Browsing by Author "Patel, Ashish"

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Comparison of Power Losses for Different Control Strategies of UPQC
(IEEE, 2020) Mathur, Hitesh Datt; Yadav, Sisir Kumar; Patel, Ashish
Unified Power Quality Compensator (UPQC) is a combination of Dynamic voltage regulator (DVR) and Dynamic Static Compensator (DSTATCOM) for mitigation of most power quality issues. Since involving two APFs, various control strategies have been proposed to enhance their utilization. Most control strategies can be classified into three categories- UPQC-P, UPQC-Q, and UPQC-S. Existing literature provides enormous details on various merits and demerits of such methods, like reduction in converter VA ratings, voltage injection etc. Still, a detailed study on power losses of such control strategies needs attention. This paper presents a comparison of different control strategies of UPQC of three-phase system such as UPQC-P, UPQC-Q, UPQC-S in terms of their power consumption losses. Losses are estimated using computer simulations performed in MATLAB/Simulink under various operating conditions of UPQC.
Digital Twin of a Single-Phase Home Converter System Integrating Distributed Energy Resources
(IEEE, 2024-02) Patel, Ashish; Yadav, Sisir Kumar; Mathur, Hitesh Datt
A digital twin (DT) is a digital representation of a physical entity or process that closely emulates the behavior of its real counterpart and is strongly connected to the real entity through data exchange links. DT technology is widely applied to various areas like smart cities, industrial automation, equipment design, manufacturing, and the automotive industry. Such applications are intended for improved design, operation, control, and maintenance of the real entity whose digital twin is prepared. Power Electronics applications heavily rely on digital electronics to model, simulate, and control the power converters. Such applications can immensely benefit from DT technology, but such applications in power converters are nascent. This paper presents a digital twin of a single-phase home inverter connected to a battery, AC load, and the grid. The inverter supplies power to the connected load in two modes- battery mode and grid mode. The digital twin of the inverter, implemented in Opal-RT, emulates the actual behavior of the hardware counterpart in both modes.
Enhancing VA sharing between the shunt and series APFs of UPQC with a modified SRF-PAC method
(Wiley, 2020-02) Mathur, Hitesh Datt; Bhanot, Surekha; Patel, Ashish
This study proposes a synchronous reference frame (SRF) theory-based modified power angle control (PAC) method for unified power quality conditioner (UPQC). In the steady state of conventional UPQC, shunt active power filter (APF) supplies total reactive power demand, and series APF sits idle, leading to unbalanced VA loading of the two APFs and increase in overall VA rating of UPQC. PAC methods of UPQC have been devised for reducing the unbalance in VA loading of series and shunt APFs of UPQC by sharing reactive load power between the two APFs. SRF-based PAC methods are robust, but existing ones support only small values of power angle, and thereby limit the improvement in unbalance of VA loading of series and shunt APFs. In this work, a modified SRF-PAC method is proposed to support larger values of power angle, to load the two APFs in proportion to their VA ratings and thus yield smaller unbalance in VA loading of the two APFs of UPQC. Also, a modified power angle estimation is proposed to ensure that voltage and VA load on series converter does not go beyond the rated values. Controller hardware in loop simulations and hardware experiments validate the proposed control method.
An improved control method for unified power quality conditioner with unbalanced load
(Elsevier, 2018-09) Mathur, Hitesh Datt; Bhanot, Surekha; Patel, Ashish
This paper proposes an improved control method for Unified Power Quality Conditioner (UPQC) with unbalanced load. In UPQC, shunt APF is overburdened when it alone supplies total load reactive power. PAC method aims at effective utilization of series and shunt APFs by sharing reactive power burden between the two. In presence of unbalanced load, existing PAC methods can lead to circulation of reactive power between two APFs and thereby result in overloading of UPQC. Also, due to unbalanced compensating currents, DC link voltage contains second order oscillations, which deteriorates source current quality. In this work, a new PAC method is proposed, which avoids circulation of reactive power and unnecessary VA burden on UPQC. To suppress DC link voltage oscillations, proposed control employs a ‘mean block’ (moving average) at output of PI controller, which ensures balanced and harmonic free source currents. Also, a ‘percentage unbalance’ parameter has been proposed to quantify the unbalance in three phase quantities. Performance of proposed UPQC system is tested in the presence of non-linear, reactive and unbalanced loads. Dynamic performance of system is studied during grid disturbances such as voltage sag, swell, and change in load. Real time simulation carried out in Opal-RT validate the effectiveness of proposed method. The electrical circuit of UPQC is simulated with sub-microsecond time step on FPGA based computational engine of Opal-RT for better verification of the proposed contro
Multi-Agent-Based Forecast Update Methods for Profit Enhancement of Intermittent Distributed Generators in a Smart Microgrid
(Taylor & Francis, 2018-12) Patel, Ashish
Uncertainty in generation from intermittent sources makes a strong case to have effective forecasting methods. However, errors in forecast lead to losses to the distributed generation (DG) owners. In this article, multi-agent-based forecast update methods are proposed which minimize the forecast errors. The effectiveness of the proposed methods in enhancing the profit of intermittent generators and microgrid operational cost is analyzed using a microgrid with two scenarios, namely simple ownership and multiple ownership. A modified IEEE 13 bus system is used as the case study system and the system simulation for the microgrid is performed on the OpenDSS platform and the proposed multi-agent system is developed using JAVA Agent DEvelopment (JADE) framework. From the simulation results, the proposed approaches are found effective in increasing profit margins for the investors or owners of the DGs.
A new and simple SRF based power angle control for UPQCdg to integrate solar PV into grid
(IEEE, 2017) Mathur, Hitesh Datt; Bhanot, Surekha; Patel, Ashish
In this paper, a new Power Angle Control (PAC) method for Unified Power Quality Conditioner with Distributed Generation (UPQC DG ) is proposed for effective grid integration of solar PV. In UPQC DG shunt Active Power Filter (APF) feeds power from solar PV to load, apart from supplying reactive power demand, leading to increased rating of shunt APF. PAC method aims at effective utilization of series and shunt APFs of UPQC DG to reduce their ratings. In this work a new power angle estimation method based on instantaneous power calculation is proposed. Proposed estimation technique is simple, robust and utilizes already available measurements of UPQC DG . Performance of proposed system is tested in the presence of non-linear and reactive loads with detailed model of solar PV generation system. Dynamic performance of system is studied during grid disturbances such as voltage sag and swell, solar irradiation variation, and change in load. MATLAB/Simulink based simulations validate effectiveness of proposed method.
A novel particle swarm optimization based plant-in-loop tuning method for PI controller of integrated power converters
(IEEE, 2025-04) Yadav, Sisir Kumar; Patel, Ashish; Mathur, Hitesh Datt
Integrated Power Converters such as Shunt Active Power Filters (APFs), when integrated with renewable sources like solar PV, offer a more capable and cost-effective solution for both their core function and for feeding the renewable power to the grid. Shunt APF is generally integrated with PV arrays on the common DC link to compensate for power quality issues and feed solar PV power simultaneously. However, the regulation of the DC link, which is the foundation of the operation of such converters, can be more challenging due to the inclusion of PV intermittency. So, the PI controller, mostly used for DC link regulation, should be tuned optimally considering the variable operating conditions. Most tuning methods, whether offline or online, rely on mathematical modeling of the converter and are affected by inherent inaccuracies. Therefore, this work proposes an in-plant PI tuning method for shunt APF, which doesn’t require mathematical modeling and can be implemented in realtime within the actual plant and operating conditions therein. The method tunes the PI controller without having to relax the limits on its output, which are required for the safety of the hardware. The proposed method has been validated using realtime simulation and hardware setup of the PV-integrated shunt APF, and, in both cases, the method shows superior performance in regulating the DC link voltage of the integrated converter system under various operating conditions.
Optimum sizing of PV based UPQC-DG with improved power angle control
(Elsevier, 2020-05) Bhanot, Surekha; Mathur, Hitesh Datt; Patel, Ashish; Yadav, Sisir K.
Unified power quality conditioner with distributed generation (UPQC-DG) is a solution to the problems of power quality and integration of distributed renewable sources. UPQC, being a combination of series and shunt converters, can compensate for most power quality issues, but the use of two power converters increases the cost, and hence optimal sizing methods have been proposed in the literature. Sizing of UPQC-DG components, however, requires special consideration of power injected by DG. This paper proposes an optimum sizing method for UPQC-DG based on an improved power angle control (PAC) technique, which shares reactive power burden between series and shunt converters. Apart from optimal-sizing, this paper incorporates Volt-Ampere (VA) limits in the PAC method to ensure the operation of converters within designed ratings under all conditions. The performance of the proposed power angle control method has been tested for a case study system using Controller Hardware in Loop (CHIL), implemented with Opal-RT and Dspace/micro-labbox, and has been found superior to existing methods.
Particle Swarm Optimization based Tuning Method of PI Regulator for PV fed Shunt Active Power Filter
(IEEE, 2022) Mathur, Hitesh Datt; Yadav, Sisir Kumar; Patel, Ashish
Performance of SRF-UVTG based UPQCDG for integration of solar PV with non-linear loads
(IEEE, 2016) Patel, Ashish
This paper proposes a simple control technique of Unified Power Quality Conditioner with Distributed Generation (UPQC DG ) for grid integration of solar photovoltaic (PV) system. In proposed technique shunt Active Power Filter (APF) of UPQC DG is controlled using Synchronous Reference Frame (SRF) theory and series APF is controlled using Unit Vector Template Generation (UVTG) method. Proposed control technique utilizes only one PI controller and incorporates directly measured PV array current without estimating power generated by PV array. Performance of proposed system is validated in the presence of non-linear load. System performance is also studied during grid disturbances such as voltage sag, change in load and solar irradiation variation. Simulation carried out in MATLAB/Simulink validates system performance.
PSO-Based Online PI Tuning of UPQC-DG in Real-Time
(IEEE, 2024-08) Patel, Ashish; Mathur, Hitesh Datt; Yadav, Sisir Kumar
Power quality is critical in ensuring the efficient operation of electrical systems, and Unified Power Quality Conditioners with Distributed Generation (UPQC-DG) systems play a vital role in mitigating power quality issues such as voltage sags, swells, harmonics, and flicker. Proportional-integral (PI) control UPQC-DG systems are crucial for maintaining power quality by stabilizing the DC link voltage, which is also essential for the seamless integration of distributed generation into the power grid. Effective PI control ensures minimal voltage fluctuations and rapid response to disturbances, thereby enhancing overall system reliability and efficiency. However, traditional PI tuning methods, like the Ziegler-Nichols (ZN) approach, often fail to provide optimal performance under dynamic conditions in such complex converters. To address these limitations, this paper presents an innovative approach for real-time tuning of PI controllers in UPQC-DG systems using Particle Swarm Optimization (PSO). The primary objective is to dynamically optimize the PI controller parameters to enhance the stability and performance of the DC link voltage under varying operational conditions. The proposed method was validated in a real-time simulation environment using the OPAL-RT 4512 platform. The results demonstrate the PSO-based method's superior ability to reduce steady-state errors and enhance dynamic response as well. This study underscores the potential of PSO for real-time adaptive control, providing a robust solution for maintaining high power quality in UPQC-DG systems and improving the stability and reliability of distributed generation systems.
A Simple Approach to Improvement in Performance of UPQCDG in presence of Unbalanced Load
(IEEE, 2017) Bhanot, Surekha; Mathur, Hitesh Datt; Patel, Ashish
In this paper, an improved Power Angle Control (PAC) method for UPQC-DG has been proposed for effective compensation of unbalanced loads. UPQC-DG provides a simultaneous solution to power quality and renewable integration. PAC methods have been developed for UPQC-DG to enhance VA utilization of series and shunt APFs of UPQC-DG. In case of unbalanced loads, existing PAC methods result in circulation of reactive power and increased VA loading of UPQC-DG. PAC method proposed in this work, is designed to tackle above-mentioned issues. Also, proposed PAC method is based on Synchronous Reference Frame (SRF) theory, which makes it robust to non-ideal voltages. Performance of proposed PAC method has been tested using real time simulation performed in Opal-RT. Simulation results show superior performance of UPQC-DG in presence of unbalanced and non-linear loads using proposed PAC method.
A Single-Phase Grid-Tied Converter System Integrating Solar PV, Battery and Compensating Power Quality
(IEEE, 2023) Patel, Ashish; Yadav, Sisir Kumar; Mathur, Hitesh Datt
Single-phase inverters integrating battery storage and renewable energy sources are becoming popular among resi-dential electricity consumers because of the need for reliable and quality power, pollution reduction, and savings in electricity costs. Gird-connected inverters have a multi-mode operation and are preferable over isolated ones, but their high complexity and cost are a concern. Battery integration with such inverters requires a high-voltage battery bank, which increases the cost further. Also, most single-phase grid-tied inverters don't support power quality compensation. This paper proposes an integrated power converter system forming a single-phase home grid, addressing the above-mentioned issues. The proposed approach integrates a low-voltage battery (48V) at the DC link of the grid-tied inverter using a high-gain bidirectional converter. It also enhances the capability of the single-phase grid-tied inverter to compensate for the power quality issues such as reactive power and non-linear current of the load. The proposed system is validated using MATLAB/Simulink simulation.
Study on Comparison of Power Losses Between UPQC and UPQC-DG
(IEEE, 2022) Mathur, Hitesh Datt; Yadav, Sisir Kumar; Patel, Ashish
In the era of modern power distribution network, the motivation to use green and clean energy resources for fulfilling the need of energy demand is gaining abruptly. This has enhanced the use of power electronics-based conversion devices leading to deterioration of power quality in the power distribution network. Several compensating custom devices, such as static compensators (STATCOMs), dynamic voltage restorers (DVRs), and unified power quality conditioner (UPQC), etc., have been developed in recent decades. UPQC consists of shunt active power filter (APF) and series APF connected in back-to-back fashion with a shared DC-link. In the case of UPQC-DG, a distributed generator (DG) is also connected at the DC-link. In the existing literature available, UPQC integrated with DG is found to be a promising topology which can simultaneously compensate for power quality issues and integrate DG into the grid. Its functionality and performances have been presented by many researchers, but a detailed investigation on its power losses is missing. This article presents a detailed comparison of conventional UPQC, UPQC-DG, and UPQC-independent DG (UPQC-IDG) in terms of their respective power losses and further enhances the criteria for selecting the best possible configuration to be used practically based on requirements and economical viability. In this executed work, the power losses are compared among UPQC, UPQC-DG, and UPQC-IDG for different steady-state and dynamic operating conditions. The power losses in all configurations are inclusive of conduction losses, filtering losses, and switching losses, found using simulation and empirical studies. The comparative study is based on computer simulations performed in MATLAB/Simulink and real-time simulation using Opal-RT.
Utilizing UPQC-DG to export reactive power to grid with power angle control method
(Elsevier, 2022-08) Mathur, Hitesh Datt; Patel, Ashish; Yadav, Sisir Kumar
Unified Power Quality Conditioner with Distributed Generation (UPQC-DG) is combined equipment that not only compensates power quality issues but also integrates distributed generation into the grid. This paper proposes to incorporate additional functionality in UPQC-DG to provide reactive power support to the grid. The proposed functionality enables the UPQC-DG to not only compensate for load reactive power but also to export it to the grid in a controllable and regulated manner. The control method of the proposed UPQC-DG system is based on a combination of Synchronous Reference Frame (SRF) theory and Unit Vector Template Generation (UVTG) and utilizes an additional PI controller to control the reactive power flow to the grid. Since the UPQC-DG in the proposed research handles an increased quantity of reactive power, the work incorporates the Power Angle Control (PAC) method to share reactive power burden between series and shunt Active Power Filters (APFs) of UPQC-DG for reducing the overall rating. The proposed UPQC-DG system is validated using exhaustive real-time simulations in Opal-RT for steady-state and dynamic performance.