An analytical approach for removal of decaying DC component considering frequency deviation

Tajdinian, Mohsen; Jahromi, Mehdi Zareian; Mohseni, Kazem; Kouhsari, Shahram Montaser

doi:10.1016/j.epsr.2015.09.007

Cited by 39 publications

(44 citation statements)

References 33 publications

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“…It must be noted that, due to severe disturbances in power system, the system frequency may differ from its nominal value f 0 . The latter causes undesirable instability in estimating phasor, and as a result, it must be considered in phasor estimation of numerical relays.…”

Section: Consideration Of Ccvt Model In the Fault Voltage Signalmentioning

confidence: 99%

“…As it was mentioned before, in practical application, voltage signal does not experience even harmonic component, especially during fault condition. Also, it was mentioned that DFT‐based phasor estimation algorithms must minimize the unwanted instability of frequency deviation in off‐nominal frequency condition. To overcome the abovementioned drawbacks, applying half‐cycle Fourier transform and , the real and imaginary parts of the fundamental phasor component can be written as below:

U_{Re} = \frac{4}{T} \int_{t}^{t + \frac{true}{T}} \overset{u}{true} ((), t) sin ((), ω_{0} t) italicdt,

U_{Im} = \frac{4}{T} \int_{t}^{t + \frac{true}{T}} \overset{u}{true} ((), t) cos ((), ω_{0} t) italicdt,

wherein and , U Re and U Im are real and imaginary parts of fundamental component of

\overset{u}{true} ((), t)

, respectively.…”

Section: Calculation Of the Ccvt Characteristics And Phasor Estimationmentioning

confidence: 99%

“…Having U hfr , U hfi , U lfr , U lfi , and U dc , the unwanted effect the CCVT components can be calculated, and as a result, by applying , the unwanted effect the CCVT components are subtracted from the input signal. Step 3 (Updating frequency coefficient) After subtracting, utilizing frequency tracking, expressions , , , and are updated. Except for the first cycle, this action is done in one cycle Step 4 (Phasor estimation process) Applying and , fundamental phasor will be calculated while analytically all the undesirable issues have been considered.…”

Section: Calculation Of the Ccvt Characteristics And Phasor Estimationmentioning

confidence: 99%

“…This paper attempts to minimize the unwanted effects of the transient coupling capacitor voltage transformer (CCVT) due to fault condition on the phasor estimation. It is worth to mention that the same studies have been conducted on the impact of current transformer (CT) on the phasor estimation of the fault current signal and CT saturation detection prevention. It was observed that taking dynamic behavior of CT into account will result in more accuracy and speed and robustness into estimated phasor component.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Minimizing the undesirable effect of coupling capacitor voltage transformer on DFT-based phasor estimation method

Tajdinian

Allahbakhshi²,

Seifi

et al. 2018

Int Trans Electr Energ Syst

Self Cite

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Summary This paper presents an innovative half‐cycle method to minimize the undesirable effects of coupling capacitor voltage transformer (CCVT) on the discrete Fourier transform (DFT)‐based phasor estimation methods during fault condition. The proposed method analytically calculates transient components of the CCVT by using a combination of half‐cycle phase shifting along with the modified least squares technique. The latter combination is used to obtain the transient characteristics of CCVT. Afterward, subtracting estimated transient behavior from original voltage fault signal, modified half‐cycle DFT is utilized to estimate fundamental phasor component. Half‐cycle DFT formulation is modified to cope with the instability caused by off‐nominal frequency condition. Based on some case studies conducted on MATLAB software environment, the performance of the proposed phasor estimator is investigated. The results illustrate that the proposed method estimates fundamental phasor component with an ignorable effect of CCVT transient in almost half cycle after disturbance happening under different fault conditions.

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Section: Consideration Of Ccvt Model In the Fault Voltage Signalmentioning

confidence: 99%

U_{Re} = \frac{4}{T} \int_{t}^{t + \frac{true}{T}} \overset{u}{true} ((), t) sin ((), ω_{0} t) italicdt,

U_{Im} = \frac{4}{T} \int_{t}^{t + \frac{true}{T}} \overset{u}{true} ((), t) cos ((), ω_{0} t) italicdt,

wherein and , U Re and U Im are real and imaginary parts of fundamental component of

\overset{u}{true} ((), t)

, respectively.…”

Section: Calculation Of the Ccvt Characteristics And Phasor Estimationmentioning

confidence: 99%

Section: Calculation Of the Ccvt Characteristics And Phasor Estimationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Minimizing the undesirable effect of coupling capacitor voltage transformer on DFT-based phasor estimation method

Tajdinian

Allahbakhshi²,

Seifi

et al. 2018

Int Trans Electr Energ Syst

Self Cite

View full text Add to dashboard Cite

show abstract

“…Hilbert Transform (HT) and Discrete Fourier Transform (DFT) based combined approach is proposed for estimation of fundamental phasor for removing decaying DC components [20]. This approach includes limited frequency switching speed and general complexity.…”

Section: Introductionmentioning

confidence: 99%

Use of Rogowski Coil as Current Transducer for Distance Relay Reach Correction

Sarwade¹,

Katti²,

Ghodekar³

2016

ijeei

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Conventional iron core CT gets saturated with increase in system X/R ratio, burden connected across it under normal condition and presence of DC component in symmetrical current waveform under faulty condition. CT saturation causes distance relay (DR) to under reach and operate it with certain time delay. The problem becomes more critical when fault takes place near to the boundary of first zone of DR. RC has become more popular for measurement of normal and complex transient current due to its inherent linearity, wide operating current range, reduced size, cost and its flexibility in operation. With the development of today's microprocessor/numerical relay, Rogowski coil (RC) has become more suitable for protective relaying applications. This paper presents use of RC for measurement of current in distance protection scheme (DPS). Case study for validation of use of RC is carried out on Electric furnace system. The simulation results of DPS used for protection of part of 220kV IEEE 9 Bus system shows excellent performance of RC over conventional CT during normal and abnormal conditions.

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Probabilistic analysis of current‐transformer dimensioning: A criterion for determining the level of exposure to saturation

Hashemi

Tajdinian

Seifi

2018

Int Trans Electr Energ Syst

Self Cite

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Summary Saturation of the current transformer (CT) results in maloperation of current‐dependent protective relays. While enhancing in the core area may prevent the saturation, it simultaneously increases the size, the weight, and, subsequently, the price of the CT, which is desirable for neither the CT manufactures nor the operators. This paper conducts a probabilistic analysis to investigate the impact of influential factors on CT saturation for CT dimensioning. The main aim of the probabilistic analysis is to identify the busses of the power network in which they may be highly exposed to the CT saturation phenomena. The proposed probabilistic framework is performed based on the time‐domain fault analysis. In the probabilistic time‐domain fault analysis, the effects of fault location, fault type, and fault resistance are investigated. Also, the effects of load and generation are considered probabilistically. On the basis of the selected random variables (RVs), the probability density function (PDF) of the voltage of the knee point (VKP) is obtained. Also, a new criterion so‐called depth of saturation (DofS) is introduced that shows the level of exposure to saturation phenomena for each bus. The results show that the proposed probabilistic framework helps to find a general observation to VKP of each CT from the CT‐dimensioning aspect. Also, the proposed probabilistic framework provides some useful information about the probability of saturation area in the power system.

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An analytical approach for removal of decaying DC component considering frequency deviation

Cited by 39 publications

References 33 publications

Minimizing the undesirable effect of coupling capacitor voltage transformer on DFT-based phasor estimation method

Minimizing the undesirable effect of coupling capacitor voltage transformer on DFT-based phasor estimation method

Use of Rogowski Coil as Current Transducer for Distance Relay Reach Correction

Probabilistic analysis of current‐transformer dimensioning: A criterion for determining the level of exposure to saturation

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