CN104865432A - Method for calculating oscillation center voltage, and device for calculating oscillation center voltage - Google Patents

Method for calculating oscillation center voltage, and device for calculating oscillation center voltage Download PDF

Info

Publication number
CN104865432A
CN104865432A CN201410058449.3A CN201410058449A CN104865432A CN 104865432 A CN104865432 A CN 104865432A CN 201410058449 A CN201410058449 A CN 201410058449A CN 104865432 A CN104865432 A CN 104865432A
Authority
CN
China
Prior art keywords
voltage
dis
oscillation center
vector
sample values
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.)
Granted
Application number
CN201410058449.3A
Other languages
Chinese (zh)
Other versions
CN104865432B (en
Inventor
赵青春
朱晓彤
谢华
李园园
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NR Electric Co Ltd
Original Assignee
NR Electric Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NR Electric Co Ltd filed Critical NR Electric Co Ltd
Priority to CN201410058449.3A priority Critical patent/CN104865432B/en
Priority to PCT/CN2015/070595 priority patent/WO2015124046A1/en
Publication of CN104865432A publication Critical patent/CN104865432A/en
Application granted granted Critical
Publication of CN104865432B publication Critical patent/CN104865432B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
    • G01R19/2513—Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Phase Differences (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

The present invention discloses a method for calculating an oscillation center voltage. The method comprises the steps of obtaining the discrete sampling values of the three phase voltages and the discrete sampling values of the three phase currents, obtaining the positive sequence voltage vectors and the positive sequence current vectors respectively according to the obtained discrete sampling values of the three phase voltages and the three phase currents, and calculating the oscillation center voltage according to the obtained positive sequence voltage vectors and the positive sequence current vectors. The present invention also discloses a device for calculating the oscillation center voltage.

Description

A kind of method and device calculating voltage of oscillation center
Technical field
The present invention relates to electric network protection technology, particularly relate to a kind of method and the device that calculate voltage of oscillation center.
Background technology
In network system, system oscillation center voltage, is generally used for and differentiates whether the out-of-step blocking of distance protection opens, prevents distance protection overload and security and stability control field.Usually, the method for computing system voltage of oscillation center as shown in Figure 1, comprising: first sampling obtains three-phase voltage and three-phase current sample sequence, and utilizes fourier algorithm to obtain the vector value of three-phase voltage and the vector value of three-phase current; Again according to the vector value of three-phase voltage and the vector value of three-phase current, calculate positive sequence voltage vector sum forward-order current vector; Afterwards, phase compensation is carried out to positive sequence current vector, positive sequence voltage vector is projected to the forward-order current vector after phase compensation, obtains voltage of oscillation center.
But, when utilizing fourier algorithm to obtain the vector value of the vector value of three-phase voltage and three-phase current, certain data window must be used could to obtain complete data message; Under some applicable cases, such as: when quick oscillation latch open and vibration differentiate, often need the voltage data obtaining oscillation center fast, this just requires that the data window obtained needed for voltage of oscillation center is more short better; And in actual applications, data window often can not meet the time calculated needed for voltage of oscillation center.
Summary of the invention
In view of this, the embodiment of the present invention is expected to provide a kind of method and the device that calculate voltage of oscillation center, just can not obtain voltage of oscillation center by usage data window, thus avoid affecting quick oscillation latch open and vibration differentiation because data window can not meet calculating voltage of oscillation center required time.
For achieving the above object, the technical scheme of the embodiment of the present invention is achieved in that
The embodiment of the present invention provides a kind of method calculating voltage of oscillation center, comprising: obtain the dis-crete sample values of three-phase voltage and the dis-crete sample values of three-phase current; According to the dis-crete sample values of the three-phase voltage of described acquisition and the dis-crete sample values of three-phase current, obtain positive sequence voltage vector sum forward-order current vector respectively; According to the positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center of described acquisition.
Preferably, the dis-crete sample values of described three-phase voltage comprises: U a(k), U b(k) and U c(k); The dis-crete sample values of described three-phase current comprises: I a(k), I b(k) and I c(k);
Wherein, k is sampled point label.
Preferably, the described described three-phase voltage dis-crete sample values acquisition positive sequence voltage vector according to obtaining is: U · 1 = U c ( k ) - U b ( k ) 3 + j × U a ( k ) ;
Wherein, for positive sequence voltage vector; J is imaginary unit.
Preferably, the described described three-phase current dis-crete sample values acquisition forward-order current vector according to obtaining is: I · 1 = I c ( k ) - I b ( k ) 3 + j × I a ( k ) ;
Wherein, for forward-order current vector, j is imaginary unit.
Preferably, the described positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center according to described acquisition comprises: carry out line impedance angle compensation to positive sequence current vector, by positive sequence voltage vector to the forward-order current vector projection after compensation, calculate and obtain voltage of oscillation center.
The embodiment of the present invention also provides a kind of device calculating voltage of oscillation center, comprising: the first acquisition module, the second acquisition module and computing module; Wherein,
First acquisition module, for the dis-crete sample values of the dis-crete sample values and three-phase current that obtain three-phase voltage;
Second acquisition module, for according to the dis-crete sample values of three-phase voltage and the dis-crete sample values of three-phase current, obtains positive sequence voltage vector sum forward-order current vector respectively;
Computing module, for according to positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center.
Preferably, the dis-crete sample values of the three-phase voltage of described first acquisition module acquisition comprises: U a(k), U b(k) and U c(k); The dis-crete sample values of described three-phase current comprises: I a(k), I b(k) and I c(k);
Wherein, k is sampled point label.
Preferably, the described three-phase voltage dis-crete sample values acquisition positive sequence voltage vector that described second acquisition module obtains according to the first acquisition module is: U · 1 = U c ( k ) - U b ( k ) 3 + j × U a ( k ) ;
Wherein, for positive sequence voltage vector; J is imaginary unit.
Preferably, the described three-phase current dis-crete sample values acquisition forward-order current vector that described second acquisition module obtains according to the first acquisition module is: I · 1 = I c ( k ) - I b ( k ) 3 + j × I a ( k ) ;
Wherein, for forward-order current vector, j is imaginary unit.
Preferably, the positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center that described computing module obtains according to described second acquisition module comprises: carry out line impedance angle compensation to positive sequence current vector, by positive sequence voltage vector to the forward-order current vector projection after compensation, calculate and obtain voltage of oscillation center.
The method of the calculating voltage of oscillation center that the embodiment of the present invention provides and device, first obtain the dis-crete sample values of three-phase voltage and the dis-crete sample values of three-phase current; Again according to the dis-crete sample values of three-phase voltage obtained and the dis-crete sample values of three-phase current, obtain positive sequence voltage vector sum forward-order current vector respectively; Finally according to the positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center obtained; So, just can not obtain voltage of oscillation center by usage data window, thus avoid due to data window can not meet calculate voltage of oscillation center required time and affect quick oscillation latch open and vibration differentiate; When require to obtain oscillating voltage desired data window more short better, the voltage data of oscillation center can be obtained fast.
Accompanying drawing explanation
Fig. 1 is the computation process schematic diagram calculating voltage of oscillation center based on fourier algorithm;
Fig. 2 is the basic realization flow schematic diagram that the embodiment of the present invention calculates the method for voltage of oscillation center;
Fig. 3 is the realization flow schematic diagram of the embodiment of the present invention according to the positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center of described acquisition;
Fig. 4 is the detailed realization flow schematic diagram that the embodiment of the present invention calculates the method for voltage of oscillation center;
Fig. 5 is the computation process schematic diagram that the embodiment of the present invention obtains positive sequence voltage vector sum forward-order current vector;
Fig. 6 is the composition structural representation that the embodiment of the present invention calculates the device of voltage of oscillation center.
Embodiment
The embodiment of the present invention calculates the basic realization flow of the method for voltage of oscillation center, as shown in Figure 2, comprises the following steps:
Step 101, obtains the dis-crete sample values of three-phase voltage and the dis-crete sample values of three-phase current;
Concrete, the dis-crete sample values of three-phase voltage comprises: U a(k), U b(k) and U c(k); The dis-crete sample values of three-phase current comprises: I a(k), I b(k) and I c(k); K is sampled point label;
Wherein, how to obtain the dis-crete sample values of three-phase voltage and the dis-crete sample values of three-phase current, belong to prior art, repeat no more here.
Step 102, according to the dis-crete sample values of the three-phase voltage of described acquisition and the dis-crete sample values of three-phase current, obtains positive sequence voltage vector sum forward-order current vector respectively;
Concrete, obtaining positive sequence voltage vector according to the dis-crete sample values of the described three-phase voltage obtained is: U · 1 = U c ( k ) - U b ( k ) 3 + j × U a ( k ) ;
Obtaining forward-order current vector according to the dis-crete sample values of the described three-phase current obtained is: I · 1 = I c ( k ) - I b ( k ) 3 + j × I a ( k ) ;
Wherein, for positive sequence voltage vector; for positive sequence voltage vector; J is imaginary unit.
Step 103, according to the positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center of described acquisition;
Concrete, according to the realization flow of the positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center of described acquisition, as shown in Figure 3, comprise the following steps:
Step 103a, carries out line impedance angle compensation to positive sequence current vector;
Concrete, the forward-order current vector after compensation is:
Wherein, for the forward-order current after compensating is vectorial; for circuit positive sequence impedance angle; J is imaginary unit.
Step 103b, by positive sequence voltage vector to the forward-order current vector projection after compensation, calculates and obtains voltage of oscillation center;
Concrete, calculating the voltage of oscillation center obtained is:
Wherein, real for getting real part computing, for conjugate vector, U 1.osfor voltage of oscillation center value.
The embodiment of the present invention calculates the detailed realization flow of the method for voltage of oscillation center as shown in Figure 4, comprises the following steps:
Step 201, obtains the dis-crete sample values of three-phase voltage and the dis-crete sample values of three-phase current;
Wherein, the dis-crete sample values of three-phase voltage comprises: U a(k), U b(k) and U c(k); The dis-crete sample values of three-phase current comprises: I a(k), I b(k) and I c(k);
Concrete, when three-phase system is symmetrical, system three-phase voltage value is:
U a(t)=U M×sin(ωt+α)
U b(t)=U M×sin(ωt+α+240°)
U c(t)=U M×sin(ωt+α+120°)
Wherein, U mfor voltage magnitude, ω is system frequency, and t is random time, and α is initial phase angle.
At t 0in the moment, system three-phase voltage synchronized sampling value is:
U a(k)=U M×sin(ωt 0+α)
U b(k)=U M×sin(ωt 0+α+240°)
U c(k)=U M×sin(ωt 0+α+120°)
Wherein, t 0for sampling instant, k is sampled point label, U mfor the positive sequence voltage amplitude being benchmark with A phase is, ω t 0+ α is phase place.
In like manner, at t 0in the moment, system three-phase current synchronized sampling value is:
I a(k)=I M×sin(ωt 0+β)
I b(k)=I M×sin(ωt 0+β+240°)
I c(k)=I M×sin(ωt 0+β+120°)
Wherein, I mfor current amplitude, ω is system frequency, and β is initial phase angle, t 0for sampling instant, k is sampled point label.
Step 202, according to the dis-crete sample values of the three-phase voltage of described acquisition and the dis-crete sample values of three-phase current, obtains positive sequence voltage vector sum forward-order current vector respectively;
Obtain the computation process schematic diagram of positive sequence voltage vector sum forward-order current vector, as shown in Figure 5;
Concrete, composition of vector A · = U M × cos ( ωt 0 + α ) + j × U M × sin ( ωt 0 + α ) ;
Wherein, vector amplitude be U m, phase place is ω t 0+ α, consistent with the positive sequence voltage amplitude being benchmark with A phase and phase place, that is: vector for system positive sequence voltage vector
Therefore,
In like manner, I · 1 = I c ( k ) - I b ( k ) 3 + j × I a ( k ) ;
Wherein, for positive sequence voltage vector; for positive sequence voltage vector; J is imaginary unit.
Step 203, carries out line impedance angle compensation to positive sequence current vector;
Concrete, the forward-order current vector after compensation is:
Wherein, for the forward-order current after compensating is vectorial; for circuit positive sequence impedance angle; J is imaginary unit.
Step 204, by positive sequence voltage vector to the forward-order current vector projection after compensation, calculates and obtains voltage of oscillation center;
Concrete, calculating the voltage of oscillation center obtained is:
Wherein, real for getting real part computing, for conjugate vector, U 1.osfor voltage of oscillation center value.
For realizing the method for above-mentioned calculating voltage of oscillation center, the embodiment of the present invention additionally provides a kind of device calculating voltage of oscillation center, the device composition structure of described calculating voltage of oscillation center, and as shown in Figure 6, this device comprises:
First acquisition module 10, for the dis-crete sample values of the dis-crete sample values and three-phase current that obtain three-phase voltage;
Second acquisition module 20, for the dis-crete sample values of three-phase voltage that obtains according to the first acquisition module 10 and the dis-crete sample values of three-phase current, obtains positive sequence voltage vector sum forward-order current vector respectively;
Computing module 30, for the positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center obtained according to the second acquisition module 20.
Here, the dis-crete sample values of the three-phase voltage of described first acquisition module acquisition comprises: U a(k), U b(k) and U c(k); The dis-crete sample values of described three-phase current comprises: I a(k), I b(k) and I c(k); Wherein, k is sampled point label.
Described second acquisition module obtains positive sequence voltage vector according to the described three-phase voltage dis-crete sample values that the first acquisition module obtains: U · 1 = U c ( k ) - U b ( k ) 3 + j × U a ( k ) ; Wherein, for positive sequence voltage vector; J is for getting imaginary unit.
Described second acquisition module obtains forward-order current vector according to the described three-phase current dis-crete sample values that the first acquisition module obtains: I · 1 = I c ( k ) - I b ( k ) 3 + j × I a ( k ) ; Wherein, for forward-order current vector, j is imaginary unit.
The positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center that described computing module obtains according to described second acquisition module comprises: carry out line impedance angle compensation to positive sequence current vector, by positive sequence voltage vector to the forward-order current vector projection after compensation, calculate and obtain voltage of oscillation center.
It should be noted that, in actual applications, the function of described first acquisition module 10, second acquisition module 20 and computing module 30 can be realized by central processing unit (CPU) or microprocessor (MPU) or digital signal processor (DSP) or programmable gate array (FPGA).
The above, be only preferred embodiment of the present invention, be not intended to limit protection scope of the present invention.

Claims (10)

1. calculate a method for voltage of oscillation center, it is characterized in that, described method comprises:
Obtain the dis-crete sample values of three-phase voltage and the dis-crete sample values of three-phase current;
According to the dis-crete sample values of the three-phase voltage of described acquisition and the dis-crete sample values of three-phase current, obtain positive sequence voltage vector sum forward-order current vector respectively;
According to the positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center of described acquisition.
2. calculate the method for voltage of oscillation center according to claim 1, it is characterized in that, the dis-crete sample values of described three-phase voltage comprises: U a(k), U b(k) and U c(k); The dis-crete sample values of described three-phase current comprises: I a(k), I b(k) and I c(k);
Wherein, k is sampled point label.
3. calculate the method for voltage of oscillation center according to claim 2, it is characterized in that, the described described three-phase voltage dis-crete sample values according to obtaining obtains positive sequence voltage vector and is:
Wherein, for positive sequence voltage vector; J is imaginary unit.
4. calculate the method for voltage of oscillation center according to claim 2, it is characterized in that, the described described three-phase current dis-crete sample values according to obtaining obtains forward-order current vector and is:
Wherein, for forward-order current vector, j is imaginary unit.
5. calculate the method for voltage of oscillation center according to claim 1, it is characterized in that, the described positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center according to described acquisition comprises: carry out line impedance angle compensation to positive sequence current vector, by positive sequence voltage vector to the forward-order current vector projection after compensation, calculate and obtain voltage of oscillation center.
6. calculate a device for voltage of oscillation center, it is characterized in that, described device comprises: the first acquisition module, the second acquisition module and computing module; Wherein,
First acquisition module, for the dis-crete sample values of the dis-crete sample values and three-phase current that obtain three-phase voltage;
Second acquisition module, for according to the dis-crete sample values of three-phase voltage and the dis-crete sample values of three-phase current, obtains positive sequence voltage vector sum forward-order current vector respectively;
Computing module, for according to positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center.
7. calculate the device of voltage of oscillation center according to claim 6, it is characterized in that, the dis-crete sample values of the three-phase voltage that described first acquisition module obtains comprises: U a(k), U b(k) and U c(k); The dis-crete sample values of described three-phase current comprises: I a(k), I b(k) and I c(k);
Wherein, k is sampled point label.
8. calculate the device of voltage of oscillation center according to claim 7, it is characterized in that, described second acquisition module obtains positive sequence voltage vector according to the described three-phase voltage dis-crete sample values that the first acquisition module obtains and is: U · 1 = U c ( k ) - U b ( k ) 3 + j × U a ( k ) ;
Wherein, for positive sequence voltage vector; J is imaginary unit.
9. calculate the device of voltage of oscillation center according to claim 7, it is characterized in that, described second acquisition module obtains forward-order current vector according to the described three-phase current dis-crete sample values that the first acquisition module obtains and is: I · 1 = I c ( k ) - I b ( k ) 3 + j × I a ( k ) ;
Wherein, for forward-order current vector, j is imaginary unit.
10. obtain the device calculating voltage of oscillation center according to claim 6, it is characterized in that, the positive sequence voltage vector sum forward-order current vector calculation voltage of oscillation center that described computing module obtains according to described second acquisition module comprises: carry out line impedance angle compensation to positive sequence current vector, by positive sequence voltage vector to the forward-order current vector projection after compensation, calculate and obtain voltage of oscillation center.
CN201410058449.3A 2014-02-20 2014-02-20 A kind of method and device for calculating voltage of oscillation center Active CN104865432B (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN201410058449.3A CN104865432B (en) 2014-02-20 2014-02-20 A kind of method and device for calculating voltage of oscillation center
PCT/CN2015/070595 WO2015124046A1 (en) 2014-02-20 2015-01-13 Method and device for calculating oscillation center voltage

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201410058449.3A CN104865432B (en) 2014-02-20 2014-02-20 A kind of method and device for calculating voltage of oscillation center

Publications (2)

Publication Number Publication Date
CN104865432A true CN104865432A (en) 2015-08-26
CN104865432B CN104865432B (en) 2018-03-13

Family

ID=53877626

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201410058449.3A Active CN104865432B (en) 2014-02-20 2014-02-20 A kind of method and device for calculating voltage of oscillation center

Country Status (2)

Country Link
CN (1) CN104865432B (en)
WO (1) WO2015124046A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111211561B (en) * 2020-03-06 2022-09-02 中国电力科学研究院有限公司 Positioning method and device for power grid self-adaptive out-of-step disconnection section

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1419133A (en) * 2002-09-30 2003-05-21 南京南瑞继保电气有限公司 UCOS 'phi' based electric power system pull-out dectection judging method
CN101034128A (en) * 2007-02-09 2007-09-12 田伟 Method for quickly recognizing symmetrical failure in vibration
WO2008132258A1 (en) * 2007-04-30 2008-11-06 Universidad Politechnica De Valencia Method and practical use system for measuring the imbalance power in electrical installations, and the device for calibration thereof
CN102200564A (en) * 2011-03-10 2011-09-28 北京四方继保自动化股份有限公司 Power system oscillation identification method based on power angle calculation
CN103336161A (en) * 2013-06-05 2013-10-02 南方电网科学研究院有限责任公司 Multi-terminal oscillation voltage measuring method based on optical fiber communication

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5714755A (en) * 1980-06-30 1982-01-26 Mitsubishi Electric Corp Method of reducing effect due to quantization error of digital processing locator
DE19746719C1 (en) * 1997-10-15 1999-05-06 Siemens Ag Power swing indication signal determination method e.g. for power supply network
CN101593983B (en) * 2009-07-06 2011-11-16 中国电力科学研究院 Method for quickly positioning oscillating center of electric system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1419133A (en) * 2002-09-30 2003-05-21 南京南瑞继保电气有限公司 UCOS 'phi' based electric power system pull-out dectection judging method
CN101034128A (en) * 2007-02-09 2007-09-12 田伟 Method for quickly recognizing symmetrical failure in vibration
WO2008132258A1 (en) * 2007-04-30 2008-11-06 Universidad Politechnica De Valencia Method and practical use system for measuring the imbalance power in electrical installations, and the device for calibration thereof
CN102200564A (en) * 2011-03-10 2011-09-28 北京四方继保自动化股份有限公司 Power system oscillation identification method based on power angle calculation
CN103336161A (en) * 2013-06-05 2013-10-02 南方电网科学研究院有限责任公司 Multi-terminal oscillation voltage measuring method based on optical fiber communication

Also Published As

Publication number Publication date
WO2015124046A1 (en) 2015-08-27
CN104865432B (en) 2018-03-13

Similar Documents

Publication Publication Date Title
JP4038484B2 (en) Synchronous phasor measuring device
US10942209B2 (en) Floating neutral detection and localization system and methods
EP2859635B1 (en) Method for identifying fault by current differential protection and device thereof
EP2713172B1 (en) Measurement apparatus for electricity distribution grids
Xia et al. Complex-valued least squares frequency estimation for unbalanced power systems
Dash et al. Dynamic phasor and frequency estimation of time-varying power system signals
Xue et al. Power system frequency estimation method in the presence of harmonics
US20200088780A1 (en) Distance protection of electric power delivery systems using time domain and frequency domain
Xia et al. A widely linear least mean phase algorithm for adaptive frequency estimation of unbalanced power systems
CN108155643A (en) A kind of robust estimation method of the single-phase mains voltage parameter based on sliding mode observer
Kumar et al. Simulation of phasor measurement unit (PMU) in MATLAB
Fan et al. Gaussian mixture model-based ensemble Kalman filter for machine parameter calibration
Tosato et al. Implementation of phasor measurement units on low-cost embedded platforms: A feasibility study
Reza et al. Robust technique for accurate estimation of single‐phase grid voltage fundamental frequency and amplitude
Marčetić et al. Unbalanced three‐phase distribution system frequency estimation using least mean squares method and positive voltage sequence
KR101918189B1 (en) Device and method for measuring electric power
CN104865432A (en) Method for calculating oscillation center voltage, and device for calculating oscillation center voltage
Wu et al. Effect of adding DC‐offset estimation integrators in there‐phase enhanced phase‐locked loop on dynamic performance and alternative scheme
CN105277780A (en) Voltage zero-crossing point obtaining method and device
JP5188449B2 (en) Synchronous phasor measuring device
Ozsoy et al. Instantaneous symmetrical component estimator using second order generalized integrator under distorted voltage conditions
ES2913980T3 (en) System and method of data decimation to facilitate the transmission and display of waveforms generated by an electrical device
CN103293440A (en) Line single-phase earth fault single-terminal ranging method implemented by aid of sequence components
Malpani et al. High precision frequency estimation using internet-based phasor measurement unit
Xia et al. A balancing voltage transformation for robust frequency estimation in unbalanced power systems

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
EXSB Decision made by sipo to initiate substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant