Method for verifying single-phase rectifier system impedance model

Abstract

The invention discloses a method for verifying a single-phase rectifier system impedance model. The method includes the following steps: 1, injecting disturbance into the single-phase rectifier system, and measuring voltage v<s> and current i<s> responding at an alternating current side; 2, extracting amplitude and phase at frequencies of |f+ / -f<1>| and |f+ / -3f<1>| through a fast Fourier transform method according to the voltage v<s> and current i<s> obtained in the Step 1, and calculating a voltage frequency spectrum coefficient and a current frequency spectrum coefficient at the corresponding frequencies, wherein f is disturbance frequency, and f<1> is fundamental frequency; 3, correcting the voltage frequency spectrum coefficient and current frequency spectrum coefficient obtained in the Step 2; 4, substituting results after correction in the Step 3 into an impedance model expression, and calculating an error result; and 5, according to an error result criterion, judging model correctness. The method for verifying the single-phase rectifier system impedance model is suitable for all single-phase rectifier system impedance models, corrects defects of alternating voltageand current negative frequency spectrum coefficient extraction, and calculation results are accurate.

Description

technical field [0001] The invention relates to the field of automatic control, in particular to a method for verifying the impedance model of a single-phase rectifier system. Background technique [0002] With higher requirements for energy generation, transmission and utilization, more power electronic converters are used in today's power systems due to their high efficiency and flexible control; considering the complex control of each converter, based on The stability analysis method of impedance is widely used; the stability of the whole system can be analyzed by analyzing the external impedance or admittance of each subsystem connected in cascade or parallel; the application of multiple harmonic linearization method and harmonic transfer function matrix method In the analysis, it is revealed that the rectifier system is a MIMO system, and its impedance matrix is ​​a high-order matrix; Shahil Shah found that it is more accurate to consider the third harmonic component mo...

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Problems solved by technology

[0002] With higher requirements for energy generation, transmission and utilization, more power electronic converters are put into use in today's power systems due to their high efficiency and flexible control; considering the complex control of each converter, based on The stability analysis method of impedance is widely used; the stability of the whole system can be analyzed by analyzing the external impedance or admittance of each subsystem connected in cascade or parallel; the application of multiple harmonic linearization method and harmonic transfer function matrix method In the analysis and analysis, it is revealed that the rectifier system is a MIMO system, and its impedance matrix is ​​a high-order matrix; Shahil Shah found that in the single-phase inverter impedance modeling, it is more accurate to consider the third harmonic component model on the AC side; consider the third harmonic The impedance matrix becomes a fourth-order matrix; different single-phase rectifier systems in current verification methods require different verification methods, which are more complicated; there is no method to directly calculate the matrix by injecting disturbances; The calculation will have the problems of large amount of calculation, many and complicated disturbance injection circuits

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