Control technique for integration of smart dc microgrid to the utility grid

2020 ◽  
pp. 99-129
Keyword(s):  
Control Technique ◽  
Dc Microgrid ◽  
Utility Grid

scholarly journals A Novel Modified Switched Inductor Boost Converter with Reduced Switch Voltage Stress

2020 ◽  
Author(s):  
Shima Sadaf ◽  
Nasser Al-Emadi ◽  
Atif Iqbal ◽  
Mohammad Meraj ◽  
Mahajan Sagar Bhaskar
Keyword(s):  
Output Voltage ◽  
Low Voltage ◽  
Electric Utility ◽  
Boost Converter ◽  
Conversion Ratio ◽  
Total Output ◽  
Dc Microgrid ◽  
Power Circuit ◽  
Voltage Stress ◽  
Utility Grid

DC-DC power converters are necessary to step-up the voltage or current with high conversion ratio for many applications e.g. photovoltaic and fuel cell energy conversion, uninterruptible power supply, DC microgrid, automobile, high intensity discharged lamp ballast, hybrid vehicle, etc. in order to use low voltage sources. In this project, a modified SIBC (mSIBC) is proposed with reduced voltage stress across active switches. The proposed mSIBC configuration is transformerless and simply derived by replacing one diode of the classical switched inductor structure with an active switch. As a result, mSIBC required low voltage rating active switches, as the total output voltage is shared between two active switches. Moreover, the proposed mSIBC is low in cost, provides higher efficiency and required the same number of components compared to the classical SIBC. The experimental results are presented which validated the theoretical analysis and functionality, and the efficiency of the designed converter is 97.17%. The proposed mSIBC converter provides higher voltage conversion ratio compared to classical converters e.g. boost, buck-boost, cuk, and SEPIC. The newly designed configurations will aid the intermediate power stage between the renewable sources and utility grid or high voltage DC or AC load. Since, the total output voltage is distributed among the two active switches, low voltage rating switches can be employed to design the power circuit of the proposed converter. The classical boost converter or recently proposed switched inductor based boost converter can be replaced by the proposed mSIBC converter in real-time applications such as DC microgrid, DC-DC charger, battery backup system, UPS, EV, an electric utility grid. The proposed power circuitry is cost effective, compact in size, easily diagnostic, highly efficient and reliable.

scholarly journals Bidirectional Power Flow Control in AC/DC Hybrid System under AC and DC Fault Conditions

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
Wai Wai Hnin
Keyword(s):  
Power Flow ◽  
Storage System ◽  
Control Technique ◽  
Diesel Generator ◽  
Dc Microgrid ◽  
Photovoltaic Array ◽  
Hybrid Microgrid ◽  
Dc Bus ◽  
Bidirectional Power Flow ◽  
Ac Microgrid

This paper presents a hybrid AC-DC microgrid to reduce the process of multiple conversions in an individual AC microgrid or DC microgrid. The proposed hybrid microgrid compose of both AC microgrid and DC microgrid connected together by bidirectional interlink converter (BIC). Utility grid, 150kVA diesel generator (DG) and 100kW AC load are connected in AC microgrid. DC microgrid is composed of 100 kW photovoltaic array (PV), 20kW battery energy storage system (BESS) and 20kW DC load. The droop control technique is applied to control the system for power sharing within the sources in AC/DC hybrid microgrid in proportion to the power rating. When the faults occur at AC bus, protection signal applied to breaker for isolating the healthy and faults system. DC faults occur at DC bus, DC breaker isolate the AC and DC bus. The system performance for power flow sharing on hybrid AC-DC microgrid is demonstrated by using MATLAB/SIMULINK.

scholarly journals Design of an interconnection and damping assignment-passivity based control technique for energy management and damping improvement of a DC microgrid

2020 ◽  
Vol 14 (11) ◽  
pp. 2082-2091 ◽  
Author(s):  
Soumya Samanta ◽  
Saumitra Barman ◽  
Jyoti Prakash Mishra ◽  
Prasanta Roy ◽  
Binoy Krishna Roy
Keyword(s):  
Energy Management ◽  
Control Technique ◽  
Dc Microgrid ◽  
Passivity Based Control

scholarly journals Sliding Mode Control of dc-dc Buck Converter using Typhoon Hardware in Loop Software

2019 ◽  
Vol 9 (2) ◽  
pp. 5022-5028
Keyword(s):  
Dynamic Response ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Pi Controller ◽  
Buck Converter ◽  
Control Technique ◽  
Sliding Mode Controller ◽  
Dc Microgrid ◽  
Proportional Integral ◽  
Mode Control

In this paper, a small standalone solar powered DC microgrid is designed and analysed. The control technique used here is sliding mode control. The common control technique of controlling dc-dc converter is proportional Integral (PI) controller, which is not able to execute well under variations of load. DC-DC converter is nonlinear and time variant system therefore sliding mode controller can be used for dc-dc converter. DC microgrid model is designed and analysed by simulation using Typhoon HIL to observe the system’s dynamic response in view of load impact and battery charging. The buck converter is designed with PWM (pulse width modulation) based sliding mode controller. The tool chain have processor with ultra low latency and unprecedented execution rate for the converter. Dynamic equations associated with the control logic is derived for buck converter. The control technique is tested for step load changes. Sliding mode controller performance is compared with proportional integral (PI) controller. Fast and robust dynamic response of output voltage is obtained.

scholarly journals Improving the Stability of Islanded DC Microgrid with Constant Power Loads

2022 ◽  
Vol 12 (1) ◽  
pp. 11
Author(s):  
Sajid Ali Murtaza ◽  
Nazam Siddique ◽  
Javaid Aslam ◽  
Waqas Latif ◽  
Muhammad Wasif ◽  
...  
Keyword(s):  
Power System ◽  
High Reliability ◽  
Renewable Energy Sources ◽  
Control Technique ◽  
Communication Link ◽  
Droop Control ◽  
Constant Power ◽  
Dc Microgrid ◽  
Constant Power Loads ◽  
The Stability

The AC power system is leading due to its established standards. The depleting thread of fossil fuels, the significant increase in cost and the alarming environmental situation raises concerns. An Islanded DC microgrid, due to its novel characteristics of being able to withstand faulty conditions, has increased the reliability, accuracy, ease of integration, and efficiency of the power system. Renewable energy sources, characteristically DC, have wide usability in a distributive network and, accordingly, less circuitry and conversion stages are required, eliminating the need of reactive power compensation and frequency sync. Constant power loads (CPLs) are the reason for instability in the DC microgrid. Various centralized stability techniques have been proposed in the literature; however, the grid system collapses if there is a fault. To compensate, an efficient distributive control architecture, i.e., droop control method is proposed in this research. The significant advantage of using the droop control technique includes easy implementation, high reliability and flexibility, a reduced circulating current, a decentralized control with local measurements, the absence of a communication link and, thus, it is economic. Moreover, it offers local control for each individual power source in the microgrid. To investigate the stability of the islanded DC microgrid with constant power loads using the droop control technique, a small signal model of the islanded DC microgrid was developed in MATLAB/Simulink. Simulations were carried out to show the efficiency of the proposed controller and analyze the stability of the power system with constant power loads.

scholarly journals Enhanced controller for a four-leg inverter operating in a stand-alone microgrid with unbalanced loads

2021 ◽  
Vol 12 (4) ◽  
pp. 2372
Author(s):  
Effat Ayoubi ◽  
Mohammad Reza Miveh ◽  
Ali Asghar Ghadimi ◽  
Sajad Bagheri
Keyword(s):  
Distribution Systems ◽  
Low Voltage ◽  
Neutral Current ◽  
Superior Performance ◽  
Control Technique ◽  
Unequal Distribution ◽  
Current Path ◽  
Three Phase ◽  
Unbalanced Load ◽  
Utility Grid

<span lang="EN-US">Stand-alone low voltage (LV) microgrids supplying small local loads far from the utility grid are becoming an increasingly popular alternative to a total reliance on the centralized utility grid. In most of LV microgrids, three-phase four-wire distribution systems are used to supply both single- and three-phase loads. Unequal distribution of loads can result in voltage unbalance problems. The use of the four-leg inverter is one of the best solutions for providing a neutral current path and compensating unbalanced load conditions in stand-alone LV microgrids. This paper proposes a fast control technique to compensate unbalanced voltage conditions for a four-leg inverter operating in a stand-alone LV microgrid. The suggested technique provides the current controller’s orthogonal component without introducing any additional dynamics or distortions. The major benefits of the recommended per-phase control technique over conventional orthogonal signal generation (OSG) methods are enhanced steady-state and dynamic performances as well as independency to the system parameters. Several simulation results are provided to confirm the superior performance of the suggested methods.</span>

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