Hu Cungang

Auto disturbance rejection control of single-phase PWM inverter

This article summarizes the improvements of ADRC that compared with PID, introduces the basic structure of ADRC and its main modules of the common forms and analyzes the basic principle of ADRC. This article mainly introduces the application of ADRC in single-phase PWM inverter system. Also introduces the parameter setting works of ADRC and some matters needing attention. Use MATLAB/SIMULINK as the simulation software. The simulation result of single-phase PWM inverter proves that ADRC is obviously better than PID.

Estimation for power quality frequency based on a variable-step ANF algorithm

In this paper, a variable-step ANF for estimation of power quality frequency is presented. This algorithm is fast and accurate. It still get a satisfied result under a high sampling rate. The algorithm of adaptive IIR notch filter with variable-step is presented in detail, and some variable-step method is presented. At last, the simulation is performed by Matlab and the result is compared under different SNR.

On-line parameter identification of asynchronous motor using improved least squares

The value of stator and rotor resistance, inductance is important to controller design and condition monitoring of an asynchronous motor system. This paper proposes an improved least squarest to identify the parameters of asynchronous motor. Instead of using signal of rotor magnetic linkage, we measuring the stator current, voltage and signal of rotational speed, made use of the method of forgetting factor recursive least squares to carry on recognizing motor parameters.

Research on speed adaptive DTC strategy for induction motor

In order to get better performance at different speed regions in Direct Torque Control (DTC) for induction motor system, a speed adaptive strategy combining two control models are established-hexagon flux linkage control model and SVM-DTC control model. The new method takes full advantage of two models and makes a transition between them according to rotor speed. According to the result analysis and comparative study, the proposed scheme is feasible and correct by combination and smooth transition of two control models.