Design Of A Non Pll Grid Forming Inverter For Smooth Microgrid Transition Operation
DOWNLOAD
Download Design Of A Non Pll Grid Forming Inverter For Smooth Microgrid Transition Operation PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Design Of A Non Pll Grid Forming Inverter For Smooth Microgrid Transition Operation book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Design Of A Non Pll Grid Forming Inverter For Smooth Microgrid Transition Operation
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2020
Design Of A Non Pll Grid Forming Inverter For Smooth Microgrid Transition Operation written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020 with categories.
This paper develops a controller for a grid-forming (GFM) inverter that is capable of operating as either a GFM or grid-feeding source that can improve the operation of a microgrid during on-off grid transitions through use of a novel synchronization approach. Furthermore, this controller avoids use of a phase-locked loop (PLL) and the inverter is able to synchronize with the grid with self-generated voltage and frequency. This prevents the inverter from replicating any grid voltage disturbances in its output - a key disadvantage of many grid-connected inverters that use a PLL. To enable fast synchronization, active synchronization control is adopted both during inverter start-up and microgrid reconnection operation and a method of coordinating synchronization of the inverter with a microgrid controller and grid interconnection circuit breaker is presented. Simulation results for multiple microgrid transition operations and unplanned islanding events demonstrate that the developed non-PLL grid-connected GFM inverter controller and synchronization method are effective in synchronizing the inverter and microgrid to the grid, avoiding phase jump during microgrid transition operation, and improving microgrid islanding transients versus a traditional configuration.
Design Of A Non Pll Grid Forming Inverter For Smooth Microgrid Transition Operation Preprint
DOWNLOAD
Author : Jing Wang (Senior Research Engineer)
language : en
Publisher:
Release Date : 2020
Design Of A Non Pll Grid Forming Inverter For Smooth Microgrid Transition Operation Preprint written by Jing Wang (Senior Research Engineer) and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020 with Electric inverters categories.
Design Power Control Strategies Of Grid Forming Inverters For Microgrid Application Preprint
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2021
Design Power Control Strategies Of Grid Forming Inverters For Microgrid Application Preprint written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021 with categories.
This paper compares two control schemes in the application control layer of a non-PLL grid-forming (GFM) inverter to gain the insights and understanding of how the two schemes affect the dynamic responses of the GFM inverters and the transition operation of microgrids. Both schemes can achieve smooth microgrid transition operation and power tracking, however, the first scheme expects to exhibit more transients due to the feedforward of the inverse dynamic model of the output filter. Simulation results show that both control schemes achieve successful transition operation with smooth transients, and the second control scheme exhibits slightly better transients in the system frequency during islanding operation and the first one has slightly superior transients in the system frequency during reconnection operation. The power tracking performance in the grid-connected mode is evaluated, which shows that the first scheme has better active power tracking and the second one has better reactive power tracking. The analysis and results are useful to develop reliable control schemes for non-PLL GFM inverters because more and more inverters will work as non-PLL grid-forming sources in the future grids due to better stability and reliability.
Design Power Control Strategies Of Grid Forming Inverters For Microgrid Application
DOWNLOAD
Author : Jing Wang (Architectural engineer)
language : en
Publisher:
Release Date : 2021
Design Power Control Strategies Of Grid Forming Inverters For Microgrid Application written by Jing Wang (Architectural engineer) and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021 with Electric inverters categories.
Integrated Synchronization Control Of Grid Forming Inverters For Smooth Microgrid Transition Preprint
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2019
Integrated Synchronization Control Of Grid Forming Inverters For Smooth Microgrid Transition Preprint written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019 with categories.
This paper develops an integrated synchronization control technique for a grid-forming inverter operating within a microgrid that can improve the microgrid's transients during microgrid transition operation. This integrated synchronization control includes the disconnection synchronization control and the reconnection synchronization control. The simulation results show that the developed synchronization control works effectively to smooth the angle change of the grid-forming inverter during microgrid transition operation. Thus, the microgrid's transients are significantly improved compared to the case without synchronization control.
Integrated Synchronization Control Of Grid Forming Inverters For Smooth Microgrid Transition
DOWNLOAD
Author : Jing Wang
language : en
Publisher:
Release Date : 2019
Integrated Synchronization Control Of Grid Forming Inverters For Smooth Microgrid Transition written by Jing Wang and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019 with categories.
Integrated Synchronization Control Of Grid Forming Inverters For Smooth Microgrid Transition
DOWNLOAD
Author : Jing Wang
language : en
Publisher:
Release Date : 2019
Integrated Synchronization Control Of Grid Forming Inverters For Smooth Microgrid Transition written by Jing Wang and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019 with Electric inverters categories.
Universal Passive Synchronization Method For Grid Forming Inverters Without Mode Transition Preprint
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2023
Universal Passive Synchronization Method For Grid Forming Inverters Without Mode Transition Preprint written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023 with categories.
Power systems are transforming with increasing levels of inverter-based resources (IBRs). This transformation requires critical roles of grid-forming (GFM) inverters replacing synchronous generators for bulk power system stabilization and ancillary services, also allowing flexible power system operation, such as microgrid that is operated by multiple GFM IBRs to achieve system resilience against contingencies. To realize the resilient power systems allowing flexible in-and-out operation of GFM IBRs potentially programmed with different primary controls, a synchronization method universally applicable, i.e., independent of control types, would be beneficial to ease the integration process, but it has not been actively studied. To fill the gap, this paper proposes a universal synchronization method that achieves a passive synchronization to enable a smooth transition in a grid with off-nominal system parameters, i.e., voltage and frequency. The logic proposed requires no modification on the primary control, thus applicable to any type of GFMs with a voltage reference input. To validate the concept, a simulation of an IEEE 13-bus benchmark system modified with 3 GFM inverters is presented. It simulates an inverter-driven black start scenario in which GFM inverters autonomously turn on and connect to the grid under heavy loading, using the synchronization logic. The case study demonstrates that GFM inverters can tune their voltage reference to smoothly synchronize without severe transients, and contribute to a seamless black start of the grid under unbalanced load conditions. Two GFM methods-Droop and dispatchable virtual oscillator control-are used for the demo to validate feasibility and interoperability of the passive synchronization.
Restoration And Universal Operation Of Grid Forming Inverters
DOWNLOAD
Author : Fahmid Sadeque
language : en
Publisher:
Release Date : 2022
Restoration And Universal Operation Of Grid Forming Inverters written by Fahmid Sadeque and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2022 with categories.
This dissertation presents novel control methods for frequency and voltage restoration, and universal operation of grid-forming (GFM) inverters. The developed controllers solve the technical challenges for a microgrid with multiple GFM inverters in synchronization and power-sharing, phase-angle detection under asymmetrical conditions, capability to operate in the grid-following (GFL) mode, and frequency and voltage restoration. First, two synchronization methods for GFM inverters are presented. In the output-sync method, an incoming GFM inverter synchronizes its output voltage parameters, i.e., amplitude, phase angle, and frequency, at its point of common coupling (PCC) before closing the circuit breaker. The task is uniquely performed by introducing two proportional-integral (PI) controllers that adjust the output voltage and the angular frequency of the inverter. In the controller-sync method, two sets of controller paths are run in parallel and kept synchronized to produce the same PWM reference. But, only one set of the controller is engaged at a time. The uniqueness of this method is that it allows an inverter to stay connected to the microgrid in a standby mode without injecting any power. Then, when enabled, the inverter gradually shifts to decentralized power-sharing mode without switching the controller. Finally, the controller seamlessly switches to GFM mode, where the inverters are completely independent but synchronized. Another noteworthy fact is that, unlike the output-sync method that used two sets of voltage measurements, the controller sync method only uses one set of voltage measurements. A state-space model of the GFM inverter with the controller-sync method is derived to show the stability at every mode. The efficacy of the developed methods is experimentally validated in a microgrid with both droop and virtual inertia for power-sharing. A new phase-angle detection method, called signal reformation-based direct phase-angle detection (DPD-SR), is developed that provides an enhanced phase-angle detection capability for the GFM inverter under asymmetrical conditions of the system. The developed DPD-SR can directly estimate the phase-angle by using a mathematical function. The unique signal-reformation technique used in this method can process the asymmetrical voltage measurements into a symmetrical form and extract the phase-angle of the system without using any complicated closed-loop control. The DPD-SR method is verified through hardware experiments and compared with state-of-the-art method. Eventually, a universal controller is developed that combines the feature of the controller-sync and the DPD-SR methods. Furthermore, the developed universal controller enables an inverter to operate in GFL and GFM mode is developed. With the universal controller, the inverter can inject desired active and reactive power to the grid or microgrid in GFL mode and seamlessly transit to GFM mode if islanding is detected. The universal controller has two sets of parallel paths, where one path provide GFM control and the other path provides the GFL control and synchronization. A frequency-based islanding detection is added to the developed controller. The uniqueness of the universal controller is, the two paths are always synchronized and can provide seamless GFL to GFM transition when a fault occurs. The controller's stability is analyzed through a state-space model, and the performance of the developed controller is verified in a microgrid for grid-connected and islanded operation in this dissertation. Finally, a frequency and voltage restoration controller is developed to overcome the frequency and voltage deviation problem with the droop controller for power-sharing. In droop-controlled power-sharing, the frequency and voltage are required to deviate from their nominal values. On the contrary, the frequency and voltage of the system are expected to be regulated by the GFM inverters. This dissertation develops a threshold-based frequency and voltage restoration method for the GFM inverters without compromising the effectiveness of the decentralized power-sharing methods. The novelty of this method is that the restoration control paths are only enabled when a load change or plug-in of an inverter is identified and disabled when the frequency and voltage parameters are restored. A state-space model is developed to perform stability analysis. The developed method is compared with a timer-based method to demonstrate its superiority. The efficacy of the restoration method is verified through experiments.
A Novel Power Hardware In The Loop Interface Method For Grid Forming Inverter Systems Preprint
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2022
A Novel Power Hardware In The Loop Interface Method For Grid Forming Inverter Systems Preprint written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2022 with categories.
Power Hardware-in-the-Loop (PHIL) simulation of grid-forming (GFM) inverter systems facilitates the testing of drastic scenarios like on-grid to off-grid transition, islanded microgrid operation without stiff grid etc. To the authors best knowledge, most of studies in literature are focused on PHIL simulation for grid-following inverter systems and only few studies are focused on GFM inverters and those are challenging and problematic especially for high-power applications. In this article, a novel PHIL simulation platform is proposed that enables interfacing of high-power GFM inverter systems. It proposes the concept of a virtual GFM inverter as a part of the proposed PHIL interface for GFM inverter. This addition of virtual GFM inverter in the PHIL interface expands the conventional Ideal Transformer Model (ITM) method and enables it to overcome the issues of instability of existing ITM methods. In the validation stage, a PHIL experiment is conducted on a 3-phase 480 V, 125 kVA GFM inverter system with proposed interfacing method. The results corroborates the fact that the proposed PHIL simulation method performs well and stable for GFM inverter system.