An Enhanced Double Quasi-PR Controller for Grid-Side Inverter with Long Transmission Cable

Author(s):  
Weibiao Wu ◽  
Ke Hu ◽  
Ming Zhang ◽  
Gujing Han
Keyword(s):  
2013 ◽  
Vol 340 ◽  
pp. 611-616
Author(s):  
Qiong Feng Zhu ◽  
Xun Bo Fu ◽  
Shu Ju Hu ◽  
Bin Zhao

Presently, with regard to the research in control of three-phase PWM-VSC under unbalanced dips, most of the literatures gain the current commands through the phase voltages based on the PQ power theory and the control flow is complicate too much. This paper, based on the instantaneous power analysis of VSC grid-side, calculate the current commands through line voltages and use the line voltages instead of the phase voltages in the feedforward. Not only the equation of current commands calculation is simplified, but also avoids the transformation of line voltages to phase voltages. In addition, this method adopts neither PLL nor coordinate transformation, and current sequential extraction is eliminated by adopting the PR controller in the current loop. In the end, the simulation results testify the efficiency of the proposed scheme in resisting grid voltage harmonics and nullifying fluctuation of dc-voltage.


2014 ◽  
Vol 1061-1062 ◽  
pp. 1031-1038
Author(s):  
Wen Ming Zhang ◽  
Yong Xin Li ◽  
Xing Lai Ge ◽  
Yang Lu

Research on the lightweight issue of DC-link is an important direction in modern AC drive electric locomotive. Canceling LC filter circuit is an important way to achieve the goal of lightweight. Therefore, this paper focuses on single-phase pulse rectifier without LC filter circuit. The generation mechanism of DC voltage ripple and network-side current harmonics in grid-side converter is derived. Then, aiming to eliminate the current harmonics, the N-order notch filter and PR controller are introduced to the double-loops controller. The loop of voltage outer controller with N-order notch filter can filter out the ripple of DC-side voltage effectively without affecting the dynamic performance of the controller system. Meanwhile, the loop of current inner controller with PR controller can achieve zero steady-state error control to both the fundamental and harmonic current, and can suppress the low order harmonics in the line current effectively. Analysis shows that replacing the original L2C2 filter circuit with software controller is feasible. Finally, the validity and effectiveness of the proposed scheme are verified in computer simulation.


2021 ◽  
Vol 13 (6) ◽  
pp. 3400
Author(s):  
Jia Ning ◽  
Sipeng Hao ◽  
Aidong Zeng ◽  
Bin Chen ◽  
Yi Tang

The high penetration of renewable energy brings great challenges to power system operation and scheduling. In this paper, a multi-timescale coordinated method for source-grid-load is proposed. First, the multi-timescale characteristics of wind forecasting power and demand response (DR) resources are described, and the coordinated framework of source-grid-load is presented under multi-timescale. Next, economic scheduling models of source-grid-load based on multi-timescale DR under network constraints are established in the process of day-ahead scheduling, intraday scheduling, and real-time scheduling. The loads are classified into three types in terms of different timescale. The security constraints of grid side and time-varying DR potential are considered. Three-stage stochastic programming is employed to schedule resources of source side and load side in day-ahead, intraday, and real-time markets. The simulations are performed in a modified Institute of Electrical and Electronics Engineers (IEEE) 24-node system, which shows a notable reduction in total cost of source-grid-load scheduling and an increase in wind accommodation, and their results are proposed and discussed against under merely two timescales, which demonstrates the superiority of the proposed multi-timescale models in terms of cost and demand response quantity reduction.


2021 ◽  
Vol 11 (5) ◽  
pp. 2410
Author(s):  
Nakisa Farrokhseresht ◽  
Arjen A. van der Meer ◽  
José Rueda Torres ◽  
Mart A. M. M. van der Meijden

The grid integration of renewable energy sources interfaced through power electronic converters is undergoing a significant acceleration to meet environmental and political targets. The rapid deployment of converters brings new challenges in ensuring robustness, transient stability, among others. In order to enhance transient stability, transmission system operators established network grid code requirements for converter-based generators to support the primary control task during faults. A critical factor in terms of implementing grid codes is the control strategy of the grid-side converters. Grid-forming converters are a promising solution which could perform properly in a weak-grid condition as well as in an islanded operation. In order to ensure grid code compliance, a wide range of transient stability studies is required. Time-domain simulations are common practice for that purpose. However, performing traditional monolithic time domain simulations (single solver, single domain) on a converter-dominated power system is a very complex and computationally intensive task. In this paper, a co-simulation approach using the mosaik framework is applied on a power system with grid-forming converters. A validation workflow is proposed to verify the co-simulation framework. The results of comprehensive simulation studies show a proof of concept for the applicability of this co-simulation approach to evaluate the transient stability of a dominant grid-forming converter-based power system.


2020 ◽  
pp. 0309524X2098177
Author(s):  
Mohamed Metwally Mahmoud ◽  
Hossam S Salama ◽  
Mohamed M Aly ◽  
Abdel-Moamen M Abdel-Rahim

Fault ride-through (FRT) capability enhancement for the growth of renewable energy generators has become a crucial issue for their incorporation into the electricity grid to provide secure, reliable, and efficient electricity. This paper presents a new FRT capability scheme for a permanent magnet synchronous generator (PMSG)-based wind energy generation system using a hybrid solution. The hybrid solution is a combination of a braking chopper (BC) and a fuzzy logic controller (FLC). All proportional-integral (PI) controllers which control the generator and grid side converters are replaced with FLC. Moreover, a BC system is connected to the dc link to improve the dynamic response of the PMSG during fault conditions. The PMSG was evaluated on a three-phase fault that occurs on an electrical network in three scenarios. In the first two scenarios, a BC is used with a PI controller and FLC respectively. While the third scenario uses only FLC without a BC. The obtained results showed that the suggested solution can not only enhance the FRT capability of the PMSG but also can diminish the occurrence of hardware systems and reduce their impact on the PMSG system. The simulation tests are performed using MATLAB/SIMULINK software.


Sign in / Sign up

Export Citation Format

Share Document