| Electrified railway traction load,as a high-voltage,large-capacity power load in the power system,has serious power impact and current distortion and other complex features during operation,causing increasingly serious pollution to the power system and deteriorating power quality.These pollutions will not only adversely affect the operation of the power grid and electrical equipment,but also cause energy metering errors.In order to reduce the energy metering error of the traction load of the electrified railway,this paper proposes a traction load electric energy metering method of electrified railway based on generalized S-transform simplified algorithm.Firstly,power quality problems and hazards caused by electrified railway traction loads are analyzed from the aspects of harmonics,negative sequence currents,voltage fluctuations and flicker,and voltage deviations.The development status of electrified measurement of electrified railway traction loads at home and abroad is discussed in detail.When discussing the influence of electrified railway traction load on electronic energy meter,it is found that the metering performance of existing energy meter is greatly affected by the traction load.The principle and characteristics of S-transform are discussed,and a time-frequency analysis method for traction load voltage and current signals based on the generalized S-transform simplified algorithm is proposed.The adjustment factor is introduced to control the rate of Gauss window width varying with frequency,and the concentration measure method is used to adaptively select the regulatory factor to improve the time-frequency resolution of the algorithm.The second-order extreme method extracts the characteristic frequency of the signal,which greatly reduces the computational complexity of the algorithm.The time-frequency information of traction load voltage and current signals is extracted by this algorithm,which has a good effect on signal analysis and measurement under traction load.An energy metering method based on generalized S-transform is proposed and established.The simulation results show that under the steady state harmonic signal and the unsteady state harmonic signal,the energy metering method based on the generalized S-transform simplified algorithm has a high degree of accuracy.Aiming at the urgent demand of traction load energy metering,a three phase multi-functional traction load energy metering device hardware architecture with ADC,DSP and ARM is designed.The working principle of the energy metering device is introduced.The traction load energy metering method based on generalized S-transformation simplified algorithm is discussed,and this method is applied to the traction load electric energy metering device.The simulation experiment shows that the proposed method for electrified railway traction load energy metering method based on the generalized S-transform simplified algorithm is feasible and can accurately measure the traction load energy. |
