Research of Passive Power and Harmonics Current Detection Based on56F8036
|School||Hefei University of Technology|
|Course||Power Electronics and Power Drives|
|Keywords||harmonic active power filter IIR filter EPLL algorithm APM algorithm linear-sinusoid Tracer algorithm fourth-order Runge-Kutta|
A lot of power electronic equipment is widely used in the power system, resulting in alarge number of harmonics which are required to be managed. For example, the activepower filter has been developed in recent years and its key technology is how to quicklyand accurately detect harmonics and reactive component of the power system. The methodbased on traditional instantaneous reactive power theory to detect harmonics and reactivecomponent is widely used in engineering with its simple and practical features, but thelow-pass filter is contained in its algorithm, so that the dynamic performance is lower andonly the fundamental component is detected but harmonics and inter harmonics of thepower system can’t be detected.A variety of algorithms are first introduced in this paper and certain comparative studyis carried out. Then the algorithm based on EPLL and APM is analyzed on the basis ofInfinite impulse response (IIR) filter in detail. The strong coupling relations amongparameters of this algorithm are pointed out and the advantages of the APM algorithm inamplitude coupling over the EPLL algorithm are indicated based on simulation. And thenthe linear sinusoidal tracking algorithm which is changed from the nonlinear sinusoidaltracking algorithm by rotation transformation is analyzed in this paper. The physicalsignificance of various parameters of the algorithm, that is the degree of influence of theadjustment of parameters to this algorithm, is analyzed in detail by analyzing itsamplitude-frequency response and phase frequency response characteristics and thissinusoidal tracking algorithm is applied in detection of harmonics and reactive componentby mathematical formula transformation. The above analysis of the algorithm is carried outin a continuous-time situation. In order to apply this algorithm to engineering, analysismust be conducted in a discrete-time situation, that is algorithm discretization. Ordinarydifferential equations are contained in linear sinusoidal tracking algorithm, so the numericalsolution of these equations must be obtained in order to carry out the discretization. Thenthe advantages and disadvantages of various numerical solutions are analyzed in detail tofind that the numerical solution based on the method of fourth-order Runge-Kutta issuitable for linear sinusoidal tracking algorithm. The detailed implementation process of thelinear sinusoidal tracking algorithm is given in this paper and the discretization algorithmcan be achieved by programming in the use of Matlab m-files. The conclusion obtained byrunning the simulation module proves the effectiveness of the algorithm based onfourth-order Runge-Kutta method.In order to further verify the validity of the algorithm, an experimental platformbased on linear sinusoidal tracking algorithm is built in this paper. The linear sinusoidaltracking algorithm from the algorithm research stage to the experimental validation stage isimplemented by adopting the embedded system based on the DSP processing core. Results displayed in experiment are identical with the simulation results to verify a goodapplication of the linear sinusoidal tracking algorithm in the detection of harmonics andreactive component.