Zhou Luowei

Self-Stable Chaos Control of dc?dc Converter

A new concept related to self-stable chaos control is first put forward, and its theoretical basis and realization are presented from the frequency-domain perspective. With a new analogous-circuit realization of this control its applications in the voltage-mode Buck converter is discussed. The harmonic-balance method is applied to determine the control range of the control parameter. The experiment results given in the last part confirm the validity of the proposed control method.

Dynamic Feedback Controlling Chaos in Current-Mode Boost Converter

A method for the control of chaos in the current-mode boost converter is presented by using the first-order dynamic feedback control. The feedback part consists of a resistance and a capacitance in series. The system to be controlled is treated as a third-order model, and then the discrete mapping model is obtained by using the data-sampling method. By analysing the position of the maximum norm eigenvalue, the stable range of feedback gain is ascertained out and its optimization is also carried out. Finally, the results of simulation and experiment confirm the correctness of the theoretical analysis and the validity of the proposed means.

Notch filter feedback controlled chaos in buck converter

A method of controlling chaos in the voltage-mode buck converter is presented by using an improved notch filter feedback control in this paper. The proposed control part comprises a notch filter and a low-pass filter. The discrepancy between the outputs of the two filters is introduced into the control prototype of the power converter. In this way, the system period-1 solution is kept unchanged. The harmonic balance method is applied to analysing the variation law of the system bifurcation point, and then the stable range of the feedback gain is ascertained. The results of simulation and experiment are also given finally.

Bifurcation Control of Current-Mode Buck Converter via TDFC

Considering the TDFC controlled current-mode Buck converter featuring periodicity we propose a Fourier-decomposition based method for the bifurcation analysis of this system, hence the theoretical range of control gain of TDFC is determined. In addition, the power-stage experiment circuit is built and the control part is realized in a digital controller. The experimental results show that either bifurcation or chaos in the current-mode Buck converter can be controlled into the expectant period-1 orbit rapidly.

Unified constant-frequency integration control of four-arm three-phase four-wire active power filter with vector operation

This paper presents a unified constant-frequency integration (UCI) control for a three-phase four-wire active power filter (APF) with vector operation. Using this method only AC mains current and zero voltage crossing point are sensed. No sensors for the load current and the APF inductor current are required. Furthermore, there is no need to calculate the reference for APF inductor current so that complicated digital computation is eliminated. Three-phase unity-power-factor and low THD are achieved by integration with reset along with a few logic and linear components. And the amount of switching are operated at high frequency reduced, thus, the switching losses is optimized. In this paper analysis and simulation are carried out with the four-arm inverter, the simulation results verified that the APF with UCI control can effectually compensate the harmonics, reactive current and zero sequence current.

One-cycle control for three-phase four-leg active power filter

This paper presents a three-phase four-leg active power filter design based on one-cycle control. We extend the constant-frequency integration control method to three-phase four-wire systems. The control circuit is composed of four integrators with reset along with several flip-flops, comparators and some linear components. The proposed APF does not require load current and phase voltage sensing, nor the harmonics and reactive current calculation, and does not use any multipliers. Moreover, it employs constant switching frequency modulation, which is desirable for industrial applications. Simulation results demonstrate that the proposed active power filter is capable of compensating current harmonics and reactive power, and reducing the neutral current in an effective and robust manner.

Active power filter based on i/sub p/-i/sub q/ detecting method and one-cycle control

As one-cycle controlled active power filter (APF) only can compensate harmonics and reactive currents simultaneously, this paper presents a scheme which uses i/sub p/-i/sub q/ method as harmonic currents detecting circuit of APF and one-cycle control instead of PWM control as currents tracing control circuit. Then, simulation of harmonics compensation is performed and compared with both APF based on triangular wave modulation and one-cycle controlled APF. The simulation results verify that this scheme not only makes structure of control circuit simple, gains high control accuracy and fast response, but compensates harmonics effectively and makes APF multifunctional as well.