The characterization of sinusoidal signals with time varying amplitude and phase is useful and applicable for many fields.Therefore several algorithms have been suggested to estimate main aspects of these signals.With...The characterization of sinusoidal signals with time varying amplitude and phase is useful and applicable for many fields.Therefore several algorithms have been suggested to estimate main aspects of these signals.Within no standard approach to test the properties of these algorithms,it seems to be helpful to discuss a large class of algorithms according to their properties.In this paper,six methods of estimating dynamic phasor have been reviewed and discussed which three of them are based on least square and others are based on Kalman filter.Taylor expansion is used as a first step and continued with least square or Kalman filter in accordance with the proposal observer of each method.The theoretical processes of these methods are briefly clarified.The characterizations have been made by some tests in time and frequency domains.The tests include amplitude step,phase step,frequency step,frequency response,total vector error,transient monitor,noise,sample number,computation time,harmonic and DC offset which build a framework to compare the different methods.展开更多
The main purpose of power swing blocking is to distinguish faults from power swings.However,the faults occur during a power swing should be detected and cleared promptly.This paper proposes an adaptive concentric powe...The main purpose of power swing blocking is to distinguish faults from power swings.However,the faults occur during a power swing should be detected and cleared promptly.This paper proposes an adaptive concentric power swing blocker(PSB)to overcome incapability of traditional concentric PSB in detecting symmetrical fault during power swing.Based on proposed method,two pairs of concentric characteristics are anticipated which the first one is placed in a stationary position(outer of zone3)but the position of the second pair is adjustable.In order to find the position of the second pair of characteristic,Static Phasor Estimation Error(SPEE)of current signal is utilized in this paper.The proposed method detects the abrupt change in SPEE and puts the second pair of characteristic in location of impedance trajectory correspondingly.Second concentric characteristic records travelling time of impedance trajectory between outer and inner zones and compares to threshold value to detect symmetrical fault during power swing.If recorded time is lower than threshold,three-phase fault is detected during power swing.Intensive studies have been performed and the merit of the method is demonstrated by some test signals simulations.展开更多
文摘The characterization of sinusoidal signals with time varying amplitude and phase is useful and applicable for many fields.Therefore several algorithms have been suggested to estimate main aspects of these signals.Within no standard approach to test the properties of these algorithms,it seems to be helpful to discuss a large class of algorithms according to their properties.In this paper,six methods of estimating dynamic phasor have been reviewed and discussed which three of them are based on least square and others are based on Kalman filter.Taylor expansion is used as a first step and continued with least square or Kalman filter in accordance with the proposal observer of each method.The theoretical processes of these methods are briefly clarified.The characterizations have been made by some tests in time and frequency domains.The tests include amplitude step,phase step,frequency step,frequency response,total vector error,transient monitor,noise,sample number,computation time,harmonic and DC offset which build a framework to compare the different methods.
文摘The main purpose of power swing blocking is to distinguish faults from power swings.However,the faults occur during a power swing should be detected and cleared promptly.This paper proposes an adaptive concentric power swing blocker(PSB)to overcome incapability of traditional concentric PSB in detecting symmetrical fault during power swing.Based on proposed method,two pairs of concentric characteristics are anticipated which the first one is placed in a stationary position(outer of zone3)but the position of the second pair is adjustable.In order to find the position of the second pair of characteristic,Static Phasor Estimation Error(SPEE)of current signal is utilized in this paper.The proposed method detects the abrupt change in SPEE and puts the second pair of characteristic in location of impedance trajectory correspondingly.Second concentric characteristic records travelling time of impedance trajectory between outer and inner zones and compares to threshold value to detect symmetrical fault during power swing.If recorded time is lower than threshold,three-phase fault is detected during power swing.Intensive studies have been performed and the merit of the method is demonstrated by some test signals simulations.
