Adaptive Neural PLL for Grid-connected DFIG Synchronization

Abstract

In this paper, an adaptive neural phase-locked loop (AN-PLL) based on adaptive linear neuron is proposed for grid-connected doubly fed induction generator (DFIG) synchronization. The proposed AN-PLL architecture comprises three stages, namely, the frequency of polluted and distorted grid voltages is tracked online; the grid voltages are filtered, and the voltage vector amplitude is detected; the phase angle is estimated. First, the AN-PLL architecture is implemented and applied to a real three-phase power supply. Thereafter, the performances and robustness of the new AN-PLL under voltage sag and two-phase faults are compared with those of conventional PLL. Finally, an application of the suggested AN-PLL in the grid-connected DFIG-decoupled control strategy is conducted. Experimental results prove the good performances of the new AN-PLL in grid-connected DFIG synchronization.

A Novel Fast Open-loop Phase Locking Scheme Based on Synchronous Reference Frame for Three-phase Non-ideal Power Grids

“…Dynamic behavior, steady-state performance, and adaptability to grid disturbance are key indicators for evaluating phase locking schemes [7]- [11]. Existing phase locking schemes could generally be categorized into two groups [9]- [13]: closed-loop phase locking (CPL) and open-loop phase locking (OPL).…”

“…In sum, a desirable phase locking method should exhibit strong robustness even in unbalanced and distorted utility conditions and be able to achieve a good dynamic and steady-state performance that satisfies the need for the high-performance control of grid-tied inverters [4], [9], [22], [23]. Hence, this study develops a novel fast OPL based on a synchronous reference frame (OPL-SRF), which possesses adaptive properties with respect to grid disturbances and remarkable dynamic performance.…”

“…When the grid frequency is fixed, the proposed OPL-SRF method can precisely track the synchronous phase of the unbalanced grid within 3 ms. The proposed method can also deal with the adverse effects of frequency fluctuations and voltage distortions with the aid of a frequency detector [4], [9] and the harmonic elimination method [17], [24]- [26]. Consequently, the developed OPL-SRF scheme can precisely synchronize the phase of non-ideal grids and significantly improve the phase locking speed.…”

A Quantitative Evaluation and Comparison of Harmonic Elimination Algorithms Based on Moving Average Filter and Delayed Signal Cancellation in Phase Synchronization Applications

“…When a utility signal is seriously distorted by harmonics, it is virtually impossible for phase synchronization control to acquire the accurate synchronous phase of a power grid. Therefore, the security and stability of grid-connected converters cannot be ensured [2]- [4]. Consequently, performing accurate phase synchronization under distorted grid conditions has become a major concern in both industrial applications and in the research field [5]- [8].…”

A Novel Active Damping Control of a Three-phase PWM Inverter with LC Filter

“…As the maximum output power of a generator produced in a given wind speed is related to the rotor speed of DFIG, PWM inverter should control the rotor speed of DFIG to extract the maximum power. The speed control of a generator/motor is based on a field oriented control in a synchronous reference frame [3][4][5].…”