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EPE 2023 - DS3d: Standard and Advanced Current / Voltage / Synchronization Control Techniques
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2023 ECCE Europe - Conference > EPE 2023 - Topic 04: Electrical Machines and Drive Systems > EPE 2023 - DS3d: Standard and Advanced Current / Voltage / Synchronization Control Techniques
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	A Combined-Compensation Control on Harmonic Resonance for Grid-Connected Converters   By Kei SEKIGUCHI, Koji MAKI, Takahiro ISHIGURO	[View]   [Download]
Abstract: This paper presents a theoretical discussion on a combined-compensation control and its stability on harmonic resonance for grid-connected converters. The interaction between the gird impedance and the grid-connected converter potentially brings harmonic resonance. The compensation control with a digital filter and a virtual impedance is an effective approach of impedance shaping. Theoretical analysis reveals that the proper use of the two effectively enhances system stability. The theoretical design considering a compensation limit can minimize the effect of phase lag on the virtual impedance. Moreover, the trade-off issue between stability and transient response always comes up in impedance shaping. The disturbance observer with a dead band restores transient response only during faults and make up for the low sensitivity due to the digital filter. Finally, simulated results on a typical converter system verify this analysis.
	A Comparative Study of Current Control Strategies for Modular Multilevel Converters   By Homa SHEIKHI JOUYBARY, Davood ARAB KHABURI, Ahmed EL HAJJAJI, Augustin MPANDA MABWE	[View]   [Download]
Abstract: This paper conducts a comparison between a hybrid Sliding Mode Control (SMC) and a conventional PI controller. The hybrid SMC integrates SMC and linear PI controller to regulate output current and the circulating current, respectively. This paper examines the tuning procedures of controller parameters by focusing on the impact of each parameter. The effectiveness of the designed controllers in terms of their steady-state and dynamic performance is confirmed through simulation results using MATLAB/Simulink. Additionally, several robustness tests have been carried out to demonstrate the robust property of the sliding mode control approach in comparison to the PI controller.
	A comparative study of different PLL techniques for synchronization of grid-connected converters under unbalanced and distorted grid conditions   By Bassem SALEH, Mahyar GARMABAD, Thomas WOHLFAHRT, Imer PALOJA, Faical TURKI	[View]   [Download]
Abstract: The Synchronous Reference Frame Phase-LockedLoop (SRF-PLL) is a commonly used technique for synchronizinggrid-tied converters. However, its performance suffers underunbalanced and distorted grid conditions. This paper presentsexperimental results comparing two alternative techniques toSRF-PLL. Results indicate remarkable improvement of over 77\%in the accuracy of the estimation.
	A Distributed predictive control for inter-cell and inter-cluster voltage balancing of a Cascaded H-Bridge Based STATCOM   By Alex NAVAS-FONSECA, Claudio BURGOS-MELLADO, Yeiner ARIAS-ESQUIVEL, Anant Kumar VERMA, Andres MORA, Diego MUNOZ-CARPINTERO, Roberto CARDENAS	[View]   [Download]
Abstract: This paper proposes a distributed model predictive control (DMPC) scheme for inter-cell and inter-cluster capacitor voltage balancing control of a cascaded H-bridge multilevel static synchronous compensator (STATCOM). The proposed DMPC does not require a central controller to perform these control tasks as they are cooperatively performed by local controllers placed in the STATCOM cells. Three case scenarios are analysed to highlight the features of the proposed control scheme. The results demonstrate that the DMPC scheme is able to manage large communication delays and communication failures.
	A Port-Hamiltonian Droop Control for Grid Forming Inverters   By Manuel BRAVO, Alejandro GARCÉS, Pedro RODRIGUEZ	[View]   [Download]
Abstract: Modern power systems include inverter-based resources that may reduce equivalent inertia, resulting in instability issues. A common way to add inertia is by increasing the energy storage capacity in each inverter. Although viable, this option may be expensive in practice. This article proposes a new approach to improve stability in grid-forming inverters. The conventional droop of frequency/power is equipped with additional angle feedback based on the port-Hamiltonian structure of the dynamic system. Phasor-measurement units allow this type of control. The control proofs to be asymptotically stable for a single-inverter infinite bus system. Simulation results under different fault conditions demonstrate a superior performance of the proposed control compared to a conventional droop.
	A Review of Recent Requirements for Inverter-Based Resources and Grid-Forming Technologies   By Hao LUO, Yi XIAO, Yinxiao ZHU, Yongheng YANG, Nikolaos PAPANIKOLAOU, Marta MOLINAS	[View]   [Download]
Abstract: Inverter-based resources (IBRs) are playing a major role in modern power systems, and the installation of IBRs is still growing in recent years, which necessitates the continuous development of grid codes and requirements, e.g. National Grid GC0137 in 2021 and IEEE Std. 2800 in 2022. In the meanwhile, conventional control strategies (i.e., grid-following, GFL) are facing challenges when dealing with a high-percentation-IBR power system, especially in faulty conditions. Considering this, new control schemes like grid-forming (GFM) control has been put forward to offer a stable voltage for the grid. However, certain concepts and definitions remain unclear. With the above concerns, a review of the recent requirements for IBRs and GFM technologies is given in this paper, where further perspectives and open discussions are presented.
	A Robust and Effective Control Method for the Cascaded Buck-Boost Converter Using a Single Controller   By Eric FRITZE, Bogdan-Adrian MIREA, Oliver WOYWODE, Klaus F. HOFFMANN	[View]   [Download]
Abstract: This paper proposes a simple but robust control method for the effective operation of the cascaded buck-boost converter using only one output voltage controller in combination with logic circuits. The converter has an input voltage range from 450 V to 750 V, providing an output voltage of 600 V and up to 15 A RMS output current. An analytical single-controller design approach shows stable and robust behavior throughout the whole input voltage range in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM).
	A simple DC-Link Voltage Balancing Strategy for NPC Three-level Inverters   By Salvatore FOTI, Haseeb Hassan KHAN, Antonio TESTA, Antonino Oscar DI TOMMASO, Rosario MICELI, Claudio NEVOLOSO	[View]   [Download]
Abstract: Three-level neutral point clamped PWM inverters overcome some limitations of two-level inverters in medium voltage applications, leading to lower device ratings and greater efficiency. However, they are burdened by an intrinsic drawback of the neutral point clamped structure, which causes, under some operating conditions, a voltage imbalance of the DC link capacitors. In this paper, such an issue is faced on a system driven by a dual-carrier PWM strategy through a simple hysteretic control. The proposed technique features a very low computational burden and does not need additional power circuits or sensors. It is first presented theoretically, then its performance is evaluated through simulations.
	A Voltage-Following Strategy Used in Programmable Electronic Loads with Shared DC Bus   By Chia-Chou CHANG, Tzu-Hsuan HO, Ming-Yuan XIE, Yaow-Ming CHEN	[View]   [Download]
Abstract: This paper introduces a voltage-following strategy for programmable electronic loads (PEL) with its DC bus shared with the converter under test (CUT) to reduce the zero-sequence current, phase current error, and switching loss. The effectiveness of the proposed strategy is verified with simulations and experiments.
	An Iterative Learning Based Compensation in Model Predictive Control for DC/DC Boost Converter   By Yuan LI, Subham SAHOO, Zhihao LIN, Yichao ZHANG, Tomislav DRAGICEVIC, Frede BLAABJERG	[View]   [Download]
Abstract: Attributed to the increased processingpower of modern microprocessors, model predictive control(MPC) for power converters is gaining more attention.However, the non-minimum phase behavior in DC/DCboost converters complicates the design of model predictivecontrol. When controlling the output voltage directly, itfails to track the reference with short prediction horizons,nevertheless, long prediction horizons cause a heavycomputational burden. Although controlling the inductorcurrent is a feasible option with a short prediction horizon,the control accuracy of the output voltage cannot beguaranteed. To address this issue, this work introducesa compensation term into the difference equation of theinductor current. Then the proportion of the compensationterm is designed with an iterative learning method to improvethe control accuracy. Finally, the results indicate theproposed method can ensure a good control performancewith different load occasions.
	Bidirectional frequency control and inertia provision with grid interties and HVDC links   By Mario SCHWEIZER	[View]   [Download]
Abstract: A control approach for HVDC links and grid interties is presented that allows adjustable, bidirectional frequency control and synthetic inertia provision without the need for additional storage in the DC link. The amount of grid support can be adjusted easily and independently on each terminal. The control approach is just a simple extension to standard vector current control, but it is fully equivalent to virtual synchronous generator (VSG) control running on both terminals simultaneously.
	DC-Side Impedance Modeling and Stability Assessment in Grid-Forming Modular Multilevel Converters   By Mehrdad NAHALPARVARI, Mohsen ASOODAR, Staffan NORRGA, Hans-Peter NEE	[View]   [Download]
Abstract: Incorporation of inverter-based resources is progressively increasing in modern power systems. The absence of inherent physical inertia in converter-based systems has resulted in a decrease in the total inertia of the grid. Grid-forming control of voltage source converters emulates the workings of a conventional synchronous generator through frequency droop control, allowing the converter to provide inertial support while contributing to the support of grid voltage. This paper presents a dc-side impedance model of a grid-forming modular multilevel converter. A control interaction between a grid-forming and a grid-following converter in a back-to-back structure is investigated and a stabilizing compensator is proposed.
	Decoupled Control Structure of a Modular Solid State Transformer   By Nikolas MENGER, Tobias MERZ, Georg ZIEGLMAIER, Rüdiger SCHWENDEMANN, Marc HILLER	[View]   [Download]
Abstract: This paper proposes a new control strategy for a three phase modular Cascaded-H-Bridge based Solid-State Transformer operating with a wide output voltage range. The control scheme incorporates AC grid side control, output voltage control and distributed cell voltage balancing. The balancing is assisted by feed forward of the oscillating phase powers. The cascaded structure enables highly dynamic and decoupled control of the DC output and AC grid side while limiting the cell voltage deviation. Measurements on a five-level laboratory prototype validate the control concept.
	Design and Implementation of Grid-Forming Control Strategies for Parallel Converters in an Islanded Microgrid Setup   By Christina BISCHOFF, Dominik SCHULZ, Stefan MERSCHE, Lukas STEFANSKI, Marc HILLER	[View]   [Download]
Abstract: In this paper a grid-forming control struc-ture is presented that enables the parallel operation ofmultiple such power converters within a microgrid. Thecontrol is based on a cascaded voltage and current con-troller that receives its reference values from a precededcontroller which contains the grid-forming characteristics.This controller can be adapted both for a droop controlmethod and a virtual synchronous machine implementa-tion in order to allow a comparison. Further, the proposedcontrol was developed through simulation and verified ina laboratory setting. Especially the process of successivelyconnecting multiple grid-forming converters in paralleland the investigation of their interactions are considered.
	Digital Control Implementation for a Rapid Control Prototyping of a 200kW Hybrid Interleaved ANPC Active Rectifier   By Mohammad NAJJAR, Flemming JOHANSEN, Henning Roar NIELSEN, Lars Bech RASMUSSEN	[View]   [Download]
Abstract: Rapid Control Prototyping (RCP) can play a significant role during the proof-of-concept (POC) stage of a power electronic converter, particularly for evaluating an idea, reducing the time spend coding, and debugging. Therefore, in this paper the RCP design of a 200kW three-level Active Neutral-Point-Clamp (ANPC) voltage source converter is presented. Considering a hybrid modulation technique, two different semiconductor technologies including SiC MOSFETs and consequently switching frequencies are used. A control system is developed for the converter and the combination of DSP and FPGA of RCP is utilized for the implementation of both control system and signal patterns of switches, in which different platforms as MATLAB/Simulink, Xilinx System Generator (XSG) and Vivado are used. A test setup is built for verification and the experimental results are presented.
	Implementation and Operation of a Grid-Forming Fictitious Synchronous Generator Control on a 300 kVA Power Converter Test Bench   By Florian REDMANN, Antonio MIELACH, Alexander ERNST, Bernd ORLIK, Holger RAFFEL	[View]   [Download]
Abstract: In this paper a grid-forming control based on the fictitious synchronous generator is developed and implemented on a converter test bench. The testing scenario consists of a black start and subsequent islanded operation. In this state the converter also supplies different loads in the microgrid. The acquired measurement results demonstrate that the control method accurately models a synchronous generator and is well suited for the control of a microgrid.
	Model Predictive Control Based Full Operation Modes of Dual Active Bridge Converters to Minimize Current Stress   By Dehao KONG, Zhongchen PEI, Xiaonan GAO, Di ZHU, Marcelo Lobo HELDWEIN, Ralph KENNEL	[View]   [Download]
Abstract: This paper proposed a model predictive control based triple-phase shift modulation considering all five operation modes to enable a high-efficiency operation with low current stress of dual active bridge converters. Compared with the conventional method, this method possesses a high dynamic response and introduces a lower current stress in some operation range. Simulative comparisons with other optimization schemes verify the improvement of the proposed method.
	Model Predictive Control of Hybrid Distribution Transformer based on Back-to-Back Converter for Power Quality Management at Grid Edge   By Zhongchen PEI, Dehao KONG, Dongbo GUO, Di ZHU, Xinming SHAO, Chuang LIU	[View]   [Download]
Abstract: This paper proposes a model predictive control (MPC) method for hybrid distribution transformers (HDT), which improves the dynamic response of the voltage regulation and harmonic current compensating. The circuit model, control method, and simulation result are given in this paper. The simulation results verify the advantages of the proposed control method.
	Multi-Parameter Analysis and Measurement of Resonances in Grid-Connected Converters with LCL Filters   By Dominik SCHULZ, Andreas LISKE, Marc HILLER	[View]   [Download]
Abstract: LCL filters offer high attenuation of grid current ripple, but are challenging from a control perspective due to the resonant peak in their transfer function. The influence of selected individual parameters has already been the studied in several papers. This paper builds on this existing body of work and provides a more comprehensive analysis of all relevant variables influencing the resonance. In addition, dependencies between the parameters are explored. Stability and resonances are evaluated using frequency responses and an impedance based approach. Finally, the analysis results are confirmed with measurements.
	On the design of a model predictive controller for a DC-DC buck converter   By Marco GUERREIRO, Pedro DOS SANTOS, Steven LIU	[View]   [Download]
Abstract: This paper discusses a systematic approach to employ model predictive control (MPC) on a DC-DC buck converter. The design procedure requires the closed-loop bandwidth as input specification and produces the controller parameters. The procedure is derived based on a qualitative and quantitative analysis of the converter under a constrained MPC controller. The results are verified in an experimental setup, where a converter switching at 200~kHz is controlled with the proposed controller.
	Passivity Design for LCL-Type Grid-Connected Inverter Based on PCC Voltage Feedforward Control   By Shaojie LI, Hua LIN, Xingwei WANG	[View]   [Download]
Abstract: In this article, the admittance model for LCL-type grid-connected inverter with proportional PCC voltage feedforward control is built to design the passivity. It is found that if the LCL parameters are designed in a certain range, i.e., _rsup._s/6 and _L1Cinf._s/3 (_r is the resonance frequency of the LCL filter, _L1C is the resonance frequency of the inverter-side inductor and the filter capacitor and _s is the sampling frequency), the passivity can be achieved while the grid background harmonics can also be well suppressed. The simulation and experimental results verify the correctness of the theoretical analysis.
	Power Hardware-in-the-loop Validation of Grid-Forming Control and Current Limitation for Start up of Induction Motors in Microgrids   By Tobias ERCKRATH, Christian BENDFELD, Ron BRANDL, Marco JUNG	[View]   [Download]
Abstract: The start of induction motors in converterbased microgrids poses particular challenges for gridformingconverters due to the limited over-current capabilities.To avoid undesirable over-current operation ofthe converters during start up, suitable current limitationmethods are required to limit both the provided amplitudeand the provided angle of the grid-forming control in anappropriate way. In this paper, a grid-forming controlwith voltage phasor based current limitation is validatedusing power hardware-in-the-loop for the case of inductionmotor start up in an exemplary industrial microgrid.For validation, two different prioritization methods ofamplitude and angle prioritization of the provided voltagephasor are analyzed during current limiting operation atstart up with different torques of the induction motor.
	Robust Predictive Control Strategy of 3L-NPC Wind Power ConverterAgainst Filter Inductor Variations   By Pedro CATALÁN, Yanbo WANG, Joseba ARZA, Zhe CHEN	[View]   [Download]
Abstract: Finite-control-set model predictive control (FCSMPC) has emerged as an effective solution tooperate high-power wind turbine based on neutralpoint-clamped (NPC) converter. However, modeling uncertainties can degrade the performance of MPC. This paper first analyzes the impact of grid parameter error on current prediction accuracy and develops a robust FCS-MPC strategy combined with Extended Kalman Filter (EKF) parameter observer. Simulation results are given to validate the effectiveness of the proposed control structure to mitigate filterinductor parameter mismatch. The proposed approach aims to enhance the performance of MPC against grid filter variations.
	V/f controlled Virtual PM Machine for Grid-connected Inverter   By Kodai NISHIKAWA, Hiroki WATANABE, Jun-Ichi ITOH	[View]   [Download]
Abstract: The paper proposes a V/f-controlled virtual PM synchronous generator (VSG). The V/f control is used as a speed control for permanent magnet synchronous motors (PMSM). However, speed control is unnecessary for the grid-tied operation because the power grid frequency cannot be controlled by the grid-tied inverter. A VSG provides the relationship between a motor torque, a load torque, and a rotation speed for a speed controller. Thus, the V/f controlled VSG achieves the grid-tied operation by a torque control of VSG. In this paper, control response and stability are analyzed by simplification. The experimental results with the 1-kW inverter demonstrate the validity of the proposed V/f-controlled VSG.
	Virtual Power-Based Technique for Enhancing the Large Voltage Disturbance Stability of HV Grid-Forming Converters   By Yorgo LABA, Antoine BRUYERE, Frédéric COLAS, Xavier GUILLAUD	[View]   [Download]
Abstract: Grid-forming control plays an essential role in the modernization of HV electrical transmission grids, particularly in mitigating challenges imposed by large voltage disturbances. In this context, the concept of virtual power has gained prominence as a potential approach that improves stability following such disturbances. This paper illustrates the use of virtual power method in enhancing the large disturbance stability given by the grid-forming control. An adaptive virtual impedance is also proposed to further improve system dynamics. The methods are evaluated through large disturbance stability analysis and time-domain simulations.