CN105092956B - Power Systems factor measurement apparatus, method and its system - Google Patents
Power Systems factor measurement apparatus, method and its system Download PDFInfo
- Publication number
- CN105092956B CN105092956B CN201410181976.3A CN201410181976A CN105092956B CN 105092956 B CN105092956 B CN 105092956B CN 201410181976 A CN201410181976 A CN 201410181976A CN 105092956 B CN105092956 B CN 105092956B
- Authority
- CN
- China
- Prior art keywords
- voltage
- transformer
- power
- secondary side
- short
- 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.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 28
- 238000005259 measurement Methods 0.000 title abstract description 13
- 238000012360 testing method Methods 0.000 claims abstract description 55
- 238000012545 processing Methods 0.000 claims abstract description 11
- 238000010586 diagram Methods 0.000 description 14
- 230000000630 rising effect Effects 0.000 description 8
- 230000001681 protective effect Effects 0.000 description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000010363 phase shift Effects 0.000 description 1
Landscapes
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
Include supply lines, protection switch, power transformer and short switch for the power-factor measurement device of power system, measuring method and its short-circuit test system, power system the invention provides a kind of, power-factor measurement device includes：Voltage transformer, the primary side of voltage transformer are connected on supply lines；Voltage measuring apparatus, when protection switch is in closure state and short switch is off, for simultaneously obtain voltage transformer secondary side first voltage waveform and power transformer secondary side second voltage waveform；Current measuring device, when protection switch is in closure state and short switch is in closure state, the current waveform of the secondary side for obtaining power transformer, while voltage measuring apparatus obtains the tertiary voltage waveform of the secondary side of voltage transformer；Data processing equipment, for calculating power factor.According to the present invention can more accurate measurement Power System Shortcuts when power factor.
Description
Technical Field
The invention relates to the field of power electronics, in particular to a power factor measuring device, a measuring method and a test system thereof.
Background
With the increase of the electrical load and the improvement of the electrical quality, the requirements on the safety of low-voltage high-current switch equipment are higher and higher, so that factory inspection and type tests need to be carried out on complete sets of switch equipment such as circuit breakers and switch cabinets. In the low-voltage high-current short-circuit test system, in addition to providing the test voltage and the test current required by the sample test, the power factor provided by the short-circuit test system must meet the requirements, so that the power factor, namely the power factor angle, of the short-circuit test system needs to be accurately measured and calculated.
The method for calculating the power factor in the short-circuit test system at present comprises an impact coefficient method, a direct current component method and a phase angle difference method, wherein the impact coefficient method and the direct current component method can accurately calculate the power factor only under the condition that a line closing angle is 0 degrees, when the power factor is measured on the short-circuit test system for providing three-phase alternating current, three-phase electricity needs to be tested and calculated under the condition that the closing angle is 0 degrees, and therefore testing time and testing difficulty are increased.
The phase angle difference method is to detect the phase difference of the voltage and current signals at the same position and time and then directly calculate to obtain the power factor. Chinese patent publication No. CN1621851A discloses a power factor measuring device and a measuring method thereof, which uses a voltage transformer to measure a voltage signal, uses a current transformer to measure a current signal, detects a rising edge and a period of the voltage signal and a rising edge of the current signal, and finally calculates to obtain a period of the signal, a phase difference between the voltage and the current, and a power factor. However, the current for testing the test sample with low voltage and large current is very large, usually above 65kA (even above 120 kA), that is, the current value of the low voltage side (secondary side) of the transformer is very large, and the protection switch (low voltage circuit breaker) on the secondary side of the transformer cannot bear the arc generated by such large current in the on-off process, so that the low voltage circuit breaker is easily damaged, and therefore, the phase angle difference method cannot measure the voltage signal and the current signal of low voltage and large current at the same time, resulting in that the power factor of the short circuit test system during short circuit cannot be measured.
Disclosure of Invention
In view of the above-mentioned prior art, an embodiment of the present invention provides a power factor measurement device for an electric power system, the electric power system including a power supply line, a protection switch, an electric power transformer, and a short-circuit switch, a primary side of the electric power transformer being connected to the power supply line through the protection switch, the short-circuit switch being connected to a secondary side of the electric power transformer, the power factor measurement device including:
a voltage transformer, a primary side of which is connected to the power supply line;
the voltage measuring device is used for simultaneously acquiring a first voltage waveform of the secondary side of the voltage transformer and a second voltage waveform of the secondary side of the power transformer when the protection switch is in a closed state and the short-circuit switch is in an open state; when the protection switch is in a closed state and the short-circuit switch is in a closed state, acquiring a third voltage waveform of a secondary side of the voltage transformer;
the current measuring device is used for acquiring a current waveform of the secondary side of the power transformer when the protection switch is in a closed state and the short-circuit switch is in a closed state;
data processing means for calculating a power factor from the first voltage waveform, the second voltage waveform, the current waveform and the third voltage waveform;
wherein obtaining the third voltage waveform on the secondary side of the voltage transformer and obtaining the current waveform on the secondary side of the power transformer are performed simultaneously.
The power factor measuring device can simultaneously obtain the analog voltage waveform of the secondary side of the power transformer and the current waveform of the secondary side, thereby accurately calculating the power factor.
Preferably, the data processing device is configured to calculate a phase time difference according to the first voltage waveform and the second voltage waveform, and then calculate a power factor according to the phase time difference, the current waveform, and the third voltage waveform. The data processing device calculates the power factor accurately by calculating the phase offsets of the first voltage waveform and the second voltage waveform.
Another aspect of the present invention also provides a method of measuring a power factor of an electric power system including a power supply line, a protection switch, an electric power transformer, and a short-circuit switch, a primary side of the electric power transformer being connected to the power supply line through the protection switch, the short-circuit switch being connected to a secondary side of the electric power transformer, comprising the steps of:
-connecting a voltage transformer on said supply line;
-bringing the short-circuit switch in an open state and the protection switch in a closed state while acquiring a first voltage waveform on the secondary side of the voltage transformer and a second voltage waveform on the secondary side of the power transformer;
-bringing the protection switch in an open state, the short-circuit switch in a closed state, and the protection switch in a closed state while acquiring a current waveform on the secondary side of the power transformer and a third voltage waveform on the secondary side of the voltage transformer;
-calculating a power factor from the first, second, current and third voltage waveforms.
The measuring method of the invention simultaneously obtains the analog voltage waveform of the secondary side of the power transformer and the current waveform of the secondary side, thereby accurately calculating the power factor.
Preferably, a phase time difference is calculated from the first voltage waveform and the second voltage waveform, and then a power factor is calculated from the phase time difference, the current waveform, and the third voltage waveform. The power factor is accurately calculated by calculating the phase offsets of the first voltage waveform and the second voltage waveform.
In still another aspect of the present invention, there is provided a short circuit test system including:
the power factor testing device as described above.
The short circuit test system can provide a low voltage and a large current for a test sample, and can acquire the waveforms of the low voltage and the large current.
Drawings
The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention. Wherein,
FIG. 1 is a schematic diagram of a circuit configuration of a short circuit test system according to a first embodiment of the present invention;
FIG. 2 is a schematic diagram of waveforms of phase voltages on the secondary side of a voltage transformer and phase voltages on the secondary side of a power transformer in accordance with one embodiment of the present invention;
fig. 3 is a schematic diagram of a simulated waveform diagram of an actual voltage on the secondary side of the power transformer and a waveform diagram of a current in a current loop on the secondary side of the power transformer according to an embodiment of the present invention.
Fig. 4 is a schematic circuit diagram of a short circuit testing system according to an embodiment of the present invention.
Symbolic description of main devices
1 supply line
2 Voltage mutual inductor
3 power transformer
4 protective switch
5 closing switch
6 Adjustable load
7 protective switch
8 test sample
9 Voltage measuring device
10 Current measuring device
11 data processing device
12 power factor measuring device
13 short-circuit switch
Detailed Description
In order to more clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will now be described with reference to the accompanying drawings.
Fig. 1 is a schematic circuit configuration diagram of a short circuit test system according to a first embodiment of the present invention. As shown in fig. 1, the power system includes a power supply line 1, a protection switch 4, a short-circuit switch 13, and a power transformer 3, wherein the power supply line 1 is a power supply line for supplying three-phase ac power, a primary side of the power transformer 3 is connected to the power supply line 1 through the protection switch 4, and the short-circuit switch 13 is further connected to a secondary side of the power transformer 3. The power factor measuring device 12 of the present embodiment includes a voltage transformer 2, a voltage measuring device 9, a current measuring device 10, and a data processing device 11. The primary side of the voltage transformer 2 is connected to the power supply line 1, and the voltage measuring device 9 measures the phase voltage of the secondary side of the voltage transformer 2 as U1’、U2' and U3'. When the short-circuit switch 13 is opened and the protection switch 4 is closed, the voltage measuring device 9 is used for measuring the phase voltage U of the secondary side of the power transformer 31、U2And U3。
A method of measuring a power factor of an electric power system according to an embodiment of the present invention is described in detail below with reference to fig. 1. Referring to fig. 1, the power system includes a power supply line 1, a protection switch 4, a power transformer 3, a short-circuit switch 13, and a test specimen 8, a primary side of the power transformer 3 is connected to the power supply line 1 through the protection switch 4,the short-circuit switch 13 is connected to the secondary side of the power transformer 3, and the voltage transformer 2 is connected to the power supply line 1; then, the short-circuit switch 13 is sequentially turned off, the protection switch 4 is turned on, and simultaneously, a first voltage waveform of the secondary side of the voltage transformer 2 and a second voltage waveform of the secondary side of the power transformer 3 are obtained and marked as U respectively1’U2’U3' and U1U2U3(ii) a Then, the protection switch 4 is opened, the short-circuit switch 13 is closed, the protection switch 4 is closed, and simultaneously, the current waveform of the secondary side of the power transformer 3 and the third voltage waveform of the secondary side of the voltage transformer 2 are obtained and are respectively marked as I1I2I3And UU’UV’UW' (not shown in FIG. 1); and finally, calculating the power factor of the power system according to the obtained first voltage waveform, second voltage waveform, current waveform and third voltage waveform.
More specifically, a measuring apparatus and method according to an embodiment of the present invention are described in conjunction with fig. 2 and 3. Fig. 2 is a schematic diagram of waveform diagrams of phase voltages of the secondary side of the voltage transformer 2 and phase voltages of the secondary side of the power transformer 3 according to an embodiment of the present invention. The upper three voltage waveforms of FIG. 2 are phase voltages U1', phase voltage U2' sum phase voltage U3', the lower three voltage waveforms are phase voltage U1Phase voltage U2And phase voltage U3The data processing device 11 calculates the phase voltages U separately1' phase-to-phase voltage U1Phase difference, phase voltage U of2' phase-to-phase voltage U2And phase voltage U, and3' phase-to-phase voltage U3The phase difference of (1). For more accurate calculation, for example, the phase voltage U is selected1' the time at which the falling edge crosses zero minus the phase voltage U1The time of the falling edge zero crossing point obtains the phase time difference T1Of course, the phase voltage U may also be selected1' the time at which the rising edge crosses zero minus the phase voltage U1The time of the rising edge zero crossing point is the phase time difference T1. The phase voltage U is calculated in the same way2' phase-to-phase voltage U2Phase time difference of (T)2Phase voltage U3' phase-to-phase voltage U3Phase time difference of (T)3. Theoretical phase time difference T1、T2And T3Are all equal.
After that the protection switch 4 is opened, the short-circuit switch 13 is closed, the protection switch 4 is closed again for a certain time (for example, for 150 ms-500 ms), and the current measuring device 10 measures the phase current I in the secondary side of the power transformer 31、I2And I3. At the same time, in this time period, the voltage measuring device 9 measures the phase voltage U on the secondary side of the voltage transformer 2U’、UV' and UW'. At phase current I1、I2And I3And phase voltage UU’、UV' and UWAfter the measurement is finished, the protection switch 4 is switched off, and the current of the primary side of the power transformer 3 is much smaller than the current of the secondary side, so that air breakdown or damage to the protection switch 4 due to large arc generation can be avoided in the process of switching off the protection switch 4.
Fig. 3 is a schematic diagram of a simulated waveform diagram of an actual voltage on the secondary side of the power transformer 3 and a waveform diagram of a current in a current loop on the secondary side of the power transformer 3 according to an embodiment of the present invention. As shown in fig. 3, the phase voltage U1”、U2' and U3"is the phase voltage U of the secondary side of the voltage transformer 2U’、UV' and UW' analog waveform diagram of the voltage on the secondary side of the power transformer 3 obtained after the phase shift. Phase voltage U1”、U2' and U3"and phase voltage UU’、UV' and UWThe phase time difference of the phase to delay is T1、T2And T3. Also, for more accurate calculation, for example, phase current I is selected1Minus the phase voltage U at the time of the falling edge zero crossing1"the time of the falling edge zero crossing point, namely the phase time difference △ T between the phase current and the voltage1Then, based on the relationship between the phase time and the phase angle, the calculation can be madePhase angle (power factor angle) theta1＝△T1X (2 pi/period), and finally calculating the power factor of the phase to be cos theta1The power factors cos theta of other two phases can be calculated2And cos θ3Finally, cos θ is calculated1、cosθ2And cos θ3To determine whether the low-voltage switchgear and control device international standard IEC60947-1 and the national standard GB14048.1 are fulfilled.
Since the function of the power factor is a cosine function, when the zero crossing point of the falling edge of the phase voltage and the phase current is selected, the function is not limited to the falling edge of a specific waveform. Similarly, the timing of the zero crossing of the rising edges of the phase voltage and the phase current is not limited to the rising edge of a specific waveform. And selecting the zero crossing point after the voltage and current waveforms are stable.
Fig. 4 is a schematic circuit diagram of a short circuit testing system according to an embodiment of the present invention. The short circuit testing system is basically the same as that in fig. 1, except that the short circuit testing system further comprises a closing switch 5, an adjustable load 6 and a protection switch 7. The closing switch 5 and the adjustable load 6 are connected in sequence between the protection switch 4 and the primary side of the power transformer 3. In other embodiments, the closing switch 5 may not be present, in which case the adjustable load 6 is connected between the protection switch 4 and the primary side of the power transformer 3. The protection switch 7 is connected between the secondary side of the power transformer 3 and the short-circuit switch 13, i.e., the protection switch 7 is connected to the front end of the test specimen 8. The adjustable load 6 is used for adjusting the power factor value of the test system so as to meet the test parameters required by the test sample 8 type test.
In the process of measuring the voltage waveform of the secondary side of the power transformer 3, the protection switch 7 is opened, the protection switch 4 is closed, and the closing switch 5 is closed. After the voltage measurement is finished, the protection switch 4 is turned off. In measuring the current waveform on the secondary side of the power transformer 3, the following cases are described: (1) without being connected to the test sample 8, the short-circuit switch 13 and the protection switch 7 are first turned on, and then the protection switch 4 and the closing switch 5 on the primary side of the power transformer 3 are sequentially turned on. And after the current measurement is finished, the protection switch 4 and the closing switch 5 are sequentially switched off. (2) The testing sample 8 is connected, the short-circuit switch 13 is disconnected firstly, then the protection switch 7 and the testing sample 8 are in a conducting state, finally the protection switch 4 and the closing switch 5 on the primary side of the power transformer 3 are in a conducting state in sequence, after the current measurement is finished, the current loop on the secondary side of the power transformer 3 is disconnected through the testing sample 8, and finally the protection switch 4 and the closing switch 5 are disconnected in sequence. (3) The test sample 8 in the disconnected state is connected, the short-circuit switch 13 is disconnected firstly, then the protection switch 7 is in the connected state, then the protection switch 4 and the closing switch 5 on the primary side of the power transformer 3 are in the connected state, finally the test sample 8 is in the connected state, after the current measurement is finished, the loop on the secondary side of the power transformer 3 is disconnected through the test sample 8, and finally the protection switch 4 and the closing switch 5 are disconnected in sequence. In this embodiment, the test sample may be a switch device such as a circuit breaker, a contactor, a switch cabinet, etc., and during the power factor measurement process by connecting the test sample, the method (2) or (3) is tested as required to ensure whether the test sample meets the international or national standard.
In other embodiments of the invention, the protection switch 7 may not be present. The adjustable load 6 may also be connected on the secondary side of the power transformer 3 and between the protection switch 7 and the test specimen 8 (i.e. at the front end of the test specimen 8) when the short circuit test system is used to provide a small current. The short-circuit switch 13 in the present invention can be implemented by using a copper wire with negligible impedance.
Since the function of the power factor is a cosine function, when the zero crossing point of the falling edge of the phase voltage and the phase current is selected, the function is not limited to the falling edge of a specific waveform. Similarly, the timing of the zero crossing of the rising edges of the phase voltage and the phase current is not limited to the rising edge of a specific waveform. And selecting the zero crossing point after the voltage and current waveforms are stable.
The voltage measuring device 9 and the current measuring device 10 in the present invention may be any measuring devices capable of acquiring voltage and current waveforms. In other embodiments of the present invention, the data processing device 11 may not be provided, and the power factor may be calculated directly from the three sets of voltage waveforms measured by the voltage measuring device 9 and the set of current waveforms measured by the current measuring device 10. The data processing device 11 of the present invention can be implemented by a programmable logic device, a single chip microcomputer, or the like.
In other embodiments of the present invention, the closing switch 5 may also be connected to the secondary side of the power transformer 3, for example, between the secondary side of the power transformer 3 and the test specimen 8.
In other embodiments of the present invention, the voltage transformer 2 may be any transformer as long as it can safely measure the voltage waveform of the secondary side thereof.
By adopting the measuring method of the invention, the current loop of the secondary side of the power transformer 3 is cut off by cutting off the protective switch 4 of the primary side of the power transformer 3, the whole short-circuit test system is effectively protected and the protective switch 7 is prevented from being damaged, so that the protective switch 7 can select an air circuit breaker with ordinary breaking capacity and low price, and does not need to select an expensive vacuum circuit breaker. In addition, when the waveform of the current is measured, the phase voltage waveform of the voltage transformer 2 is obtained at the same time, and the phase angles of the voltage and the current of the short-circuit test system under the conditions of low voltage and large current are indirectly obtained according to the fixed value of the phase time of the phase voltages of the voltage transformer 2 and the power transformer 3, so that the accurate power factor of the large-current short-circuit test system is obtained, and accurate test conditions are provided for test samples.
In addition, the impact coefficient method and the direct current component method both need to measure the power factor of each phase when the voltage switching-on angle is 0 degrees, and the method can simultaneously obtain the power factor of each phase in three-phase power, thereby saving the test time and facilitating the measurement of the power factor.
In other embodiments of the present invention, the voltage and current are not limited to three-phase power, but may be single-phase power.
It should be understood that although the present description has been described in terms of various embodiments, not every embodiment includes only a single embodiment, and such description is for clarity purposes only, and those skilled in the art will recognize that the embodiments described herein may be combined as suitable to form other embodiments, as will be appreciated by those skilled in the art.
The above description is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. Any equivalent alterations, modifications and combinations can be made by those skilled in the art without departing from the spirit and principles of the invention.
Claims (5)
1. A power factor measuring device for an electric power system including a power supply line (1), a protection switch (4), an electric power transformer (3), and a short-circuit switch (13), a primary side of the electric power transformer (3) being connected to the power supply line (1) through the protection switch (4), the short-circuit switch (13) being connected to a secondary side of the electric power transformer (3), characterized in that the power factor measuring device (12) comprises:
a voltage transformer (2), the primary side of the voltage transformer (2) being connected to the power supply line (1);
a voltage measuring device (9) for simultaneously acquiring a first voltage waveform on the secondary side of the voltage transformer (2) and a second voltage waveform on the secondary side of the power transformer (3) when the protection switch (4) is in a closed state and the short-circuit switch (13) is in an open state; and when the protection switch (4) is in a closed state and the short-circuit switch (13) is in a closed state, acquiring a third voltage waveform of the secondary side of the voltage transformer (2);
a current measuring device (10) for acquiring a current waveform of a secondary side of the power transformer (3) when the protection switch (4) is in a closed state and the short-circuit switch (13) is in a closed state;
-data processing means (11) for calculating a power factor from the first, second, current and third voltage waveforms;
wherein the obtaining of the third voltage waveform of the secondary side of the voltage transformer (2) and the obtaining of the current waveform of the secondary side of the power transformer (3) are performed simultaneously.
2. The power factor measuring device for an electric power system according to claim 1, wherein the data processing device (11) is configured to calculate a phase time difference from the first voltage waveform and the second voltage waveform, and then calculate the power factor from the phase time difference, the current waveform, and the third voltage waveform.
3. A method of measuring the power factor of an electric power system comprising a supply line (1), a protection switch (4), an electric power transformer (3) and a short-circuit switch (13), the primary side of the electric power transformer (3) being connected to the supply line (1) through the protection switch (4), the short-circuit switch (13) being connected to the secondary side of the electric power transformer (3), characterized by the steps of:
-connecting a voltage transformer (2) on the power supply line (1);
-bringing the short-circuit switch (13) in an open state and the protection switch (4) in a closed state while acquiring a first voltage waveform on the secondary side of the voltage transformer (2) and a second voltage waveform on the secondary side of the power transformer (3);
-bringing the protection switch (4) in an open state, the short-circuit switch (13) in a closed state, and the protection switch (4) in a closed state while acquiring a current waveform on the secondary side of the power transformer (3) and a third voltage waveform on the secondary side of the voltage transformer (2);
-calculating a power factor from the first, second, current and third voltage waveforms.
4. A method of measuring power factor of a power system according to claim 3, wherein a phase time difference is calculated from the first and second voltage waveforms, and a power factor is calculated from the phase time difference, the current waveform and the third voltage waveform.
5. A short circuit testing system, comprising:
a power factor test device (12) according to claim 1 or 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410181976.3A CN105092956B (en) | 2014-04-30 | 2014-04-30 | Power Systems factor measurement apparatus, method and its system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410181976.3A CN105092956B (en) | 2014-04-30 | 2014-04-30 | Power Systems factor measurement apparatus, method and its system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105092956A CN105092956A (en) | 2015-11-25 |
| CN105092956B true CN105092956B (en) | 2018-02-02 |
Family
ID=54573847
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410181976.3A Active CN105092956B (en) | 2014-04-30 | 2014-04-30 | Power Systems factor measurement apparatus, method and its system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105092956B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI695986B (en) * | 2018-10-08 | 2020-06-11 | 博計電子股份有限公司 | Analog power factor AC load system and method |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000356659A (en) * | 1998-05-28 | 2000-12-26 | Matsushita Electric Ind Co Ltd | Multiple circuit type wattmeter, multiple circuit type watt-hour meter, multiple circuit type power-factor meter, multiple circuit tire reactive power meter, multiple circuit type reactive energy meter |
| EP2241898A1 (en) * | 2008-02-06 | 2010-10-20 | Mitsubishi Electric Corporation | Power measuring system, measuring apparatus, load terminal, and device control system |
| CN102288821A (en) * | 2011-04-29 | 2011-12-21 | 北京合康亿盛变频科技股份有限公司 | Measuring method, measuring device, measuring procedure and carrier for phase difference of three-phase circuit |
| CN102830278A (en) * | 2012-09-05 | 2012-12-19 | 茂硕电源科技股份有限公司 | Power factor detection circuit |
| CN103185833A (en) * | 2013-02-06 | 2013-07-03 | 上海交通大学 | Method for measuring peak area ratio of short-time energizing test loop power factor |
| CN203118311U (en) * | 2013-02-28 | 2013-08-07 | 朱云开 | Experimental device measuring power factors |
| CN103630775A (en) * | 2013-11-16 | 2014-03-12 | 中国科学院电工研究所 | Equipment and method for testing alternating current big current impact |
-
2014
- 2014-04-30 CN CN201410181976.3A patent/CN105092956B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000356659A (en) * | 1998-05-28 | 2000-12-26 | Matsushita Electric Ind Co Ltd | Multiple circuit type wattmeter, multiple circuit type watt-hour meter, multiple circuit type power-factor meter, multiple circuit tire reactive power meter, multiple circuit type reactive energy meter |
| EP2241898A1 (en) * | 2008-02-06 | 2010-10-20 | Mitsubishi Electric Corporation | Power measuring system, measuring apparatus, load terminal, and device control system |
| CN102288821A (en) * | 2011-04-29 | 2011-12-21 | 北京合康亿盛变频科技股份有限公司 | Measuring method, measuring device, measuring procedure and carrier for phase difference of three-phase circuit |
| CN102830278A (en) * | 2012-09-05 | 2012-12-19 | 茂硕电源科技股份有限公司 | Power factor detection circuit |
| CN103185833A (en) * | 2013-02-06 | 2013-07-03 | 上海交通大学 | Method for measuring peak area ratio of short-time energizing test loop power factor |
| CN203118311U (en) * | 2013-02-28 | 2013-08-07 | 朱云开 | Experimental device measuring power factors |
| CN103630775A (en) * | 2013-11-16 | 2014-03-12 | 中国科学院电工研究所 | Equipment and method for testing alternating current big current impact |
Non-Patent Citations (2)
| Title |
|---|
| 功率因数的实时精确测量方案探讨;范春菊 等;《继电器》;20030715;第31卷(第7期);第47-49页 * |
| 电力系统功率因数的测量方法;刘彬 等;《电测与仪表》;19881231(第6期);第12页，第29-30页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105092956A (en) | 2015-11-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8217536B2 (en) | Magnetizing inrush current suppression device for transformer and control method of same | |
| JP4825648B2 (en) | Switch control device | |
| US9082562B2 (en) | Inrush-current suppressing device and inrush-current suppressing method | |
| CA2824263A1 (en) | Method and apparatus for the measurement of a resistance of a switching contact of an electrical circuit breaker | |
| CN103823179A (en) | Non-contact spatial high-frequency high-voltage circuit breaker operation characteristics measurement method | |
| JP2004170093A (en) | Testing device and testing method for electric equipment protection circuit | |
| CA2815464C (en) | Inrush current suppressing device | |
| Sweeting | Applying IEC 60909, short-circuit current calculations | |
| EP2778694B1 (en) | Apparatus and method for insulation testing of an electrical supply network | |
| CN104133152B (en) | DC detecting device during single-phase earthing of small current earthing system | |
| CN105092956B (en) | Power Systems factor measurement apparatus, method and its system | |
| US10088509B2 (en) | Checking a multi-pole electrical circuit breaker | |
| CN110703146A (en) | Excitation surge current measuring instrument | |
| CN113156276B (en) | Method for checking and debugging secondary voltage loop of bus alternating-current withstand voltage test of switching equipment | |
| CN106602516B (en) | PT secondary resonance elimination device and harmonic elimination method | |
| KR101854212B1 (en) | Method and system for testing a switching installation for power transmission installations | |
| Czapp et al. | A new method of fault loop resistance measurement in low voltage systems with residual current devices | |
| CA2969893C (en) | Demagnetization device and method for demagnetizing a transformer core | |
| Venkata et al. | Advanced and adaptive protection for active distribution grid | |
| CN114280428A (en) | High-voltage power insulation level online monitoring system | |
| JP7222100B2 (en) | Method and Apparatus for Monitoring Operation of Switching Devices for Controlled Switching Applications | |
| JP2012198124A (en) | Power distribution device and voltage measurement method | |
| KR101528072B1 (en) | multiwinding Epstein apparatus | |
| CN110703003A (en) | Device and method for detecting current loop of total step-down substation | |
| RU2244941C2 (en) | Method for locating single-phase ground fault in three-phase power transmission line |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |