication function piece (41) is connected to the output of multiplication function piece (341) to input, the input of filter function piece (42) is connected to the output of multiplication function piece (41), the output of filter function piece (42) is connected to a pair of input of divider (61) and (71), and the ripple factor of filter function piece (42) is 0.1%.
4, measuring instrument according to claim 1, it is characterized in that, with reference to idle component detecting device (5), by peak detctor (3451), squarer functional block (51) and multiplication function piece (52) are formed, two pairs of inputs of squarer functional block (51) all are connected to the output of peak detctor (3451), the output of squarer functional block (51) is connected to a pair of input of multiplier function piece (52), another of multiplier function piece (52) is connected to the output of peak detctor (3451) to input, and the output of multiplier function piece (52) is connected to a pair of input of division function device (7).
5, measuring instrument according to claim 1, it is characterized in that, division function device (6) is made up of divider (61) and voltage regulator (62), the a pair of input of divider (61) is connected to the output of real component detecting device (3), another of divider (61) is connected to the output of idle component detecting device (4) to input, the output of divider (61) is connected to the input of voltage regulator (62), and the output of voltage regulator (62) is connected to indicator (8).
6, measuring instrument according to claim 1, it is characterized in that, division function device (7) is made up of divider (71) and voltage regulator (72), the a pair of input of divider (71) is connected to the output of idle component detecting device (4), another of divider (71) is connected to output with reference to idle component detecting device (5) to input, the output of divider (71) is connected to the input of voltage regulator (72), and the output of voltage regulator (72) is connected to indicator (9).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 88104054 CN1018027B (en) | 1988-06-26 | 1988-06-26 | Automatic dielectic-loss and capacitance measure instrument for power plants |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 88104054 CN1018027B (en) | 1988-06-26 | 1988-06-26 | Automatic dielectic-loss and capacitance measure instrument for power plants |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1039118A CN1039118A (en) | 1990-01-24 |
| CN1018027B true CN1018027B (en) | 1992-08-26 |
Family
ID=4832865
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 88104054 Expired CN1018027B (en) | 1988-06-26 | 1988-06-26 | Automatic dielectic-loss and capacitance measure instrument for power plants |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1018027B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101551420B (en) * | 2009-05-08 | 2010-12-08 | 北京航空航天大学 | A weak capacitive detection circuit of MEMS device |
| CN102109556B (en) * | 2010-11-29 | 2013-01-30 | 北京航空航天大学 | Circuit for detecting dynamic weak capacitance of MEMS device |
| CN108008171B (en) * | 2017-12-29 | 2023-09-01 | 深圳市锐能微科技有限公司 | Circuit parameter detection circuit and electric energy meter |
| CN108196130A (en) * | 2018-03-08 | 2018-06-22 | 云南电网有限责任公司电力科学研究院 | The dielectric loss test method and device of comparison current signal are acquired using resitstance voltage divider |
-
1988
- 1988-06-26 CN CN 88104054 patent/CN1018027B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| CN1039118A (en) | 1990-01-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6026355A (en) | Solid state watt-hour meter using GMR sensor | |
| Djokic et al. | Phase measurement of distorted periodic signals based on nonsynchronous digital filtering | |
| CN101738584A (en) | Measuring method of micro internal resistance of industrial storage battery | |
| US4937520A (en) | Instrument to measure the errors of apparent power meters | |
| CN1018027B (en) | Automatic dielectic-loss and capacitance measure instrument for power plants | |
| Koponen et al. | Adding power quality monitoring to a smart kWh meter | |
| CN2427816Y (en) | Instrument for measuring and calibrating electricity meter testing device | |
| CN1087835C (en) | Method for measuring capacity and current between earth and electric network | |
| CA1276234C (en) | Electrical measuring instrument for high voltage power measurements | |
| Dán et al. | What do and what should digital revenue meters measure on distorted networks? | |
| Marais et al. | Reduction of static electricity meter errors by broadband compensation of voltage and current channel differences | |
| RU2115131C1 (en) | Device determining loss tangent of dielectric | |
| Simonson et al. | A comparison of power measuring systems | |
| So et al. | A new current-comparator-based high-voltage low-power-factor wattmeter | |
| US3452274A (en) | Apparatus for measuring loss characteristics of dielectric test specimens including an electrical bridge with sine to square wave conversion means and integration means | |
| MXPA02007467A (en) | Method and apparatus for determining the internal impedance of a distribution transformer and sensing dc current through an ac power meter. | |
| EP0055810A2 (en) | A dielectric moisture monitor | |
| Stanton | Instrumentation for thyristor control | |
| SU1221578A1 (en) | Apparatus for electromagnetic inspection of metal articles | |
| US3973190A (en) | Infralow frequency transfer function analyzer | |
| SU1147985A1 (en) | Bridge-type meter of four-element passive two-terminal network parameters | |
| Castelli | Industrial transfer instrument standards and distorted wave analysis by a method of detecting and compensating to 50 kHz the cause of the frequency error of the electrodynamic converter | |
| RU2028625C1 (en) | Device for determining active power of sine-wave current in complex-impedance circuit | |
| CN1007091B (en) | Method and device for directly reading and ckecking dc mutual inductor comparison value difference | |
| Drew et al. | A new approach to the measurement of power, reactive volt-amperes, and volt-amperes by electronic analog multiplication |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C13 | Decision | ||
| GR02 | Examined patent application | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |